US20210071217A1

US20210071217A1 - Gelling dextran ethers

Info

Publication number: US20210071217A1
Application number: US16/856,559
Authority: US
Inventors: Jayme L. Paullin; Rakesh Nambiar
Original assignee: Nutrition and Biosciences USA 4 Inc
Current assignee: Nutrition and Biosciences USA 4 Inc
Priority date: 2015-04-03
Filing date: 2020-04-23
Publication date: 2021-03-11
Also published as: AU2016243411A1; US10633683B2; WO2016160738A3; CN107580606B; US20180237816A1; EP3277730A2; CA2975289A1; CN107580606A; AU2016243411B2; JP2018511684A; EP3277730B1; WO2016160738A2

Abstract

Compositions are disclosed herein comprising at least one dextran ether compound that comprises uncharged, anionic, and/or cationic organic groups. The degree of substitution of one or more dextran ether compounds is about 0.0025 to about 3.0. Dextran from which the disclosed ether compounds can be derived can have a weight-average molecular weight of about 50-200 million Daltons and/or a z-average radius of gyration of about 200-280 nm. Also disclosed are methods of producing dextran ether compounds, as well as methods of using these ether compounds in various applications.

Description

This application claims the benefit of U.S. Provisional Application Nos. 62/142,654 (filed Apr. 3, 2015) and 62/142,658 (filed Apr. 3, 2015), which are both incorporated herein by reference in their entirety.

FIELD OF INVENTION

The present disclosure is in the field of polysaccharide derivatives. For example, the disclosure pertains to certain anionic, uncharged, or cationic dextran ethers and methods of their preparation and use as viscosity modifiers.

REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY

The official copy of the sequence listing is submitted electronically via EFS-Web as an ASCII formatted sequence listing with a file named 20160317_CL6423WOPCT_SequenceListingST25.txt created on Mar. 17, 2016, and having a size of 164 kilobytes and is filed concurrently with the specification. The sequence listing contained in this ASCII-formatted document is part of the specification and is herein incorporated by reference in its entirety.

BACKGROUND

Driven by a desire to find new structural polysaccharides using enzymatic syntheses or genetic engineering of microorganisms, researchers have discovered polysaccharides that are biodegradable and can be made economically from renewably sourced feedstocks. One such family of polysaccharides are alpha-glucans, which are polymers comprising glucose monomers linked by alpha-glycosidic bonds.
Dextrans represent a family of complex, branched alpha-glucans generally comprising chains of alpha-1,6-linked glucose monomers, with periodic side chains (branches) linked to the straight chains by alpha-1,3-linkage (loan et al., Macromolecules 33:5730-5739). Production of dextrans is typically done through fermentation of sucrose with bacteria (e.g., Leuconostoc or Streptococcus species), where sucrose serves as the source of glucose for dextran polymerization (Naessens et al., J. Chem. Technol. Biotechnol. 80:845-860; Sarwat et al., Int. J. Biol. Sci. 4:379-386; Onilude et al., Int. Food Res. J. 20:1645-1651). Although dextrans are used in several applications given their high solubility in water (e.g., adjuvants, stabilizers), this high solubility can negatively affect their general utility as thickening agents in hydrocolloid applications.
Thus, there is interest in developing new, higher viscosity dextran polymers, and ether derivatives thereof, that are more amenable to high viscosity applications.

SUMMARY OF INVENTION

In one embodiment, the disclosure concerns a composition comprising a dextran ether compound that comprises: (i) about 87-93 wt % glucose linked at positions 1 and 6; (ii) about 0.1-1.2 wt % glucose linked at positions 1 and 3; (iii) about 0.1-0.7 wt % glucose linked at positions 1 and 4; (iv) about 7.7-8.6 wt % glucose linked at positions 1, 3 and 6; (v) about 0.4-1.7 wt % glucose linked at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6; and (vi) a degree of substitution (DoS) with at least one organic group of about 0.0025 to about 3.0; wherein the weight-average molecular weight (Mw) of the dextran ether compound is about 50-200 million Daltons.
In another embodiment, the dextran ether compound comprises: (i) about 89.5-90.5 wt % glucose linked at positions 1 and 6; (ii) about 0.4-0.9 wt % glucose linked at positions 1 and 3; (iii) about 0.3-0.5 wt % glucose linked at positions 1 and 4; (iv) about 8.0-8.3 wt % glucose linked at positions 1, 3 and 6; and (v) about 0.7-1.4 wt % glucose linked at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6.
In another embodiment, the dextran ether compound comprises chains linked together within a branching structure, wherein the chains are similar in length and comprise substantially alpha-1,6-glucosidic linkages.
In another embodiment, the z-average radius of gyration of the dextran from which the dextran ether compound is derived is about 200-280 nm.
In another embodiment, the dextran from which the dextran ether compound is derived is a product of a glucosyltransferase enzyme comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:5, SEQ ID NO:9, SEQ ID NO:13, or SEQ ID NO:17.
In another embodiment, at least one organic group of the dextran ether compound is a carboxyalkyl, alkyl, or hydroxyalkyl group. At least one organic group is a carboxymethyl, methyl, ethyl, hydroxypropyl, dihydroxypropyl, or hydroxyethyl group in another embodiment.
In another embodiment, at least one organic group of the dextran ether compound is a positively charged organic group. In another embodiment, at least one positively charged organic group comprises a substituted ammonium group. Such a positively charged organic group comprises a trimethylammonium group in another embodiment. In another embodiment, at least one positively charged organic group comprises an alkyl group or hydroxy alkyl group. Such a positively charged organic group is a quaternary ammonium hydroxypropyl group in another embodiment.
In another embodiment, (i) the dextran ether compound contains one type of organic group, or (ii) the dextran ether compound contains two or more types of organic group.
In another embodiment, the composition comprising a dextran ether compound is an aqueous composition having a viscosity of at least about 3 cPs.
In another embodiment, the composition comprising a dextran ether compound is in the form of a household product, personal care product, pharmaceutical product, industrial product, or food product.
In another embodiment, the disclosure concerns a method of producing a dextran ether compound. This method comprises:

- (a) contacting a dextran in a reaction under alkaline conditions with at least one etherification agent comprising an organic group, wherein at least one organic group is etherified to the dextran thereby producing a dextran ether compound, wherein the dextran ether compound has a degree of substitution with at least one organic group of about 0.0025 to about 3.0 and the weight-average molecular weight (Mw) of the dextran ether compound is about 50-200 million Daltons, wherein the dextran comprises: (i) about 87-93 wt % glucose linked at positions 1 and 6; (ii) about 0.1-1.2 wt % glucose linked at positions 1 and 3; (iii) about 0.1-0.7 wt % glucose linked at positions 1 and 4; (iv) about 7.7-8.6 wt % glucose linked at positions 1, 3 and 6; and (v) about 0.4-1.7 wt % glucose linked at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6; and
- (b) optionally, isolating the dextran ether compound produced in step (a).

In another embodiment, the disclosure concerns a method of increasing the viscosity of an aqueous composition. This method comprises: contacting a dextran ether compound as disclosed herein with an aqueous composition, wherein the viscosity of the aqueous composition is increased by the dextran ether compound compared to the viscosity of the aqueous composition before the contacting step.
In another embodiment, the disclosure concerns a method of treating a material. This method comprises: contacting a material with an aqueous composition comprising a dextran ether compound as disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS AND SEQUENCES

FIG. 1: HPLC analysis of sucrose consumption by a glucosyltransferase reaction comprising 100 g/L sucrose and a 0768 gtf (SEQ ID NO:1). Refer to Example 2.

FIG. 2A: Map of plasmid pZZHB583 used to express 2919 gtf (SEQ ID NO:5) in B. subtilis. Refer to Example 3.

FIG. 2B: Map of plasmid pZZHB582 used to express 2918 gtf (SEQ ID NO:9) in B. subtilis. Refer to Example 4.

FIG. 2C: Map of plasmid pZZHB584 used to express 2920 gtf (SEQ ID NO:13) in B. subtilis. Refer to Example 5.

FIG. 2D: Map of plasmid pZZHB585 used to express 2921 gtf (SEQ ID NO:17) in B. subtilis. Refer to Example 6.

FIG. 3: HPLC analysis of sucrose consumption by a reaction comprising a commercially available dextran sucrase. Refer to Example 7.

TABLE 1

Summary of Nucleic Acid and Protein SEQ ID Numbers

		Protein
	Nucleic acid	SEQ ID
Description	SEQ ID NO.	NO.

“0768 gtf”, Leuconostoc pseudomesenteroides.		1
Mature form of GENBANK Identification No.		(1447 aa)
497964659.
“0768 gtf”, Leuconostoc pseudomesenteroides.		2
Mature form of GENBANK Identification No.		(1457 aa)
497964659, but including a start methionine and
additional N- and C-terminal amino acids.
WciGtf1, Weissella cibaria. Full length form	3	4
comprising signal sequence. GENBANK	(4347 bases)	(1448 aa)
Accession No. ZP_08417432 (amino acid
sequence).
“2919 gtf”, Weissella cibaria. Mature form of		5
GENBANK Identification No. ZP_08417432.		(1422 aa)
“2919 gtf”, Weissella cibaria. Sequence	6
optimized for expression in B. subtilis. Encodes	(4269 bases)
2919 gtf with a heterologous signal sequence
and additional N-terminal amino acids.
LfeGtf1, Lactobacillus fermentum. Full length	7	8
form comprising signal sequence. GENBANK	(4392 bases)	(1463 aa)
Accession No. AAU08008 (amino acid
sequence).
“2918 gtf”, Lactobacillus fermentum. Mature		9
form of GENBANK Identification No.		(1426 aa)
AAU08008.
“2918 gtf”, Lactobacillus fermentum. Sequence	10
optimized for expression in B. subtilis. Encodes	(4281 bases)
2918 gtf with a heterologous signal sequence
and additional N-terminal amino acids.
SsoGtf4, Streptococcus sobrinus. Full length	11	12
form comprising signal sequence. GENBANK	(4521 bases)	(1506 aa)
Accession
No. AAX76986 (amino acid sequence).
“2920 gtf”, Streptococcus sobrinus. Mature		13
form of GENBANK Identification No.		(1465 aa)
AAX76986.
“2920 gtf”, Streptococcus sobrinus. Sequence	14
optimized for expression in B. subtilis. Encodes	(4398 bases)
2920 gtf with a heterologous signal sequence
and additional N-terminal amino acids.
SdoGtf7, Streptococcus downei. Full length	15	16
form comprising signal sequence. GENBANK	(4360 bases)	(1453 aa)
Accession No. ZP_08549987.1
(amino acid sequence).
“2921 gtf”, Streptococcus downei. Mature		17
form of GENBANK Identification No.		(1409 aa)
ZP_08549987.1.
“2921 gtf”, Streptococcus downei. Sequence	18
optimized for expression in B. subtilis.	(4230 bases)
Encodes 2921 gtf with a heterologous signal
sequence and additional N-terminal amino acids.

DETAILED DESCRIPTION

The disclosures of all patent and non-patent literature cited herein are incorporated herein by reference in their entirety.
Unless otherwise disclosed, the terms “a” and “an” as used herein are intended to encompass one or more (i.e., at least one) of a referenced feature.
Where present, all ranges are inclusive and combinable, except as otherwise noted. For example, when a range of “1 to 5” is recited, the recited range should be construed as including ranges “1 to 4”, “1 to 3”, “1-2”, “1-2 & 4-5”, “1-3 & 5”, and the like.
The term “glucan” herein refers to a polysaccharide of D-glucose monomers that are linked by glucosidic linkages, which are a type of glycosidic linkage. An “alpha-glucan” herein refers to a glucan in which the constituent D-glucose monomers are alpha-D-glucose monomers.
The terms “dextran”, “dextran polymer”, “dextran compound” and the like are used interchangeably herein and refer to complex, branched alpha-glucans generally comprising chains of substantially (mostly) alpha-1,6-linked glucose monomers, with side chains (branches) linked mainly by alpha-1,3-linkage. The term “gelling dextran” herein refers to the ability of one or more dextrans disclosed herein to form a viscous solution or gel-like composition (i) during enzymatic dextran synthesis and, optionally, (ii) when such synthesized dextran is isolated (e.g., >90% pure) and then placed in an aqueous composition.
Dextran “long chains” herein can comprise “substantially [or mostly] alpha-1,6-glucosidic linkages”, meaning that they can have at least about 98.0% alpha-1,6-glucosidic linkages in some aspects. Dextran herein can comprise a “branching structure” (branched structure) in some aspects. It is contemplated that in this structure, long chains branch from other long chains, likely in an iterative manner (e.g., a long chain can be a branch from another long chain, which in turn can itself be a branch from another long chain, and so on). It is contemplated that long chains in this structure can be “similar in length”, meaning that the length (DP [degree of polymerization]) of at least 70% of all the long chains in a branching structure is within plus/minus 30% of the mean length of all the long chains of the branching structure.
Dextran in some embodiments can also comprise “short chains” branching from the long chains, typically being one to three glucose monomers in length, and comprising less than about 10% of all the glucose monomers of a dextran polymer. Such short chains typically comprise alpha-1,2-, alpha-1,3-, and/or alpha-1,4-glucosidic linkages (it is believed that there can also be a small percentage of such non-alpha-1,6 linkages in long chains in some aspects).
The terms “glycosidic linkage”, “glycosidic bond” and the like are used interchangeably herein and refer to the covalent bond that joins a carbohydrate molecule to another carbohydrate molecule. The terms “glucosidic linkage”, “glucosidic bond” and the like are used interchangeably herein and refer to a glycosidic linkage between two glucose molecules. The term “alpha-1,6-glucosidic linkage” as used herein refers to the covalent bond that joins alpha-D-glucose molecules to each other through carbons 1 and 6 on adjacent alpha-D-glucose rings. The term “alpha-1,3-glucosidic linkage” as used herein refers to the covalent bond that joins alpha-D-glucose molecules to each other through carbons 1 and 3 on adjacent alpha-D-glucose rings. The term “alpha-1,2-glucosidic linkage” as used herein refers to the covalent bond that joins alpha-D-glucose molecules to each other through carbons 1 and 2 on adjacent alpha-D-glucose rings. The term “alpha-1,4-glucosidic linkage” as used herein refers to the covalent bond that joins alpha-D-glucose molecules to each other through carbons 1 and 4 on adjacent alpha-D-glucose rings. Herein, “alpha-D-glucose” will be referred to as “glucose.” All glucosidic linkages disclosed herein are alpha-glucosidic linkages, except where otherwise noted.
“Glucose (glucose monomers) linked at positions 1 and 6” herein refers to a glucose monomer of dextran in which only carbons 1 and 6 of the glucose monomer are involved in respective glucosidic linkages with two adjacent glucose monomers. This definition likewise applies to glucose (i) “linked at positions 1 and 3”, and (ii) “linked at positions 1 and 4”, taking into account, accordingly, the different carbon positions involved in each respective linkage.
“Glucose (glucose monomers) linked at positions 1, 3 and 6” herein refers to a glucose monomer of dextran in which carbons 1, 3 and 6 of the glucose monomer are involved in respective glucosidic linkages with three adjacent glucose monomers. A glucose linked only at positions 1, 3 and 6 is a branch point. This definition likewise applies to glucose linked at (i) positions 1, 2 and 6, and (ii) positions 1, 4 and 6, but taking into account, accordingly, the different carbon positions involved in each respective linkage.
Glucose positions (glucose carbon positions) 1, 2, 3, 4 and 6 herein are as known in the art (depicted in the following structure):
The glycosidic linkage profile of a dextran or dextran ether compound herein can be determined using any method known in the art. For example, a linkage profile can be determined using methods that use nuclear magnetic resonance (NMR) spectroscopy (e.g., ¹³C NMR or ¹H NMR). These and other methods that can be used are disclosed in Food Carbohydrates: Chemistry, Physical Properties, and Applications (S. W. Cui, Ed., Chapter 3, S. W. Cui, Structural Analysis of Polysaccharides, Taylor & Francis Group LLC, Boca Raton, Fla., 2005), which is incorporated herein by reference.
The term “sucrose” herein refers to a non-reducing disaccharide composed of an alpha-D-glucose molecule and a beta-D-fructose molecule linked by an alpha-1,2-glycosidic bond. Sucrose is known commonly as table sugar.
The “molecular weight” of a dextran or dextran ether compound herein can be represented as number-average molecular weight (M_n) or as weight-average molecular weight (M_w), the units of which are in Daltons or grams/mole. Alternatively, molecular weight can be represented as DP_w(weight average degree of polymerization) or DP_n(number average degree of polymerization). Various means are known in the art for calculating these molecular weight measurements such as with high-pressure liquid chromatography (HPLC), size exclusion chromatography (SEC), or gel permeation chromatography (GPC).
The term “radius of gyration” (Rg) herein refers to the mean radius of dextran, and is calculated as the root-mean-square distance of a dextran molecule's components (atoms) from the molecule's center of gravity. Rg can be provided in Angstrom or nanometer (nm) units, for example. The “z-average radius of gyration” of dextran herein refers to the Rg of dextran as measured using light scattering (e.g., MALS). Methods for measuring z-average Rg are known and can be used herein, accordingly. For example, z-average Rg can be measured as disclosed in U.S. Pat. No. 7,531,073, U.S. Patent Appl. Publ. Nos. 2010/0003515 and 2009/0046274, Wyatt (Anal. Chim. Acta 272:1-40), and Mori and Barth (Size Exclusion Chromatography, Springer-Verlag, Berlin, 1999), all of which are incorporated herein by reference.
The terms “glucosyltransferase enzyme”, “gtf enzyme”, “gtf enzyme catalyst”, “gtf”, “glucansucrase” and the like are used interchangeably herein. The activity of a gtf enzyme herein catalyzes the reaction of the substrate sucrose to make the products glucan and fructose. A gtf enzyme that produces a dextran (a type of glucan) can also be referred to as a dextransucrase. Other products (byproducts) of a gtf reaction can include glucose (where glucose is hydrolyzed from the glucosyl-gtf enzyme intermediate complex), and various soluble oligosaccharides (e.g., DP2-DP7) such as leucrose, Wild type forms of glucosyltransferase enzymes generally contain (in the N-terminal to C-terminal direction) a signal peptide, a variable domain, a catalytic domain, and a glucan-binding domain. A gtf herein is classified under the glycoside hydrolase family 70 (GH70) according to the CAZy (Carbohydrate-Active EnZymes) database (Cantarel et al., Nucleic Acids Res. 37:D233-238, 2009).
The terms “glucosyltransferase catalytic domain” and “catalytic domain” are used interchangeably herein and refer to the domain of a glucosyltransferase enzyme that provides glucan-producing activity to the glucosyltransferase enzyme.
The terms “gtf reaction”, “gtf reaction solution”, “glucosyltransferase reaction”, “enzymatic reaction”, “dextran synthesis reaction”, “dextran reaction” and the like are used interchangeably herein and refer to a reaction that is performed by a glucosyltransferase enzyme. A gtf reaction as used herein generally refers to a reaction initially comprising at least one active glucosyltransferase enzyme in a solution comprising sucrose and water, and optionally other components. Other components that can be in a gtf reaction after it has commenced include fructose, glucose, soluble oligosaccharides (e.g., DP2-DP7) such as leucrose, and dextran products. It is in a gtf reaction where the step of contacting water, sucrose and a glucosyltransferase enzyme is performed. The term “under suitable gtf reaction conditions” as used herein, refers to gtf reaction conditions that support conversion of sucrose to dextran via glucosyltransferase enzyme activity. A gtf reaction herein is not naturally occurring.
A “control” gtf reaction as used herein can refer to a reaction using a glucosyltransferase not comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:5, SEQ ID NO:9, SEQ ID NO:13, or SEQ ID NO:17. All the other features (e.g., sucrose concentration, temperature, pH, time) of a control reaction solution can be the same as the reaction to which it is being compared.
The “percent dry solids” of a gtf reaction refers to the wt % of all the sugars in a gtf reaction. The percent dry solids of a gtf reaction can be calculated, for example, based on the amount of sucrose used to prepare the reaction.
The “yield” of dextran by a gtf reaction herein represents the weight of dextran product expressed as a percentage of the weight of sucrose substrate that is converted in the reaction. For example, if 100 g of sucrose in a reaction solution is converted to products, and 10 g of the products is dextran, the yield of the dextran would be 10%. This yield calculation can be considered as a measure of selectivity of the reaction toward dextran.
The terms “polynucleotide”, “polynucleotide sequence”, and “nucleic acid sequence” are used interchangeably herein. These terms encompass nucleotide sequences and the like. A polynucleotide may be a polymer of DNA or RNA that is single- or double-stranded, that optionally contains synthetic, non-natural or altered nucleotide bases. A polynucleotide may be comprised of one or more segments of cDNA, genomic DNA, synthetic DNA, or mixtures thereof.
The terms “sequence identity” or “identity” as used herein with respect to polynucleotide or polypeptide sequences refer to the nucleic acid bases or amino acid residues in two sequences that are the same when aligned for maximum correspondence over a specified comparison window. Thus, “percentage of sequence identity” or “percent identity” refers to the value determined by comparing two optimally aligned sequences over a comparison window, wherein the portion of the polynucleotide or polypeptide sequence in the comparison window may comprise additions or deletions (i.e., gaps) as compared to the reference sequence (which does not comprise additions or deletions) for optimal alignment of the two sequences. The percentage is calculated by determining the number of positions at which the identical nucleic acid base or amino acid residue occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison and multiplying the results by 100 to yield the percentage of sequence identity. It would be understood that, when calculating sequence identity between a DNA sequence and an RNA sequence, T residues of the DNA sequence align with, and can be considered “identical” with, U residues of the RNA sequence. For purposes of determining percent complementarity of first and second polynucleotides, one can obtain this by determining (i) the percent identity between the first polynucleotide and the complement sequence of the second polynucleotide (or vice versa), for example, and/or (ii) the percentage of bases between the first and second polynucleotides that would create canonical Watson and Crick base pairs.
The Basic Local Alignment Search Tool (BLAST) algorithm, which is available online at the National Center for Biotechnology Information (NCBI) website, may be used, for example, to measure percent identity between or among two or more of the polynucleotide sequences (BLASTN algorithm) or polypeptide sequences (BLASTP algorithm) disclosed herein. Alternatively, percent identity between sequences may be performed using a Clustal algorithm (e.g., ClustalW, ClustalV, or Clustal-Omega). For multiple alignments using a Clustal method of alignment, the default values may correspond to GAP PENALTY=10 and GAP LENGTH PENALTY=10. Default parameters for pairwise alignments and calculation of percent identity of protein sequences using a Clustal method may be KTUPLE=1, GAP PENALTY=3, WINDOW=5 and DIAGONALS SAVED=5. For nucleic acids, these parameters may be KTUPLE=2, GAP PENALTY=5, WINDOW=4 and DIAGONALS SAVED=4. Alternatively still, percent identity between sequences may be performed using an EMBOSS algorithm (e.g., needle) with parameters such as GAP OPEN=10, GAP EXTEND=0.5, END GAP PENALTY=false, END GAP OPEN=10, END GAP EXTEND=0.5 using a BLOSUM matrix (e.g., BLOSUM62).
Various polypeptide amino acid sequences and polynucleotide sequences are disclosed herein as features of certain embodiments. Variants of these sequences that are at least about 70-85%, 85-90%, or 90%-95% identical to the sequences disclosed herein can be used. Alternatively, a variant amino acid sequence or polynucleotide sequence can have at least 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identity with a sequence disclosed herein. The variant amino acid sequence or polynucleotide sequence may have the same function/activity of the disclosed sequence, or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% of the function/activity of the disclosed sequence.
The terms “dextran ether compound”, “dextran ether”, “dextran ether derivative” and the like are used interchangeably herein. A dextran ether compound herein is dextran that has been etherified with one or more organic groups (uncharged, anionic, and/or cationic) such that the compound has a degree of substitution (DoS) with one or more organic groups of about 0.0025 to about 3.0. Such etherification can occur at one or more hydroxyl groups of at least 30% of the monosaccharide monomeric units of the dextran, for example.
A dextran ether compound is termed an “ether” herein by virtue of comprising the substructure —C_M—O—C—, where “—C_M—” represents a carbon atom of a monosaccharide monomeric unit of a dextran ether compound (where such carbon atom was bonded to a hydroxyl group [—OH] in the dextran precursor of the ether), and where “—C—” is a carbon atom of an organic group. It would be understood that a monosaccharide monomeric unit of a dextran ether compound herein typically has one or more organic groups in ether linkage. Thus, such a monosaccharide monomeric unit can also be referred to as an etherized monosaccharide monomeric unit.
An “organic group” group as used herein can refer to a chain of one or more carbons that (i) has the formula —C_nH_2n+1(i.e., an alkyl group, which is completely saturated) or (ii) is mostly saturated but has one or more hydrogens substituted with another atom or functional group (i.e., a “substituted alkyl group”). Such substitution may be with one or more hydroxyl groups, oxygen atoms (thereby forming an aldehyde or ketone group), carboxyl groups, or other alkyl groups. Thus, as examples, an organic group herein can be an alkyl group, carboxy alkyl group, or hydroxy alkyl group. An organic group herein may thus be uncharged or anionic (an example of an anionic organic group is a carboxy alkyl group) in some embodiments.
A “carboxy alkyl” group herein refers to a substituted alkyl group in which one or more hydrogen atoms of the alkyl group are substituted with a carboxyl group. A “hydroxy alkyl” group herein refers to a substituted alkyl group in which one or more hydrogen atoms of the alkyl group are substituted with a hydroxyl group.
An “organic group” can alternatively refer to a “positively charged organic group”. A positively charged organic group as used herein refers to a chain of one or more carbons (“carbon chain”) that has one or more hydrogens substituted with another atom or functional group (i.e., a “substituted alkyl group”), where one or more of the substitutions is with a positively charged group. Where a positively charged organic group has a substitution in addition to a substitution with a positively charged group, such additional substitution may be with one or more hydroxyl groups, oxygen atoms (thereby forming an aldehyde or ketone group), alkyl groups, and/or additional positively charged groups. A positively charged organic group has a net positive charge since it comprises one or more positively charged groups.
The terms “positively charged group”, “positively charged ionic group”, “cationic group” and the like are used interchangeably herein. A positively charged group comprises a cation (a positively charged ion). Examples of positively charged groups include substituted ammonium groups, carbocation groups and acyl cation groups.
A composition that is “positively charged” or “cationic” herein typically has more protons than electrons and is repelled from other positively charged substances, but attracted to negatively charged substances. Dextran ether compounds herein can optionally be characterized as cationic dextran ether compounds.
The terms “substituted ammonium group”, “substituted ammonium ion” and “substituted ammonium cation” are used interchangeably herein. A substituted ammonium group herein comprises structure I:
R₂, R₃and R₄in structure I each independently represent a hydrogen atom or an alkyl, aryl, cycloalkyl, aralkyl, or alkaryl group. The carbon atom (C) in structure I is part of the chain of one or more carbons (“carbon chain”) of the positively charged organic group. The carbon atom is either directly ether-linked to a monosaccharide monomeric unit of dextran, or is part of a chain of two or more carbon atoms ether-linked to a monosaccharide monomeric unit of dextran. The carbon atom in structure I can be —CH₂—, —CH— (where a H is substituted with another group such as a hydroxy group), or —C— (where both H's are substituted).
A substituted ammonium group can be a “primary ammonium group”, “secondary ammonium group”, “tertiary ammonium group”, or “quaternary ammonium” group, depending on the composition of R₂, R₃and R₄in structure I. A primary ammonium group herein refers to structure I in which each of R₂, R₃and R₄is a hydrogen atom (i.e., —C—NH₃ ⁺). A secondary ammonium group herein refers to structure I in which each of R₂and R₃is a hydrogen atom and R₄is an alkyl, aryl, or cycloalkyl group. A tertiary ammonium group herein refers to structure I in which R₂is a hydrogen atom and each of R₃and R₄is an alkyl, aryl, or cycloalkyl group. A quaternary ammonium group herein refers to structure I in which each of R₂, R₃and R₄is an alkyl, aryl, or cycloalkyl group (i.e., none of R₂, R₃and R₄is a hydrogen atom).
A quaternary ammonium dextran ether herein can comprise a trialkyl ammonium group (where each of R₂, R₃and R₄is an alkyl group), for example. A trimethylammonium group is an example of a trialkyl ammonium group, where each of R₂, R₃and R₄is a methyl group. It would be understood that a fourth member (i.e., R₁) implied by “quaternary” in this nomenclature is the chain of one or more carbons of the positively charged organic group that is ether-linked to a monosaccharide monomeric unit of dextran.
An example of a quaternary ammonium dextran ether compound is trimethylammonium hydroxypropyl dextran. The positively charged organic group of this ether compound can be represented as structure II:
where each of R₂, R₃and R₄is a methyl group. Structure II is an example of a quaternary ammonium hydroxypropyl group.
A “halide” herein refers to a compound comprising one or more halogen atoms (e.g., fluorine, chlorine, bromine, iodine). A halide herein can refer to a compound comprising one or more halide groups such as fluoride, chloride, bromide, or iodide. A halide group may serve as a reactive group of an etherification agent.
The term “etherification reaction” and similar terms refer to a reaction comprising at least dextran and an etherification agent. These components are typically dissolved and/or mixed in an aqueous solvent comprising alkali hydroxide. A reaction is placed under suitable conditions (e.g., time, temperature) for the etherification agent to etherify one or more hydroxyl groups of monosaccharide monomeric units of dextran with an organic group herein, thereby yielding a dextran ether compound.
The term “alkaline conditions” herein refers to a solution or mixture pH of at least 11 or 12. Alkaline conditions can be prepared by any means known in the art, such as by dissolving an alkali hydroxide in a solution or mixture.
The terms “etherification agent”, “alkylation agent” and the like are used interchangeably herein. An etherification agent herein refers to an agent that can be used to etherify one or more hydroxyl groups of one or more monosaccharide monomeric units of dextran with an organic group. An etherification agent thus comprises at least one organic group.
The term “degree of substitution” (DoS) as used herein refers to the average number of hydroxyl groups substituted in each monomeric unit of a dextran ether compound.
The term “molar substitution” (M.S.) as used herein refers to the moles of an organic group per monomeric unit of a dextran ether compound. M.S. can alternatively refer to the average moles of etherification agent used to react with each monomeric unit in dextran (M.S. can thus describe the degree of derivatization with an etherification agent). It is noted that the M.S. value for dextran may have no upper limit in some cases. For example, when an organic group containing a hydroxyl group (e.g., hydroxyethyl or hydroxypropyl) has been etherified to dextran, the hydroxyl group of the organic group may undergo further reaction, thereby coupling more of the organic group to the dextran.
An “aqueous composition” herein has a liquid component that comprises at least about 10 wt % water, for example. Examples of aqueous compositions include mixtures, solutions, dispersions (e.g., colloidal dispersions), suspensions and emulsions, for example. Aqueous compositions in certain embodiments comprise dextran or dextran ether that is dissolved in the aqueous composition (i.e., in solution, and typically has viscosity).
As used herein, the term “colloidal dispersion” refers to a heterogeneous system having a dispersed phase and a dispersion medium, i.e., microscopically dispersed insoluble particles (e.g., some forms of dextran ether herein) are suspended throughout another substance (e.g., an aqueous composition such as water or aqueous solution). An example of a colloidal dispersion herein is a hydrocolloid. All, or a portion of, the particles of a colloidal dispersion such as a hydrocolloid can comprise certain dextran ether compounds of the present disclosure. The terms “dispersant” and “dispersion agent” are used interchangeably herein to refer to a material that promotes the formation and/or stabilization of a dispersion.
The terms “hydrocolloid” and “hydrogel” are used interchangeably herein. A hydrocolloid refers to a colloid system in which water is the dispersion medium.
The term “aqueous solution” herein refers to a solution in which the solvent comprises water. An aqueous solution can serve as a dispersant in certain aspects herein. Dextran ether compounds in certain embodiments can be dissolved, dispersed, or mixed within an aqueous solution.
The term “viscosity” as used herein refers to the measure of the extent to which a fluid or an aqueous composition such as a hydrocolloid resists a force tending to cause it to flow. Various units of viscosity that can be used herein include centipoise (cPs) and Pascal-second (Pa·s). One poise is equal to 0.100 kg·m⁻¹·s⁻¹. Thus, the terms “viscosity modifier” and “viscosity-modifying agent” as used herein refer to anything that can alter/modify the viscosity of a fluid or aqueous composition.
The term “shear thinning behavior” as used herein refers to a decrease in the viscosity of an aqueous composition as shear rate increases. The term “shear thickening behavior” as used herein refers to an increase in the viscosity of an aqueous composition as shear rate increases. “Shear rate” herein refers to the rate at which a progressive shearing deformation is applied to an aqueous composition. A shearing deformation can be applied rotationally.
The term “contacting” as used herein with respect to methods of increasing the viscosity of an aqueous composition refers to any action that results in bringing together an aqueous composition with a dextran ether. Contacting can be performed by any means known in the art, such as dissolving, mixing, shaking, or homogenization, for example.
The terms “confectionery”, “confection”, “sweets”, “sweetmeat”, “candy” and the like are used interchangeably herein. A confectionary refers to any flavored food product having a sweet taste, the consistency of which may be hard or soft, which is typically consumed by sucking and/or by chewing within the oral cavity. A confectionary can contain sugar or otherwise be sugar-free.
The terms “fabric”, “textile”, “cloth” and the like are used interchangeably herein to refer to a woven material having a network of natural and/or artificial fibers. Such fibers can be thread or yarn, for example.
A “fabric care composition” herein is any composition suitable for treating fabric in some manner. Examples of such a composition include laundry detergents and fabric softeners.
The terms “heavy duty detergent” “all-purpose detergent” and the like are used interchangeably herein to refer to a detergent useful for regular washing of white and colored textiles at any temperature. The terms “low duty detergent”, “fine fabric detergent” and the like are used interchangeably herein to refer to a detergent useful for the care of delicate fabrics such as viscose, wool, silk, microfiber or other fabric requiring special care. “Special care” can include conditions of using excess water, low agitation, and/or no bleach, for example.
A “detergent composition” herein typically comprises at least one surfactant (detergent compound) and/or at least one builder. A “surfactant” herein refers to a substance that tends to reduce the surface tension of a liquid in which the substance is dissolved. A surfactant may act as a detergent, wetting agent, emulsifier, foaming agent, and/or dispersant, for example.
The terms “anti-redeposition agent”, “anti-soil redeposition agent”, “anti-greying agent” and the like herein refer to agents that help keep soils from redepositing onto clothing in laundry wash water after these soils have been removed, therefore preventing greying/discoloration of laundry. Anti-redeposition agents can function by helping keep soil dispersed in wash water and/or by blocking attachment of soil onto fabric surfaces.
An “oral care composition” herein is any composition suitable for treating an soft or hard surface in the oral cavity such as dental (teeth) and/or gum surfaces.
The term “adsorption” herein refers to the adhesion of a compound (e.g., dextran ether compound herein) to the surface of a material.
The terms “cellulase”, “cellulase enzyme” and the like are used interchangeably herein to refer to an enzyme that hydrolyzes beta-1,4-D-glucosidic linkages in cellulose, thereby partially or completely degrading cellulose. Cellulase can alternatively be referred to as “beta-1,4-glucanase”, for example, and can have endocellulase activity (EC 3.2.1.4), exocellulase activity (EC 3.2.1.91), or cellobiase activity (EC 3.2.1.21). “Cellulose” refers to an insoluble polysaccharide having a linear chain of beta-1,4-linked D-glucose monomeric units.
The terms “percent by volume”, “volume percent”, “vol %”,“v/v %” and the like are used interchangeably herein. The percent by volume of a solute in a solution can be determined using the formula: [(volume of solute)/(volume of solution)]×100%.
The terms “percent by weight”, “weight percentage (wt %)”, “weight-weight percentage (% w/w)” and the like are used interchangeably herein. Percent by weight refers to the percentage of a material on a mass basis as it is comprised in a composition, mixture, or solution.
The term “increased” as used herein can refer to a quantity or activity that is at least about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 50%, 100%, or 200% more than the quantity or activity for which the increased quantity or activity is being compared. The terms “increased”, “elevated”, “enhanced”, “greater than”, “improved” and the like are used interchangeably herein.
The term “isolated” as used herein can characterize a dextran or dextran ether compound. As such, dextran and dextran ether compounds of the present disclosure are synthetic, man-made compounds, and/or exhibit properties not believed to naturally occur.
There is interest in developing new high viscosity dextran polymers, and ether derivatives thereof, that are more amenable to gelling and other applications.
Embodiments of the present disclosure concern a composition comprising a dextran ether compound that comprises:

