CN114685695A - Modified chitosan and preparation method thereof - Google Patents
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- 229920001661 Chitosan Polymers 0.000 title claims abstract description 144
- 238000002360 preparation method Methods 0.000 title claims abstract description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 21
- 239000000126 substance Substances 0.000 claims abstract description 14
- 238000006243 chemical reaction Methods 0.000 claims abstract description 13
- 239000004753 textile Substances 0.000 claims abstract description 5
- 238000003756 stirring Methods 0.000 claims description 30
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 28
- 238000000502 dialysis Methods 0.000 claims description 27
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 26
- 239000000243 solution Substances 0.000 claims description 23
- 238000010438 heat treatment Methods 0.000 claims description 18
- KEQGZUUPPQEDPF-UHFFFAOYSA-N 1,3-dichloro-5,5-dimethylimidazolidine-2,4-dione Chemical compound CC1(C)N(Cl)C(=O)N(Cl)C1=O KEQGZUUPPQEDPF-UHFFFAOYSA-N 0.000 claims description 17
- XTHPWXDJESJLNJ-UHFFFAOYSA-N chlorosulfonic acid Substances OS(Cl)(=O)=O XTHPWXDJESJLNJ-UHFFFAOYSA-N 0.000 claims description 17
- 239000000047 product Substances 0.000 claims description 17
- FSSPGSAQUIYDCN-UHFFFAOYSA-N 1,3-Propane sultone Chemical compound O=S1(=O)CCCO1 FSSPGSAQUIYDCN-UHFFFAOYSA-N 0.000 claims description 16
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 14
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 14
- 235000019253 formic acid Nutrition 0.000 claims description 14
- SMQUZDBALVYZAC-UHFFFAOYSA-N salicylaldehyde Chemical compound OC1=CC=CC=C1C=O SMQUZDBALVYZAC-UHFFFAOYSA-N 0.000 claims description 14
- 238000005406 washing Methods 0.000 claims description 14
- 238000002156 mixing Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 11
- 238000004108 freeze drying Methods 0.000 claims description 10
- 239000003638 chemical reducing agent Substances 0.000 claims description 9
- 238000001914 filtration Methods 0.000 claims description 9
- 150000001299 aldehydes Chemical class 0.000 claims description 7
- 238000011049 filling Methods 0.000 claims description 7
- 239000002244 precipitate Substances 0.000 claims description 6
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 5
- 238000001035 drying Methods 0.000 claims description 5
- 239000011259 mixed solution Substances 0.000 claims description 5
- HUMNYLRZRPPJDN-UHFFFAOYSA-N benzaldehyde Chemical compound O=CC1=CC=CC=C1 HUMNYLRZRPPJDN-UHFFFAOYSA-N 0.000 claims description 4
- 239000012279 sodium borohydride Substances 0.000 claims description 4
- 229910000033 sodium borohydride Inorganic materials 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 3
- 230000003115 biocidal effect Effects 0.000 claims description 2
- 238000009920 food preservation Methods 0.000 claims description 2
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 claims description 2
- DXASQZJWWGZNSF-UHFFFAOYSA-N n,n-dimethylmethanamine;sulfur trioxide Chemical compound CN(C)C.O=S(=O)=O DXASQZJWWGZNSF-UHFFFAOYSA-N 0.000 claims description 2
- QNGNSVIICDLXHT-UHFFFAOYSA-N para-ethylbenzaldehyde Natural products CCC1=CC=C(C=O)C=C1 QNGNSVIICDLXHT-UHFFFAOYSA-N 0.000 claims description 2
- 238000000746 purification Methods 0.000 claims description 2
- BEOOHQFXGBMRKU-UHFFFAOYSA-N sodium cyanoborohydride Chemical compound [Na+].[B-]C#N BEOOHQFXGBMRKU-UHFFFAOYSA-N 0.000 claims description 2
- 150000001875 compounds Chemical class 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 claims 1
- 230000000844 anti-bacterial effect Effects 0.000 abstract description 16
- 230000004048 modification Effects 0.000 abstract description 9
- 238000012986 modification Methods 0.000 abstract description 9
- 239000002994 raw material Substances 0.000 abstract description 5
- 235000013305 food Nutrition 0.000 abstract description 3
- 229940079593 drug Drugs 0.000 abstract description 2
- 239000003814 drug Substances 0.000 abstract description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 21
- 238000006277 sulfonation reaction Methods 0.000 description 11
- 239000007864 aqueous solution Substances 0.000 description 9
- 229910052739 hydrogen Inorganic materials 0.000 description 9
- 239000001257 hydrogen Substances 0.000 description 9
- 125000000542 sulfonic acid group Chemical group 0.000 description 8
- 239000002608 ionic liquid Substances 0.000 description 7
- 230000029936 alkylation Effects 0.000 description 5
- 238000005804 alkylation reaction Methods 0.000 description 5
- 238000007069 methylation reaction Methods 0.000 description 5
- 229920002101 Chitin Polymers 0.000 description 4
- 230000009471 action Effects 0.000 description 4
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- 230000000694 effects Effects 0.000 description 4
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 4
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- 102000004882 Lipase Human genes 0.000 description 3
- 108090001060 Lipase Proteins 0.000 description 3
