WO2006043906A1 - Procede de dissolution de stereoisomeres d'un compose - Google Patents

Procede de dissolution de stereoisomeres d'un compose Download PDF

Info

Publication number
WO2006043906A1
WO2006043906A1 PCT/SG2005/000359 SG2005000359W WO2006043906A1 WO 2006043906 A1 WO2006043906 A1 WO 2006043906A1 SG 2005000359 W SG2005000359 W SG 2005000359W WO 2006043906 A1 WO2006043906 A1 WO 2006043906A1
Authority
WO
WIPO (PCT)
Prior art keywords
enzyme
compound
enantiomer
stereoisomer
organic solvent
Prior art date
Application number
PCT/SG2005/000359
Other languages
English (en)
Inventor
Jinchuan Wu
Yvonne Chow
Original Assignee
Agency For Science, Technology And Research
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Agency For Science, Technology And Research filed Critical Agency For Science, Technology And Research
Publication of WO2006043906A1 publication Critical patent/WO2006043906A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P41/00—Processes using enzymes or microorganisms to separate optical isomers from a racemic mixture
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P7/00—Preparation of oxygen-containing organic compounds
    • C12P7/40—Preparation of oxygen-containing organic compounds containing a carboxyl group including Peroxycarboxylic acids

Definitions

  • the present invention relates generally to methods to resolve two stereoisomers, including two enantiomers, from a mixture of same, and particularly to methods using a resolving agent to resolve stereoisomers, particularly enantiomers.
  • a racemic compound or racemic mixture contains equal amounts of each of a pair of enantiomers.
  • a mixture of two enantiomers of a compound results when chemical reactions are conducted in an achiral environment, since there is no selection for the formation of one enantiomer in favour of the other.
  • Physically and chemically, the two enantiomers in a pair are identical, but each of the pair often reacts selectively and specifically when it comes to interactions with other molecules, including chiral molecules, including enzymes and other biomolecules.
  • selectivity and specificity can be crucial, since each of the pair of enantiomers can have vastly different physiological effects from the other. Even if one enantiomer of a pair produces the desired therapeutic effects, the other may be inactive or produce undesirable side effects.
  • enzymes as biocatalysts for enantioselective resolution requires that the enzyme possesses at least a minimum level of activity or stability in order to be able to catalyse biotransformation of the substrates. Accordingly, enzymes that have almost no or low activity, stability or ability to transform the substrates would not be useful' in such enzymatic resolution processes. Since enzymes tend to be very sensitive molecules that denature or lose activity fairly readily, it would be advantageous to be able to deVelop methods of enantiomeric resolution that did not depend on an enzyme retaining its biological activity or ability to bind enantio- specifically to a substrate or other ligand.
  • the present invention provides a method for resolving a first stereoisomer and a second stereoisomer of a compound from a mixture of said first stereoisomer and said second stereoisomer, said method comprising: dissolving said compound and a resolving agent in an organic solvent, said resolving agent forming a first complex with said first stereoisomer and a second complex with said second stereoisomer, said first complex having a faster dissociation rate than said second complex; crystallizing said compound from said organic solvent, whereby as a result of the faster dissociation rate of the first complex relative to the second complex, more of the first stereoisomer crystallizes than said second stereoisomer and separating crystals of said compound from said organic solvent, to obtain a crystalline fraction enriched in said first stereoisomer and an organic solvent fraction enriched in said second stereoisomer.