- (i) about 87-93 wt % glucose linked at positions 1 and 6;
- (ii) about 0.1-1.2 wt % glucose linked at positions 1 and 3;
- (iii) about 0.1-0.7 wt % glucose linked at positions 1 and 4;
- (iv) about 7.7-8.6 wt % glucose linked at positions 1, 3 and 6;
- (v) about 0.4-1.7 wt % glucose linked at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6; and
- (vi) a degree of substitution (DoS) with at least one organic group of about 0.0025 to about 3.0;
- wherein the weight-average molecular weight (Mw) of the dextran ether compound is about 50-200 million Daltons.
  Significantly, such dextran ether compounds as presently disclosed are expected to exhibit high viscosity in aqueous compositions, even at relatively low concentrations of the dextran ether compound.

A dextran ether compound herein comprises (i) about 87-93 wt % glucose linked only at positions 1 and 6; (ii) about 0.1-1.2 wt % glucose linked only at positions 1 and 3; (iii) about 0.1-0.7 wt % glucose linked only at positions 1 and 4; (iv) about 7.7-8.6 wt % glucose linked only at positions 1, 3 and 6; and (v) about 0.4-1.7 wt % glucose linked only at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6. In certain embodiments, a dextran can comprise (i) about 89.5-90.5 wt % glucose linked only at positions 1 and 6; (ii) about 0.4-0.9 wt % glucose linked only at positions 1 and 3; (iii) about 0.3-0.5 wt % glucose linked only at positions 1 and 4; (iv) about 8.0-8.3 wt % glucose linked only at positions 1, 3 and 6; and (v) about 0.7-1.4 wt % glucose linked only at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6.
A dextran ether compound in some aspects can comprise about 87, 87.5, 88, 88.5, 89, 89.5, 90, 90,5, 91, 91.5, 92, 92.5, or 93 wt % glucose linked only at positions 1 and 6. There can be about 87-92.5, 87-92, 87-91.5, 87-91, 87-90.5, 87-90, 87.5-92.5, 87.5-92, 87.5-91.5, 87.5-91, 87.5-90.5, 87.5-90, 88-92.5, 88-92, 88-91.5, 88-91, 88-90.5, 88-90, 88.5-92.5, 88.5-92, 88.5-91.5, 88.5-91, 88.5-90.5, 88.5-90, 89-92.5, 89-92, 89-91.5, 89-91, 89-90.5, 89-90, 89.5-92.5, 89.5-92, 89.5-91.5, 89.5-91, or 89.5-90.5 wt % glucose linked only at positions 1 and 6, in some instances.
A dextran ether compound in some aspects can comprise about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, or 1.2 wt % glucose linked only at positions 1 and 3. There can be about 0.1-1.2, 0.1-1.0, 0.1-0.8, 0.3-1.2, 0.3-1.0, 0.3-0.8, 0.4-1.2, 0.4-1.0, 0.4-0.8, 0.5-1.2, 0.5-1.0, 0.5-0.8, 0.6-1.2, 0.6-1.0, or 0.6-0.8 wt % glucose linked only at positions 1 and 3, in some instances.
A dextran ether compound in some aspects can comprise about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7 wt % glucose linked only at positions 1 and 4. There can be about 0.1-0.7, 0.1-0.6, 0.1-0.5, 0.1-0.4, 0.2-0.7, 0.2-0.6, 0.2-0.5, 0.2-0.4, 0.3-0.7, 0.3-0.6, 0.3-0.5, or 0.3-0.4 wt % glucose linked only at positions 1 and 4, in some instances.
A dextran ether compound in some aspects can comprise about 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, or 8.6 wt % glucose linked only at positions 1, 3 and 6. There can be about 7.7-8.6, 7.7-8.5, 7.7-8.4, 7.7-8.3, 7.7-8.2, 7.8-8.6, 7.8-8.5, 7.8-8.4, 7.8-8.3, 7.8-8.2, 7.9-8.6, 7.9-8.5, 7.9-8.4, 7.9-8.3, 7.9-8.2, 8.0-8.6, 8.0-8.5, 8.0-8.4, 8.0-8.3, 8.0-8.2, 8.1-8.6, 8.1-8.5, 8.1-8.1, 8.1-8.3,or 8.1-8.2 wt % glucose linked only at positions 1, 3 and 6, in some instances.
A dextran ether compound in some aspects can comprise about 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, or 1.7 wt % glucose linked only at (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6. There can be about 0.4-1.7, 0.4-1.6, 0.4-1.5, 0.4-1.4, 0.4-1.3, 0.5-1.7, 0.5-1.6, 0.5-1.5, 0.5-1.4, 0.5-1.3, 0.6-1.7, 0.6-1.6, 0.6-1.5, 0.6-1.4, 0.6-1.3, 0.7-1.7, 0.7-1.6, 0.7-1.5, 0.7-1.4, 0.7-1.3, 0.8-1.7, 0.8-1.6, 0.8-1.5, 0.8-1.4, 0.8-1.3 wt % glucose linked only at (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6, in some instances.
The glucosidic linkage profile of a dextran ether compound herein can be based on the linkage profile of dextran used to produce the ether compound. The linkage profile of such dextran can be determined following any protocol disclosed herein. An example of a suitable linkage determination protocol can be similar to, or the same as, the protocol disclosed in Example 9: For example, an 0768 gtf enzyme reaction that has been deactivated by heating the reaction at about 70-90° C. (e.g., 80° C.) for about 5-30 minutes (e.g., 10 minutes) is placed into dialysis tubing (e.g., made with regenerated cellulose) with an MWCO of 12-14 kDa (e.g., Spectra/Por® 4 Dialysis Tubing, Part No. 132706, Spectrum Laboratories, Inc.). The deactivated reaction is then dialyzed against a large volume of water (e.g., 3-5 L) at about 20-25° C. (room temp) over about 4-10 days (e.g., 7 days); this water can be exchanged every day during the dialysis. The dextran product is then (i) precipitated by mixing the dialyzed deactivated reaction with about 1-2× (1.5×) reaction volume of 100% methanol, (ii) washed at least two times with the same volume of 100% methanol, and (iii) dried at about 40-50° C. (e.g., 45° C.) (optionally under a vacuum). A dissolvable amount of dry dextran is dissolved in dimethyl sulfoxide (DMSO) or DMSO/5% LiCl, after which all free hydroxyl groups are methylated (e.g., by sequential addition of a NaOH/DMSO slurry followed with iodomethane). The methylated dextran is then extracted (e.g., into methylene chloride) and hydrolyzed to monomeric units using aqueous trifluoroacetic acid (TFA) at about 110-125° C. (e.g., 120° C.). The TFA is then evaporated and reductive ring opening is done using sodium borodeuteride. The hydroxyl groups created by hydrolyzing the glycosidic linkages are then acetylated by treating with acetyl chloride and TFA at a temperature of about 40-60° C. (e.g., 50° C.). Next, the derivatizing reagents are evaporated and the resulting methylated/acetylated monomers are reconstituted in acetonitrile; this preparation is then analyzed by GC/MS using an appropriate column (e.g., biscyanopropyl cyanopropylphenyl polysiloxane). The relative positioning of the methyl and acetyl functionalities render species with distinctive retention time indices and mass spectra that can be compared to published databases. In this way, the derivatives of the monomeric units indicate how each monomer was originally linked in the dextran polymer.
It is believed that a dextran ether compound herein has the same or similar structure as the dextran used to produce the ether compound. Dextran used to produce a dextran ether compound herein is contemplated to have a branched structure in which there are long chains (containing mostly or all alpha-1,6-linkages) that iteratively branch from each other (e.g., a long chain can be a branch from another long chain, which in turn can itself be a branch from another long chain, and so on). The branched structure may also comprise short branches from the long chains; these short chains are believed to mostly comprise alpha-1,3 and -1,4 linkages, for example. Branch points in the dextran, whether from a long chain branching from another long chain, or a short chain branching from a long chain, appear to comprise alpha-1,3, -1,4, or -1,2 linkages off of a glucose involved in alpha-1,6 linkage. On average, about 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 15-35%, 15-30%, 15-25%, 15-20%, 20-35%, 20-30%, 20-25%, 25-35%, or 25-30% of all branch points of dextran in some embodiments branch into long chains. Most (>98% or 99%) or all the other branch points branch into short chains.
The long chains of a dextran branching structure can be similar in length in some aspects. By being similar in length, it is meant that the length (DP) of at least 70%, 75%, 80%, 85%, or 90% of all the long chains in a branching structure is within plus/minus 15% (or 10%, 5%) of the mean length of all the long chains of the branching structure. In some aspects, the mean length (average length) of the long chains is about 10-50 DP (i.e., 10-50 glucose monomers). For example, the mean individual length of the long chains can be about 10, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 10-50, 10-40, 10-30, 10-25, 10-20, 15-50, 15-40, 15-30, 15-25, 15-20, 20-50, 20-40, 20-30, or 20-25 DP.
Dextran long chains in certain embodiments can comprise substantially alpha-1,6-glucosidic linkages and a small amount (less than 2.0%) of alpha-1,3- and/or alpha-1,4-glucosidic linkages. For example, dextran long chains can comprise about, or at least about, 98%, 98.25%, 98.5%, 98.75%, 99%, 99.25%, 99.5%, 99.75%, or 99.9% alpha-1,6-glucosidic linkages. A dextran long chain in certain embodiments does not comprise alpha-1,4-glucosidic linkages (i.e., such a long chain has mostly alpha-1,6 linkages and a small amount of alpha-1,3 linkages). Conversely, a dextran long chain in some embodiments does not comprise alpha-1,3-glucosidic linkages (i.e., such a long chain has mostly alpha-1,6 linkages and a small amount of alpha-1,4 linkages). Any dextran long chain of the above embodiments may further not comprise alpha-1,2-glucosidic linkages, for example. Still in some aspects, a dextran long chain can comprise 100% alpha-1,6-glucosidic linkages (excepting the linkage used by such long chain to branch from another chain).
Short chains of dextran in some aspects are one to three glucose monomers in length and comprise less than about 5-10% of all the glucose monomers of the dextran polymer. At least about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or all of, short chains herein are 1-3 glucose monomers in length. The short chains of dextran can comprise less than about 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% of all the glucose monomers of the dextran, for example.
Short chains of dextran in some aspects can comprise alpha-1,2-, alpha-1,3-, and/or alpha-1,4-glucosidic linkages. Short chains, when considered all together (not individually) may comprise (i) all three of these linkages, or (ii) alpha-1,3- and alpha-1,4-glucosidic linkages, for example. It is believed that short chains of dextran herein can be heterogeneous (i.e., showing some variation in linkage profile) or homogeneous (i.e., sharing similar or same linkage profile) with respect to the other short chains of the dextran.
The above disclosure regarding linkage and branching profiles of dextran is believed to likewise or similarly apply to the linkage and branching profiles of dextran ether compounds herein, since such ether compounds can be derived from the above-disclosed dextran.
A dextran ether compound in certain embodiments can have an Mw of about, or at least about, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, or 200 million (or any integer between 50 and 200 million) (or any range between two of these values). The Mw of a dextran ether compound can be about 50-200, 60-200, 70-200, 80-200, 90-200, 100-200, 110-200, 120-200, 50-180, 60-180, 70-180, 80-180, 90-180, 100-180, 110-180, 120-180, 50-160, 60-160, 70-160, 80-160, 90-160, 100-160, 110-160, 120-160, 50-140, 60-140, 70-140, 80-140, 90-140, 100-140, 110-140, 120-140, 50-120, 60-120, 70-120, 80-120, 90-120, 100-120, 110-120, 50-110, 60-110, 70-110, 80-110, 90-110, 100-110, 50-100, 60-100, 70-100, 80-100, 90-100, or 95-105 million, for example. In some aspects, the dextran used to prepare a dextran ether compound herein has an Mw as disclosed herein.
A dextran ether compound in certain embodiments can be derived from dextran with a z-average radius of gyration (Rg) of about 200-280 nm. For example, the z-average Rg can be about 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, or 280 nm (or any integer between 200-280 nm). As other examples, the z-average Rg can be about 200-280, 200-270, 200-260, 200-250, 200-240, 200-230, 220-280, 220-270, 220-260, 220-250, 220-240, 220-230, 230-280, 230-270, 230-260, 230-250, 230-240, 240-280, 240-270, 240-260, 240-250, 250-280, 250-270, or 250-260 nm.
The Mw and/or z-average Rg of dextran used to derive a dextran ether compound in some aspects can be measured following a protocol similar to, or the same as, the protocol disclosed in Example 9. For example, a Mw and/or z-average Rg herein can be measured by first dissolving dextran produced by an 0768 gtf at 0.4-0.6 mg/mL (e.g., ˜0.5 mg/mL) in 0.05-1.0 M (e.g., ˜0.075 M) Tris(hydroxymethyl)aminomethane buffer with 150-250 ppm (e.g., ˜200 ppm) NaN₃. Solvation of dry dextran can be achieved by shaking for 12-18 hours at 45-55° C. (e.g., ˜50° C.). The resulting dextran solution can be entered into a suitable flow injection chromatographic apparatus comprising a separation module (e.g., Alliance™ 2695 separation module from Waters Corporation, Milford, Mass.) coupled with three online detectors: a differential refractometer (e.g., Waters 2414 refractive index detector), a multiangle light scattering (MALS) photometer (e.g., Heleos™-2 18-angle multiangle MALS photometer) equipped with a quasielastic light scattering (QELS) detector (e.g., QELS detector from Wyatt Technologies, Santa Barbara, Calif.), and a differential capillary viscometer (e.g., ViscoStar™ differential capillary viscometer from Wyatt). Two suitable size-exclusion columns (e.g., AQUAGEL-OH GUARD columns from Agilent Technologies, Santa Clara, Calif.) can be used to separate the dextran polymer peak from the injection peak, where the mobile phase can be the same as the sample solvent (above), the flow rate can be about 0.2 mL/min, the injection volumes can be about 0.1 mL, and column temperature can be about 30° C. Suitable software can be used for data acquisition (e.g., Empower™ version 3 software from Waters) and for multidetector data reduction (Astra™ version 6 software from Wyatt). MALS data can provide weight-average molecular weight (Mw) and z-average radius of gyration (Rg), and QELS data can provide z-average hydrodynamic radius, for example.
A dextran from which a dextran ether compound herein can be derived can be a product of a glucosyltransferase enzyme comprising, or consisting of, an amino acid sequence that is 100% identical to, or at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to, SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:5, SEQ ID NO:9, SEQ ID NO:13, or SEQ ID NO:17 (and have gtf activity). Non-limiting examples of a glucosyltransferase enzyme comprising SEQ ID NO:1 (or a related sequence) include glucosyltransferase enzymes comprising, or consisting of, an amino acid sequence that is 100% identical to, or at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to, SEQ ID NO:2 (and have gtf activity). Production of dextran can be accomplished with a gtf reaction as disclosed herein, for example. Dextran as disclosed in the instant detailed description (e.g., molecular weight, linkage and branching profile) can optionally be characterized as a product of a glucosyltransferase enzyme comprising or consisting of SEQ ID NO:1 or 2 (or a related sequence thereof that is at least 90% identical [above]). In some other aspects, a glucosyltransferase enzyme comprises or consists of an amino acid sequence that is 100% identical to, or at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to, the secreted portion (i.e., signal peptide removed) of the amino acid sequence encoded by SEQ ID NO:6, 10, 14, or 18.
A glucosyltransferase enzyme herein may be from various microbial sources, such as a bacteria or fungus. Examples of bacterial glucosyltransferase enzymes are those derived from a Streptococcus species, Leuconostoc species, Lactobacillus species, or Weissella species. Examples of Streptococcus species include S. sobrinus, S. downei, S. salivarius, S. dentirousetti, S. mutans, S. oralis, S. gallolyticus and S. sanguinis. Examples of Leuconostoc species include L. pseudomesenteroides, L. amelibiosum, L. argentinum, L. camosum, L. citreum, L. cremoris, L. dextranicum and L. fructosum. Examples of Lactobacillus species include L. fermentum, L. acidophilus, L. delbrueckii, L. helveticus, L. salivarius, L. casei, L. curvatus, L. plantarum, L. sakei, L. brevis, L. buchneri and L. reuteri. Examples of Weissella species include W. cibaria, W. confusa, W. halotolerans, W. hellenica, W. kandleri, W. kimchii, W. koreensis, W. minor, W. paramesenteroides, W. soli and W. thailandensis. A glucosyltransferase in some aspects is not from L. mesenteroides, thus in some aspects dextran used to produce a dextran ether compound is not a product of a Leuconostoc mesenteroides glucosyltransferase enzyme.
Examples of glucosyltransferase enzymes herein can be any of the amino acid sequences disclosed herein and that further include 1-300 (or any integer there between [e.g., 10, 15, 20, 25, 30, 35, 40, 45, or 50]) residues on the N-terminus and/or C-terminus. Such additional residues may be from a corresponding wild type sequence from which the glucosyltransferase enzyme is derived, or may be a heterologous sequence such as an epitope tag (at either N- or C-terminus) or a heterologous signal peptide (at N-terminus), for example.
A glucosyltransferase enzyme used to produce dextran herein is typically in a mature form lacking an N-terminal signal peptide. An expression system for producing a mature glucosyltransferase enzyme herein may employ an enzyme-encoding polynucleotide that further comprises sequence encoding an N-terminal signal peptide to direct extra-cellular secretion. The signal peptide in such embodiments is cleaved from the enzyme during the secretion process. The signal peptide may either be native or heterologous to the glucosyltransferase. An example of a signal peptide useful herein is one from a bacterial (e.g., a Bacillus species such as B. subtilis) or fungal species. An example of a bacterial signal peptide is an aprE signal peptide, such as one from Bacillus (e.g., B. subtilis, see Vogtentanz et al., Protein Expr. Purif. 55:40-52, which is incorporated herein by reference).
SEQ ID NO:1, SEQ ID NO:5, SEQ ID NO:9, SEQ ID NO:13 and SEQ ID NO:17 are examples of mature glucosyltransferase enzymes that lack an N-terminal signal peptide. Since these and related amino acid sequences do not begin with a methionine residue, it would be understood that an N-terminal start-methionine is preferably added to the sequence (directly or via an intervening heterologous amino acid sequence such as an epitope) if expressing any of these enzymes without using a signal peptide (such as with an expression system where the enzyme is expressed intracellularly and obtained from a cell lysate).
A glucosyltransferase enzyme in certain embodiments can be produced by any means known in the art. For example, a glucosyltransferase enzyme can be produced recombinantly in a heterologous expression system, such as a microbial heterologous expression system. Examples of heterologous expression systems include bacterial (e.g., E. coli such as TOP10, MG1655, or BL21 DE3; Bacillus sp. such as B. subtilis) and eukaryotic (e.g., yeasts such as Pichia sp. and Saccharomyces sp.) expression systems.
A glucosyltransferase enzyme disclosed herein may be used in any purification state (e.g., pure or non-pure). For example, the glucosyltransferase enzyme may be purified and/or isolated prior to its use. Examples of glucosyltransferase enzymes that are non-pure include those in the form of a cell lysate. A cell lysate or extract may be prepared from a bacteria (e.g., E. coli) used to heterologously express the enzyme. For example, the bacteria may be subjected to disruption using a French pressure cell. In alternative embodiments, bacteria may be homogenized with a homogenizer (e.g., APV, Rannie, Gaulin). A glucosyltransferase enzyme is typically soluble in these types of preparations. A bacterial cell lysate, extract, or homogenate herein may be used at about 0.15-0.3% (v/v) in a reaction for producing dextran from sucrose.
The activity of a glucosyltransferase enzyme herein can be determined using any method known in the art. For example, glucosyltransferase enzyme activity can be determined by measuring the production of reducing sugars (fructose and glucose) in a reaction containing sucrose (˜50 g/L), dextran T10 (˜1 mg/mL) and potassium phosphate buffer (˜pH 6.5, 50 mM), where the solution is held at ˜22-25° C. for ˜24-30 hours. The reducing sugars can be measured by adding 0.01 mL of the reaction to a mixture containing ˜1 N NaOH and ˜0.1% triphenyltetrazolium chloride and then monitoring the increase in absorbance at OD_{480 nm}for ˜five minutes. Also for instance, a unit of an enzyme such as gtf 0768 (comprising SEQ ID NO:1) herein can be defined as the amount of enzyme required to consume 1 g of sucrose in 1 hour at 26° C., pH 6.5, and with 100 g/L of sucrose.
A dextran ether compound herein can be derived from a dextran that is a product of a glucosyltransferase as comprised in a glucosyltransferase reaction. The temperature of a gtf reaction herein can be controlled, if desired. In certain embodiments, the temperature is between about 5° C. to about 50° C. The temperature in certain other embodiments is between about 20° C. to about 40° C. Alternatively, the temperature may be about 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40° C. The temperature of a gtf reaction herein may be maintained using various means known in the art. For example, the temperature can be maintained by placing the vessel containing the reaction in an air or water bath incubator set at the desired temperature.
The initial concentration of sucrose in a gtf reaction herein can be about 20 g/L to 900 g/L, 20 g/L to 400 g/L, 75 g/L to 175 g/L, or 50 g/L to 150 g/L. The initial concentration of sucrose can be about 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 200, 300, 400, 500, 600, 700, 800, 900, 50-150, 75-125, 90-110, 50-500, 100-500, 200-500, 300-500, 400-500, 50-400, 100-400, 200-400, 300-400, 50-300, 100-300, 200-300, 50-200, 100-200, or 50-100 g/L (or any integer between 20 and 900 g/L), for example. “Initial concentration of sucrose” refers to the sucrose concentration in a gtf reaction just after all the reaction components have been added (at least water, sucrose, gtf enzyme).
The pH of a gtf reaction in certain embodiments can be between about 4.0 to about 8.0. Alternatively, the pH can be about 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, or 8.0. The pH can be adjusted or controlled by the addition or incorporation of a suitable buffer, including but not limited to: phosphate, tris, citrate, or a combination thereof. Buffer concentration in a gtf reaction can be from 0 mM to about 100 mM, or about 10, 20, or 50 mM, for example.
A gtf reaction herein can optionally be agitated via stirring or orbital shaking, for example. Such agitation can be at about 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 50-150, 60-140, 70-130, 80-120, or 90-110 rpm, for example.
The concentration of gtf enzyme in a reaction can be at least about 15, 20, 25, 30, 35, or 40 U/L, for example. In some aspects, 15-35, 15-30, 15-25, 20-35, 20-30, 20-25, 25-35, 25-30, or 30-35 U/L of glucosyltransferase can be used.
A gtf reaction herein can take about 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 18, 24, 30, 36, 48, 60, 72, 84, 96, 18-30, 20-28, or 22-26 hours to complete. Reaction time may depend, for example, on certain parameters such as the amount of sucrose and gtf enzyme used in the reaction.
All the features herein defining a glucosyltransferase reaction can be combined, accordingly. Simply as an example, a reaction using an 0768 gtf (comprising SEQ ID NO:1 or related sequence thereof) can initially contain 90-110 g/L (e.g., ˜100 g/L) sucrose, 10-30 mM (e.g., ˜20 mM) sodium phosphate buffer at pH 6.0-7.0 (e.g., ˜pH 6.5), and 20-30 U/L (e.g., ˜25 U/L) enzyme. Such a reaction can be held for about 20-28 hours (e.g., ˜24 hours) with 50-150 rpm (e.g., ˜100 rpm) shaking at 24-28° C. (e.g., ˜26° C.).
Still in additional embodiments, conditions for performing a gtf reaction as disclosed in the below Examples can be used to prepare dextran from which a dextran ether compound herein can be derived.
The degree of substitution (DoS) of a dextran ether compound with an organic group as disclosed herein can be about 0.0025 to about 3.0. Alternatively, the DoS can be about, or at least about, 0.0025, 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0.
The percentage of the monosaccharide units of a dextran ether compound herein that are ether-linked to an organic group (i.e., where one or more hydroxyl groups of a monosaccharide monomeric unit have been etherified with an organic group) can vary depending on the degree to which a dextran herein is etherified with an organic group in an etherification reaction. This percentage can be at least about 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% (or any integer value between 30% and 100%), for example.
It would be understood that, depending on the glycosidic linkages with which a glucose monomeric unit of a dextran ether compound is involved, certain carbon atoms of the glucose monomeric unit may independently be linked to an OH group or be in ether linkage to an organic group.
A dextran ether compound as presently disclosed comprises one or more organic groups that are ether-linked to the dextran polymer. Any ether compound disclosed herein can be derived from a dextran as disclosed herein.
An organic group herein can be an alkyl group such as a methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, or decyl group, for example.
Alternatively, an organic group may be a substituted alkyl group in which there is a substitution on one or more carbons of the alkyl group. The substitution(s) may be one or more hydroxyl, aldehyde, ketone, and/or carboxyl groups. For example, a substituted alkyl group may be a hydroxy alkyl group, dihydroxy alkyl group, or carboxy alkyl group.
Examples of suitable hydroxy alkyl groups are hydroxymethyl (—CH₂OH), hydroxyethyl (e.g., —CH₂CH₂OH, —CH(OH)CH₃), hydroxypropyl (e.g., —CH₂CH₂CH₂OH, —CH₂CH(OH)CH₃, —CH(OH)CH₂CH₃), hydroxybutyl and hydroxypentyl groups. Other examples include dihydroxy alkyl groups (diols) such as dihydroxymethyl, dihydroxyethyl (e.g., —CH(OH)CH₂OH), dihydroxypropyl (e.g., —CH₂CH(OH)CH₂OH, —CH(OH)CH(OH)CH₃), dihydroxybutyl and dihydroxypentyl groups.
Examples of suitable carboxy alkyl groups are carboxymethyl (—CH₂COOH), carboxyethyl (e.g., —CH₂CH₂COOH, —CH(COOH)CH₃), carboxypropyl (e.g., —CH₂CH₂CH₂COOH, —CH₂CH(COOH)CH₃, —CH(COOH)CH₂CH₃), carboxybutyl and carboxypentyl groups.
Alternatively still, one or more carbons of an alkyl group can have a substitution(s) with another alkyl group. Examples of such substituent alkyl groups are methyl, ethyl and propyl groups. To illustrate, an organic group can be —CH(CH₃)CH₂CH₃or —CH₂CH(CH₃)CH₃, for example, which are both propyl groups having a methyl substitution.
As should be clear from the above examples of various substituted alkyl groups, a substitution (e.g., hydroxy or carboxy group) on an alkyl group in certain embodiments may be bonded to the terminal carbon atom of the alkyl group, where the terminal carbon group is opposite the terminus that is in ether linkage to a monomeric unit (monosaccharide unit) in a dextran ether compound. An example of this terminal substitution is the hydroxypropyl group —CH₂CH₂CH₂OH. Alternatively, a substitution may be on an internal carbon atom of an alkyl group. An example of an internal substitution is the hydroxypropyl group —CH₂CH(OH)CH₃. An alkyl group can have one or more substitutions, which may be the same (e.g., two hydroxyl groups [dihydroxy]) or different (e.g., a hydroxyl group and a carboxyl group).
Dextran ether compounds in certain embodiments disclosed herein may contain one type of organic group. Examples of such compounds contain a carboxy alkyl group as the organic group (carboxyalkyl dextran, generically speaking). A specific non-limiting example of such a compound is carboxymethyl dextran. Other examples include dextran ether compounds containing an alkyl group as the organic group (alkyl dextran, generically speaking). A specific non-limiting example of such a compound is methyl dextran. Other examples include dextran ether compounds containing a dihydroxyalkyl as the organic group (dihydroxyalkyl dextran, generically speaking). A specific non-limiting example of such a compound is dihydroxypropyl dextran.
Alternatively, dextran ether compounds disclosed herein can contain two or more different types of organic groups. Examples of such compounds contain (i) two different alkyl groups as organic groups, (ii) an alkyl group and a hydroxy alkyl group as organic groups (alkyl hydroxyalkyl dextran, generically speaking), (iii) an alkyl group and a carboxy alkyl group as organic groups (alkyl carboxyalkyl dextran, generically speaking), (iv) a hydroxy alkyl group and a carboxy alkyl group as organic groups (hydroxyalkyl carboxyalkyl dextran, generically speaking), (v) two different hydroxy alkyl groups as organic groups, or (vi) two different carboxy alkyl groups as organic groups. Specific non-limiting examples of such compounds include ethyl hydroxyethyl dextran, hydroxyalkyl methyl dextran, carboxymethyl hydroxyethyl dextran, and carboxymethyl hydroxypropyl dextran.
Dextran ether compounds herein can comprise at least one nonionic organic group and at least one anionic group, for example. As another example, dextran ether compounds herein can comprise at least one nonionic organic group and at least one positively charged organic group.
An organic group herein can alternatively be a positively charged organic group in some aspects. A positively charged group herein can be a substituted ammonium group, for example. Examples of substituted ammonium groups are primary, secondary, tertiary and quaternary ammonium groups. Structure I depicts a primary, secondary, tertiary or quaternary ammonium group, depending on the composition of R₂, R₃and R₄in structure I. Each of R₂, R₃and R₄in structure I independently represents a hydrogen atom or an alkyl, aryl, cycloalkyl, aralkyl, or alkaryl group. Alternatively, each of R₂, R₃and R₄can independently represent a hydrogen atom or an alkyl group. An alkyl group can be a methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, or decyl group, for example. Where two or three of R₂, R₃and R₄are an alkyl group, they can be the same or different alkyl groups.
A “primary ammonium dextran ether compound” herein can comprise a positively charged organic group having an ammonium group. In this example, the positively charged organic group comprises structure I in which each of R₂, R₃and R₄is a hydrogen atom. A non-limiting example of such a positively charged organic group is represented by structure II when each of R₂, R₃and R₄is a hydrogen atom. An example of a primary ammonium dextran ether compound can be represented in shorthand as ammonium dextran ether. It would be understood that a first member (i.e., R₁) implied by “primary” in the above nomenclature is the chain of one or more carbons of the positively charged organic group that is ether-linked to a monosaccharide unit of the dextran component of the ether compound.
A “secondary ammonium dextran ether compound” herein can comprise a positively charged organic group having a monoalkylammonium group, for example. In this example, the positively charged organic group comprises structure I in which each of R₂and R₃is a hydrogen atom and R₄is an alkyl group. A non-limiting example of such a positively charged organic group is represented by structure II when each of R₂and R₃is a hydrogen atom and R₄is an alkyl group. An example of a secondary ammonium dextran ether compound can be represented in shorthand herein as monoalkylammonium dextran ether (e.g., monomethyl-, monoethyl-, monopropyl-, monobutyl-, monopentyl-, monohexyl-, monoheptyl-, monooctyl-, monononyl-, or monodecyl-ammonium dextran ether). It would be understood that a second member (i.e., R₁) implied by “secondary” in the above nomenclature is the chain of one or more carbons of the positively charged organic group that is ether-linked to a monosaccharide unit of the dextran component of the ether compound.
A “tertiary ammonium dextran ether compound” herein can comprise a positively charged organic group having a dialkylammonium group, for example. In this example, the positively charged organic group comprises structure I in which R₂is a hydrogen atom and each of R₃and R₄is an alkyl group. A non-limiting example of such a positively charged organic group is represented by structure II when R₂is a hydrogen atom and each of R₃and R₄is an alkyl group. An example of a tertiary ammonium dextran ether compound can be represented in shorthand as dialkylammonium dextran ether (e.g., dimethyl-, diethyl-, dipropyl-, dibutyl-, dipentyl-, dihexyl-, diheptyl-, dioctyl-, dinonyl-, or didecyl-ammonium dextran ether). It would be understood that a third member (i.e., R₁) implied by “tertiary” in the above nomenclature is the chain of one or more carbons of the positively charged organic group that is ether-linked to a monosaccharide unit of the dextran component of the ether compound.
A “quaternary ammonium dextran ether compound” herein can comprise a positively charged organic group having a trialkylammonium group, for example. In this example, the positively charged organic group comprises structure I in which each of R₂, R₃and R₄is an alkyl group. A non-limiting example of such a positively charged organic group is represented by structure II when each of R₂, R₃and R₄is an alkyl group. An example of a quaternary ammonium dextran ether compound can be represented in shorthand as trialkylammonium dextran (e.g., trimethyl-, triethyl-, tripropyl-, tributyl-, tripentyl-, trihexyl-, triheptyl-, trioctyl-, trinonyl-, or tridecyl-ammonium dextran ether). It would be understood that a fourth member (i.e., R₁) implied by “quaternary” in the above nomenclature is the chain of one or more carbons of the positively charged organic group that is ether-linked to a monosaccharide unit of the dextran component of the ether compound.
Additional non-limiting examples of substituted ammonium groups that can serve as a positively charged group herein are represented in structure I when each of R₂, R₃and R₄independently represent a hydrogen atom; an alkyl group such as a methyl, ethyl, or propyl group; an aryl group such as a phenyl or naphthyl group; an aralkyl group such as a benzyl group; an alkaryl group; or a cycloalkyl group. Each of R₂, R₃and R₄may further comprise an amino group or a hydroxyl group, for example.
The nitrogen atom in a substituted ammonium group represented by structure I is bonded to a chain of one or more carbons as comprised in a positively charged organic group. This chain of one or more carbons (“carbon chain”) is ether-linked to a monosaccharide unit of the dextran component of the ether compound, and may have one or more substitutions in addition to the substitution with the nitrogen atom of the substituted ammonium group. There can be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbons, for example, in a carbon chain. To illustrate, the carbon chain of structure II is 3 carbon atoms in length.
Examples of a carbon chain of a positively charged organic group that do not have a substitution in addition to the substitution with a positively charged group include —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂— and —CH₂CH₂CH₂CH₂CH₂—. In each of these examples, the first carbon atom of the chain is ether-linked to a monosaccharide unit of the dextran component of the ether compound, and the last carbon atom of the chain is linked to a positively charged group. Where the positively charged group is a substituted ammonium group, the last carbon atom of the chain in each of these examples is represented by the C in structure I.
Where a carbon chain of a positively charged organic group has a substitution in addition to a substitution with a positively charged group, such additional substitution may be with one or more hydroxyl groups, oxygen atoms (thereby forming an aldehyde or ketone group), alkyl groups (e.g., methyl, ethyl, propyl, butyl), and/or additional positively charged groups. A positively charged group is typically bonded to the terminal carbon atom of the carbon chain.
Examples of a carbon chain of a positively charged organic group having one or more substitutions with a hydroxyl group include hydroxyalkyl (e.g., hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl) groups and dihydroxyalkyl (e.g., dihydroxyethyl, dihydroxypropyl, dihydroxybutyl, dihydroxypentyl) groups. Examples of hydroxyalkyl and dihydroxyalkyl (diol) carbon chains include —CH(OH)—, —CH(OH)CH₂—, —C(OH)2CH₂—, —CH₂CH(OH)CH₂—, —CH(OH)CH₂CH₂—, —CH(OH)CH(OH)CH₂—, —CH₂CH₂CH(OH)CH₂—, —CH₂CH(OH)CH₂CH₂—, —CH(OH)CH₂CH₂CH₂—, —CH₂CH(OH)CH(OH)CH₂—, —CH(OH)CH(OH)CH₂CH₂— and —CH(OH)CH₂CH(OH)CH₂—. In each of these examples, the first carbon atom of the chain is ether-linked to a monosaccharide unit of the dextran component of the ether compound, and the last carbon atom of the chain is linked to a positively charged group. Where the positively charged group is a substituted ammonium group, the last carbon atom of the chain in each of these examples is represented by the C in structure I.
Examples of a carbon chain of a positively charged organic group having one or more substitutions with an alkyl group include chains with one or more substituent methyl, ethyl and/or propyl groups. Examples of methylalkyl groups include —CH(CH₃)CH₂CH₂— and —CH₂CH(CH₃)CH₂—, which are both propyl groups having a methyl substitution. In each of these examples, the first carbon atom of the chain is ether-linked to a monosaccharide unit of the dextran component of the ether compound, and the last carbon atom of the chain is linked to a positively charged group. Where the positively charged group is a substituted ammonium group, the last carbon atom of the chain in each of these examples is represented by the C in structure I.
Dextran ether compounds in certain embodiments disclosed herein can contain one type of positively charged organic group. For example, one or more positively charged organic groups ether-linked to a monosaccharide unit of the dextran component of the ether compound can be trimethylammonium hydroxypropyl groups (structure II). Alternatively, dextran ether compounds disclosed herein can contain two or more different types of positively charged organic groups.
Dextran ether compounds herein with at least one cationic group can further comprise at least one nonionic organic group and/or at least one anionic group, for example. As another example, dextran ether compounds herein can comprise at least one nonionic organic group and at least one positively charged organic group.
A composition comprising a dextran ether compound herein can be non-aqueous (e.g., a dry composition). Examples of such embodiments include powders, granules, microcapsules, flakes, or any other form of particulate matter. Other examples include larger compositions such as pellets, bars, kernels, beads, tablets, sticks, or other agglomerates. A non-aqueous or dry composition herein typically has less than 3, 2, 1, 0.5, or 0.1 wt % water comprised therein. The amount of dextran ether compound herein in a non-aqueous or dry composition can be about, or at least about, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, or 99.9 wt %, for example. A non-aqueous composition herein can be in the form of a household product, personal care product, pharmaceutical product, industrial product, or food product, for example. A non-aqueous composition herein can be in the form of a household product, personal care product, pharmaceutical product, industrial product, or food product, for example.
In certain embodiments of the present disclosure, a composition comprising a dextran ether compound can be an aqueous composition having a viscosity of about, or at least about 3 cPs. Alternatively, such an aqueous composition herein can have a viscosity of about, or at least about 4, 5, 10, 25, 50, 75, 100, 250, 500, 750, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000, 25000, 30000, 35000, 40000, 45000, or 50000 cPs (or any integer between 3 and 50000 cPs), for example. Examples of aqueous compositions herein include hydrocolloids and aqueous solutions.
Viscosity can be measured with an aqueous composition herein at any temperature between about 3° C. to about 110° C. (or any integer between 3 and 110° C.). Alternatively, viscosity can be measured at a temperature between about 4° C. to 30° C., or about 20° C. to 25° C., for example. Viscosity can be measured at atmospheric pressure (about 760 torr) or any other higher or lower pressure.
The viscosity of an aqueous composition disclosed herein can be measured using a viscometer or rheometer, or using any other means known in the art. It would be understood by those skilled in the art that a viscometer or rheometer can be used to measure the viscosity of aqueous compositions herein that exhibit rheological behavior (i.e., having viscosities that vary with flow conditions). The viscosity of such embodiments can be measured at a rotational shear rate of about 0.1 to 1000 rpm (revolutions per minute), for example. Alternatively, viscosity can be measured at a rotational shear rate of about 10, 60, 150, 250, or 600 rpm.
In certain embodiments, viscosity can be measured with an aqueous composition in which the constituent dextran was synthesized. For example, viscosity can be measured for a gtf reaction herein that is at or near completion. Viscosity can thus be measured with an aqueous composition in which the constituent dextran is not purified (e.g., other components in the composition, aside from water, are present at greater than 1, 5, or 10 wt %); such a composition can contain one or more salts, buffers, proteins (e.g., gtf enzymes), sugars (e.g., fructose, glucose, leucrose, oligosaccharides)
The pH of an aqueous composition disclosed herein can be between about 2.0 to about 12.0, for example. Alternatively, pH can be about 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0; or between 5.0 to about 12.0; or between about 4.0 and 8.0; or between about 5.0 and 8.0, for example.
An aqueous composition herein such as a hydrocolloid or aqueous solution can comprise a solvent having at least about 10 wt % water. In other embodiments, a solvent is at least about 20, 30, 40, 50, 60, 70, 80, 90, or 100 wt % water (or any integer value between 10 and 100 wt %), for example.
A dextran ether compound herein can be present in an aqueous composition at a wt % of about, or at least about, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, or 90 wt %, for example.
An aqueous composition herein can comprise other components in addition to a dextran ether compound. For example, an aqueous composition can comprise one or more salts such as a sodium salt (e.g., NaCl, Na₂SO₄). Other non-limiting examples of salts include those having (i) an aluminum, ammonium, barium, calcium, chromium (II or III), copper (I or II), iron (II or III), hydrogen, lead (II), lithium, magnesium, manganese (II or III), mercury (I or II), potassium, silver, sodium strontium, tin (II or IV), or zinc cation, and (ii) an acetate, borate, bromate, bromide, carbonate, chlorate, chloride, chlorite, chromate, cyanamide, cyanide, dichromate, dihydrogen phosphate, ferricyanide, ferrocyanide, fluoride, hydrogen carbonate, hydrogen phosphate, hydrogen sulfate, hydrogen sulfide, hydrogen sulfite, hydride, hydroxide, hypochlorite, iodate, iodide, nitrate, nitride, nitrite, oxalate, oxide, perchlorate, permanganate, peroxide, phosphate, phosphide, phosphite, silicate, stannate, stannite, sulfate, sulfide, sulfite, tartrate, or thiocyanate anion. Thus, any salt having a cation from (i) above and an anion from (ii) above can be in an aqueous composition, for example. A salt can be present in an aqueous composition herein at a wt % of about 0.01 to about 10.00 (or any hundredth increment between 0.01 and 10.00), for example.
Those skilled in the art would understand that, in certain embodiments of the disclosure, a dextran ether compound can be in an anionic form in an aqueous composition. Examples may include those dextran ether compounds having an organic group comprising an alkyl group substituted with a carboxyl group. Carboxyl (COOH) groups in a carboxyalkyl dextran ether compound can convert to carboxylate (COO⁻) groups in aqueous conditions. Such anionic groups can interact with salt cations such as any of those listed above in (i) (e.g., potassium, sodium, or lithium cation). Thus, a dextran ether compound can be a sodium carboxyalkyl dextran ether (e.g., sodium carboxymethyl dextran), potassium carboxyalkyl dextran ether (e.g., potassium carboxymethyl dextran), or lithium carboxyalkyl dextran ether (e.g., lithium carboxymethyl dextran), for example.
A dextran ether compound in certain aspects is in a cationic form when comprised within an aqueous composition. The cationic groups of a dextran ether compound herein can interact with salt anions that may be present in an aqueous composition. Such salt anions can be any of those listed above in (ii) (e.g., chloride anion), for example.
A composition herein may optionally contain one or more active enzymes. Non-limiting examples of suitable enzymes include proteases, cellulases, hemicellulases, peroxidases, lipolytic enzymes (e.g., metallolipolytic enzymes), xylanases, lipases, phospholipases, esterases (e.g., arylesterase, polyesterase), perhydrolases, cutinases, pectinases, pectate lyases, mannanases, keratinases, reductases, oxidases (e.g., choline oxidase), phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, beta-glucanases, arabinosidases, hyaluronidases, chondroitinases, laccases, metalloproteinases, amadoriases, glucoamylases, arabinofuranosidases, phytases, isomerases, transferases and amylases. If an enzyme(s) is included, it may be comprised in a composition herein at about 0.0001-0.1 wt % (e.g., 0.01-0.03 wt %) active enzyme (e.g., calculated as pure enzyme protein), for example.