- 239000004367 Lipase Substances 0.000 description 3
- 125000003047 N-acetyl group Chemical group 0.000 description 3
- 125000003277 amino group Chemical group 0.000 description 3
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- 238000004090 dissolution Methods 0.000 description 3
- 239000001963 growth medium Substances 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 230000002401 inhibitory effect Effects 0.000 description 3
- 235000019421 lipase Nutrition 0.000 description 3
- 241000894006 Bacteria Species 0.000 description 2
- DHMQDGOQFOQNFH-UHFFFAOYSA-N Glycine Chemical compound NCC(O)=O DHMQDGOQFOQNFH-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000008351 acetate buffer Substances 0.000 description 2
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- 210000000170 cell membrane Anatomy 0.000 description 2
- 230000009920 chelation Effects 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 125000000118 dimethyl group Chemical group [H]C([H])([H])* 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 208000030159 metabolic disease Diseases 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- -1 nitrogenous polysaccharide Chemical class 0.000 description 2
- 235000015097 nutrients Nutrition 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 229920001282 polysaccharide Polymers 0.000 description 2
- 239000005017 polysaccharide Substances 0.000 description 2
- 125000000467 secondary amino group Chemical class [H]N([*:1])[*:2] 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 241000588724 Escherichia coli Species 0.000 description 1
- 239000004471 Glycine Substances 0.000 description 1
- 239000001888 Peptone Substances 0.000 description 1
- 108010080698 Peptones Proteins 0.000 description 1
- 241000191967 Staphylococcus aureus Species 0.000 description 1
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- 238000005917 acylation reaction Methods 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
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- 230000004071 biological effect Effects 0.000 description 1
- 229940041514 candida albicans extract Drugs 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 238000007385 chemical modification Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000007810 chemical reaction solvent Substances 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 239000002537 cosmetic Substances 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 238000012258 culturing Methods 0.000 description 1
- 230000006196 deacetylation Effects 0.000 description 1
- 238000003381 deacetylation reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000003937 drug carrier Substances 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
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- 235000012055 fruits and vegetables Nutrition 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
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- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
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- 230000001737 promoting effect Effects 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
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- 239000012429 reaction media Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000012138 yeast extract Substances 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof
- C08B37/0006—Homoglycans, i.e. polysaccharides having a main chain consisting of one single sugar, e.g. colominic acid
- C08B37/0024—Homoglycans, i.e. polysaccharides having a main chain consisting of one single sugar, e.g. colominic acid beta-D-Glucans; (beta-1,3)-D-Glucans, e.g. paramylon, coriolan, sclerotan, pachyman, callose, scleroglucan, schizophyllan, laminaran, lentinan or curdlan; (beta-1,6)-D-Glucans, e.g. pustulan; (beta-1,4)-D-Glucans; (beta-1,3)(beta-1,4)-D-Glucans, e.g. lichenan; Derivatives thereof
- C08B37/0027—2-Acetamido-2-deoxy-beta-glucans; Derivatives thereof
- C08B37/003—Chitin, i.e. 2-acetamido-2-deoxy-(beta-1,4)-D-glucan or N-acetyl-beta-1,4-D-glucosamine; Chitosan, i.e. deacetylated product of chitin or (beta-1,4)-D-glucosamine; Derivatives thereof
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- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
- A23L3/34—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals
- A23L3/3454—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by treatment with chemicals in the form of liquids or solids
- A23L3/3463—Organic compounds; Microorganisms; Enzymes
- A23L3/3562—Sugars; Derivatives thereof
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
- D06M15/01—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with natural macromolecular compounds or derivatives thereof
- D06M15/03—Polysaccharides or derivatives thereof
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- D—TEXTILES; PAPER
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- D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
- D06M16/00—Biochemical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. enzymatic