  • the first stereoisomer is a first enantiomer and the second stereoisomer is a second enantiomer. In another embodiment, the first stereoisomer is a first diastereomer and the second stereoisomer is a second diastereomer. In one embodiment, the resolving agent used is an enzyme.
  • the present invention provides a method for resolving a first enantiomer and a second enantiomer from a racemic compound, comprising: dissolving in an organic solvent the racemic compound and an enzyme that is capable of specifically binding the racemic compound to form a first complex with said first enantiomer and a second complex with said second enantiomer; crystallizing the compound to form crystals enriched for the first enantiomer over the second enantiomer; and separating the remaining organic solvent from the crystals.
  • Figure 1 contains the chemical structure for ketoprofen
  • Figures 2A-C are HPLC chromatograms of (A) the beginning solution of racemic ketoprofen, (B) filtrate I and (C) filtrate II showing the absorbance peaks for acetone, and the R and S enantiomers of ketoprofen, respectively, for (A) and the absorbance peaks for the R and S enantiomers of ketoprofen, respectively, for both (B) and (C).
  • This invention provides a novel method for stereoisomeric resolution, including enantiomeric resolution, for example by using enzymes to form enzyme- enantiomer complexes for enantioselective separation by crystallisation.
  • the enzyme- mediated enantioselective separation is carried out by making use of the difference in dissociation of the enzyme-enantiomer complexes regardless of the enzymes' activity and stability.
  • a chiral resolving agent such as an enzyme that binds to a chiral compound in a specific manner can be used to separate the enantiomers of that compound, even when the enzyme is not recognizing the compound as a substrate for catalysis.
  • the enzyme will interact differently with each enantiomer, thus leading to greater sequestering of one enantiomer by the enzyme than the other enantiomer due to the different dissociation constants of the two enantiomer-enzyme complexes, leaving the less sequestered enantiomer available for crystallization. Since the catalytic activity of the enzyme is not required for resolution, this novel resolution method can be conveniently performed in organic solvents.
  • stereoisomer refers to one of a set of isomers whose molecules have the same number and kind of atoms bonded to each other, but which differ in the way these atoms are arranged in space.
  • a starting mixture of two enantiomers of a compound is used, the compound being a compound which is desired to be resolved into separate solutions of each enantiomer, or which is desired to be further enantiomerically enriched.
  • the mixture may already be enantiomerically enriched for one enantiomer, or the mixture may be a racemic mixture of the two enantiomers.
  • enantiomerically enriched describes a mixture of two enantiomers in which one enantiomer is present in greater quantity than the other ' enantiomer.
  • racemic compound is used to refer to a mixture of equal amounts of two compounds that are mirror images of each other, or enantiomers.
  • racemate refers to a homogeneous phase containing equimolar amounts of enantiomers.
  • a racemic compound is for a chemical having one or more than one chiral center, each chiral center in one of the two compounds forming the racemic compound will be of opposite chirality to the corresponding chiral center in the other compound in the racemic compound.
  • enantiomer used interchangeably with enantiomeric compound, refers to one of the two compounds that are mirror images of each other, and which form a racemic compound when present in equal quantities.
  • a resolving agent is dissolved in an organic solvent.
  • the resolving agent is a chiral compound that can interact with and bind specifically to the compound that is to be resolved into enantiomers, to form a resolving agent/enantiomer complex for each of the two enantiomers.
  • Each resolving agent/enantiomer complex will have different dissociation rates.
  • the resolving agent may be a chiral small molecule, a protein, or another chiral biomolecule.