A cellulase herein can have endocellulase activity (EC 3.2.1.4), exocellulase activity (EC 3.2.1.91), or cellobiase activity (EC 3.2.1.21). A cellulase herein is an “active cellulase” having activity under suitable conditions for maintaining cellulase activity; it is within the skill of the art to determine such suitable conditions. Besides being able to degrade cellulose, a cellulase in certain embodiments can also degrade cellulose ether derivatives such as carboxymethyl cellulose. Examples of cellulose ether derivatives which are expected to not be stable to cellulase are disclosed in U.S. Pat. Nos. 7,012,053, 7,056,880, 6,579,840, 7,534,759 and 7,576,048.
A cellulase herein may be derived from any microbial source, such as a bacteria or fungus. Chemically-modified cellulases or protein-engineered mutant cellulases are included. Suitable cellulases include, but are not limited to, cellulases from the genera Bacillus, Pseudomonas, Streptomyces, Trichoderma, Humicola, Fusarium, Thielavia and Acremonium. As other examples, a cellulase may be derived from Humicola insolens, Myceliophthora thermophila or Fusarium oxysporum; these and other cellulases are disclosed in U.S. Pat. Nos. 4,435,307, 5,648,263, 5,691,178, 5,776,757 and 7,604,974, which are all incorporated herein by reference. Exemplary Trichoderma reesei cellulases are disclosed in U.S. Pat. Nos. 4,689,297, 5,814,501, 5,324,649, and International Patent Appl. Publ. Nos. WO92/06221 and WO92/06165, all of which are incorporated herein by reference. Exemplary Bacillus cellulases are disclosed in U.S. Pat. No. 6,562,612, which is incorporated herein by reference. A cellulase, such as any of the foregoing, preferably is in a mature form lacking an N-terminal signal peptide. Commercially available cellulases useful herein include CELLUZYME® and CAREZYME® (Novozymes A/S); CLAZINASE® and PURADAX® HA (DuPont Industrial Biosciences), and KAC-500(B)® (Kao Corporation).
One or more cellulases can be directly added as an ingredient when preparing a composition disclosed herein. Alternatively, one or more cellulases can be indirectly (inadvertently) provided in the disclosed composition. For example, cellulase can be provided in a composition herein by virtue of being present in a non-cellulase enzyme preparation used for preparing a composition. Cellulase in compositions in which cellulase is indirectly provided thereto can be present at about 0.1-10 ppb (e.g., less than 1 ppm), for example. A contemplated benefit of a composition herein, by virtue of employing a dextran ether compound, is that non-cellulase enzyme preparations that might have background cellulase activity can be used without concern that the desired effects of the dextran will be negated by the background cellulase activity.
A cellulase in certain embodiments can be thermostable. Cellulase thermostability refers to the ability of the enzyme to retain activity after exposure to an elevated temperature (e.g. about 60-70° C.) for a period of time (e.g., about 30-60 minutes). The thermostability of a cellulase can be measured by its half-life (t1/2) given in minutes, hours, or days, during which time period half the cellulase activity is lost under defined conditions.
A cellulase in certain embodiments can be stable to a wide range of pH values (e.g. neutral or alkaline pH such as pH of ˜7.0 to ˜11.0). Such enzymes can remain stable fora predetermined period of time (e.g., at least about 15 min., 30 min., or 1 hour) under such pH conditions.
At least one, two, or more cellulases may be included in the composition. The effective concentration of cellulase in an aqueous composition in which a fabric is treated can be readily determined by a skilled artisan. In fabric care processes, cellulase can be present in an aqueous composition (e.g., wash liquor) in which a fabric is treated in a concentration that is minimally about 0.01-0.1 ppm total cellulase protein, or about 0.1-10 ppb total cellulase protein (e.g., less than 1 ppm), to maximally about 100, 200, 500, 1000, 2000, 3000, 4000, or 5000 ppm total cellulase protein, for example.
Dextran ethers provided herein are believed to be mostly or completely stable (resistant) to being degraded by cellulase. For example, the percent degradation of a dextran herein by one or more cellulases is believed to be less than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1%, or is 0%. Such percent degradation can be determined, for example, by comparing the molecular weight of dextran ether before and after treatment with a cellulase for a period of time (e.g., ˜24 hours).
Aqueous compositions in certain embodiments are believed to have shear thinning behavior or shear thickening behavior. Shear thinning behavior is observed as a decrease in viscosity of the aqueous composition as shear rate increases, whereas shear thickening behavior is observed as an increase in viscosity of the aqueous composition as shear rate increases. Modification of the shear thinning behavior or shear thickening behavior of an aqueous composition herein can be due to the admixture of a dextran ether compound to the aqueous composition. Thus, one or more dextran ether compounds as presently disclosed can be added to an aqueous composition to modify its rheological profile (i.e., the flow properties of an aqueous liquid, solution, or mixture are modified). Also, one or more dextran ether compounds herein can be added to an aqueous composition to modify its viscosity in some aspects.
The rheological properties of aqueous compositions herein can be observed by measuring viscosity over an increasing rotational shear rate (e.g., from about 0.1 rpm to about 1000 rpm). For example, shear thinning behavior of an aqueous composition disclosed herein can be observed as a decrease in viscosity (cPs) by at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% (or any integer between 5% and 95%) as the rotational shear rate increases from about 10 rpm to 60 rpm, 10 rpm to 150 rpm, 10 rpm to 250 rpm, 60 rpm to 150 rpm, 60 rpm to 250 rpm, or 150 rpm to 250 rpm. As another example, shear thickening behavior of an aqueous composition can be observed as an increase in viscosity (cPs) by at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 125%, 150%, 175%, or 200% (or any integer between 5% and 200%) as the rotational shear rate increases from about 10 rpm to 60 rpm, 10 rpm to 150 rpm, 10 rpm to 250 rpm, 60 rpm to 150 rpm, 60 rpm to 250 rpm, or 150 rpm to 250 rpm.
An aqueous composition disclosed herein can be in the form of, and/or comprised in, a household product, personal care product, pharmaceutical product, industrial product, or food product, for example, such as any of those products described below. Dextran ether compounds herein can be used as thickening agents (structural agents) and/or anti-redeposition agents in one or more of these products, for example. Such a thickening agent may be used in conjunction with one or more other types of thickening agents if desired, such as those disclosed in U.S. Pat. No. 8,541,041, which is incorporated herein by reference.
Dextran ether compounds disclosed herein are believed to be useful for providing one or more of the following physical properties to a personal care product, pharmaceutical product, household product, industrial product, or food product: thickening, freeze/thaw stability, lubricity, moisture retention and release, texture, consistency, shape retention, emulsification, binding, suspension, dispersion, gelation, reduced mineral hardness, for example. Examples of a concentration or amount of a dextran ether compound in a product can be any of the weight percentages provided herein, for example.
Personal care products herein are not particularly limited and include, for example, skin care compositions, cosmetic compositions, antifungal compositions, and antibacterial compositions. Personal care products herein may be in the form of, for example, lotions, creams, pastes, balms, ointments, pomades, gels, liquids, combinations of these and the like. The personal care products disclosed herein can include at least one active ingredient, if desired. An active ingredient is generally recognized as an ingredient that causes an intended pharmacological effect. A personal care product herein can be used in personal care cleaning applications in certain embodiments.
In certain embodiments, a skin care product can be applied to skin for addressing skin damage related to a lack of moisture. A skin care product may also be used to address the visual appearance of skin (e.g., reduce the appearance of flaky, cracked, and/or red skin) and/or the tactile feel of the skin (e.g., reduce roughness and/or dryness of the skin while improved the softness and subtleness of the skin). A skin care product typically may include at least one active ingredient for the treatment or prevention of skin ailments, providing a cosmetic effect, or for providing a moisturizing benefit to skin, such as zinc oxide, petrolatum, white petrolatum, mineral oil, cod liver oil, lanolin, dimethicone, hard fat, vitamin A, allantoin, calamine, kaolin, glycerin, or colloidal oatmeal, and combinations of these. A skin care product may include one or more natural moisturizing factors such as ceramides, hyaluronic acid, glycerin, squalane, amino acids, cholesterol, fatty acids, triglycerides, phospholipids, glycosphingolipids, urea, linoleic acid, glycosaminoglycans, mucopolysaccharide, sodium lactate, or sodium pyrrolidone carboxylate, for example. Other ingredients that may be included in a skin care product include, without limitation, glycerides, apricot kernel oil, canola oil, squalane, squalene, coconut oil, corn oil, jojoba oil, jojoba wax, lecithin, olive oil, safflower oil, sesame oil, shea butter, soybean oil, sweet almond oil, sunflower oil, tea tree oil, shea butter, palm oil, cholesterol, cholesterol esters, wax esters, fatty acids, and orange oil.
A personal care product herein can also be in the form of makeup, lipstick, mascara, rouge, foundation, blush, eyeliner, lip liner, lip gloss, other cosmetics, sunscreen, sun block, nail polish, nail conditioner, bath gel, shower gel, body wash, face wash, lip balm, skin conditioner, cold cream, moisturizer, body spray, soap, body scrub, exfoliant, astringent, scruffing lotion, depilatory, permanent waving solution, antidandruff formulation, antiperspirant composition, deodorant, shaving product, pre-shaving product, after-shaving product, cleanser, skin gel, rinse, dentifrice composition, toothpaste, or mouthwash, for example.
A personal care product in some aspects can be a hair care product. Examples of hair care products herein include shampoo, hair conditioner (leave-in or rinse-out), cream rinse, hair dye, hair coloring product, hair shine product, hair serum, hair anti-frizz product, hair split-end repair product, mousse, hair spray, and styling gel. A hair care product can be in the form of a liquid, paste, gel, solid, or powder in some embodiments. A hair care product as presently disclosed typically comprises one or more of the following ingredients, which are generally used to formulate hair care products: anionic surfactants such as polyoxyethylenelauryl ether sodium sulfate; cationic surfactants such as stearyltrimethylammonium chloride and/or distearyltrimethylammonium chloride; nonionic surfactants such as glyceryl monostearate, sorbitan monopalmitate and/or polyoxyethylenecetyl ether; wetting agents such as propylene glycol, 1,3-butylene glycol, glycerin, sorbitol, pyroglutamic acid salts, amino acids and/or trimethylglycine; hydrocarbons such as liquid paraffins, petrolatum, solid paraffins, squalane and/or olefin oligomers; higher alcohols such as stearyl alcohol and/or cetyl alcohol; superfatting agents; antidandruff agents; disinfectants; anti-inflammatory agents; crude drugs; water-soluble polymers such as methyl cellulose, hydroxycellulose and/or partially deacetylated chitin (in addition to one or more dextran ethers as disclosed herein); antiseptics such as paraben; ultra-violet light absorbers; pearling agents; pH adjustors; perfumes; and pigments.
A pharmaceutical product herein can be in the form of an emulsion, liquid, elixir, gel, suspension, solution, cream, or ointment, for example. Also, a pharmaceutical product herein can be in the form of any of the personal care products disclosed herein, such as an antibacterial or antifungal composition. A pharmaceutical product can further comprise one or more pharmaceutically acceptable carriers, diluents, and/or pharmaceutically acceptable salts. A dextran ether compound disclosed herein can also be used in capsules, encapsulants, tablet coatings, and excipients for medicaments and drugs.
Non-limiting examples of food products herein include vegetable, meat, and soy patties; reformed seafood; reformed cheese sticks; cream soups; gravies and sauces; salad dressing; mayonnaise; onion rings; jams, jellies, and syrups; pie filling; potato products such as French fries and extruded fries; batters for fried foods, pancakes/waffles and cakes; pet foods; confectioneries (candy); beverages; frozen desserts; ice cream; cultured dairy products such as cottage cheese, yogurt, cheeses, and sour creams; cake icing and glazes; whipped topping; leavened and unleavened baked goods; bars; and the like.
In certain embodiments, a dextran ether compound can be comprised in a foodstuff or any other ingestible material (e.g., enteral pharmaceutical preparation) in an amount that provides the desired degree of thickening and/or dispersion. For example, the concentration or amount of a dextran ether in a product can be about 0.1-3 wt %, 0.1-4 wt %, 0.1-5 wt %, or 0.1-10 wt %.
A household and/or industrial product herein can be in the form of drywall tape-joint compounds; mortars; grouts; cement plasters; spray plasters; cement stucco; adhesives; pastes; wall/ceiling texturizers; binders and processing aids for tape casting, extrusion forming, injection molding and ceramics; spray adherents and suspending/dispersing aids for pesticides, herbicides, and fertilizers; fabric care products such as fabric softeners and laundry detergents; dishwashing detergents; hard surface cleaners; air fresheners; polymer emulsions; gels such as water-based gels; surfactant solutions; paints such as water-based paints; protective coatings; adhesives; sealants and caulks; inks such as water-based ink; metal-working fluids; or emulsion-based metal cleaning fluids used in electroplating, phosphatizing, galvanizing and/or general metal cleaning operations, for example. A household product or industrial product herein can be used in cleaning applications in certain embodiments, and as such can be comprised in detergent compositions, for example.
Dextran ether compounds disclosed herein are believed to be useful for providing one or more of the following physical properties to a personal care product, pharmaceutical product, household product, industrial product, or food product: thickening, freeze/thaw stability, lubricity, moisture retention and release, texture, consistency, shape retention, emulsification, binding, suspension, dispersion, gelation, reduced mineral hardness, for example. Examples of a concentration or amount of a dextran ether in a product can be any of the weight percentages provided above, for example.
A food product herein can be in the form of a confectionery, for example. A confectionary herein can contain one or more sugars (e.g., sucrose, fructose, dextrose) for sweetening, or otherwise be sugar-free.
Examples of confectioneries herein include boiled sugars (hard boiled candies [i.e., hard candy]), dragees, jelly candies, gums, licorice, chews, caramels, toffee, fudge, chewing gums, bubble gums, nougat, chewy pastes, halawa, tablets, lozenges, icing, frosting, pudding, and gels (e.g., fruit gels, gelatin dessert). Other examples of confectioneries include aerated confectioneries such as marshmallows, and baked confectioneries.
A confectionery herein can optionally be prepared with chocolate, in any form (e.g., bars, candies, bonbons, truffles, lentils). A confectionary can be coated with chocolate, sugar-coated, candied, glazed, and/or film-coated, for example. Film-coating processes typically comprise applying to the surface of a confectionery a film-forming liquid composition which becomes, after drying, a protective film. This film-coating serves, for example, to protect the active principles contained in the confectionery; to protect the confectionery itself from moisture, shocks, and/or friability; and/or to confer the confectionery attractive visual properties (e.g., shine, uniform color, smooth surface).
In certain embodiments, a confectionery can be filled with a filling that is liquid, pasty, solid, or powdered. A dextran ether compound herein can be comprised in such a filling, in which case a dextran ether compound is optionally also included in the confectionery component being filled.
A confectionery herein is optionally sugar-free, comprising no sugar and typically instead having one or more artificial and/or non-sugar sweeteners (optionally non-caloric) (e.g., aspartame, saccharin, STEVIA, SUCRALOSE). A sugar-free confectionery in certain embodiments can comprise one or more polyols (e.g., erythritol, glycerol, lactitol, mannitol, maltitol, xylitol), soluble fibers, and/or proteins in place of sugar.
A food product herein can be in the form of a pet food, for example. A pet food herein can be a food for a domesticated animal such as a dog or cat (or any other companion animal), for example. A pet food in certain embodiments provides to a domestic animal one or more of the following: necessary dietary requirements, treats (e.g., dog biscuits), food supplements. Examples of pet food include dry pet food (e.g., kernels, kibbles), semi-moist compositions, wet pet food (e.g., canned pet food), or any combination thereof. Wet pet food typically has a moisture content over 65%. Semi-moist pet food typically has a moisture content of 20-65% and can include humectants such as propylene glycol, potassium sorbate, and ingredients that prevent microbial growth (bacteria and mold). Dry pet food typically has a moisture content less than 20% and its processing usually includes extruding, drying and/or baking. A pet food can optionally be in the form of a gravy, yogurt, powder, suspension, chew, or treat (e.g., biscuits); all these compositions can also be used as pet food supplements, if desired. Pet treats can be semi-moist chewable treats; dry treats; chewable bones; baked, extruded or stamped treats; or confection treats, for example. Examples of pet food compositions/formulations in which a dextran ether compound herein can be added include those disclosed in U.S. Patent Appl. Publ. Nos. 2013/0280352 and 2010/0159103, and U.S. Pat. No. 6,977,084, which are all incorporated herein by reference.
Compositions disclosed herein can be in the form of a fabric care composition. A fabric care composition herein can be used for hand wash, machine wash and/or other purposes such as soaking and/or pretreatment of fabrics, for example. A fabric care composition may take the form of, for example, a laundry detergent; fabric conditioner; any wash-, rinse-, or dryer-added product; unit dose or spray. Fabric care compositions in a liquid form may be in the form of an aqueous composition as disclosed herein. In other aspects, a fabric care composition can be in a dry form such as a granular detergent or dryer-added fabric softener sheet. Other non-limiting examples of fabric care compositions herein include: granular or powder-form all-purpose or heavy-duty washing agents; liquid, gel or paste-form all-purpose or heavy-duty washing agents; liquid or dry fine-fabric (e.g. delicates) detergents; cleaning auxiliaries such as bleach additives, “stain-stick”, or pre-treatments; substrate-laden products such as dry and wetted wipes, pads, or sponges; sprays and mists.
A detergent composition herein may be in any useful form, e.g., as powders, granules, pastes, bars, unit dose, or liquid. A liquid detergent may be aqueous, typically containing up to about 70 wt % of water and 0 wt % to about 30 wt % of organic solvent. It may also be in the form of a compact gel type containing only about 30 wt % water.
A detergent composition herein typically comprises one or more surfactants, wherein the surfactant is selected from nonionic surfactants, anionic surfactants, cationic surfactants, ampholytic surfactants, zwitterionic surfactants, semi-polar nonionic surfactants and mixtures thereof. In some embodiments, the surfactant is present at a level of from about 0.1% to about 60%, while in alternative embodiments the level is from about 1% to about 50%, while in still further embodiments the level is from about 5% to about 40%, by weight of the detergent composition. A detergent will usually contain 0 wt % to about 50 wt % of an anionic surfactant such as linear alkylbenzenesulfonate (LAS), alpha-olefinsulfonate (AOS), alkyl sulfate (fatty alcohol sulfate) (AS), alcohol ethoxysulfate (AEOS or AES), secondary alkanesulfonates (SAS), alpha-sulfo fatty acid methyl esters, alkyl- or alkenylsuccinic acid, or soap. In addition, a detergent composition may optionally contain 0 wt % to about 40 wt % of a nonionic surfactant such as alcohol ethoxylate (AEO or AE), carboxylated alcohol ethoxylates, nonylphenol ethoxylate, alkylpolyglycoside, alkyldimethylamineoxide, ethoxylated fatty acid monoethanolamide, fatty acid monoethanolamide, or polyhydroxy alkyl fatty acid amide (as described for example in WO92/06154, which is incorporated herein by reference).
A detergent composition herein typically comprises one or more detergent builders or builder systems. One or more oxidized poly alpha-1,3-glucan compounds can be included as a builder, for example. In some aspects, oxidized poly alpha-1,3-glucan can be included as a co-builder, in which it is used together with one or more additional builders such as any disclosed herein. Oxidized poly alpha-1,3-glucan compounds for use herein are disclosed in U.S. Patent Appl. Publ. No. 2015/0259439. In some embodiments incorporating at least one builder, the cleaning compositions comprise at least about 1%, from about 3% to about 60%, or even from about 5% to about 40%, builder by weight of the composition. Builders (in addition to oxidized poly alpha-1,3-glucan) include, but are not limited to, alkali metal, ammonium and alkanolammonium salts of polyphosphates, alkali metal silicates, alkaline earth and alkali metal carbonates, aluminosilicates, polycarboxylate compounds, ether hydroxypolycarboxylates, copolymers of maleic anhydride with ethylene or vinyl methyl ether, 1,3,5-trihydroxy benzene-2,4,6-trisulphonic acid, and carboxymethyloxysuccinic acid, various alkali metal, ammonium and substituted ammonium salts of polyacetic acids such as ethylenediamine tetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates such as mellitic acid, succinic acid, citric acid, oxydisuccinic acid, polymaleic acid, benzene 1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and soluble salts thereof. Indeed, it is contemplated that any suitable builder will find use in various embodiments of the present disclosure. Additional examples of a detergent builder or complexing agent include zeolite, diphosphate, triphosphate, phosphonate, citrate, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTMPA), alkyl- or alkenylsuccinic acid, soluble silicates or layered silicates (e.g., SKS-6 from Hoechst).
In some embodiments, builders form water-soluble hardness ion complexes (e.g., sequestering builders), such as citrates and polyphosphates (e.g., sodium tripolyphosphate and sodium tripolyphospate hexahydrate, potassium tripolyphosphate, and mixed sodium and potassium tripolyphosphate, etc.). It is contemplated that any suitable builder will find use in embodiments of the present disclosure, including those known in the art (See, e.g., EP2100949).
In some embodiments, suitable builders can include phosphate builders and non-phosphate builders. In some embodiments, a builder is a phosphate builder. In some embodiments, a builder is a non-phosphate builder. A builder can be used in a level of from 0.1% to 80%, or from 5% to 60%, or from 10% to 50%, by weight of the composition. In some embodiments, the product comprises a mixture of phosphate and non-phosphate builders. Suitable phosphate builders include mono-phosphates, di-phosphates, tri-polyphosphates or oligomeric-polyphosphates, including the alkali metal salts of these compounds, including the sodium salts. In some embodiments, a builder can be sodium tripolyphosphate (STPP). Additionally, the composition can comprise carbonate and/or citrate, preferably citrate that helps to achieve a neutral pH composition. Other suitable non-phosphate builders include homopolymers and copolymers of polycarboxylic acids and their partially or completely neutralized salts, monomeric polycarboxylic acids and hydroxycarboxylic acids and their salts. In some embodiments, salts of the above mentioned compounds include ammonium and/or alkali metal salts, i.e., lithium, sodium, and potassium salts, including sodium salts. Suitable polycarboxylic acids include acyclic, alicyclic, hetero-cyclic and aromatic carboxylic acids, wherein in some embodiments, they can contain at least two carboxyl groups which are in each case separated from one another by, in some instances, no more than two carbon atoms.
A detergent composition herein can comprise at least one chelating agent. Suitable chelating agents include, but are not limited to copper, iron and/or manganese chelating agents and mixtures thereof. In embodiments in which at least one chelating agent is used, the composition comprises from about 0.1% to about 15%, or even from about 3.0% to about 10%, chelating agent by weight of the composition.
A detergent composition herein can comprise at least one deposition aid. Suitable deposition aids include, but are not limited to, polyethylene glycol, polypropylene glycol, polycarboxylate, soil release polymers such as polytelephthalic acid, clays such as kaolinite, montmorillonite, atapulgite, illite, bentonite, halloysite, and mixtures thereof.
A detergent composition herein can comprise one or more dye transfer inhibiting agents. Suitable polymeric dye transfer inhibiting agents include, but are not limited to, polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinyloxazolidones and polyvinylimidazoles or mixtures thereof. Additional dye transfer inhibiting agents include manganese phthalocyanine, peroxidases, polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinyloxazolidones and polyvinylimidazoles and/or mixtures thereof; chelating agents examples of which include ethylene-diamine-tetraacetic acid (EDTA); diethylene triamine penta methylene phosphonic acid (DTPMP); hydroxy-ethane diphosphonic acid (HEDP); ethylenediamine N,N′-disuccinic acid (EDDS); methyl glycine diacetic acid (MGDA); diethylene triamine penta acetic acid (DTPA); propylene diamine tetracetic acid (PDT A); 2-hydroxypyridine-N-oxide (HPNO); or methyl glycine diacetic acid (MGDA); glutamic acid N,N-diacetic acid (N,N-dicarboxymethyl glutamic acid tetrasodium salt (GLDA); nitrilotriacetic acid (NTA); 4,5-dihydroxy-m-benzenedisulfonic acid; citric acid and any salts thereof; N-hydroxyethyl ethylenediaminetri-acetic acid (HEDTA), triethylenetetraaminehexaacetic acid (TTHA), N-hydroxyethyliminodiacetic acid (HEIDA), dihydroxyethylglycine (DHEG), ethylenediaminetetrapropionic acid (EDTP) and derivatives thereof, which can be used alone or in combination with any of the above. In embodiments in which at least one dye transfer inhibiting agent is used, a composition herein may comprise from about 0.0001% to about 10%, from about 0.01% to about 5%, or even from about 0.1% to about 3%, by weight of the composition.
A detergent composition herein can comprise silicates. In some of these embodiments, sodium silicates (e.g., sodium disilicate, sodium metasilicate, and/or crystalline phyllosilicates) find use. In some embodiments, silicates are present at a level of from about 1% to about 20% by weight of the composition. In some embodiments, silicates are present at a level of from about 5% to about 15% by weight of the composition.
A detergent composition herein can comprise dispersants. Suitable water-soluble organic materials include, but are not limited to the homo- or co-polymeric acids or their salts, in which the polycarboxylic acid comprises at least two carboxyl radicals separated from each other by not more than two carbon atoms.
A detergent composition herein may additionally comprise one or more enzymes. Examples of enzymes include proteases, cellulases, hemicellulases, peroxidases, lipolytic enzymes (e.g., metallolipolytic enzymes), xylanases, lipases, phospholipases, esterases (e.g., arylesterase, polyesterase), perhydrolases, cutinases, pectinases, pectate lyases, mannanases, keratinases, reductases, oxidases (e.g., choline oxidase, phenoloxidase), phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, beta-glucanases, arabinosidases, hyaluronidases, chondroitinases, laccases, metalloproteinases, amadoriases, glucoamylases, alpha-amylases, beta-amylases, galactosidases, galactanases, catalases, carageenases, hyaluronidases, keratinases, lactases, ligninases, peroxidases, phosphatases, polygalacturonases, pullulanases, rhamnogalactouronases, tannases, transglutaminases, xyloglucanases, xylosidases, metalloproteases, arabinofuranosidases, phytases, isomerases, transferases and/or amylases in any combination.
In some embodiments, a detergent composition can comprise one or more enzymes (e.g., any disclosed herein), each at a level from about 0.00001% to about 10% by weight of the composition and the balance of cleaning adjunct materials by weight of composition. In some other embodiments, a detergent composition can also comprise each enzyme at a level of about 0.0001% to about 10%, about 0.001% to about 5%, about 0.001% to about 2%, or about 0.005% to about 0.5%, by weight of the composition.
Enzymes that may be comprised in a detergent composition herein may be stabilized using conventional stabilizing agents, e.g., a polyol such as propylene glycol or glycerol; a sugar or sugar alcohol; lactic acid; boric acid or a boric acid derivative (e.g., an aromatic borate ester).
A detergent composition in certain embodiments may comprise one or more other types of polymers in addition to a dextran ether compound as disclosed herein. Examples of other suitable polymers include carboxymethyl cellulose (CMC), poly(vinylpyrrolidone) (PVP), polyethylene glycol (PEG), poly(vinyl alcohol) (PVA), polycarboxylates such as polyacrylates, maleic/acrylic acid copolymers and lauryl methacrylate/acrylic acid copolymers.
A detergent composition herein may contain a bleaching system. For example, a bleaching system can comprise an H₂O₂source such as perborate or percarbonate, which may be combined with a peracid-forming bleach activator such as tetraacetylethylenediamine (TAED) or nonanoyloxybenzenesulfonate (NOBS). Alternatively, a bleaching system may comprise peroxyacids (e.g., amide, imide, or sulfone type peroxyacids). Alternatively still, a bleaching system can be an enzymatic bleaching system comprising perhydrolase, for example, such as the system described in WO2005/056783.
A detergent composition herein may also contain conventional detergent ingredients such as fabric conditioners, clays, foam boosters, suds suppressors, anti-corrosion agents, soil-suspending agents, anti-soil redeposition agents, dyes, bactericides, tarnish inhibiters, optical brighteners, or perfumes. The pH of a detergent composition herein (measured in aqueous solution at use concentration) is usually neutral or alkaline (e.g., pH of about 7.0 to about 11.0).
It is believed that a dextran ether compound herein can be included as an anti-redeposition agent and/or clay soil removal agent in a detergent composition such as a fabric care composition, if desired (such agents can optionally be characterized as whiteness maintenance agents in certain aspects). Examples of other suitable anti-redeposition and/or clay soil removal agents herein include polyethoxy zwitterionic surfactants, water-soluble copolymers of acrylic or methacrylic acid with acrylic or methacrylic acid-ethylene oxide condensates (e.g., U.S. Pat. No. 3,719,647), cellulose derivatives such as carboxymethylcellulose and hydroxypropylcellulose (e.g., U.S. Pat. Nos. 3,597,416 and 3,523,088), and mixtures comprising nonionic alkyl polyethoxy surfactant, polyethoxy alkyl quaternary cationic surfactant and fatty amide surfactant (e.g., U.S. Pat. No. 4,228,044). Non-limiting examples of other suitable anti-redeposition and clay soil removal agents are disclosed in U.S. Pat. Nos. 4,597,898 and 4,891,160, and Int. Pat. Appl. Publ. No. WO95/32272, all of which are incorporated herein by reference.
Particular forms of detergent compositions that can be adapted for purposes disclosed herein are disclosed in, for example, US20090209445A1, US20100081598A1, U.S. Pat. No. 7,001,878B2, EP1504994B1, WO2001085888A2, WO2003089562A1, WO2009098659A1, WO2009098660A1, WO2009112992A1, WO2009124160A1, WO2009152031A1, WO2010059483A1, WO2010088112A1, WO2010090915A1, WO2010135238A1, WO2011094687A1, WO2011094690A1, WO2011127102A1, WO2011163428A1, WO2008000567A1, WO2006045391A1, WO2006007911A1, WO2012027404A1, EP1740690B1, WO2012059336A1, U.S. Pat. No. 6,730,646B1, WO2008087426A1, WO2010116139A1, and WO2012104613A1, all of which are incorporated herein by reference.
Laundry detergent compositions herein can optionally be heavy duty (all purpose) laundry detergent compositions. Exemplary heavy duty laundry detergent compositions comprise a detersive surfactant (10%-40% wt/wt), including an anionic detersive surfactant (selected from a group of linear or branched or random chain, substituted or unsubstituted alkyl sulphates, alkyl sulphonates, alkyl alkoxylated sulphate, alkyl phosphates, alkyl phosphonates, alkyl carboxylates, and/or mixtures thereof), and optionally non-ionic surfactant (selected from a group of linear or branched or random chain, substituted or unsubstituted alkyl alkoxylated alcohol, e.g., C8-C18 alkyl ethoxylated alcohols and/or C6-C12 alkyl phenol alkoxylates), where the weight ratio of anionic detersive surfactant (with a hydrophilic index (HIc) of from 6.0 to 9) to non-ionic detersive surfactant is greater than 1:1. Suitable detersive surfactants also include cationic detersive surfactants (selected from a group of alkyl pyridinium compounds, alkyl quaternary ammonium compounds, alkyl quaternary phosphonium compounds, alkyl ternary sulphonium compounds, and/or mixtures thereof); zwitterionic and/or amphoteric detersive surfactants (selected from a group of alkanolamine sulpho-betaines); ampholytic surfactants; semi-polar non-ionic surfactants and mixtures thereof.
A detergent herein such as a heavy duty laundry detergent composition may optionally include, a surfactancy boosting polymer consisting of amphiphilic alkoxylated grease cleaning polymers (selected from a group of alkoxylated polymers having branched hydrophilic and hydrophobic properties, such as alkoxylated polyalkylenimines in the range of 0.05 wt %-10 wt %) and/or random graft polymers (typically comprising of hydrophilic backbone comprising monomers selected from the group consisting of: unsaturated C1-C6 carboxylic acids, ethers, alcohols, aldehydes, ketones, esters, sugar units, alkoxy units, maleic anhydride, saturated polyalcohols such as glycerol, and mixtures thereof; and hydrophobic side chain(s) selected from the group consisting of: C4-C25 alkyl group, polypropylene, polybutylene, vinyl ester of a saturated C1-C6 mono-carboxylic acid, C1-C6 alkyl ester of acrylic or methacrylic acid, and mixtures thereof.
A detergent herein such as a heavy duty laundry detergent composition may optionally include additional polymers such as soil release polymers (include anionically end-capped polyesters, for example SRP1, polymers comprising at least one monomer unit selected from saccharide, dicarboxylic acid, polyol and combinations thereof, in random or block configuration, ethylene terephthalate-based polymers and co-polymers thereof in random or block configuration, for example REPEL-O-TEX SF, SF-2 AND SRP6, TEXCARE SRA100, SRA300, SRN100, SRN170, SRN240, SRN300 AND SRN325, MARLOQUEST SL), anti-redeposition agent(s) herein (0.1 wt % to 10 wt %), include carboxylate polymers, such as polymers comprising at least one monomer selected from acrylic acid, maleic acid (or maleic anhydride), fumaric acid, itaconic acid, aconitic acid, mesaconic acid, citraconic acid, methylenemalonic acid, and any mixture thereof, vinylpyrrolidone homopolymer, and/or polyethylene glycol, molecular weight in the range of from 500 to 100,000 Da); and polymeric carboxylate (such as maleate/acrylate random copolymer or polyacrylate homopolymer).
A detergent herein such as a heavy duty laundry detergent composition may optionally further include saturated or unsaturated fatty acids, preferably saturated or unsaturated C12-C24 fatty acids (0 wt % to 10 wt %); deposition aids in addition to a dextran ether compound disclosed herein (examples for which include polysaccharides, cellulosic polymers, poly diallyl dimethyl ammonium halides (DADMAC), and co-polymers of DAD MAC with vinyl pyrrolidone, acrylamides, imidazoles, imidazolinium halides, and mixtures thereof, in random or block configuration, cationic guar gum, cationic starch, cationic polyacylamides, and mixtures thereof.
A detergent herein such as a heavy duty laundry detergent composition may optionally further include dye transfer inhibiting agents, examples of which include manganese phthalocyanine, peroxidases, polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinyloxazolidones and polyvinylimidazoles and/or mixtures thereof; chelating agents, examples of which include ethylene-diamine-tetraacetic acid (EDTA), diethylene triamine penta methylene phosphonic acid (DTPMP), hydroxy-ethane diphosphonic acid (HEDP), ethylenediamine N,N′-disuccinic acid (EDDS), methyl glycine diacetic acid (MGDA), diethylene triamine penta acetic acid (DTPA), propylene diamine tetracetic acid (PDTA), 2-hydroxypyridine-N-oxide (HPNO), or methyl glycine diacetic acid (MGDA), glutamic acid N,N-diacetic acid (N,N-dicarboxymethyl glutamic acid tetrasodium salt (GLDA), nitrilotriacetic acid (NTA), 4,5-dihydroxy-m-benzenedisulfonic acid, citric acid and any salts thereof, N-hydroxyethylethylenediaminetriacetic acid (HEDTA), triethylenetetraaminehexaacetic acid (TTHA), N-hydroxyethyliminodiacetic acid (HEI DA), dihydroxyethylglycine (DHEG), ethylenediaminetetrapropionic acid (EDTP), and derivatives thereof.
A detergent herein such as a heavy duty laundry detergent composition may optionally include silicone or fatty-acid based suds suppressors; hueing dyes, calcium and magnesium cations, visual signaling ingredients, anti-foam (0.001 wt % to about 4.0 wt %), and/or a structurant/thickener (0.01 wt % to 5 wt %) selected from the group consisting of diglycerides and triglycerides, ethylene glycol distearate, microcrystalline cellulose, microfiber cellulose, biopolymers, xanthan gum, gellan gum, and mixtures thereof). Such structurant/thickener would be, in certain embodiments, in addition to the one or more dextran ether compounds comprised in the detergent. A structurant can also be referred to as a structural agent.
A detergent herein can be in the form of a heavy duty dry/solid laundry detergent composition, for example. Such a detergent may include: (i) a detersive surfactant, such as any anionic detersive surfactant disclosed herein, any non-ionic detersive surfactant disclosed herein, any cationic detersive surfactant disclosed herein, any zwitterionic and/or amphoteric detersive surfactant disclosed herein, any ampholytic surfactant, any semi-polar non-ionic surfactant, and mixtures thereof; (ii) a builder, such as any phosphate-free builder (e.g., zeolite builders in the range of 0 wt % to less than 10 wt %), any phosphate builder (e.g., sodium tri-polyphosphate in the range of 0 wt % to less than 10 wt %), citric acid, citrate salts and nitrilotriacetic acid, any silicate salt (e.g., sodium or potassium silicate or sodium meta-silicate in the range of 0 wt % to less than 10 wt %); any carbonate salt (e.g., sodium carbonate and/or sodium bicarbonate in the range of 0 wt % to less than 80 wt %), and mixtures thereof; (iii) a bleaching agent, such as any photobleach (e.g., sulfonated zinc phthalocyanines, sulfonated aluminum phthalocyanines, xanthenes dyes, and mixtures thereof), any hydrophobic or hydrophilic bleach activator (e.g., dodecanoyl oxybenzene sulfonate, decanoyl oxybenzene sulfonate, decanoyl oxybenzoic acid or salts thereof, 3,5,5-trimethy hexanoyl oxybenzene sulfonate, tetraacetyl ethylene diamine-TAED, nonanoyloxybenzene sulfonate-NOBS, nitrile quats, and mixtures thereof), any source of hydrogen peroxide (e.g., inorganic perhydrate salts, examples of which include mono or tetra hydrate sodium salt of perborate, percarbonate, persulfate, perphosphate, or persilicate), any preformed hydrophilic and/or hydrophobic peracids (e.g., percarboxylic acids and salts, percarbonic acids and salts, perimidic acids and salts, peroxymonosulfuric acids and salts, and mixtures thereof); and/or (iv) any other components such as a bleach catalyst (e.g., imine bleach boosters examples of which include iminium cations and polyions, iminium zwitterions, modified amines, modified amine oxides, N-sulphonyl imines, N-phosphonyl imines, N-acyl imines, thiadiazole dioxides, perfluoroimines, cyclic sugar ketones, and mixtures thereof), and a metal-containing bleach catalyst (e.g., copper, iron, titanium, ruthenium, tungsten, molybdenum, or manganese cations along with an auxiliary metal cations such as zinc or aluminum and a sequestrate such as EDTA, ethylenediaminetetra(methylenephosphonic acid).
Compositions disclosed herein can be in the form of a dishwashing detergent composition. Examples of dishwashing detergents include automatic dishwashing detergents (typically used in dishwasher machines) and hand-washing dish detergents. A dishwashing detergent composition can be in any dry or liquid/aqueous form as disclosed herein, for example. Components that may be included in certain embodiments of a dishwashing detergent composition include, for example, one or more of a phosphate; oxygen- or chlorine-based bleaching agent; non-ionic surfactant; alkaline salt (e.g., metasilicates, alkali metal hydroxides, sodium carbonate); any active enzyme disclosed herein; anti-corrosion agent (e.g., sodium silicate); anti-foaming agent; additives to slow down the removal of glaze and patterns from ceramics; perfume; anti-caking agent (in granular detergent); starch (in tablet-based detergents); gelling agent (in liquid/gel based detergents); and/or sand (powdered detergents).
Dishwashing detergents such as an automatic dishwasher detergent or liquid dishwashing detergent can comprise (i) a non-ionic surfactant, including any ethoxylated non-ionic surfactant, alcohol alkoxylated surfactant, epoxy-capped poly(oxyalkylated) alcohol, or amine oxide surfactant present in an amount from 0 to 10 wt %; (ii) a builder, in the range of about 5-60 wt %, including any phosphate builder (e.g., mono-phosphates, di-phosphates, tri-polyphosphates, other oligomeric-polyphosphates, sodium tripolyphosphate-STPP), any phosphate-free builder (e.g., amino acid-based compounds including methyl-glycine-diacetic acid [MGDA] and salts or derivatives thereof, glutamic-N,N-diacetic acid [GLDA] and salts or derivatives thereof, iminodisuccinic acid (IDS) and salts or derivatives thereof, carboxy methyl inulin and salts or derivatives thereof, nitrilotriacetic acid [NTA], diethylene triamine penta acetic acid [DTPA], B-alaninediacetic acid [B-ADA] and salts thereof), homopolymers and copolymers of poly-carboxylic acids and partially or completely neutralized salts thereof, monomeric polycarboxylic acids and hydroxycarboxylic acids and salts thereof in the range of 0.5 wt % to 50 wt %, or sulfonated/carboxylated polymers in the range of about 0.1 wt % to about 50 wt %; (iii) a drying aid in the range of about 0.1 wt % to about 10 wt % (e.g., polyesters, especially anionic polyesters, optionally together with further monomers with 3 to 6 functionalities—typically acid, alcohol or ester functionalities which are conducive to polycondensation, polycarbonate-, polyurethane- and/or polyurea-polyorganosiloxane compounds or precursor compounds thereof, particularly of the reactive cyclic carbonate and urea type); (iv) a silicate in the range from about 1 wt % to about 20 wt % (e.g., sodium or potassium silicates such as sodium disilicate, sodium meta-silicate and crystalline phyllosilicates); (v) an inorganic bleach (e.g., perhydrate salts such as perborate, percarbonate, perphosphate, persulfate and persilicate salts) and/or an organic bleach (e.g., organic peroxyacids such as diacyl- and tetraacylperoxides, especially diperoxydodecanedioic acid, diperoxytetradecanedioic acid, and diperoxyhexadecanedioic acid); (vi) a bleach activator (e.g., organic peracid precursors in the range from about 0.1 wt % to about 10 wt %) and/or bleach catalyst (e.g., manganese triazacyclononane and related complexes; Co, Cu, Mn, and Fe bispyridylamine and related complexes; and pentamine acetate cobalt(III) and related complexes); (vii) a metal care agent in the range from about 0.1 wt % to 5 wt % (e.g., benzatriazoles, metal salts and complexes, and/or silicates); and/or (viii) any active enzyme disclosed herein in the range from about 0.01 to 5.0 mg of active enzyme per gram of automatic dishwashing detergent composition, and an enzyme stabilizer component (e.g., oligosaccharides, polysaccharides, and inorganic divalent metal salts).