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- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23V—INDEXING SCHEME RELATING TO FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES AND LACTIC OR PROPIONIC ACID BACTERIA USED IN FOODSTUFFS OR FOOD PREPARATION
- A23V2002/00—Food compositions, function of food ingredients or processes for food or foodstuffs
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids
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- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- General Health & Medical Sciences (AREA)
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Abstract
The invention relates to the technical field of chitosan modification, and particularly discloses modified chitosan and a preparation method thereof. According to the invention, chitosan is pre-modified, and then is further modified by using a functional substance, so that the modified chitosan is obtained. The invention has the advantages of simple raw materials, mild reaction conditions and strong operability, and the prepared modified chitosan is green and environment-friendly, has excellent solubility and antibacterial performance, and can be widely applied to the fields of medicines, foods, textiles, water treatment and the like.
Description
Technical Field
The invention relates to the technical field of chitosan modification, in particular to modified chitosan and a preparation method thereof.
Background
Chitin is a natural nitrogenous polysaccharide with wide sources and abundant reserves in nature, and has the characteristics of good biocompatibility, degradability and the like. Chitosan is a deacetylated product of chitin under alkaline conditions, namely deacetylated chitin, also called soluble chitin and chitosan, has a chemical name of beta- (1,4) -2-amino-2-deoxy-D-glucose, and is the only natural alkaline polysaccharide in the nature. The chitosan has good biocompatibility, excellent antibacterial activity, biodegradability and low toxicity, and is widely applied to the fields of food, fruit and vegetable preservation, agriculture, textile industry, paper making, medical dressings, drug carriers, health care products, cosmetics and the like.
The chitosan has large molecular mass and contains a large amount of amino, hydroxyl and other groups, so strong hydrogen bonds are easily formed between molecules and in the molecules to bind the chitosan molecules, the molecular structure arrangement of the chitosan is more compact, the active groups are wrapped, the strong hydrogen bonds are easily formed in the molecules and between the molecules, the chitosan is hardly dissolved in water, alkaline solution, dilute sulfuric acid and dilute phosphoric acid solution, and the application of the chitosan is greatly limited due to poor solubility. The chitosan can be used for preparing other functionalized chitosan, so that the application performance of the chitosan is improved, the application range is widened, and the application range is wider.
The chitosan has a complex double-spiral structure, a linking unit contains a large number of amino groups, hydroxyl groups and other groups, the chemical properties of the groups are relatively active, the groups have good reaction activity, the active groups can be used for carrying out quaternization, carboxymethylation, etherification, hydrolysis, acylation, oxidation, sulfonation, crosslinking, complexation and other chemical modifications on chitosan molecules, and other groups are introduced to reduce the crystallinity of the chitosan, so that the solubility of the chitosan can be greatly improved on the premise of keeping the physical and chemical properties of the chitosan, new biological activity can be endowed to the chitosan, and the chitosan can have wider application.
The invention patent of application No. 202010374881.9 discloses a modified chitosan and a preparation method thereof, belonging to the technical field of chitosan modification. The method adopts ionic liquid as a reaction medium, combines lipase catalysis to synthesize long-chain chitosan; the ionic liquid is imidazole ionic liquid or glycine ionic liquid. The ionic liquid is used as a reaction solvent and a catalyst, has good solubility on chitosan, and can be used as a chitosan solvent; in addition, the ionic liquid can be used as an auxiliary catalyst and can simultaneously catalyze the esterification reaction with the lipase, and the ionic liquid is mild in property and very suitable for the reaction process in which the lipase participates. The long-chain chitosan prepared by the method has high degree of substitution which is close to 4.0, can increase the application range of the modified chitosan, and has good practicability. Although the chitosan prepared by the method has higher substitution degree, the chitosan has no effect on improving the solubility and the antibacterial performance, and is not beneficial to the wide application of the modified chitosan.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides modified chitosan and a preparation method thereof.