  • Binding in a specific manner or “specific binding” refers to a binding interaction between an enantiomer of the compound and the resolving agent that occurs at one or more particular sites, or between particular functional groups, on both the compound and the resolving agent, and which binding is saturable at a given concentration of either resolving agent or compound.
  • the solvent is any organic solvent in which the compound that is to be resolved is soluble and in which the resolving agent is soluble or in which the resolving agent may be solubilized through use of a suitable surfactant.
  • the organic solvent is not miscible with water, although a water-miscible solvent may be used.
  • the solvent is apolar.
  • the organic solvent may be, for example, a hydrophobic solvent, for example, isooctane, hexane, heptane, cyclohexane, octane or toluene.
  • the resolving agent is a protein or a peptide.
  • the resolving agent is an enzyme.
  • the protein, peptide or enzyme may, be any protein, peptide or enzyme that will bind the compound in a specific manner when dissolved in the organic solvent in which the compound is to be enantiomerically resolved.
  • the resolving agent is an enzyme
  • the racemic compound to be resolved may be a substrate of the enzyme, and may interact with the enzyme by binding at the active site, the enzyme need not bind the substrate at the enzyme active site, nor be active in the organic solvent. Furthermore, the compound does not need to be a substrate of the enzyme, since the enzyme is not used as a catalyst in the present method. However, if the racemic compound is a substrate of the enzyme, the enzyme need not be able to transform or catalyze the transformation of the substrate in the organic solvent. For example, when dissolved in the organic solvent, the enzyme may lack or be deficient in one or more biological activities normally associated with the enzyme. In certain embodiments, the enzyme may be an apoenzyme or a specifically mutated inactive enzyme.
  • the enzyme is a lipase or a chymotrypsin, including a lipase from Candida rugosa, Mucor jananicus or Rhizopus oryzae or ⁇ - chymotrypsin or it may be penicillin G acylase enzyme.
  • the enzyme may be solubilized with the help of a surfactant followed by addition of the enzyme/surfactant complex to an organic solvent.
  • the surfactant may be added to the organic solvent, for example an organic solvent in which the enzyme is to be solubilized.
  • An aqueous buffer containing the enzyme may then be mixed with the organic solvent containing the surfactant, which may then be separated from the aqueous solution, for example by settling of the mixture or by centrifugation to separate the aqueous and non-aqueous phases.
  • a water-miscible solvent it is not necessary to remove the aqueous phase.
  • the resulting mixture of aqueous solution and organic solvent should be suitable to dissolve and crystallize the compound that is to be resolved.
  • the surfactant may first be added to the aqueous solution containing the enzyme, which is then mixed with the organic solvent.
  • the aqueous buffer solution then is separated from the organic solvent, if immiscible with water, resulting in the enzyme solubilized by the help of the surfactant in the organic solvent.
  • the surfactant should be one that will help solubilize the resolving agent (for example an enzyme) and which is soluble in the organic solvent that is to be used.
  • the surfactant is not one which will create a microemulsion between the aqueous buffer and the organic solvent.
  • the surfactant is an ionic surfactant, which allows for the surfactant to form an ion pair with the enzyme resolving agent if the enzyme has charged surface groups.
  • the surfactant is able to form reverse micelles encapsulating the enzyme.
  • the surfactant is sodium bis (2-ethylhexyl) sulfosuccinate.
  • the amount of surfactant used will depend on the particular surfactant, the amount and type of resolving agent used, and the amount and type of organic solvent used. Enough surfactant is used to solubilize a sufficient amount of resolving agent in the desired volume of organic solvent, which can be readily determined by a skilled person. For example, sufficient amounts of surfactant are used so as to form an ion- paired complex with the enzyme or to form reverse micelles containing the enzyme.