It is believed that numerous commercially available detergent formulations can be adapted to include a dextran ether compound disclosed herein. Examples include PUREX® ULTRAPACKS (Henkel), FINISH® QUANTUM (Reckitt Benckiser), CLOROX™ 2 PACKS (Clorox), OXICLEAN MAX FORCE POWER PAKS (Church & Dwight), TIDE® STAIN RELEASE, CASCADE® ACTIONPACS, and TIDE® PODS™ (Procter & Gamble).
Compositions disclosed herein can be in the form of an oral care composition, for example. Examples of oral care compositions include dentifrices, toothpaste, mouth wash, mouth rinse, chewing gum, edible strips, and tooth cream/gel that provide some form of oral care (e.g., treatment or prevention of cavities [dental caries], gingivitis, plaque, tartar, and/or periodontal disease). An oral care composition can also be for treating an “oral surface”, which encompasses any soft or hard surface within the oral cavity including surfaces of the tongue, hard and soft palate, buccal mucosa, gums and dental surfaces. A “dental surface” herein is a surface of a natural tooth or a hard surface of artificial dentition including a crown, cap, filling, bridge, denture, or dental implant, for example.
An oral care composition herein can comprise about 0.01-15.0 wt % (e.g., ˜0.1-10 wt % or ˜0.1-5.0 wt %, ˜0.1-2.0 wt %) of one or more dextran ether compounds as disclosed herein, for example. One or more dextran ether compounds comprised in an oral care composition can sometimes be provided therein as a thickening agent and/or dispersion agent, which may be useful to impart a desired consistency and/or mouth feel to the composition. One or more other thickening or dispersion agents can also be provided in an oral care composition herein, such as a carboxyvinyl polymer, carrageenan (e.g., L-carrageenan), natural gum (e.g., karaya, xanthan, gum arabic, tragacanth), colloidal magnesium aluminum silicate, or colloidal silica, for example.
An oral care composition herein may be a toothpaste or other dentifrice, for example. Such compositions, as well as any other oral care composition herein, can additionally comprise, without limitation, one or more of an anticaries agent, antimicrobial or antibacterial agent, anticalculus or tartar control agent, surfactant, abrasive, pH-modifying agent, foam modulator, humectant, flavorant, sweetener, pigment/colorant, whitening agent, and/or other suitable components. Examples of oral care compositions to which one or more dextran ether compounds can be added are disclosed in U.S. Patent Appl. Publ. Nos. 2006/0134025, 2002/0022006 and 2008/0057007, which are incorporated herein by reference.
An anticaries agent herein can be an orally acceptable source of fluoride ions. Suitable sources of fluoride ions include fluoride, monofluorophosphate and fluorosilicate salts as well as amine fluorides, including olaflur (N′-octadecyltrimethylendiamine-N,N,N′-tris(2-ethanol)-dihydrofluoride), for example. An anticaries agent can be present in an amount providing a total of about 100-20000 ppm, about 200-5000 ppm, or about 500-2500 ppm, fluoride ions to the composition, for example. In oral care compositions in which sodium fluoride is the sole source of fluoride ions, an amount of about 0.01-5.0 wt %, about 0.05-1.0 wt %, or about 0.1-0.5 wt %, sodium fluoride can be present in the composition, for example.
An antimicrobial or antibacterial agent suitable for use in an oral care composition herein includes, for example, phenolic compounds (e.g., 4-allylcatechol; p-hydroxybenzoic acid esters such as benzylparaben, butylparaben, ethylparaben, methylparaben and propylparaben; 2-benzylphenol; butylated hydroxyanisole; butylated hydroxytoluene; capsaicin; carvacrol; creosol; eugenol; guaiacol; halogenated bisphenolics such as hexachlorophene and bromochlorophene; 4-hexylresorcinol; 8-hydroxyquinoline and salts thereof; salicylic acid esters such as menthyl salicylate, methyl salicylate and phenyl salicylate; phenol; pyrocatechol; salicylanilide; thymol; halogenated diphenylether compounds such as triclosan and triclosan monophosphate), copper (II) compounds (e.g., copper (II) chloride, fluoride, sulfate and hydroxide), zinc ion sources (e.g., zinc acetate, citrate, gluconate, glycinate, oxide, and sulfate), phthalic acid and salts thereof (e.g., magnesium monopotassium phthalate), hexetidine, octenidine, sanguinarine, benzalkonium chloride, domiphen bromide, alkylpyridinium chlorides (e.g. cetylpyridinium chloride, tetradecylpyridinium chloride, N-tetradecyl-4-ethylpyridinium chloride), iodine, sulfonamides, bisbiguanides (e.g., alexidine, chlorhexidine, chlorhexidine digluconate), piperidino derivatives (e.g., delmopinol, octapinol), magnolia extract, grapeseed extract, rosemary extract, menthol, geraniol, citral, eucalyptol, antibiotics (e.g., augmentin, amoxicillin, tetracycline, doxycycline, minocycline, metronidazole, neomycin, kanamycin, clindamycin), and/or any antibacterial agents disclosed in U.S. Pat. No. 5,776,435, which is incorporated herein by reference. One or more antimicrobial agents can optionally be present at about 0.01-10 wt % (e.g., 0.1-3 wt %), for example, in the disclosed oral care composition.
An anticalculus or tartar control agent suitable for use in an oral care composition herein includes, for example, phosphates and polyphosphates (e.g., pyrophosphates), polyaminopropanesulfonic acid (AMPS), zinc citrate trihydrate, polypeptides (e.g., polyaspartic and polyglutamic acids), polyolefin sulfonates, polyolefin phosphates, diphosphonates (e.g.,azacycloalkane-2,2-diphosphonates such as azacycloheptane-2,2-diphosphonic acid), N-methyl azacyclopentane-2,3-diphosphonic acid, ethane-1-hydroxy-1,1-diphosphonic acid (EHDP), ethane-1-amino-1,1-diphosphonate, and/or phosphonoalkane carboxylic acids and salts thereof (e.g., their alkali metal and ammonium salts). Useful inorganic phosphate and polyphosphate salts include, for example, monobasic, dibasic and tribasic sodium phosphates, sodium tripolyphosphate, tetrapolyphosphate, mono-, di-, tri- and tetra-sodium pyrophosphates, disodium dihydrogen pyrophosphate, sodium trimetaphosphate, sodium hexametaphosphate, or any of these in which sodium is replaced by potassium or ammonium. Other useful anticalculus agents in certain embodiments include anionic polycarboxylate polymers (e.g., polymers or copolymers of acrylic acid, methacrylic, and maleic anhydride such as polyvinyl methyl ether/maleic anhydride copolymers). Still other useful anticalculus agents include sequestering agents such as hydroxycarboxylic acids (e.g., citric, fumaric, malic, glutaric and oxalic acids and salts thereof) and aminopolycarboxylic acids (e.g., EDTA). One or more anticalculus or tartar control agents can optionally be present at about 0.01-50 wt % (e.g., about 0.05-25 wt % or about 0.1-15 wt %), for example, in the disclosed oral care composition.
A surfactant suitable for use in an oral care composition herein may be anionic, non-ionic, or amphoteric, for example. Suitable anionic surfactants include, without limitation, water-soluble salts of C_8-20alkyl sulfates, sulfonated monoglycerides of C_8-20fatty acids, sarcosinates, and taurates. Examples of anionic surfactants include sodium lauryl sulfate, sodium coconut monoglyceride sulfonate, sodium lauryl sarcosinate, sodium lauryl isoethionate, sodium laureth carboxylate and sodium dodecyl benzenesulfonate. Suitable non-ionic surfactants include, without limitation, poloxamers, polyoxyethylene sorbitan esters, fatty alcohol ethoxylates, alkylphenol ethoxylates, tertiary amine oxides, tertiary phosphine oxides, and dialkyl sulfoxides. Suitable amphoteric surfactants include, without limitation, derivatives of C_8-20aliphatic secondary and tertiary amines having an anionic group such as a carboxylate, sulfate, sulfonate, phosphate or phosphonate. An example of a suitable amphoteric surfactant is cocoamidopropyl betaine. One or more surfactants are optionally present in a total amount of about 0.01-10 wt % (e.g., about 0.05-5.0 wt % or about 0.1-2.0 wt %), for example, in the disclosed oral care composition.
An abrasive suitable for use in an oral care composition herein may include, for example, silica (e.g., silica gel, hydrated silica, precipitated silica), alumina, insoluble phosphates, calcium carbonate, and resinous abrasives (e.g., a urea-formaldehyde condensation product). Examples of insoluble phosphates useful as abrasives herein are orthophosphates, polymetaphosphates and pyrophosphates, and include dicalcium orthophosphate dihydrate, calcium pyrophosphate, beta-calcium pyrophosphate, tricalcium phosphate, calcium polymetaphosphate and insoluble sodium polymetaphosphate. One or more abrasives are optionally present in a total amount of about 5-70 wt % (e.g., about 10-56 wt % or about 15-30 wt %), for example, in the disclosed oral care composition. The average particle size of an abrasive in certain embodiments is about 0.1-30 microns (e.g., about 1-20 microns or about 5-15 microns).
An oral care composition in certain embodiments may comprise at least one pH-modifying agent. Such agents may be selected to acidify, make more basic, or buffer the pH of a composition to a pH range of about 2-10 (e.g., pH ranging from about 2-8, 3-9, 4-8, 5-7, 6-10, or 7-9). Examples of pH-modifying agents useful herein include, without limitation, carboxylic, phosphoric and sulfonic acids; acid salts (e.g., monosodium citrate, disodium citrate, monosodium malate); alkali metal hydroxides (e.g. sodium hydroxide, carbonates such as sodium carbonate, bicarbonates, sesquicarbonates); borates; silicates; phosphates (e.g., monosodium phosphate, trisodium phosphate, pyrophosphate salts); and imidazole.
A foam modulator suitable for use in an oral care composition herein may be a polyethylene glycol (PEG), for example. High molecular weight PEGs are suitable, including those having an average molecular weight of about 200000-7000000 (e.g., about 500000-5000000 or about 1000000-2500000), for example. One or more PEGs are optionally present in a total amount of about 0.1-10 wt % (e.g. about 0.2-5.0 wt % or about 0.25-2.0 wt %), for example, in the disclosed oral care composition.
An oral care composition in certain embodiments may comprise at least one humectant. A humectant in certain embodiments may be a polyhydric alcohol such as glycerin, sorbitol, xylitol, or a low molecular weight PEG. Most suitable humectants also may function as a sweetener herein. One or more humectants are optionally present in a total amount of about 1.0-70 wt % (e.g., about 1.0-50 wt %, about 2-25 wt %, or about 5-15 wt %), for example, in the disclosed oral care composition.
A natural or artificial sweetener may optionally be comprised in an oral care composition herein. Examples of suitable sweeteners include dextrose, sucrose, maltose, dextrin, invert sugar, mannose, xylose, ribose, fructose, levulose, galactose, corn syrup (e.g., high fructose corn syrup or corn syrup solids), partially hydrolyzed starch, hydrogenated starch hydrolysate, sorbitol, mannitol, xylitol, maltitol, isomalt, aspartame, neotame, saccharin and salts thereof, dipeptide-based intense sweeteners, and cyclamates. One or more sweeteners are optionally present in a total amount of about 0.005-5.0 wt %, for example, in the disclosed oral care composition.
A natural or artificial flavorant may optionally be comprised in an oral care composition herein. Examples of suitable flavorants include vanillin; sage; marjoram; parsley oil; spearmint oil; cinnamon oil; oil of wintergreen (methylsalicylate); peppermint oil; clove oil; bay oil; anise oil; eucalyptus oil; citrus oils; fruit oils; essences such as those derived from lemon, orange, lime, grapefruit, apricot, banana, grape, apple, strawberry, cherry, or pineapple; bean- and nut-derived flavors such as coffee, cocoa, cola, peanut, or almond; and adsorbed and encapsulated flavorants. Also encompassed within flavorants herein are ingredients that provide fragrance and/or other sensory effect in the mouth, including cooling or warming effects. Such ingredients include, without limitation, menthol, menthyl acetate, menthyl lactate, camphor, eucalyptus oil, eucalyptol, anethole, eugenol, cassia, oxanone, Irisone®, propenyl guaiethol, thymol, linalool, benzaldehyde, cinnamaldehyde, N-ethyl-p-menthan-3-carboxamine, N,2,3-trimethyl-2-isopropylbutanamide, 3-(1-menthoxy)-propane-1,2-diol, cinnamaldehyde glycerol acetal (CGA), and menthone glycerol acetal (MGA). One or more flavorants are optionally present in a total amount of about 0.01-5.0 wt % (e.g., about 0.1-2.5 wt %), for example, in the disclosed oral care composition.
An oral care composition in certain embodiments may comprise at least one bicarbonate salt. Any orally acceptable bicarbonate can be used, including alkali metal bicarbonates such as sodium or potassium bicarbonate, and ammonium bicarbonate, for example. One or more bicarbonate salts are optionally present in a total amount of about 0.1-50 wt % (e.g., about 1-20 wt %), for example, in the disclosed oral care composition.
An oral care composition in certain embodiments may comprise at least one whitening agent and/or colorant. A suitable whitening agent is a peroxide compound such as any of those disclosed in U.S. Pat. No. 8,540,971, which is incorporated herein by reference. Suitable colorants herein include pigments, dyes, lakes and agents imparting a particular luster or reflectivity such as pearling agents, for example. Specific examples of colorants useful herein include talc; mica; magnesium carbonate; calcium carbonate; magnesium silicate; magnesium aluminum silicate; silica; titanium dioxide; zinc oxide; red, yellow, brown and black iron oxides; ferric ammonium ferrocyanide; manganese violet; ultramarine; titaniated mica; and bismuth oxychloride. One or more colorants are optionally present in a total amount of about 0.001-20 wt % (e.g., about 0.01-10 wt % or about 0.1-5.0 wt %), for example, in the disclosed oral care composition.
Additional components that can optionally be included in an oral composition herein include one or more enzymes (above), vitamins, and anti-adhesion agents, for example. Examples of vitamins useful herein include vitamin C, vitamin E, vitamin B5, and folic acid. Examples of suitable anti-adhesion agents include solbrol, ficin, and quorum-sensing inhibitors.
The present disclosure also concerns a method for increasing the viscosity of an aqueous composition. This method comprises contacting at least one dextran ether compound as disclosed herein with the aqueous composition. The contacting step in this method results in increasing the viscosity of the aqueous composition, in comparison to the viscosity of the aqueous composition before the contacting step. Any hydrocolloid and aqueous solution disclosed herein, for example, can be produced or modified using this method.
An aqueous composition herein can be water (e.g., de-ionized water), an aqueous solution, or a hydrocolloid, for example. The viscosity of an aqueous composition before the contacting step, measured at about 20-25° C., can be about 0-10000 cPs (or any integer between 0-10000 cPs), for example. Since the aqueous composition can be a hydrocolloid or the like in certain embodiments, it should be apparent that the method can be used to increase the viscosity of aqueous compositions that are already viscous.
Contacting a dextran ether herein with an aqueous composition increases the viscosity of the aqueous composition in certain embodiments. This increase in viscosity can be an increase of at least about 1%, 10%, 100%, 1000%, 100000%, or 1000000% (or any integer between 1% and 1000000%), for example, compared to the viscosity of the aqueous composition before the contacting step. It should be apparent that very large percent increases in viscosity can be obtained with the disclosed method when the aqueous composition has little to no viscosity before the contacting step. An increase in viscosity can be determined, for example, by comparing the viscosity of the aqueous composition obtained by the method (i.e., after the contacting step) with the viscosity of the aqueous composition as it had existed before the method (i.e., before the contacting step).
Contacting dextran ether herein with an aqueous composition increases the shear thinning behavior or shear thickening behavior of the aqueous composition in certain embodiments. Thus, dextran ether rheologically modifies the aqueous composition in these embodiments. The increase in shear thinning behavior or shear thickening behavior can be an increase of at least about 1%, 10%, 100%, 1000%, 100000%, or 1000000% (or any integer between 1% and 1000000%), for example, compared to the shear thinning behavior or shear thickening behavior of the aqueous composition before the contacting step. It should be apparent that very large percent increases in rheologic modification can be obtained with the disclosed method when the aqueous composition has little to no rheologic behavior before the contacting step.
The contacting step in a method for increasing the viscosity of an aqueous composition can be performed by mixing or dissolving any dextran ether compound as presently disclosed in the aqueous composition by any means known in the art. For example, mixing or dissolving can be performed manually or with a machine (e.g., industrial mixer or blender, orbital shaker, stir plate, homogenizer, sonicator, bead mill). Mixing or dissolving can comprise a homogenization step in certain embodiments. Homogenization (as well as any other type of mixing) can be performed for about 5 to 60, 5 to 30, 10 to 60, 10 to 30, 5 to 15, or 10 to 15 seconds (or any integer between 5 and 60 seconds), or longer periods of time as necessary to mix dextran ether with the aqueous composition. A homogenizer can be used at about 5000 to 30000 rpm, 10000 to 30000 rpm, 15000 to 30000 rpm, 15000 to 25000 rpm, or 20000 rpm (or any integer between 5000 and 30000 rpm), for example.
After a dextran ether compound herein is mixed with or dissolved into an aqueous composition, the resulting aqueous composition may be filtered, or may not be filtered. For example, an aqueous composition prepared with a homogenization step may or may not be filtered.
Certain embodiments of the above method can be used to prepare an aqueous composition disclosed herein, such as a food product (e.g., a confectionery such as a candy filling), pharmaceutical product (e.g., excipient), household product (e.g., laundry detergent, fabric softener, dishwasher detergent), personal care product (e.g., a water-containing dentifrice such as toothpaste), or industrial product.
The present disclosure also concerns a method of treating a material. This method comprises contacting a material with an aqueous composition comprising at least one dextran ether compound disclosed herein.
A material contacted with an aqueous composition in a contacting method herein can comprise a fabric in certain embodiments. A fabric herein can comprise natural fibers, synthetic fibers, semi-synthetic fibers, or any combination thereof. A semi-synthetic fiber herein is produced using naturally occurring material that has been chemically derivatized, an example of which is rayon. Non-limiting examples of fabric types herein include fabrics made of (i) cellulosic fibers such as cotton (e.g., broadcloth, canvas, chambray, chenille, chintz, corduroy, cretonne, damask, denim, flannel, gingham, jacquard, knit, matelassé, oxford, percale, poplin, plissé, sateen, seersucker, sheers, terry doth, twill, velvet), rayon (e.g., viscose, modal, lyocell), linen, and Tencel®; (ii) proteinaceous fibers such as silk, wool and related mammalian fibers; (iii) synthetic fibers such as polyester, acrylic, nylon, and the like; (iv) long vegetable fibers from jute, flax, ramie, coir, kapok, sisal, henequen, abaca, hemp and sunn; and (v) any combination of a fabric of (i)-(iv). Fabric comprising a combination of fiber types (e.g., natural and synthetic) include those with both a cotton fiber and polyester, for example. Materials/articles containing one or more fabrics herein include, for example, clothing, curtains, drapes, upholstery, carpeting, bed linens, bath linens, tablecloths, sleeping bags, tents, car interiors, etc. Other materials comprising natural and/or synthetic fibers include, for example, non-woven fabrics, paddings, paper, and foams.
An aqueous composition that is contacted with a fabric can be, for example, a fabric care composition (e.g., laundry detergent, fabric softener). Thus, a treatment method in certain embodiments can be considered a fabric care method or laundry method if employing a fabric care composition therein. A fabric care composition herein is contemplated to effect one or more of the following fabric care benefits (i.e., surface substantive effects): wrinkle removal, wrinkle reduction, wrinkle resistance, fabric wear reduction, fabric wear resistance, fabric pilling reduction, extended fabric life, fabric color maintenance, fabric color fading reduction, reduced dye transfer, fabric color restoration, fabric soiling reduction, fabric soil release, fabric shape retention, fabric smoothness enhancement, anti-redeposition of soil on fabric, anti-greying of laundry, improved fabric hand/handle, and/or fabric shrinkage reduction.
Examples of conditions (e.g., time, temperature, wash/rinse volumes) for conducting a fabric care method or laundry method herein are disclosed in WO1997/003161 and U.S. Pat. Nos. 4,794,661, 4,580,421 and 5,945,394, which are incorporated herein by reference. In other examples, a material comprising fabric can be contacted with an aqueous composition herein: (i) for at least about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, or 120 minutes; (ii) at a temperature of at least about 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95° C. (e.g., for laundry wash or rinse: a “cold” temperature of about 15-30° C., a “warm” temperature of about 30-50° C., a “hot” temperature of about 50-95° C.), (iii) at a pH of about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 (e.g., pH range of about 2-12, or about 3-11); (iv) at a salt (e.g., NaCl) concentration of at least about 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, or 4.0 wt %; or any combination of (i)-(iv).
The contacting step in a fabric care method or laundry method can comprise any of washing, soaking, and/or rinsing steps, for example. Contacting a material or fabric in still further embodiments can be performed by any means known in the art, such as dissolving, mixing, shaking, spraying, treating, immersing, flushing, pouring on or in, combining, painting, coating, applying, affixing to, and/or communicating an effective amount of a dextran ether compound herein with the fabric or material. In still further embodiments, contacting may be used to treat a fabric to provide a surface substantive effect. As used herein, the term “fabric hand” or “handle” refers to a person's tactile sensory response towards fabric which may be physical, physiological, psychological, social or any combination thereof. In one embodiment, the fabric hand may be measured using a PhabrOmeter® System for measuring relative hand value (available from Nu Cybertek, Inc. Davis, Calif.) (American Association of Textile Chemists and Colorists (AATCC test method “202-2012, Relative Hand Value of Textiles: Instrumental Method”)).
In certain embodiments of treating a material comprising fabric, a dextran ether compound component(s) of the aqueous composition adsorbs to the fabric. This feature is believed to render dextran ether compounds herein useful as anti-redeposition agents and/or anti-greying agents in fabric care compositions disclosed (in addition to their viscosity-modifying effect). An anti-redeposition agent or anti-greying agent herein helps keep soil from redepositing onto clothing in wash water after the soil has been removed. It is further contemplated that adsorption of one or more dextran ether compounds herein to a fabric enhances mechanical properties of the fabric.
Adsorption of a dextran ether compound to a fabric herein can be measured using a colorimetric technique (e.g., Dubois et al., 1956, Anal. Chem. 28:350-356; Zemljič et al., 2006, Lenzinger Berichte 85:68-76; both incorporated herein by reference), for example, or any other method known in the art.
Other materials that can be contacted in the above treatment method include surfaces that can be treated with a dish detergent (e.g., automatic dishwashing detergent or hand dish detergent). Examples of such materials include surfaces of dishes, glasses, pots, pans, baking dishes, utensils and flatware made from ceramic material, china, metal, glass, plastic (e.g., polyethylene, polypropylene, polystyrene, etc.) and wood (collectively referred to herein as “tableware”). Thus, the treatment method in certain embodiments can be considered a dishwashing method or tableware washing method, for example. Examples of conditions (e.g., time, temperature, wash volume) for conducting a dishwashing or tableware washing method herein are disclosed in U.S. Pat. No. 8,575,083, which is incorporated herein by reference. In other examples, a tableware article can be contacted with an aqueous composition herein under a suitable set of conditions such as any of those disclosed above with regard to contacting a fabric-comprising material.
Other materials that can be contacted in the above treatment method include oral surfaces such as any soft or hard surface within the oral cavity including surfaces of the tongue, hard and soft palate, buccal mucosa, gums and dental surfaces (e.g., natural tooth or a hard surface of artificial dentition such as a crown, cap, filling, bridge, denture, or dental implant). Thus, a treatment method in certain embodiments can be considered an oral care method or dental care method, for example. Conditions (e.g., time, temperature) for contacting an oral surface with an aqueous composition herein should be suitable for the intended purpose of making such contact. Other surfaces that can be contacted in a treatment method also include a surface of the integumentary system such as skin, hair or nails.
Thus, certain embodiments of the present disclosure concern material (e.g., fabric) that comprises a dextran ether compound herein. Such material can be produced following a material treatment method as disclosed herein, for example. A material may comprise a dextran ether compound in certain embodiments if the compound is adsorbed to, or otherwise in contact with, the surface of the material.
Certain embodiments of a method of treating a material herein further comprise a drying step, in which a material is dried after being contacted with the aqueous composition. A drying step can be performed directly after the contacting step, or following one or more additional steps that might follow the contacting step (e.g., drying of a fabric after being rinsed, in water for example, following a wash in an aqueous composition herein). Drying can be performed by any of several means known in the art, such as air drying (e.g., ˜20-25° C.), or at a temperature of at least about 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 170, 175, 180, or 200° C., for example. A material that has been dried herein typically has less than 3, 2, 1, 0.5, or 0.1 wt % water comprised therein. Fabric is a preferred material for conducting an optional drying step.
An aqueous composition used in a treatment method herein can be any aqueous composition disclosed herein, such as in the above embodiments or in the below Examples. Thus, the dextran ether component(s) of an aqueous composition can be any as disclosed herein. Examples of aqueous compositions include detergents (e.g., laundry detergent or dish detergent) and water-containing dentifrices such as toothpaste.
The disclosure also concerns a method for producing a dextran ether compound. This method comprises: contacting dextran in a reaction under alkaline conditions with at least one etherification agent comprising an organic group, wherein at least one organic group is etherified to the dextran thereby producing a dextran ether compound as disclosed herein. A dextran ether compound produced in this manner has a degree of substitution with an organic group of about 0.0025 to about 3.0, and can optionally be isolated. This method can be considered to comprise an etherification reaction.
The following steps can be taken to prepare the above etherification reaction in some embodiments. A dextran compound disclosed herein is contacted in a reaction under alkaline conditions with at least one etherification agent comprising an organic group. This step can be performed, for example, by first preparing alkaline conditions by contacting dextran with a solvent (e.g., water or alcohol) and one or more alkali hydroxides to provide a preparation (e.g., a solution, where dextran is dissolved in an alkali hydroxide solution). The alkaline conditions of the etherification reaction can thus comprise an alkali hydroxide solution in some aspects. The pH of the alkaline conditions can be at least about 11.0, 11.2, 11.4, 11.6, 11.8, 12.0, 12.2, 12.4, 12.6, 12.8, or 13.0, for example.
Various alkali hydroxides can be used, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, and/or tetraethylammonium hydroxide. The concentration of alkali hydroxide in a preparation with a dextran herein and a solvent can be from about 1-54 wt %, 5-50 wt %, 5-10 wt %, 10-50 wt %, 10-40 wt %, or 10-30 wt % (or any integer between 1 and 54 wt %). Alternatively, the concentration of alkali hydroxide such as sodium hydroxide can be about, or at least about, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 wt %. An alkali hydroxide used to prepare alkaline conditions may be in a completely aqueous solution or an aqueous solution comprising one or more water-soluble organic solvents such as ethanol or isopropanol. Alternatively, an alkali hydroxide can be added as a solid, if desired, to provide alkaline conditions.
Various organic solvents that can optionally be included in a solvent, or used as the main solvent, when preparing the etherification reaction include alcohols, acetone, dioxane, isopropanol and toluene, for example. Toluene or isopropanol can be used in certain embodiments. An organic solvent can be added before or after addition of alkali hydroxide. The concentration of an organic solvent (e.g., isopropanol or toluene) in a preparation comprising dextran and an alkali hydroxide can be at least about 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 wt % (or any integer between 10 and 90 wt %).
Dextran as presently disclosed can be contacted with a solvent and one or more alkali hydroxides by dissolving and/or mixing. Such dissolving and/or mixing can be performed during or after adding these components with each other. In certain embodiments, a dextran can first be dissolved in water or an aqueous solution before it is mixed with another solvent and/or alkali hydroxide.
After contacting dextran, solvent, and one or more alkali hydroxides with each other, the resulting composition can optionally be maintained at ambient temperature for up to 14 days. The term “ambient temperature” as used herein refers to a temperature between about 15-30° C. or 20-25° C. (or any integer between 15 and 30° C.). Alternatively, the composition can be heated with or without reflux at a temperature from about 30° C. to about 150° C. (or any integer between 30 and 150° C.) for up to about 48 hours. The composition in certain embodiments can be heated at about 70° C. for about 30-60 minutes. Thus, a composition obtained from mixing a dextran compound herein, solvent, and one or more alkali hydroxides with each other can be heated at about 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, or 75° C. for about 30-90 minutes, for example.
An etherification agent comprising an organic group can be contacted with a dextran compound as presently disclosed in a reaction under alkaline conditions in a method herein of producing dextran ether compounds. For example, an etherification agent can be added to a composition prepared by contacting dextran, solvent, and one or more alkali hydroxides with each other as described above. Alternatively, an etherification agent can be included when preparing the alkaline conditions (e.g., an etherification agent can be mixed with dextran and solvent before dissolving/mixing with alkali hydroxide). One or more etherification agents may be used in an etherification reaction.
An etherification agent in certain embodiments can be used to etherify an alkyl group, hydroxy alkyl group, or carboxy alkyl group to dextran.
Etherification agents suitable for preparing an alkyl dextran ether compound include, for example, dialkyl sulfates, dialkyl carbonates, alkyl halides (e.g., alkyl chloride), iodoalkanes, alkyl triflates (alkyl trifluoromethanesulfonates) and alkyl fluorosulfonates. Thus, examples of etherification agents for producing methyl dextran ethers include dimethyl sulfate, dimethyl carbonate, methyl chloride, iodomethane, methyl triflate and methyl fluorosulfonate. Examples of etherification agents for producing ethyl dextran ethers include diethyl sulfate, diethyl carbonate, ethyl chloride, iodoethane, ethyl triflate and ethyl fluorosulfonate. Examples of etherification agents for producing propyl dextran ethers include dipropyl sulfate, dipropyl carbonate, propyl chloride, iodopropane, propyl triflate and propyl fluorosulfonate. Examples of etherification agents for producing butyl dextran ethers include dibutyl sulfate, dibutyl carbonate, butyl chloride, iodobutane and butyl triflate.
Etherification agents suitable for preparing a hydroxyalkyl dextran ether compound include, for example, alkylene oxides such as ethylene oxide, propylene oxide (e.g., 1,2-propylene oxide), butylene oxide (e.g., 1,2-butylene oxide; 2,3-butylene oxide; 1,4-butylene oxide), or combinations thereof. As examples, propylene oxide can be used as an etherification agent for preparing hydroxypropyl dextran, and ethylene oxide can be used as an etherification agent for preparing hydroxyethyl dextran. Alternatively, hydroxyalkyl halides (e.g., hydroxyalkyl chloride) can be used as etherification agents for preparing hydroxyalkyl dextran. Examples of hydroxyalkyl halides include hydroxyethyl halide, hydroxypropyl halide (e.g., 2-hydroxypropyl chloride, 3-hydroxypropyl chloride) and hydroxybutyl halide. Alternatively, alkylene chlorohydrins can be used as etherification agents for preparing hydroxyalkyl dextran. Alkylene chlorohydrins that can be used include, but are not limited to, ethylene chlorohydrin, propylene chlorohydrin, butylene chlorohydrin, or combinations of these.
Etherification agents suitable for preparing a dihydroxyalkyl dextran ether compound include dihydroxyalkyl halides (e.g., dihydroxyalkyl chloride) such as dihydroxyethyl halide, dihydroxypropyl halide (e.g., 2,3-dihydroxypropyl chloride [i.e., 3-chloro-1,2-propanediol]), or dihydroxybutyl halide, for example. 2,3-dihydroxypropyl chloride can be used to prepare dihydroxypropyl dextran, for example.
Etherification agents suitable for preparing a carboxyalkyl dextran ether compound may include haloalkylates (e.g., chloroalkylate). Examples of haloalkylates include haloacetate (e.g., chloroacetate), 3-halopropionate (e.g., 3-chloropropionate) and 4-halobutyrate (e.g., 4-chlorobutyrate). For example, chloroacetate (monochloroacetate) (e.g., sodium chloroacetate or chloroacetic acid) can be used as an etherification agent to prepare carboxymethyl dextran.
An etherification agent herein can alternatively be used to etherify a positively charged organic group to dextran. Examples of such etherification agents include dialkyl sulfates, dialkyl carbonates, alkyl halides (e.g., alkyl chloride), iodoalkanes, alkyl triflates (alkyl trifluoromethanesulfonates) and alkyl fluorosulfonates, where the alkyl group(s) of each of these agents has one or more substitutions with a positively charged group (e.g., substituted ammonium group such as trimethylammonium). Other examples of such etherification agents include dimethyl sulfate, dimethyl carbonate, methyl chloride, iodomethane, methyl triflate and methyl fluorosulfonate, where the methyl group(s) of each of these agents has a substitution with a positively charged group (e.g., substituted ammonium group such as trimethylammonium). Other examples of such etherification agents include diethyl sulfate, diethyl carbonate, ethyl chloride, iodoethane, ethyl triflate and ethyl fluorosulfonate, where the ethyl group(s) of each of these agents has a substitution with a positively charged group (e.g., substituted ammonium group such as trimethylammonium). Other examples of such etherification agents include dipropyl sulfate, dipropyl carbonate, propyl chloride, iodopropane, propyl triflate and propyl fluorosulfonate, where the propyl group(s) of each of these agents has one or more substitutions with a positively charged group (e.g., substituted ammonium group such as trimethylammonium). Other examples of such etherification agents include dibutyl sulfate, dibutyl carbonate, butyl chloride, iodobutane and butyl triflate, where the butyl group(s) of each of these agents has one or more substitutions with a positively charged group (e.g., substituted ammonium group such as trimethylammonium).
An etherification agent may be one that can etherify dextran with a positively charged organic group, where the carbon chain of the positively charged organic group has a substitution (e.g., hydroxyl group) in addition to a substitution with a positively charged group (e.g., substituted ammonium group such as trimethylammonium). Examples of such etherification agents include hydroxyalkyl halides (e.g., hydroxyalkyl chloride) such as hydroxypropyl halide and hydroxybutyl halide, where a terminal carbon of each of these agents has a substitution with a positively charged group (e.g., substituted ammonium group such as trimethylammonium); an example is 3-chloro-2-hydroxypropyl-trimethylammonium. Other examples of such etherification agents include alkylene oxides such as propylene oxide (e.g., 1,2-propylene oxide) and butylene oxide (e.g., 1,2-butylene oxide; 2,3-butylene oxide), where a terminal carbon of each of these agents has a substitution with a positively charged group (e.g., substituted ammonium group such as trimethylammonium).
A substituted ammonium group comprised in any of the foregoing etherification agent examples can be a primary, secondary, tertiary, or quaternary ammonium group. Examples of secondary, tertiary and quaternary ammonium groups are represented in structure I, where R₂, R₃and R₄each independently represent a hydrogen atom or an alkyl group such as a methyl, ethyl, propyl, or butyl group.
Etherification agents herein typically can be provided as a fluoride, chloride, bromide, or iodide salt (where each of the foregoing halides serve as an anion).
When producing a dextran ether compound with two or more different organic groups, two or more different etherification agents would be used, accordingly. For example, both an alkylene oxide and an alkyl chloride could be used as etherification agents to produce an alkyl hydroxyalkyl dextran ether. Any of the etherification agents disclosed herein may be combined to produce dextran ether compounds with two or more different organic groups. Such two or more etherification agents may be used in the reaction at the same time, or may be used sequentially in the reaction. When used sequentially, any of the temperature-treatment (e.g., heating) steps disclosed below may optionally be used between each addition. One may choose sequential introduction of etherification agents in order to control the desired DoS of each organic group. In general, a particular etherification agent would be used first if the organic group it forms in the ether product is desired at a higher DoS compared to the DoS of another organic group to be added.
The amount of etherification agent to be contacted with dextran in a reaction under alkaline conditions can be determined based on the degree of substitution (DoS) required in the dextran ether compound being produced. The amount of ether substitution groups on each monomeric unit of the dextran component of an ether compound produced herein can be determined using nuclear magnetic resonance (NMR) spectroscopy. The molar substitution (MS) value for dextran has no upper limit. In general, an etherification agent can be used in a quantity of at least about 0.05 mole per mole of dextran. There is no upper limit to the quantity of etherification agent that can be used.
A reaction herein can optionally be heated following the step of contacting dextran with an etherification agent under alkaline conditions. The reaction temperatures and time of applying such temperatures can be varied within wide limits. For example, a reaction can optionally be maintained at ambient temperature for up to 14 days. Alternatively, a reaction can be heated, with or without reflux, between about 25° C. to about 200° C. (or any integer between 25 and 200° C.). Reaction time can be varied correspondingly: more time at a low temperature and less time at a high temperature.
In certain embodiments of producing a dextran ether (e.g., carboxymethyl dextran), a reaction can be heated to about 55° C. for about 2-2.5 hours. Thus, a reaction for preparing a dextran ether compound herein can be heated to about 50-60° C. (or any integer between 50 and 60° C.) for about 1 hours to about 3 hours, for example. Etherification agents such as a haloalkylate (e.g., a chloroalkylate such chloroacetate) can be used in these embodiments, for example.
Optionally, an etherification reaction herein can be maintained under an inert gas, with or without heating. As used herein, the term “inert gas” refers to a gas which does not undergo chemical reactions under a set of given conditions, such as those disclosed for preparing a reaction herein.
All of the components of the reactions disclosed herein can be mixed together at the same time and brought to the desired reaction temperature, whereupon the temperature is maintained with or without stirring until the desired dextran ether compound is formed. Alternatively, the mixed components can be left at ambient temperature as described above. The collective processes herein for preparing an etherification reaction can optionally be characterized as providing an etherification reaction.
Following etherification, the pH of a reaction can be neutralized. Neutralization of a reaction can be performed using one or more acids. The term “neutral pH” as used herein, refers to a pH that is neither substantially acidic or basic (e.g., a pH of about 6-8, or about 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8, or 8.0). Various acids that can be used for this purpose include, but are not limited to, sulfuric, acetic (e.g., glacial acetic), hydrochloric, nitric, any mineral (inorganic) acid, any organic acid, or any combination of these acids.
A dextran ether compound produced in a reaction herein can optionally be washed one or more times with a liquid that does not readily dissolve the compound. Typically, solvents used to wash a dextran ether product would precipitate it out of solution. For example, dextran ether can typically be washed with alcohol (e.g., methanol, ethanol, propanol), acetone, aromatics, or any combination of these, depending on the solubility of the ether compound therein (where lack of solubility is desirable for washing). In general, a solvent comprising an organic solvent (e.g. 95-100%) such as alcohol is preferred for washing a dextran ether. A dextran ether product can be washed one or more times with an aqueous solution containing an alcohol (e.g., methanol or ethanol), for example. For example, 70-95 wt % or 90-95% ethanol can be used to wash the product. A dextran ether product can be washed with a methanol:acetone (e.g., 60:40) solution in another embodiment.
A dextran ether produced in the disclosed reaction can optionally be isolated. This step can be performed before or after neutralization and/or washing steps using a funnel, centrifuge, press filter, or any other method or equipment known in the art that allows removal of liquids from solids. An isolated dextran ether product can be dried using any method known in the art, such as vacuum drying, air drying, or freeze drying.
Any of the above etherification reactions can be repeated using a dextran ether product as the starting material for further modification. This approach may be suitable for increasing the DoS of an organic group, and/or adding one or more different organic groups to the ether product. Also, this approach may be suitable for adding one or more organic groups that are not positively charged, such as an alkyl group (e.g., methyl, ethyl, propyl, butyl) and/or a hydroxyalkyl group (e.g., hydroxyethyl, hydroxypropyl, hydroxybutyl) to a cationic dextran ether.
The structure, molecular weight and DoS of a dextran ether product can be confirmed using various physiochemical analyses known in the art such as NMR spectroscopy and size exclusion chromatography (SEC).
Any of the embodiments of dextran disclosed herein can be used in an etherification reaction, for example. Dextran can be provided in a dry form, or in an aqueous composition such as an aqueous solution, in certain aspects of preparing an etherification reaction.
Non-limiting examples of compositions and methods disclosed herein include:

1. A composition comprising a dextran ether compound, wherein the dextran ether compound comprises:
- (i) about 87-93 wt % glucose linked at positions 1 and 6;
- (ii) about 0.1-1.2 wt % glucose linked at positions 1 and 3;
- (iii) about 0.1-0.7 wt % glucose linked at positions 1 and 4;
- (iv) about 7.7-8.6 wt % glucose linked at positions 1, 3 and 6;
- (v) about 0.4-1.7 wt % glucose linked at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6; and
- (vi) a degree of substitution (DoS) with at least one organic group of about 0.0025 to about 3.0;
- wherein the weight-average molecular weight (Mw) of the dextran ether compound is about 50-200 million Daltons.
2. The composition of embodiment 1, wherein the dextran ether compound comprises:
- (i) about 89.5-90.5 wt % glucose linked at positions 1 and 6;
- (ii) about 0.4-0.9 wt % glucose linked at positions 1 and 3;
- (iii) about 0.3-0.5 wt % glucose linked at positions 1 and 4;
- (iv) about 8.0-8.3 wt % glucose linked at positions 1, 3 and 6; and
- (v) about 0.7-1.4 wt % glucose linked at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6.
3. The composition of embodiment 1 or 2, wherein the dextran ether compound comprises chains linked together within a branching structure, wherein the chains are similar in length and comprise substantially alpha-1,6-glucosidic linkages.
4. The composition of embodiment 3, wherein the average length of the chains is about 10-50 monomeric units.
5. The composition of embodiment 1, 2, 3, or 4, wherein the z-average radius of gyration of the dextran from which the dextran ether compound is derived is about 200-280 nm.
6. The composition of embodiment 1, 2, 3, 4, or 5, wherein the dextran from which the dextran ether compound is derived is a product of a glucosyltransferase enzyme comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:5, SEQ ID NO:9, SEQ ID NO:13, or SEQ ID NO:17.
7. The composition of embodiment 1, 2, 3, 4, 5, or 6, wherein at least one organic group is a carboxy alkyl, alkyl, or hydroxy alkyl group.
8. The composition of embodiment 7, wherein at least one organic group is a carboxymethyl, methyl, ethyl, hydroxypropyl, dihydroxypropyl, or hydroxyethyl group.
9. The composition of embodiment 1, 2, 3, 4, 5, or 6, wherein at least one organic group is a positively charged organic group.
10. The composition of embodiment 9, wherein at least one positively charged organic group comprises a substituted ammonium group.
11. The composition of embodiment 10, wherein the substituted ammonium group is a trimethylammonium group.
12. The composition of embodiment 9, wherein the positively charged organic group is a quaternary ammonium group.
13. The composition of embodiment 9, wherein at least one positively charged organic group comprises a hydroxy alkyl group or alkyl group.
14. The composition of embodiment 13, wherein the positively charged organic group comprises a hydroxy alkyl group and a trimethylammonium group.
15. The composition of any one of embodiments 1-14, wherein:
(i) the dextran ether compound contains one type of organic group, or
(ii) the dextran ether compound contains two or more types of organic group.
16. The composition of any one of embodiments 1-15, wherein the composition is an aqueous composition.
17. The composition of embodiment 16, wherein the composition has a viscosity of at least about 3 cPs.
18. The composition of any one of embodiments 1-17, wherein the composition is in the form of a household product, personal care product, pharmaceutical product, industrial product, or food product.
19. The composition of embodiment 18, wherein the composition is a fabric care product.
20. A method of producing a dextran ether compound, the method comprising:
(a) contacting a dextran in a reaction under alkaline conditions with at least one etherification agent comprising an organic group, wherein at least one organic group is etherified to the dextran thereby producing a dextran ether compound, wherein the dextran ether compound has a degree of substitution with at least one organic group of about 0.0025 to about 3.0 and the weight-average molecular weight (Mw) of the dextran ether compound is about 50-200 million Daltons, wherein the dextran comprises:
- (i) about 87-93 wt % glucose linked at positions 1 and 6;
- (ii) about 0.1-1.2 wt % glucose linked at positions 1 and 3;
- (iii) about 0.1-0.7 wt % glucose linked at positions 1 and 4;
- (iv) about 7.7-8.6 wt % glucose linked at positions 1, 3 and 6; and
- (v) about 0.4-1.7 wt % glucose linked at: (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6; and
(b) optionally, isolating the dextran ether compound produced in step (a). 21. A method for increasing the viscosity of an aqueous composition, the method comprising: contacting a dextran ether compound, as recited in any one of embodiments 1-15 or as produced in embodiment 20, with the aqueous composition, wherein the viscosity of the aqueous composition is increased by the dextran ether compound compared to the viscosity of the aqueous composition before the contacting step.
22. A method of treating a material, the method comprising: contacting a material with an aqueous composition comprising a dextran ether compound as recited in any one of embodiments 1-15 or as produced in embodiment 20.