In order to solve the technical problems, the invention adopts the technical scheme that:
a preparation method of modified chitosan comprises the following steps:
adding 8-15 parts by weight of chitosan into 180-220 parts by weight of reducing solution, heating at 60-80 ℃, stirring at the rotation speed of 1000rpm for 15-40min, then adding 30-50 parts by weight of aldehyde, continuously stirring at 60-80 ℃ for 4-6d, after the reaction is finished, adjusting the pH value to 10-12 by using 0.5-2mol/L sodium hydroxide aqueous solution, filtering, washing the product, dispersing into hydrochloric acid with the pH value of 3-5, filling into a dialysis bag for dialysis, and after 2-4d, freeze-drying the dialysate in the dialysis bag to obtain the modified chitosan.
Firstly, reacting amino of chitosan with aldehyde, and then reducing a reaction product by using a reducing agent to obtain N-alkylated modified chitosan, wherein compared with the original chitosan, intermolecular hydrogen bonding action is weakened, rigidity is reduced, and the solubility after modification is improved; in addition, the molecular weight of the modified chitosan is increased, and the antibacterial effect of the modified chitosan is improved.
Further, the preparation method of the modified chitosan comprises the following steps:
1) adding 8-15 parts by weight of chitosan into 180-220 parts by weight of reducing solution, heating at 60-80 ℃, stirring at the rotation speed of 1000rpm for 15-40min, then adding 30-50 parts by weight of aldehyde, continuously stirring at 60-80 ℃ for 4-6d, after the reaction is finished, adjusting the pH value to 10-12 by using 0.5-2mol/L sodium hydroxide aqueous solution, filtering, washing the product, dispersing into hydrochloric acid with the pH value of 3-5, filling into a dialysis bag for dialysis, and after 2-4d, freeze-drying the dialysate in the dialysis bag to obtain pre-modified chitosan;
2) adding 2-5 parts by weight of the pre-modified chitosan obtained in the step 1) into a mixed solution consisting of 70-100 parts by weight of N-methyl pyrrolidone and 15-30 parts by weight of water, heating at 50-70 ℃, stirring at the rotating speed of 800-plus 1500rpm for 40-90min, then adding 1-3 parts by weight of a functional substance, continuing heating and stirring for 5-8h, cooling to room temperature after the completion, adding 50-90 parts by weight of acetone, uniformly mixing, centrifuging, taking a bottom precipitate, washing, and drying to obtain the modified chitosan.
The reducing liquid is formed by mixing 20-40 parts by weight of reducing agent and 150-200 parts by weight of water.
The reducing agent is any one of sodium borohydride, sodium cyanoborohydride or formic acid.
Preferably, the reducing agent is formic acid.
Compared with the prior art in which sodium borohydride is used as a reducing agent, the invention adopts formic acid as the reducing agent, and the following two reasons may exist: on one hand, the formic acid can allow the chitosan to be dissolved in the aqueous solution under the condition of not using acetate buffer solution, so that the raw material cost is saved, and the experimental steps are reduced; on the other hand, the reducibility of formic acid is mild, so that alkylation modification can be promoted to mainly occur on N in C2 amino, O-methylation at C6 position is avoided, chain scission of grafted N-acetyl is prevented, the alkylation modified chitosan which does not contain O-methylation groups and has high grafting rate is generated, hydrogen bonds among chitosan molecules are weakened, the regular arrangement of the chitosan molecules is influenced, the rigidity of the chitosan is reduced, and the solubility of the chitosan is promoted to be increased.
The aldehyde is any one of formaldehyde, benzaldehyde or salicylaldehyde.
The functional substance is one or more of chlorosulfonic acid, 1, 3-propane sultone and trimethylamine sulfur trioxide.
Preferably, the functional substance is a mixture of chlorosulfonic acid and 1, 3-propane sultone, wherein the mass ratio of chlorosulfonic acid to 1, 3-propane sultone is 1 (1-3).