  • the concentration of the resolving agent in the organic solvent can be determined using standard methods, including protein staining or UV absorbance if the resolving agent is a protein, peptide or an enzyme. A protein detection method should be chosen based on the organic solvent used so as to prevent interference of the solvent with the protein concentration determination.
  • the mixture of enantiomers of the compound is then dissolved in the organic solvent containing the resolving agent. It will be understood that the order of addition of the resolving agent and the mixture of enantiomers is not critical and that alternatively, the mixture of enantiomers may be first dissolved in the organic compound, followed by addition of the resolving agent.
  • the volume of organic solvent used and the amount of the mixture of enantiomers of the compound can be varied, depending on the nature of both solvent and the compound, as well as the desired concentration of the compound and the total amount of enantiomer that is desired to be resolved.
  • the most efficient ratio of enantiomer mixture:resolving agent is 1 :1, although a ratio of >1 or ⁇ 1 may also be used. At yatios below 1 :1, the capacity of the resolving agent to resolve the enantiomers will not be fully utilized, and at ratios greater than 1 :1, each resolution step will be less efficient than at a ratio of 1 :1, which may increase the number of resolution steps required to reach a desired level of resolution of enantiomers.
  • the crystallization is achieved by reducing the volume of solvent, thereby concentrating the compound and enzyme in the remaining solvent until the compound is allowed to crystallize.
  • a convenient way to reduce the volume of the solvent is to allow the solvent to evaporate. Such a method is slow enough to allow for ordering of the enantiomer molecules within the solvent, leading to the formation of crystals.
  • other methods of reducing the volume and/or crystallizing of the enantiomers can be used. For example, for a molecule that crystallizes readily in a particular organic solvent, filtration using a filter having pores small enough to retain the resolving agent and the compound may be used.
  • the remaining solvent containing un-crystallized enantiomers and the resolving agent is separated from the crystals.
  • the un-crystallized enantiomer solution will be enriched for one enantiomer over the other (i.e. the enantiomer for which the resolving agent/enantiomer complex has a slower dissociation rate), due to the differential dissociation of the resolving agent with each of the enantiomers, and the resultant preferential sequestering of one enantiomer by the resolving agent, reducing the amount of the preferentially sequestered enantiomer available for crystallization.
  • the crystalline fraction will be enriched in other enantiomer (i.e. the enantiomer for which the resolving agent/enantiomer complex has a faster dissociation rate).
  • the crystals formed may be wholly of one enantiomer or the other, and both types of crystals may form or only one typ ⁇ 'of crystal may form, or crystals containing both enantiomers may also form.
  • the crystal phase should be enriched for one enantiomer over the other.
  • enantiomer excess e.e.
  • the enantiomer excess is defined as
  • the enantiomer excess can be determined by measurement of the amount of each enantiomer remaining, for example, by analysing an amount of the remaining solvent containing the enantiomers using a chiral HPLC column.
  • the present method can result in a percent enantiomeric enrichment of one enantiomer in the remaining solvent of, for example, 10, 20, 25, 30, 40, 50, 60, 70, 75, 80, 90, 95, 96, 97, 98 or 99%, depending on the dissociation rate of the resolving agent with each enantiomer and the number of times that the method is repeated.