EXAMPLES

The present disclosure is further exemplified in Examples 1-6 and 8-12. It should be understood that these Examples, while indicating certain preferred aspects herein, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of the disclosed embodiments, and without departing from the spirit and scope thereof, can make various changes and modifications to adapt the disclosed embodiments to various uses and conditions.

General Methods

Cloning and Expression of Glucosyltransferase Enzymes in Bacillus subtilis
Each glucosyltransferase used in Examples 3-6 was prepared as follows.
A plasmid encoding the gtf enzyme (pZZHB582, pZZHB583, pZZHB584, or pZZHB585, which allow for gtf expression and secretion from B. subtilis; see FIGS. 2A-D) was amplified using Illustra TempliPhi® 100 Amplification Kit (GE Healthcare Life Sciences, N.J.). Competent B. subtilis cells (ΔspolIE, ΔaprE, ΔnprE, degUHy32, ΔscoC, ΔnprB, Δvpr, Δepr, ΔwprA, Δmpr, ΔispA, Δbpr) were transformed with the amplification product. Cells were plated on Luria Agar plates supplemented with 5 ppm chloramphenicol. Colonies from the transformation plate were inoculated into 5 mL LB medium and incubated at 37° C. overnight. Aliquots (25-50 μL) from each culture were then transferred to 250-mL shake flasks containing 30 mL of Grant's II Medium supplemented with 5 ppm chloramphenicol and incubated at 30° C. with shaking (280 rpm) for 24 hours. Cells were harvested by centrifugation at 14000 rpm for 1 hour. Supernatants were analyzed by SDS-PAGE for secreted gtf product and further dialyzed three times against a solution containing 20 mM Tris, pH 7.5 for a total of 20 hours. Dialyzed samples were aliquoted at 25 mL per 50-mL conical centrifuge tube, and the tubes were placed at an angle at −80° C. for about 1 hour. Once the samples were frozen, the tube lid was removed and replaced with PARAFILM that was pierced 5-10 times with a high-gauge needle. The PARAFILM-covered frozen samples were lyophilized in a FreeZone® Freeze Dry System (Labconco Corp., Kansas City, Mo.) according to the manufacturer's instruction.

Stock Solutions of Glucosyltransferase Enzymes

An enzyme stock solution was made for each gtf by adding 10 mL of molecular grade H₂O into each 50-mL conical centrifuge tube containing lyophilized enzyme powder.

Example 1

Expression of a Glucosyltransferase (0768) in E. coli and Production of Active Crude Enzyme Lysate

This Example describes expression of a mature glucosyltransferase (gtf) enzyme in E. coli. Crude cell lysate of an E. coli expression strain was produced and showed gel product-forming activity in the presence of sucrose.
A putative YG repeat-containing hydrolase (categorized in GENBANK under GI number 339480768, but now having GI number 497964659) with 1484 amino acids was identified from Leuconostoc pseudomesenteroides strain KCTC3652 by whole genome shotgun sequencing. This putative glucosyltransferase (designated herein as gtf 0768) belongs to the GH70 family of glycosyl hydrolases containing a glucan-binding domain. The N-terminal 37 amino acid segment of gtf 0768 was deduced as the signal peptide of the enzyme by the SIGNALP 4.0 program (Petersen et al., Nature Methods 8:785-786). The mature form of gtf 0768 is represented by SEQ ID NO:1.
To construct a plasmid for bacterial expression of gtf 0768, a DNA sequence encoding a mature form of the gtf without the signal peptide was synthesized by GenScript USA Inc. (Piscataway, N.J.). The synthesized sequence was subcloned into the NheI and HindIII sites of the pET23D+ vector (NOVAGEN®; Merck KGaA, Darmstadt, Germany). The 0768 gtf (SEQ ID NO:2) encoded by this construct included a start methionine and 3 additional amino acids (Ala-Ser-Ala) at the N-terminus, and 6 histidine residues at the C-terminus, compared to the wild type mature (predicted) form of gtf 0768 (SEQ ID NO:1) (i.e., SEQ ID NO:1 is comprised in SEQ ID NO:2). The plasmid construct was sequence-confirmed and transformed into E. coli BL21 DE3 host cells with ampicillin selection, resulting in expression strain EC0052.
Cells of EC0052 and a control strain containing only empty pET23D+ vector were grown in LB medium with 100 μg/mL ampicillin to OD₆₀₀˜0.5, and then induced with 1 mM IPTG at 37° C. for 3 hours or alternatively induced at 23° C. overnight. Following this induction period, cells were collected by centrifugation at 4000×g for 10 min and resuspended in PBS buffer pH 6.8. The cells were then lysed by passing through a French Press at 14,000 psi (96.53 MPa) twice, after which cell debris was pelleted by centrifugation at 15,000×g for 20 min. The supernatants of each crude cell lysate were aliquoted and frozen at −80° C.
The activity of crude cell lysate from EC0052 cells was checked by reaction with sucrose. A control reaction was set up similarly using cell lysate prepared from cells containing the empty vector. Each sucrose reaction was set up using 10% (v/v) of cell lysate with 100 g/L sucrose, 10 mM sodium citrate pH 5, and 1 mM CaCl₂. After incubation of the reactions at 37° C. for a few hours, a gel-like product, believed to be a dextran, was formed in the tube in which EC0052 cell lysate had been added. No gel-like product was formed in the control reaction. HPLC analysis confirmed that sucrose was consumed in the reaction containing EC0052 cell lysate, and not in the control reaction. This result suggested that the EC0052 crude cell lysate expressed active gtf 0768 enzyme, and that this gtf produced a dextran product having high viscosity.
Thus, reactions comprising water, sucrose and an enzyme comprising SEQ ID NO:1 synthesized a gelling product, believed to be a dextran. This result demonstrated that gtf 0768 likely has glucosyltransferase activity. This product can be used to prepare dextran ethers as presently disclosed.

Example 2

Reaction of Sucrose with Gtf 0768 and Analysis of a Gelling Dextran Reaction Product

This Example describes another reaction comprising water, sucrose and gtf 0768, supplementing the results provided in Example 1. Also, this Example provides glycosidic linkage analysis of the gelling product synthesized by gtf 0768, showing that this product is a type of dextran.
Reagents for Preparing gtf Reactions:
Sucrose (Sigma Prod. No. S-9378).
Sodium phosphate buffer stock (200 mM) (pH 5.5): prepare 250 mL in water using sodium phosphate monobasic monohydrate (Sigma Prod. No. S9638) and sodium phosphate dibasic heptahydrate (Sigma Prod. No. S9390), accordingly.
Gtf 0768 enzyme solution (cell lysate as prepared in Example 1).
Conditions of Three gtf Reactions:
A 1000-mL reaction was prepared containing 2.72 g of sodium phosphate buffer stock (pH 5.5), 100 g/L sucrose, and 2 mL of gtf 0768 enzyme solution. The reaction was stirred at 26° C. for 20 hours, and became viscous. The gtf enzyme was deactivated by heating the reaction at 80° C. for 10 minutes. The deactivated viscous reaction was then mixed with 3 liters of 100% methanol to precipitate the viscous product. A white precipitate was formed, which was then filtered, followed by four washes with 120 ml of 100% methanol. The solid product was dried at room temperature under vacuum in an oven for 72 hours.
A 725-mL reaction was prepared containing 1.97 g of sodium phosphate buffer, 300 g/L sucrose, and 1.45 mL of gtf 0768 enzyme solution. The reaction was stirred at 26° C. for 20 hours, and became viscous. The gtf enzyme was deactivated by adding methanol to the reaction mixture. The deactivated reaction was then mixed with 3 liters of 100% methanol to precipitate the viscous product. A white precipitate was formed, which was then filtered, followed by four washes with 120 mL of 100% methanol. The solid product was dried at room temperature under vacuum in an oven for 72 hours.
A 200-mL reaction was prepared containing 0.544 g of sodium phosphate buffer, 400 g/L sucrose, and 0.4 mL of gtf 0768 enzyme solution. The reaction was stirred at 26° C. for 20 hours, and became viscous. The gtf enzyme was deactivated by adding methanol to the reaction mixture. The deactivated reaction was then mixed with 3 liters of 100% methanol to precipitate the viscous product. A white precipitate was formed, which was then filtered, followed by four washes with 120 mL of 100% methanol. The solid product was dried at room temperature under vacuum in an oven for 72 hours.
A 200-mL reaction was prepared containing 0.544 g of sodium phosphate buffer, 800 g/L sucrose, and 0.4 mL of gtf 0768 enzyme solution. The reaction was stirred at 26° C. for 20 hours, and became viscous. The gtf enzyme was deactivated by adding methanol to the reaction mixture. The deactivated reaction was then mixed with 3 liters of 100% methanol to precipitate the viscous product. A white precipitate was formed, which was then filtered, followed by four washes with 120 ml of 100% methanol. The solid product was dried at room temperature under vacuum in an oven for 72 hours.
Samples (100 μL) of each reaction were taken at 0, 2, 4, and 18 hours, respectively. The gtf enzyme was deactivated in each sample by heating at 80° C. for 10 minutes. Each sample was then diluted 10-fold with water and centrifuged at 14,000 rpm for 5 minutes, after which 200 μl of supernatant was used for HPLC analysis to measure sucrose consumption during the reaction. The following HPLC conditions were applied for analyzing each sample: column (AMINEX HPX-87C carbohydrate column, 300×7.8 mm, Bio-Rad, No. 125-0095), eluent (water), flow rate (0.6 mL/min), temperature (85° C.), refractive index detector. HPLC analysis of the samples indicated substantial sucrose consumption during the 0768 gtf reaction (FIG. 1, reaction comprising 100 g/L sucrose) (this sucrose consumption occurred significantly faster than the sucrose consumption observed in a reaction using a dextran sucrase obtained from a commercial source—refer to Example 7).
HPLC was also used to analyze other products of the reaction comprising 100 g/L sucrose. Polymer yield was back-calculated by subtracting the amount of all other saccharides left in the reaction from the amount of the starting sucrose. The back-calculated number was consistent with the viscous product dry weight analysis. Sucrose, leucrose, glucose and fructose were quantified by HPLC with an HPX-87C column (HPLC conditions as described above). DP2-7 disaccharides were quantified by HPLC with the following conditions: column (AMINEX HPX-42A carbohydrate column, 300×7.8 mm, Bio-Rad, No. 125-0097), eluent (water), flow rate (0.6 mL/min), temperature (85° C.), refractive index detector. These HPLC analyses indicated that the glucosyl-containing saccharide products of the 0768 gtf reaction consisted of 91% polymer product, 1% glucose, 6.5% leucrose, and 1.5% DP2-7 oligosaccharides.
The glycosidic linkage profile of the gelling polymer product of the reaction comprising 100 g/L sucrose was determined by ¹³0 NMR. Dry polymer (25-30 mg) as prepared above was dissolved in 1 mL of deuterated DMSO containing 3 wt % LiCl with stirring at 50° C. Using a glass pipet, 0.8 mL of the preparation was transferred into a 5-mm NMR tube. A quantitative ¹³C NMR spectrum was acquired using a Bruker Avance (Billerica, Mass.) 500 MHz NMR spectrometer equipped with a CPDul cryoprobe, at a spectral frequency of 125.76 MHz, using a spectral window of 26041.7 Hz. An inverse-gated decoupling pulse sequence using waltz decoupling was used with an acquisition time of 0.629 second, an inter-pulse delay of 5 seconds, and 6000 pulses. The time domain data were transformed using an exponential multiplication of 2.0 Hz.
The NMR results indicated that the gelling polymer product comprised about 90% alpha-1,6-glucosidic linkages, about 4-5% alpha-1,3-glucosidic linkages, and about 5-6% alpha-1,4 and -1,2 glucosidic linkages. The main chain(s) of the polymer product appeared to mostly comprise alpha-1,6-glucosidic linkages, but also a very small amount of alpha-1,3 and -1,4 glucosidic linkages. Other alpha-1,3 and -1,4 glucosidic linkages, and all of the alpha-1,2-glucosidic linkages, appeared to be in branches off the main chain(s). The gelling product thus appears to be a gelling dextran.
A different protocol (not the above ¹³C NMR procedure) is presently recommended herein for determining the linkage profile of dextran produced by gtf 0768. This protocol is disclosed below in Example 9, indicating a linkage profile similar to that disclosed in this Example.
The number-average molecular weight (M_n) and weight-average molecular weight (M_w) of the gelling dextran product of the reaction comprising 100 g/L sucrose was determined by size-exclusion chromatography (SEC). Dry polymer as prepared above was dissolved in DMAc and 5% LiCl (0.5 mg/mL) with shaking overnight at 100° C. The chromatographic system used was an Alliance™ 2695 separation module from Waters Corporation (Milford, Mass.) coupled with three on-line detectors: a differential refractometer 2410 from Waters, a Heleos™ 8+ multiangle light scattering photometer from Wyatt Technologies (Santa Barbara, Calif.), and a ViscoStar™ differential capillary viscometer from Wyatt. Columns used for SEC were four styrene-divinyl benzene columns from Shodex (Japan) and two linear KD-806M, KD-802 and KD-801 columns to improve resolution at the low molecular weight region of a polymer distribution. The mobile phase was DMAc with 0.11% LiCl. The chromatographic conditions used were 50° C. in the column and detector compartments, 40° C. in the sample and injector compartment, a flow rate of 0.5 mL/min, and an injection volume of 100 μL. The software packages used for data reduction were Empower™ version 3 from Waters (calibration with broad glucan polymer standard) and Astra® version 6 from Wyatt (triple detection method with column calibration). It was determined from this procedure that the gelling dextran product had an M_nof 2229400 and an M_wof 5365700.
A different protocol (not the above SEC procedure) is presently recommended herein for determining the molecular weight of dextran produced by gtf 0768. This protocol is disclosed below in Example 9, indicating a molecular weight more than one order of magnitude greater than the molecular weight disclosed in this Example.
Thus, reactions comprising water, sucrose and an enzyme comprising SEQ ID NO:1 synthesized a gelling dextran product, as determined by the product's predominant alpha-1,6 glucosidic linkage profile. Example 8 below discloses comparing the viscosity of this product versus the viscosities of certain commercially available dextrans. Example 9 discloses further production of dextran with a gtf enzyme comprising SEQ ID NO:1, along with yield, molecular weight, and linkage analysis of the dextran. The dextran produced in this Example can be used to prepare dextran ethers as presently disclosed.

Example 3

Expression of a Glucosyltransferase (2919) and Use Thereof to Produce a Gelling Dextran Product

This Example describes expression of a mature Weissella cibaria glucosyltransferase (gtf) enzyme in B. subtilis. Also, this Example shows that this enzyme produces a gelling product, likely a dextran, when used is a reaction containing water and sucrose.
A glucosyltransferase gene, WciGtf1, was identified from Weissella cibaria KACC 11862. The nucleic acid sequence of this gene (positions 23315 to 27661 of GENBANK Accession No. NZ_AEKT01000035.1) is set forth in SEQ ID NO:3 and encodes the protein sequence of SEQ ID NO:4 (GENBANK Accession No. ZP_08417432). At the N-terminus of the WciGtf1 protein (SEQ ID NO:4) is a signal peptide of 26 amino acids, as predicted by the SIGNALP 4.0 program (Petersen et al., Nature Methods 8:785-786). This indicates that WciGtf1 (SEQ ID NO:4) is a secreted protein. The mature, secreted form of the WciGtf1 protein is herein referred to as 2919 gtf, and is set forth in SEQ ID NO:5.
The nucleotide sequence encoding 2919 gtf was optimized for expression in B. subtilis. The optimized sequence (SEQ ID NO:6) was synthesized by Generay (Shanghai, China), and inserted into plasmid p2JM103BBl (Vogtentanz et al., Protein Expr. Purif. 55:40-52), resulting in plasmid pZZHB583 (FIG. 2A). Plasmid pZZHB583 contains an aprE promoter operably linked to a sequence encoding (i) an aprE signal sequence used to direct heterologous protein (2919 gtf in this case) secretion in B. subtilis, (ii) Ala-Gly-Lys to facilitate the secretion, and (iii) 2919 gtf (SEQ ID NO:5) (i-iii are fused together in the amino-to-carboxy direction).
Plasmid pZZHB583 was transformed into B. subtilis cells for 2919 gtf expression and purification (see General Methods).
The activity of 2919 gtf (SEQ ID NO:5) was determined in a 250-mL reaction at room temperature comprising 100 g/L sucrose, 20 mM sodium phosphate buffer (pH 5.5), and 6.25 mL of enzyme stock. The reaction was carried out at room temperature with shaking (150 rpm) for 48 hours.
Samples (100 μL) were taken from the reaction at 0, 1, 3, 5, 24, and 48 hour time points, respectively. Enzyme was deactivated by heating each sample at 80° C. for 10 minutes. Samples were diluted 10-fold with water and centrifuged at 14000 rpm for 5 minutes. Supernatant (200 μL) was used for HPLC analysis.
The concentrations of leucrose, glucose, and fructose in the gtf reaction were determined using HPLC, which was performed with an Agilent 1260 chromatography system equipped with an AMINEX HPX-87C column (300×7.8 mm) placed in a thermostatted column compartment at 85° C., and a refractive index detector. HPLC elution was carried out with Milli-Q® water at 0.6 mL/min. Sucrose, leucrose, glucose, and fructose were identified by comparison with corresponding standards. Their concentrations were calculated based on a peak area standard curves. Sucrose was consumed almost completely by the end of the reaction. Aside from a viscous dextran product, 2919 gtf (SEQ ID NO:5) produced mostly fructose (˜50%), and small amounts of leucrose (˜5%) and glucose (˜1%).
The concentration of oligosaccharides (DP2-DP7) in the gtf reaction was determined by HPLC analysis, which was performed with an Agilent 1260 chromatography system equipped with an AMINEX HPX-42A column (300×7.8 mm) placed in a thermostatted column compartment at 85° C., and a refractive index detector. HPLC elution was carried out with water at 0.6 mL/min. Formation of oligosaccharides was identified by comparison with corresponding standards. The concentration of the oligosaccharides was calculated based on standard curves from peak area. 2919 gtf (SEQ ID NO:5) produced a small amount of DP2-DP7 oligosaccharides (˜3%) by the end of the reaction.
Thus, reactions comprising water, sucrose and an enzyme comprising SEQ ID NO:5 synthesized a gelling product, which is believed to be a dextran polymer. This product can be used to prepare dextran ethers as presently disclosed. Experimental results demonstrated that gtf 2919 likely has glucosyltransferase activity.

Example 4

Expression of a Glucosyltransferase (2918) and Use Thereof to Produce a Gelling Dextran Product

This Example describes expression of a mature Lactobacillus fermentum glucosyltransferase (gtf) enzyme in B. subtilis. Also, this Example shows that this enzyme produces a gelling product, likely a dextran, when used is a reaction containing water and sucrose.
A glucosyltransferase gene, LfeGtf1, was identified from Lactobacillus fermentum. The nucleic acid sequence of this gene (positions 618 to 5009 of GENBANK Accession No. AY697433.1) is set forth in SEQ ID NO:7 and encodes the protein sequence of SEQ ID NO:8 (GENBANK Accession No. AAU08008). At the N-terminus of the LfeGtf1 protein (SEQ ID NO:8) is a signal peptide of 37 amino acids, as predicted by the SIGNALP 4.0 program. This indicates that LfeGtf1 (SEQ ID NO:8) is a secreted protein. The mature, secreted form of the LfeGtf1 protein is herein referred to as 2918 gtf, and is set forth in SEQ ID NO:9.
The nucleotide sequence encoding 2918 gtf was optimized for expression in B. subtilis. The optimized sequence (SEQ ID NO:10) was synthesized by Generay (Shanghai, China), and inserted into plasmid p2JM103BBI, resulting in plasmid pZZHB582 (FIG. 2B). Plasmid pZZHB582 contains an aprE promoter operably linked to a sequence encoding (i) an aprE signal sequence used to direct heterologous protein (2918 gtf in this case) secretion in B. subtilis, (ii) Ala-Gly-Lys to facilitate the secretion, and (iii) 2918 gtf (SEQ ID NO:9) (i-iii are fused together in the amino-to-carboxy direction).
Plasmid pZZHB582 was transformed into B. subtilis cells for 2918 gtf expression and purification (see General Methods).
The activity of 2918 gtf (SEQ ID NO:9) was determined in a 250-mL reaction at room temperature comprising 100 g/L sucrose, 20 mM sodium phosphate buffer (pH 5.5), and 6.25 mL of enzyme stock. The reaction was carried out at room temperature with shaking (150 rpm) for 6 days.
Samples (100 μL) were taken from the reaction at 0, 1, 3, 5, 24, 48 and 144 hour time points, respectively. Enzyme was deactivated by heating each sample at 80° C. for 10 minutes. Samples were diluted 10-fold with water and centrifuged at 14000 rpm for 5 minutes. Supernatant (200 μL) was used for HPLC analysis.
The concentrations of sucrose, leucrose, glucose, fructose and oligosaccharides (DP2-DP7) in the gtf reaction were determined using HPLC procedures as described in Example 3. Sucrose was consumed almost completely by the end of the reaction. Aside from a viscous dextran product, 2918 gtf (SEQ ID NO:9) produced mostly fructose (˜50%), and small amounts of leucrose (˜5%) and glucose (˜1%). 2918 gtf (SEQ ID NO:9) produced a small amount of DP2-DP7 oligosaccharides (˜1%).
Thus, reactions comprising water, sucrose and an enzyme comprising SEQ ID NO:9 synthesized a gelling product, which is believed to be a dextran polymer. This product can be used to prepare dextran ethers as presently disclosed. Experimental results demonstrated that gtf 2920 likely has glucosyltransferase activity.

Example 5

Expression of a Glucosyltransferase (2920) and Use Thereof to Produce a Gelling Dextran Product

This Example describes expression of a mature Streptococcus sobrinus glucosyltransferase (gtf) enzyme in B. subtilis. Also, this Example shows that this enzyme produces a gelling product, likely a dextran, when used is a reaction containing water and sucrose.
A glucosyltransferase gene, SsoGtf4, was identified from Streptococcus sobrinus B13N. The nucleic acid sequence of this gene (positions 198 to 4718 of GENBANK Accession No. AY966490) is set forth in SEQ ID NO:11 and encodes the protein sequence of SEQ ID NO:12 (GENBANK Accession No. AAX76986). At the N-terminus of the SsoGtf4 protein (SEQ ID NO:12) is a signal peptide of 41 amino acids, as predicted by the SIGNALP 4.0 program. This indicates that SsoGtf4 (SEQ ID NO:12) is a secreted protein. The mature, secreted form of the SsoGtf4 protein is herein referred to as 2920 gtf, and is set forth in SEQ ID NO:13.
The nucleotide sequence encoding 2920 gtf was optimized for expression in B. subtilis. The optimized sequence (SEQ ID NO:14) was synthesized by Generay (Shanghai, China), and inserted into plasmid p2JM103BBl, resulting in plasmid pZZHB584 (FIG. 2C). Plasmid pZZHB584 contains an aprE promoter operably linked to a sequence encoding (i) an aprE signal sequence used to direct heterologous protein (2920 gtf in this case) secretion in 8. subtilis, (ii) Ala-Gly-Lys to facilitate the secretion, and (iii) 2920 gtf (SEQ ID NO:13) (i-iii are fused together in the amino-to-carboxy direction).
Plasmid pZZHB584 was transformed into B. subtilis cells for 2920 gtf expression and purification (see General Methods).
The activity of 2920 gtf (SEQ ID NO:13) was determined in a 250-mL reaction at room temperature comprising 100 g/L sucrose, 20 mM sodium phosphate buffer (pH 5.5), and 6.25 mL of enzyme stock. The reaction was carried out at room temperature with shaking (150 rpm) for 6 days.
Samples (100 μL) were taken from the reaction at 0, 1, 3, 5, 24, 48, 72 and 144 hour time points, respectively. Enzyme was deactivated by heating each sample at 80° C. for 10 minutes. Samples were diluted 10-fold with water and centrifuged at 14000 rpm for 5 minutes. Supernatant (200 μL) was used for HPLC analysis.
The concentrations of sucrose, leucrose, glucose, fructose and oligosaccharides (DP2-DP7) in the gtf reaction were determined using HPLC procedures as described in Example 3. Sucrose was consumed almost completely by the end of the reaction. Aside from a viscous dextran product, 2920 gtf (SEQ ID NO:13) produced mostly fructose (˜50%), leucrose (˜20%), and a small amount of glucose (˜3%). 2920 gtf (SEQ ID NO:13) produced a small amount of DP2-DP7 oligosaccharides (˜1%).
Thus, reactions comprising water, sucrose and an enzyme comprising SEQ ID NO:13 synthesized a gelling product, which is believed to be a dextran polymer. This product can be used to prepare dextran ethers as presently disclosed. Experimental results demonstrated that gtf 2920 likely has glucosyltransferase activity.

Example 6

Expression of a Glucosyltransferase (2921) and Use Thereof to Produce a Gelling Dextran Product

This Example describes expression of a mature Streptococcus downei glucosyltransferase (gtf) enzyme in B. subtilis. Also, this Example shows that this enzyme produces a gelling product, likely a dextran, when used is a reaction containing water and sucrose.
A glucosyltransferase gene, SdoGtf7, was identified from Streptococcus downei MFe28. The nucleic acid sequence of this gene (positions 16 to 2375 of GENBANK Accession No. AB476746) is set forth in SEQ ID NO:15 and encodes the protein sequence of SEQ ID NO:16 (GENBANK Accession No. ZP_08549987.1). At the N-terminus of the SdoGtf7 protein (SEQ ID NO:16) is a signal peptide of 44 amino acids, as predicted by the SIGNALP 4.0 program. This indicates that SdoGtf7 protein (SEQ ID NO:16) is a secreted protein. The mature, secreted form of the SdoGtf7 protein is herein referred to as 2921 gtf, and is set forth in SEQ ID NO:17.
The nucleotide sequence encoding 2921 gtf was optimized for expression in B. subtilis. The optimized sequence (SEQ ID NO:18) was synthesized by Generay (Shanghai, China), and inserted into plasmid p2JM103BBl, resulting in plasmid pZZHB585 (FIG. 2D). Plasmid pZZHB585 contains an aprE promoter operably linked to a sequence encoding (i) an aprE signal sequence used to direct heterologous protein (2921 gtf in this case) secretion in B. subtilis, (ii) Ala-Gly-Lys to facilitate the secretion, and (iii) 2921 gtf (SEQ ID NO:17) (i-iii are fused together in the amino-to-carboxy direction).
Plasmid pZZHB585 was transformed into B. subtilis cells for 2921 gtf expression and purification (see General Methods).
The activity of 2921 gtf (SEQ ID NO:17) was determined in a 250-mL reaction at room temperature comprising 100 g/L sucrose, 20 mM sodium phosphate buffer (pH 5.5), and 6.25 mL of enzyme stock. The reaction was carried out at room temperature with shaking (150 rpm) for 8 days.
Samples (100 μL) were taken from the reaction at the reaction start and on 1, 2, 3, 6, 7 and 8 day time points, respectively. Enzyme was deactivated by heating each sample at 80° C. for 10 minutes. Samples were diluted 10-fold with water and centrifuged at 14000 rpm for 5 minutes. Supernatant (200 μL) was used for HPLC analysis.
The concentrations of sucrose, leucrose, glucose, fructose and oligosaccharides (DP2-DP7) in the gtf reaction were determined using HPLC procedures as described in Example 3. About 43% sucrose remained in the reaction on day 8. Aside from a viscous dextran product, 2921 gtf (SEQ ID NO:17) produced mostly fructose (˜31%), leucrose (˜6%), and glucose (˜3%). No obvious production of DP2-DP7 oligosaccharides was observed.
Thus, reactions comprising water, sucrose and an enzyme comprising SEQ ID NO:17 synthesized a gelling product, which is believed to be a dextran polymer. This product can be used to prepare dextran ethers as presently disclosed. Experimental results demonstrated that gtf 2921 likely has glucosyltransferase activity.

Example 7 (Comparative)

Production of Dextran Using Commercially Available Dextran Sucrase

This Example describes synthesizing dextran using a commercially available dextran sucrase in reactions comprising water and sucrose. The dextran produced in this was analyzed in Example 8 in comparison to the gelling dextran products synthesized in Examples 1-6.
Reagents for Preparing Dextran Sucrase Reaction:
Sucrose (Sigma Prod. No. S-9378). 400 g/L stock solution was prepared.
Sodium phosphate buffer stock (200 mM) (pH 5.5): prepare 250 mL in water using sodium phosphate monobasic monohydrate (Sigma Prod. No. S9638) and sodium phosphate dibasic heptahydrate (Sigma Prod. No. S9390), accordingly.
Dextran sucrase, lyophilized powder, ≥100 units/mg protein, from Leuconostoc mesenteroides (Sigma Prod. No. D9909).
A 50-mL reaction was prepared containing 20 mM sodium phosphate (pH 5.5), 110 g/L sucrose, and 10 units of dextran sucrase from Sigma-Aldrich. The dextran sucrase was added last when preparing the reaction. The reaction was carried out in a 125-mL capped shake flask at 26° C. with shaking (100 rpm) for 7 days. Samples (100 μL) of the reaction were taken at 0, 3, 6, 24, 48 and 168 hours, respectively. The dextran sucrase was deactivated in each sample by heating at 80° C. for 10 minutes. Each sample was then diluted 10-fold with water and centrifuged at 14,000 rpm for 5 minutes, after which 200 μl of supernatant was used for HPLC analysis to measure sucrose consumption during the reaction.
The following HPLC conditions were applied for analyzing each sample: column (AMINEX HPX-87C carbohydrate column, 300×7.8 mm, Bio-Rad, No. 125-0095), eluent (water), flow rate (0.6 mL/min), temperature (85° C.), refractive index detector. HPLC analysis of the samples indicated sucrose consumption during the dextran sucrase reaction (FIG. 3). It is notable that the sucrose consumption rate by the commercial dextran sucrase was much slower compared to the sucrose consumption rate of gtf 0768 (Example 2). Specifically, while gtf 0768 depleted most sucrose after about 17-18 hours of reaction time (FIG. 1), commercial dextran sucrase depleted only about 20% of sucrose within this same time period, and required about 168 hours to deplete all or most sucrose.
HPLC was also used to analyze other products of the reaction. Dextran yield was back-calculated by subtracting the amount of all other saccharides left in the reaction from the amount of the starting sucrose. The back-calculated number was consistent with dextran dry weight analysis. Sucrose, leucrose, glucose, fructose, and DP2-7 disaccharides were quantified by HPLC as described in Example 2. These HPLC analyses indicated that the saccharide products of the commercial dextran sucrase reaction consisted of 49% dextran, 0.3% sucrose, 44% fructose, 1% glucose, 5% leucrose, and 1% DP2-7 oligosaccharides.
The dextran produced in this Example was analyzed in Example 8 in comparison to the gelling dextran products synthesized in Examples 1-6.