  • the crystals of the compound will also be enantiomerically enriched, albeit for the enantiomer that is not enriched in the remaining solvent, once the desired degree of enantiomeric resolution has been obtained, the enantiomer contained in the crystals can be harvested to obtain the resolved, or partially resolved enantiomer contained in the crystals. If desired, and if the crystals contain an enriched enantiomer mixture, the crystals can be redissolved in the organic solvent and the method can be repeated in order to further resolve the enantiomer mixture.
  • the resolving agent can be readily recovered for repeated usage, for example by ultrafiltration using a filter with an appropriate molecular weight cut ⁇ off, particularly where the resolving agent is an enzyme, due to the relatively weak interaction and the large molecular weight difference between the enzyme and enantiomers.
  • the present method makes it possible to resolve a mixture of enantiomers of a compound using enzymes that cannot be used as biocatalysts due to low activity and/or stability. This method makes it possible to obtain a high enantiomer excess using enzymes that would not be useful for enantiomer selection by biotransformation methods. Furthermore, since the method is performed in an organic solvent in which the racemic compound is soluble, it is not necessary to form a diastereoisomeric salt with the racemic compound prior to crystallization, negated the requirement to subsequently isolate the free base or free acid of the enantiomer once resolved.
  • a diastereomer is a chiral compound that has more than one chiral center, and which differs from another stereoisomer of the compound (the other diastereomer in the mixture) with respect to stereochemistry at one or more chiral centers, but not at every chiral center and therefore is not an enantiomer of the other stereoisomer.
  • ketoprofen shown in Figure 1
  • a member of the profen family ibuprofen, ketoprofen, flurbiprofen, naproxen etc
  • ibuprofen a member of the profen family
  • ketoprofen a member of the profen family
  • ibuprofen a member of the profen family
  • ketoprofen a member of the profen family
  • mucor jananicus Lipase M "Amano”
  • Rhizopus oryzae Rhizopus oryzae
  • These enzymes were first made soluble in organic solvents by forming an ion-paired complex with an ionic surfactant, sodium bis (2-ethylhexyl) sulfosuccinate (AOT) 5 as follows.
  • AOT sodium bis (2-ethylhexyl) sulfosuccinate
  • lipases (10 mg/ml) (in 0.01 M phosphate buffer, pH 6.0) containing CaCl 2 (10 mM for the lipase from Candida rugosa and 100 mM for the lipase from Rhizopus oryzae) or 300 mM NaCl (for the lipase from Mucor javanicus) was mixed with 100 ml isooctane containing AOT (2 mM) under magnetic stirring at 650 rpm for 10 min. The mixture was then placed at room temperature for 15 min followed by centrifugation at 6000 rpm for 5 min. The transparent isooctane layer was collected and the protein content determined based on the UV absorption at 280 nm. The lipase concentration was adjusted by evaporating or adding isooctane when necessary.
  • ⁇ -chymotrypsin 100 ml of ⁇ -chymotrypsin (1 mg/ml) (in 0.01 M phosphate buffer, pH 7.8) containing CaCl 2 (2 mM) was mixed with 100 ml isooctane containing AOT (2 mM). The other operations were the same with those for the lipases.
  • Ketoprofen was analyzed by HPLC with a ChiralcelTM OJ-H column (4.6 x 250 mm, Daicel Industrial, Japan). Samples (5 ⁇ l) were eluted by a mixture of n- hexane: 2-propanol: acetic acid (90:10:0.5, v/v/v) at 1.0 ml min "1 and detected at 254 nm.
  • the examples for the enzyme-mediated enantioselective crystallization of ketoprofen are as follows.
  • Example 1 Ketoprofen (180 mg) was dissolved in acetone (6 ml) followed by addition of 60 ml isooctane containing the ion-paired lipase from Candida rugosa (0.36 mg/ml). The transparent solution thus formed was allowed to evaporate naturally in a fume cupboard to a final volume of 12.5 ml, leading to a crystallization of 97.0% of ketoprofen. The crystals were filtered off and the R- and S- enantiomers in the filtrate I were analyzed (HPLC) to be 0.139 and 0.286 mg/ml, respectively, corresponding to an e.e. of 34.5%.