Example 8

Viscosity of Dextran Samples

This Example describes measuring the viscosities of the dextran polymers produced in Examples 1-7, as well as the viscosity of dextran obtained from a commercial source. Viscosity measurements were made at various shear rates.
Dextran polymer samples were prepared as described in Examples 1-7. Specifically, enzymatic reactions were conducted, after which polymer was methanol-precipitated and washed with methanol (100%) four times, and then dried. Solutions (2 wt % and/or 3 wt %) of each sample were prepared by adding the appropriate amount of polymer to de-ionized (DI) water. Each preparation was then mixed using a bench top vortexer until polymer was fully in solution. Each of these samples is referred to in Tables 2 and 3 (below) as “After PPT” (after precipitation). A 2 wt % solution of dextran (M_w=956978) obtained from TCI America (Portland, Oreg.; catalogue No. D0061) was similarly prepared; this dextran is referred to below as “commercial dextran”.
To determine the viscosity of each polymer solution at various shear rates, each solution was subjected to various shear rates using a viscometer while the temperature was held constant at 20° C. Also, polymer samples obtained directly, without precipitation, from each of the enzymatic reactions described in Examples 1-7 were subjected to various shear rates (referred to in Tables 2 and 3 as “Before PPT”). The shear rate was increased using a gradient program which increased from 0-10 rpm and the shear rate was increased by 0.17 (1/s) every 30 seconds. The results of this experiment are listed in Table 2.

TABLE 2

Viscosity of Certain Dextran Solutions at Various Shear Rates

	Viscosity	Viscosity	Viscosity	Viscosity
	(cPs) @	(cPs) @	(cPs) @	(cPs) @
Dextran Sample^a	0.17 rpm	1.03 rpm	2.62 rpm	4.22 rpm

Gtf 0768	47976.13	11376.70	12956.11	14390.76
(SEQ ID NO: 1)
Before PPT
(Example 2, 100
g/L sucrose reaction)
Gtf 0768		15778.40	6245.31^b	4119.58^b
(SEQ ID NO: 1)
After PPT − 3 wt %
(Example 2, 100 g/L
sucrose reaction)
Gtf 0768		4091.84	3417.10	2874.10
(SEQ ID NO: 1)
After PPT − 2 wt %
(Example 2, 100 g/L
sucrose reaction)
Gtf 2918		n/a^b	n/a^b	n/a^b
(SEQ ID NO: 9)
Before PPT
(Example 4)
Gtf 2919		98864	38671	25580
(SEQ ID NO: 5)
Before PPT
(Example 3)
Gtf 2920		3874.85	4205.66	4119.58^b
(SEQ ID NO: 13)
Before PPT
(Example 5)
Gtf 2920		6168.76	3294.43	2288.24
(SEQ ID NO: 13)
After PPT − 3 wt %
(Example 5)
Gtf 2921		3533.86	2143.72	1748.95
(SEQ ID NO: 17)
Before PPT
(Example 6)
Gtf 2921		4634.32	2780.4	1984.89
(SEQ ID NO: 17)
After PPT − 3 wt %
(Example 6)
Commercial dextran	16759.42
sucrase Before PPT
(Example 7)

^aPolymer samples are listed according to the respective enzyme used to synthesize the sample.
^bMeasurement was outside the specification limits of the viscometer.

Polymer samples were also subjected to various higher shear rates using a viscometer while the temperature was held constant at 20° C. The shear rate was increased using a gradient program which increased from 10-250 rpm and the shear rate was increased by 7.36 (1/s) every 20 seconds. The results of this experiment are listed in Table 3.

TABLE 3

Viscosity of Certain Dextran Solutions at Various Shear Rates

	Viscosity	Viscosity	Viscosity
	(cPs) @	(cPs) @	(cPs) @
Dextran Sample^a	14.72 rpm	102.9 rpm	250 rpm

Gtf 2918 (SEQ ID NO: 9)	149.95	69.68	48.97
After PPT − 3 wt %
(Example 4)
Gtf 2919 (SEQ ID NO: 5)	80.82	41.23	29.49
After PPT − 3 wt %
(Example 3)
2 wt % Commercial dextran	241.41	105.28	68.88
Commercial dextran sucrase	11.09^b	10.31^b	8.27
After PPT − 2 wt %
(Example 7)

	Viscosity	Viscosity	Viscosity
	(cPs) @	(cPs) @	(cPs) @
	14.11 rpm	98.69 rpm	162.1 rpm

Gtf 0768 (SEQ ID NO: 1)	49.89	23.61	18.32
After PPT − 2 wt %
(Example 2, 400 g/L sucrose
reaction)
Gtf 0768 (SEQ ID NO: 1)	5.44	2.72	1.58
After PPT − 2 wt %
(Example 2, 800 g/L sucrose
reaction)

^aPolymer samples are listed according to the respective enzyme used to synthesize the sample. Alternatively, dextran obtained from a commercial source was analyzed (“Commercial dextran”).
^bMeasurement was outside the specification limits of the viscometer.

These data demonstrate that solutions of the dextran product of a glucosyltransferase comprising SEQ ID NO:1 can in most cases exhibit increased viscosity even after precipitation and resolvation, as compared to the viscosities of commercially obtained dextran and the dextran product of a commercially obtained dextran sucrase. This observation also appears to apply to the respective polymer products of glucosyltransferases comprising SEQ ID NO:5, 9, 13, or 17.
It is also noteworthy that, based on Tables 2-3, as the amount of sucrose in a gtf 0768 reaction is decreased from 800 g/L to 100 g/L, the viscosity of the dextran product appears to increase. Specifically, Table 3 indicates (at 14.11 rpm/2 wt % loading) viscosities of 5.44 cPs and 49.89 cPs for dextran products of reactions comprising 800 and 400 g/L sucrose, respectively, and Table 2 (gtf 0768, 2 wt % loading) may indicate a viscosity of about 957 cPs (exponential extrapolated at a rotation of 14.11 rpm) for dextran product of a reaction comprising 100 g/L sucrose. This result suggests that the viscosity of a dextran product can be controlled by modifying the level of sucrose initially provided to reaction.

Example 9

Further Production and Analysis of Dextran Synthesized by Gtf 0768

This Example is in addition to Example 2, describing another reaction comprising water, sucrose and gtf 0768. Also, this Example provides additional linkage and molecular weight analyses of the gelling product synthesized by gtf 0768, showing that this product is a type of dextran.
Reagents for Preparing gtf Reaction:
Sucrose (Sigma Prod. No. S-9378).
Sodium phosphate buffer stock (1 M, pH 6.5, Teknova Cat No: S0276).
Gtf 0768 enzyme solution (cell lysate as prepared in Example 1).
Gtf Reaction Conditions:
A 50-mL reaction was prepared containing 20 mM sodium phosphate buffer (buffer was diluted 50-fold with ddH2O from 1 M stock, pH 6.5), 100 g/L sucrose, and 0.1 mL of gtf 0768 enzyme solution. The reaction was shaken at 100 rpm in an incubator shaker (Innova, Model 4000) at 26° C. for 43 hours; the reaction became viscous after about 24 hours.
The gtf enzyme was deactivated by heating the reaction at 80° C. for 10 minutes. The deactivated viscous reaction was then mixed with 75 mL of 100% methanol to precipitate the viscous product. A white precipitate was formed. After carefully decanting the supernatant, the white precipitate was washed twice with 75 mL of 100% methanol. The solid product was dried at 45° C. under vacuum in an oven for 48 hours.
Samples (1 mL) of the reaction were taken at 0, 0.5, 1, 2, and 24 hours, respectively. The gtf enzyme was deactivated in each sample by heating at 80° C. for 10 minutes. Each sample was then diluted 10-fold with sterile water. 500 μL of diluted sample was transferred into a centrifuge tube filter (SPIN-X, 0.45-pm Nylon, 2.0 mL Polypropylene Tube, Costar #8170) and centrifuged at 12,000 rpm in a table centrifuge for 60 minutes, after which 200 μL of flowthrough was used for HPLC analysis to measure sucrose consumption during the reaction. The following HPLC conditions were applied for analyzing each sample: column (AMINEX HPX-87C carbohydrate column, 300×7.8 mm, Bio-Rad, No. 125-0095), eluent (water), flow rate (0.6 mL/min), temperature (85° C.), refractive index detector. HPLC analysis of the samples indicated substantial sucrose consumption during the 0768 gtf reaction.
HPLC was also used to analyze other products of the reaction. Polymer yield was back-calculated by subtracting the amount of all other saccharides left in the reaction from the amount of the starting sucrose. The back-calculated number was consistent with the viscous product dry weight analysis. Sucrose, leucrose, glucose and fructose were quantified by HPLC with an HPX-87C column (HPLC conditions as described above). DP2-7 oligosaccharides were quantified by HPLC with the following conditions: column (AMINEX HPX-42A carbohydrate column, 300×7.8 mm, Bio-Rad, No. 125-0097), eluent (water), flow rate (0.6 mL/min), temperature (85° C.), refractive index detector. These HPLC analyses indicated that the glucosyl-containing saccharide products of the 0768 gtf reaction consisted of 92.3% polymer product, 1.3% glucose, 5.0% leucrose, and 1.4% DP2-7 oligosaccharides.
A sample of dry dextran powder product (˜0.2 g) of the above reaction was used for molecular weight analysis. Molecular weight was determined by a flow injection chromatographic method using an Alliance™ 2695 separation module from Waters Corporation (Milford, Mass.) coupled with three online detectors: a differential refractometer 2414 from Waters, a Heleos™-2 18-angle multiangle light scattering (MALS) photometer with quasielastic light scattering (QELS) detector from Wyatt Technologies (Santa Barbara, Calif.), and a ViscoStar™ differential capillary viscometer from Wyatt. The dry dextran powder was dissolved at 0.5 mg/mL in aqueous Tris (Tris[hydroxymethyl]aminomethane) buffer (0.075 M) containing 200 ppm NaN₃. The dissolution of dextran was achieved by shaking overnight at 50° C. Two AQUAGEL-OH GUARD columns from Agilent Technologies (Santa Clara , Calif.) were used to separate the dextran polymer peak from the injection peak. The mobile base for this procedure was the same as the dextran solvent, the flow rate was 0.2 mL/min, the injection volume was 0.1 mL, and the column temperature was 30° C. Empower™ version 3 software from Waters was used for data acquisition, and Astra™ version 6 software from Wyatt was used for multidetector data reduction. It was determined from this work that the dextran polymer product had a weight-average molecular weight (Mw) of 1.022 (+/−0.025)×10⁸g/mol (i.e., roughly 100 million Daltons) (from MALS analysis), a z-average radius of gyration of 243.33 (+/−0.42) nm (from MALS analysis), and a z-average hydrodynamic radius of 215 nm (from QELS analysis). It was also determined from QELS analysis that the dextran has a standard deviation of particle size distribution (PSD) of about 0.259, indicating that the dextran likely is polydisperse in terms of hydrodynamic size.
For glycosidic linkage analysis purposes, a 50-mL gtf reaction was prepared as described above in this Example, except that the reaction time was 24 hours (reaction had become viscous). The gtf enzyme was deactivated by heating the reaction at 80° C. for 10 minutes. The deactivated viscous reaction was then placed into a regenerated cellulose sturdy dialysis tubing with a molecular weight cut-off (MWCO) of 12-14 kDa (Spectra/Por® 4 Dialysis Tubing, Part No. 132706, Spectrum Laboratories, Inc.) and dialyzed against 4 L of filter water at room temperature over one week. Water was exchanged every day during this dialysis. The dialyzed viscous reaction was then precipitated and dried as described above in this Example. About 0.2 g of dry powder was submitted for GC/MS linkage analysis.
Linkage analysis was performed according to methods described by Pettolino et al. (Nature Protocols 7:1590-1607), which is incorporated herein by reference. Briefly, a dry dextran sample was dissolved in dimethyl sulfoxide (DMSO) or 5% lithium chloride in DMSO, then all free hydroxyl groups were methylated by sequential addition of a sodium hydroxide/DMSO slurry followed by iodomethane. The methylated polymer was then extracted into methylene chloride and hydrolyzed to monomeric units using aqueous trifluoroacetic acid (TFA) at 120° C. The TFA was then evaporated from the sample and reductive ring opening was done using sodium borodeuteride, which also labeled the reducing end with a deuterium atom. The hydroxyl groups created by hydrolyzing the glycosidic linkages were then acetylated by treating with acetyl chloride and TFA at a temperature of 50° C. Finally, the derivatizing reagents were evaporated and the resulting methylated/acetylated monomers were reconstituted in acetonitrile and analyzed by gas chromatography with mass spectrometry (GC/MS) using a biscyanopropyl cyanopropylphenyl polysiloxane column. The relative positioning of the methyl and acetyl functionalities, along with the deuterium label, yielded species that have distinctive retention time indices and mass spectra that can be compared to published databases. In this way, the derivatives of the monomeric units indicated how each monomer was originally linked in the dextran polymer and whether the monomer was a branch point. The results of analyzing these samples (dextran initially dissolved in DMSO or DMSO/5% LiCl) are provided in Table 4.

TABLE 4

Linkage Profile of Gtf 0768 Dextran Product

	Wt %/Mol % of Glucose Monomers in Dextran

Sample	3-glc ^a	6-glc ^b	4-glc ^c	3, 6-glc ^d	2, 6- + 4,6-glc ^e
DMSO	0.4	90.2	0.4	8.3	0.7
DMSO/5% LiCl	0.9	89.3	0.4	8.0	1.4

^aGlucose monomer linked at carbon positions 1 and 3.
^bGlucose monomer linked at carbon positions 1 and 6.
^cGlucose monomer linked at carbon positions 1 and 4.
^dGlucose monomer linked at carbon positions 1, 3 and 6.
^eGlucose monomer linked at carbon positions 1, 2 and 6, or 1, 4 and 6.

In general, the results in Table 4 indicate that the dextran product analyzed above comprises:

(i) about 87-93 wt % glucose linked only at positions 1 and 6;
(ii) about 0.1-1.2 wt % glucose linked only at positions 1 and 3;
(iii) about 0.1-0.7 wt % glucose linked only at positions 1 and 4;
(iv) about 7.7-8.6 wt % glucose linked only at positions 1, 3 and 6; and
(v) about 0.4-1.7 wt % glucose linked only at (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6.
Based on this information and some other studies (data not shown), it is contemplated that this product is a branched structure in which there are long chains (containing mostly or all alpha-1,6-linkages) of about 20 DP in length (average) that iteratively branch from each other (e.g., a long chain can be a branch from another long chain, which in turn can itself be a branch from another long chain, and so on). The branched structure also appears to comprise short branches from the long chains; these short chains are believed to be 1-3 DP in length and mostly comprise alpha-1,3 and -1,4 linkages, for example. Branch points in the dextran, whether from a long chain branching from another long chain, or a short chain branching from a long chain, appear to comprise alpha-1,3, -1,4, or -1,2 linkages off of a glucose involved in alpha-1,6 linkage. Roughly 25% of all the branch points of the dextran branched into a long chain.

Thus, reactions comprising water, sucrose and an enzyme comprising SEQ ID NO:1 synthesized a very large gelling dextran product, as determined by the product's high Mw and predominant alpha-1,6 glucosidic linkage profile. The dextran produced in this Example can be used to prepare dextran ethers as presently disclosed.

Example 10

Synthesis of Dextran Ether Derivative

This Example describes producing an ether derivative of dextran as produced herein. Specifically, the ether derivative, carboxymethyl dextran, was synthesized. While the dextran product disclosed in Example 2 was used in this Example, the dextran product of Example 9 can similarly be used in the following etherification procedure.
1 g of dextran polymer as produced in Example 2 was added to 20 mL of isopropanol in a 50-mL capacity round bottom flask fitted with a thermocouple for temperature monitoring and a condenser connected to a recirculating bath, and a magnetic stir bar. 0.2 g of sodium hydroxide (15% solution) was added dropwise to the mixture, which was then heated to 25° C. on a hotplate. The mixture was stirred for 1 hour before the temperature was increased to 55° C. Sodium chloroacetate (0.1 g) was then added to provide a reaction, which was held at 55° C. for 2 hours before being neutralized with 90% acetic acid. The solid thus formed was collected by vacuum filtration and washed with ethanol (70%) four times, dried under vacuum at 20-25° C., and analyzed by NMR and SEC to determine molecular weight and DoS. The solid material obtained was identified as water-soluble sodium carboxymethyl dextran with a DoS of 0.024.
Another sample of sodium carboxymethyl dextran was prepared using the above method, but with some modifications as delineated in the Table 5.

TABLE 5

DoS of Sodium Carboxymethyl Dextran Prepared from Enzymatically
Produced Dextran

Product		Sodium
Sample	Dextran	Hydroxide	Sodium	Reaction
Designation	Substrate	(15%)	Chloroacetate	Time	DoS

109	0.66 g	2.64 g	1.64 g	5 hr.	0.88

Thus, the dextran ether derivative, sodium carboxymethyl dextran, was prepared and isolated.

Example 11

Synthesis of Cationic Dextran Ether Derivative

This Example describes synthesizing a cationic ether derivative of dextran as produced herein. Specifically, the quaternary ammonium dextran ether, trimethylammonium hydroxypropyl dextran, was synthesized. While the dextran product disclosed in Example 2 was used in this Example, the dextran product of Example 9 can similarly be used in the following etherification procedure.
1 g of dextran polymer as produced in Example 2 was added to 10 mL of isopropanol in a 50-mL capacity round bottom flask fitted with a thermocouple for temperature monitoring and a condenser connected to a recirculating bath, and a magnetic stir bar. 1.8 g of sodium hydroxide (15% solution) was added dropwise to this preparation, which was then heated to 25° C. on a hotplate. The preparation was stirred for 1 hour before the temperature was increased to 55° C. 3-chloro-2-hydroxypropyl-trimethylammonium chloride (0.7 g) was then added to provide a reaction, which was held at 55° C. for 6 hours before being neutralized with 90% acetic acid. The solid thus formed (trimethylammonium hydroxypropyl dextran) was collected by vacuum filtration and washed with ethanol (95%) four times, dried under vacuum at 20-25° C., and analyzed by NMR and SEC to determine molecular weight and DoS (0.51).
Additional samples of trimethylammonium hydroxypropyl dextran ether were synthesized following the above process, but with certain process variations. Specifically, different amounts of etherification agent (3-chloro-2-hydroxypropyl-trimethylammonium chloride) were used. Table 6 lists these process variations and the resulting DoS measurements of the quaternary ammonium dextran ether products.

TABLE 6

DoS of Quaternary Ammonium Hydroxypropyl Dextran Prepared
from Enzymatically Produced Dextran

Sample	Etherification
Product	Agent	Reaction
Designation	Amount	Time ^a	DoS

236-2	1 g	6 hr.	0.354
236-3	2 g	6 hr.	0.516

^aReaction time was measured from the time etherification agent was added to the time of reaction neutralization.

Thus, the quaternary ammonium dextran ether derivative, trimethylammonium hydroxypropyl dextran, was prepared and isolated.

Example 12

Adsorption of Dextran Ether on Various Fabrics

This Example discloses how one could test the degree of adsorption of dextran ether derivatives herein, such as those produced above, on different types of fabric.
First, calibration curves were prepared that could be useful for determining the relative level of adsorption of dextran ether onto fabric surfaces.
Solutions of known concentration (ppm) were made using Direct Red 80 and Toluidine Blue O dyes. The absorbance of these solutions were measured using a LAMOTTE SMART2 Colorimeter at either 520 or 620 nm. The absorption information was plotted in order that it can be used to determine dye concentration of solutions exposed to fabric samples. The concentration and absorbance of each calibration curve are provided in Tables 7 and 8.

TABLE 7

Direct Red 80 Dye Calibration Curve Data

	Dye	Average
	Concentration	Absorbance
	(ppm)	@ 520 nm

	25	0.823333333
	22.5	0.796666667
	20	0.666666667
	15	0.51
	10	0.37
	5	0.2

TABLE 8

Toluidine Blue O Dye Calibration Curve Data

Dye Average

Concentration Absorbance

(ppm) @ 620 nm

12.5 1.41

10 1.226666667

7 0.88

5 0.676666667

3 0.44

1 0.166666667

These calibration curves may be useful for determining the relative level of adsorption of a dextran ether on fabric surfaces, such as by following the below methodology.
0.07 wt % or 0.25 wt % solutions of a dextran ether compound in deionized water are made. Each solution is divided into several aliquots with different concentrations of compound (Table 9). Other components are added such as acid (dilute hydrochloric acid) or base (sodium hydroxide) to modify pH, or NaCl salt.

TABLE 9

Dextran Ether Compound Solutions Useful in Fabric
Adsorption Studies

Amount	Amount of	Compound
of NaCl	Solution	Concentration	Final
(g)	(g)	(wt %)	pH

0	15	0.07	~7
0.15	14.85	0.0693	~7
0.3	14.7	0.0686	~7
0.45	14.55	0.0679	~7
0	9.7713	0.0683	~3
0	9.7724	0.0684	~5
0	10.0311	0.0702	~9
0	9.9057	0.0693	~11
0	15	0.25	~7
0.15	14.85	0.2475	~7
0.3	14.7	0.245	~7
0.45	14.55	0.2425	~7
0	9.8412	0.2459	~3
0	9.4965	0.2362	~5
0	9.518	0.2319	~9
0	9.8811	0.247	~11

Four different fabric types (cretonne, polyester, 65:35 polyester/cretonne, bleached cotton) are cut into 0.17 g pieces. Each piece is placed in a 2-mL well in a 48-well cell culture plate. Each fabric sample is exposed to 1 mL of each of the above compound solutions (Table 9) (a control solution with no compound is included for each fabric test). The fabric samples are allowed to sit for at least 30 minutes in the compound solutions. The fabric samples are removed from the compound solutions and rinsed in DI water for at least one minute to remove any unbound compound. The fabric samples are then dried at 60° C. for at least 30 minutes until constant dryness is achieved. The fabric samples are weighed after drying and individually placed in 2-mL wells in a clean 48-well cell culture plate. The fabric samples are then exposed to 1 mL of a 250 ppm Direct Red 80 dye solution or a 250 ppm Toluidine Blue dye solution. The samples are left in the dye solution for at least 15 minutes. Each fabric sample is removed from the dye solution, after which the dye solution is diluted 10×.
The absorbance of the diluted solutions is measured compared to a control sample. A relative measure of dextran ether compound adsorbed to the fabric is calculated based on the calibration curve created above for Direct Red 80 and/or Toluidine Blue dye, as appropriate. Specifically, the difference in UV absorbance for the fabric samples exposed to the ether compound compared to the controls (fabric not exposed to compound) represents a relative measure of compound adsorbed to the fabric. This difference in UV absorbance could also be expressed as the amount of dye bound to the fabric (over the amount of dye bound to control), which is calculated using the calibration curve (i.e., UV absorbance is converted to ppm dye). A positive value represents the dye amount that is in excess to the dye amount bound to the control fabric, whereas a negative value represents the dye amount that is less than the dye amount bound to the control fabric. A positive value would reflect that the dextran ether compound adsorbed to the fabric surface.
It is believed that this assay would demonstrate that dextran ether compounds disclosed herein can adsorb to various types of fabric under different salt and pH conditions. This adsorption would suggest that dextran ether compounds are useful in detergents for fabric care (e.g., as anti-redeposition agents).

Claims

1-15. (canceled)

16. A composition comprising a dextran compound, wherein the dextran compound is a product of an isolated glucosyltransferase enzyme comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:1 or SEQ ID NO:2, and wherein the weight-average molecular weight (Mw) of said dextran compound is 50 million to 200 million Daltons.

17. The composition of claim 16, wherein the z-average radius of gyration of the dextran compound is 200-280 nm.

18. The composition of claim 16, wherein the dextran compound comprises chains linked together within a branching structure, wherein said chains are similar in length and comprise substantially alpha-1,6-glucosidic linkages.

19. The composition of claim 18, wherein the average length of the chains is 10-50 monomeric units.

20. The composition of claim 16, wherein the dextran compound comprises:

(i) 87-91.5 wt % glucose linked at positions 1 and 6;

(ii) 0.1-1.2 wt % glucose linked at positions 1 and 3;

(iii) 0.1-0.7 wt % glucose linked at positions 1 and 4;

(iv) 7.7-8.6 wt % glucose linked at positions 1, 3 and 6; and

(v) 0.4-1.7 wt % glucose linked at:

(a) positions 1, 2 and 6, or

(b) positions 1, 4 and 6.

21. The composition of claim 20, wherein the dextran compound comprises:

(i) 89.5-90.5 wt % glucose linked at positions 1 and 6;

(ii) 0.4-0.9 wt % glucose linked at positions 1 and 3;

(iii) 0.3-0.5 wt % glucose linked at positions 1 and 4;

(iv) 8.0-8.3 wt % glucose linked at positions 1, 3 and 6; and

(v) 0.7-1.4 wt % glucose linked at:

(a) positions 1, 2 and 6, or

(b) positions 1, 4 and 6.

22. The composition of claim 16, wherein the isolated glucosyltransferase enzyme comprises an amino acid sequence that is at least 95% identical to SEQ ID NO:1 or SEQ ID NO:2.

23. The composition of claim 16, wherein the composition is in the form of a household product, personal care product, pharmaceutical product, industrial product, or food product.

24. The composition of claim 16, further comprising said glucosyltransferase enzyme.

25. The composition of claim 16, wherein at least one organic group is in ether linkage to the dextran compound, and wherein the degree of substitution (DoS) of the dextran compound with the organic group is 0.0025 to 3.0.

26. The composition of claim 25, wherein the organic group is a carboxy alkyl, alkyl, or hydroxy alkyl group.

27. The composition of claim 26, wherein the organic group is a carboxymethyl, methyl, ethyl, hydroxypropyl, dihydroxypropyl, or hydroxyethyl group.

28. The composition of claim 25, wherein the organic group is a positively charged organic group.

29. The composition of claim 28, wherein the positively charged organic group comprises a substituted ammonium group.

30. The composition of claim 29, wherein the substituted ammonium group is a trimethylammonium group.

31. The composition of claim 25, wherein one type of organic group is in ether linkage to the dextran compound.

32. The composition of claim 25, wherein two or more different organic groups are in ether linkage to the dextran compound.

33. The composition of claim 25, wherein the composition is in the form of a household product, personal care product, pharmaceutical product, industrial product, or food product.

34. A method for increasing the viscosity of an aqueous composition, the method comprising:

contacting a dextran compound as recited in claim 16 with the aqueous composition, wherein the viscosity of the aqueous composition is increased by the dextran compound compared to the viscosity of the aqueous composition before the contacting step.

35. A method for increasing the viscosity of an aqueous composition, the method comprising:

contacting a dextran compound as recited in claim 25 with the aqueous composition, wherein the viscosity of the aqueous composition is increased by the dextran compound compared to the viscosity of the aqueous composition before the contacting step.

36. A method of treating a material, said method comprising:

contacting a material with an aqueous composition comprising a dextran compound as recited in claim 16.

37. A method of treating a material, said method comprising:

contacting a material with an aqueous composition comprising a dextran compound as recited in claim 25.