  • the filtrate I was further evaporated to 1.8 ml, leading to 38.5% of ketoprofen crystallized from filtrate I.
  • the crystals were removed by filtration and the R- and S-enantiomers in the filtrate II were respectively 0.306 and 1.51 mg/ml, corresponding to an e.e. of 66.7%.
  • the chromatograms of the beginning solution of racemic ketoprofen, filtrate I and filtrate II are show ⁇ 'ih Figures 2A-C, respectively.
  • Example 2 Ketoprofen (180 mg) was dissolved in acetone (12 ml) followed by addition of 60 ml isooctane containing the ion-paired lipase from Mucor javanicus (0.36 mg/ml). The transparent solution thus formed was let evaporate naturally in a fume cupboard to 15.5 ml, leading to a crystallization of 96.5% of ketoprofen. The crystals were filtered off and the R- and S-enantiomers in the filtrate I were 0.173 and 0.228 mg/ml, respectively, corresponding to an e.e. of 13.7%.
  • Example 3 Ketoprofen (180 rag) was dissolved in acetone (12 ml) followed by addition of 60 ml isooctane containing the ion-paired lipase from Rhizopus oryzae (0.36 mg/ml).
  • the transparent solution thus formed was let evaporate naturally in a fume cupboard to 12.5 ml, leading to a crystallization of 98.2% of ketoprofen.
  • the crystals were removed and , the R- and S-enantiomers in the filtrate were 0.116 and 0.142 mg/ml, respectively, corresponding to an e.e. of 10.1%.
  • the filtrate was further evaporated to 2.0 ml, leading to 63.2% of ketoprofen crystallized from filtrate I.
  • the crystals were removed and the R- and S-enantiomers in the filtrate II were 0.211 and 0.382 mg/ml, respectively, corresponding to an e.e. of 28.7%.
  • the three lipases showed almost no activity or very low activity and enantioselectivity (E ⁇ 2) for ketoprofen esterification with ethanol in isooctane, which makes them not feasible to be used as biocatalysts for commercial resolution of ketoprofen through the esterification route, but they worked well in the' ⁇ dnzyme-mediated crystallization process, giving a high e.e. of the S- ketoprofen in the remaining filtrate after a two-step crystallization, although further improvement is still possible fey further evaporation of the solvents.
  • the enzymes are expected to be easily recovered and reused by ultrafiltration considering the large weight difference and weak interaction between enzyme and enantiomer molecules.
  • Example 4 Ketoprofen (360 mg) was dissolved in acetone (30 ml) followed by addition of 120 ml isooctane containing the ion-paired ⁇ -chymotrypsin (0.70 mg/ml). The transparent solution thus formed was let evaporate naturally in a fume cupboard to 83 ml, leading to a crystallization of 89.5% of ketoprofen. The crystals were filtered off and the R- and S-enantiomers in the filtrate I were analyzed (HPLC) to be 0.180 and 0.227/ml, respectively, corresponding to an e.e. of 21.2%.
  • the filtrate I was further evaporated to 8.4 ml, leading to 88.4% of ketoprofen crystallized from filtrate I.
  • the crystals were removed by filtration and the R- and S- enantiomers in the filtrate II were respectively 0.085 and 0.440 mg/ml, corresponding to an e.e. of 67.6%.
  • this invention provides a novel tool for resolving racemic compounds using enzymes especially those that cannot be used as biocatalysts due to low activity and/or stability, let alone low enantioselectivity.
  • Table 1 shows the resolution of ketoprofen by lipases from Candida Rugosa, Mucorjavanicus, Rhizopus oryzae and by ⁇ -chymotrypsin.
  • ketoprofen 180 mg was dissolved in acetone (6 or 12 ml) followed by addition of isooctane (60 ml) containing the ion- paired lipases (0.36 mg/ml) and the transparent solution was evaporated naturally. The remaining solvent was separated from the crystals by filtration and let evaporate to further improve the e.e. in the remaining solvent.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Zoology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Genetics & Genomics (AREA)
  • General Chemical & Material Sciences (AREA)
  • Biotechnology (AREA)
  • Microbiology (AREA)
  • Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Preparation Of Compounds By Using Micro-Organisms (AREA)

Abstract

L'invention concerne un procédé permettant de dissoudre deux stéréoisomères, par exemple, énantiomères, de leur mélange à l'aide d'un agent de dissolution chiral pour, de préférence, cristalliser un stéréoisomère sur l'autre dans un solvant organique.
PCT/SG2005/000359 2004-10-20 2005-10-18 Procede de dissolution de stereoisomeres d'un compose WO2006043906A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US61996004P 2004-10-20 2004-10-20
US60/619,960 2004-10-20

Publications (1)

Publication Number Publication Date
WO2006043906A1 true WO2006043906A1 (fr) 2006-04-27

Family

ID=36203233

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SG2005/000359 WO2006043906A1 (fr) 2004-10-20 2005-10-18 Procede de dissolution de stereoisomeres d'un compose

Country Status (1)

Country Link
WO (1) WO2006043906A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995020590A1 (fr) * 1994-01-27 1995-08-03 The Trustees Of Columbia University In The City Of New York Recepteurs enantioselectifs pour derives d'acide amine et autres composes
WO2001025478A1 (fr) * 1999-10-04 2001-04-12 Exiqon A/S Procede d'augmentation de la specificite d'oligonucleotides oxy-lna
WO2001068729A1 (fr) * 2000-03-10 2001-09-20 Ibc Advanced Technologies, Inc. Compositions et procedes de liaison selective d'enantiomeres d'amines ou d'acides amines a leurs contre-enantiomeres

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995020590A1 (fr) * 1994-01-27 1995-08-03 The Trustees Of Columbia University In The City Of New York Recepteurs enantioselectifs pour derives d'acide amine et autres composes
WO2001025478A1 (fr) * 1999-10-04 2001-04-12 Exiqon A/S Procede d'augmentation de la specificite d'oligonucleotides oxy-lna
WO2001068729A1 (fr) * 2000-03-10 2001-09-20 Ibc Advanced Technologies, Inc. Compositions et procedes de liaison selective d'enantiomeres d'amines ou d'acides amines a leurs contre-enantiomeres

Similar Documents

Publication Publication Date Title
Dreyer et al. Ionic liquids for aqueous two‐phase extraction and stabilization of enzymes
Colton et al. A 2-propanol treatment increases the enantioselectivity of Candida rugosa lipase toward esters of chiral carboxylic acids
US5932212A (en) Crosslinked protein crystal formulations and their use as catalysts in organic solvents
Fernández‐Lorente et al. Self‐assembly of Pseudomonas fluorescens lipase into bimolecular aggregates dramatically affects functional properties
Agustian et al. Single enantiomeric β-blockers—The existing technologies
Kamiya et al. Surfactant‐coated lipase suitable for the enzymatic resolution of menthol as a biocatalyst in organic media
WO1991005594A1 (fr) Separation de melanges a l'aide de systemes a deux phases
US6211422B1 (en) Enzyme catalysis in carbon dioxide fluids
CN109234252B (zh) 一种印迹脂肪酶及其应用
CN111662898A (zh) 一种脂肪酶固定化新技术及其应用于对映体拆分的方法
Ghanem Direct enantioselective HPLC monitoring of lipase‐catalyzed kinetic resolution of flurbiprofen
Hernández-Fernández et al. On the development of an integrated membrane process with ionic liquids for the kinetic resolution of rac-2-pentanol
US5346816A (en) Enzymatic process for the enantioselective preparation of optically active cyanohydrins
Berglund et al. Esterification of 2-methylalkanoic acids catalysed by lipase from Candida rugosa: enantioselectivity as a function of water activity and alcohol chain length
Ceynowa et al. High enantioselective resolution of racemic 2-arylpropionic acids in an enzyme membrane reactor
Long et al. Enzyme kinetics of kinetic resolution of racemic ibuprofen ester using enzymatic membrane reactor
Dai et al. Lipase-facilitated separation of organic acids in a hollow fiber contained liquid membrane module
WO2006043906A1 (fr) Procede de dissolution de stereoisomeres d'un compose
Yasufuku et al. Effect of temperature on lipase-catalyzed esterification in organic solvent
Miyako et al. Transport of organic acids through a supported liquid membrane driven by lipase-catalyzed reactions
EP0423133B1 (fr) Systemes de resolution enzymatique et composes utilises dans ces systemes, et leurs preparations
Allenmark et al. Enantioselectivity of lipase‐catalyzed hydrolysis of some 2‐chloroethyl 2‐arylpropanoates studied by chiral reversed‐phase liquid chromatography
Gais et al. Activation of pig liver esterase in organic media with organic polymers. Application to the enantioselective acylation of racemic functionalized secondary alcohols
EP0440723A1 (fr) Procede de preparation d'esters de glycidate optiquement actifs.
US5274300A (en) Enzymatic hydrolysis of glycidate esters in the presence of bisulfite anion

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KP KR KZ LC LK LR LS LT LU LV LY MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 05792948

Country of ref document: EP

Kind code of ref document: A1