The method adopts chlorosulfonic acid and 1, 3-propane sultone as functional substances together to carry out further functional modification on the pre-modified chitosan, and mainly adopts chlorosulfonic acid and 1, 3-propane sultone as sulfonation reagents, so that the pre-modified chitosan can be further sulfonated and modified, the grafted sulfonic group is a hydrophilic group, the solubility of the chitosan can be effectively improved, and the degree of molecular aggregates formed by intermolecular hydrogen bonds of chitosan molecules in a solution is reduced; meanwhile, chlorosulfonic acid has strong oxidizing property, can be used as sulfonation sites for hydroxyl groups at C3 and C6 on chitosan molecules, introduces sulfonic acid groups, and 1, 3-propane sultone can be subjected to sulfonation reaction with secondary amine at C2 on pre-modified chitosan molecules, introduces sulfonic acid groups, and effectively improves the sulfonation rate of chitosan under the combined action of the two, and promotes the improvement of the solubility and antibacterial property of chitosan.
The modified chitosan prepared by the invention has obviously improved solubility, and the main possibility is that the original crystal structure of the chitosan is damaged due to the introduction of sulfonic acid groups, the hydrogen bond acting force among C2, C3 and C6 is weakened, and the regular arrangement of chitosan molecules is damaged, so that the rigidity of the chitosan is reduced, and the solubility of the chitosan is greatly improved.
The modified chitosan prepared by the invention has excellent antibacterial performance, and the antibacterial mechanism is supposed to be as follows: 1) the modified chitosan has smaller particle size and large specific surface area, and the number of thalli which can be effectively adsorbed on the surface of the chitosan is increased, thereby being beneficial to the improvement of antibacterial performance; 2) sulfonic acid group (RSO) contained in modified chitosan molecule3 -) Has negative charge, and can react with metal ions (such as Ca) essential for thallus growth2+) Chelation, which causes the thallus to be unable to synthesize some metalloenzyme necessary for growth, thereby inhibiting the growth of the thallus; 3) because the dimethyl group is introduced to the chitosan structure, the positive charge density on amino can be increased, and the chitosan can be better adsorbed on the surface of the thallus by combining with the negative charge on the surface of the thallus cell membrane to form a compact membrane, so that the transportation of nutrient substances is blocked, and thallus metabolism disorder is caused, thereby achieving the purpose of inhibitingThe growth effect of the bacteria is controlled.
Further, the modified chitosan can be used in the fields of food preservation, water purification, textile antibiosis and the like.
The invention has the beneficial effects that: the invention has the advantages of simple raw materials, mild reaction conditions and strong operability, and the prepared modified chitosan is green and environment-friendly, has excellent solubility and antibacterial performance, and can be widely applied to the fields of medicines, foods, textiles, water treatment and the like.
Detailed Description
The above summary of the present invention is described in further detail below with reference to specific embodiments, but it should not be understood that the scope of the above subject matter of the present invention is limited to the following examples.
Introduction of some raw materials in this application:
chitosan, CAS No.: 9012-76-4, degree of deacetylation: 90%, viscosity: 50-200 mPas, supplied by Kaga Biotech, Suzhou.
Example 1
A preparation method of modified chitosan comprises the following steps:
adding 10 parts by weight of chitosan into 200 parts by weight of reducing solution, heating at 70 ℃, stirring at 800rpm for 30min, then adding 40 parts by weight of salicylaldehyde, continuing stirring at 70 ℃ for 5d, after the reaction is finished, adjusting the pH value to 11 by using 1mol/L sodium hydroxide aqueous solution, filtering, washing the product, then dispersing into hydrochloric acid with the pH value of 4, filling into a dialysis bag for dialysis, and after 3d, freeze-drying the dialysate in the dialysis bag to obtain the modified chitosan.
The reducing solution is prepared by mixing 30 parts by weight of sodium borohydride and 180 parts by weight of water.
Example 2
A preparation method of modified chitosan comprises the following steps:
adding 10 parts by weight of chitosan into 200 parts by weight of reducing solution, heating at 70 ℃, stirring at 800rpm for 30min, then adding 40 parts by weight of salicylaldehyde, continuing stirring at 70 ℃ for 5d, after the reaction is finished, adjusting the pH value to 11 by using 1mol/L sodium hydroxide aqueous solution, filtering, washing the product, then dispersing into hydrochloric acid with the pH value of 4, filling into a dialysis bag for dialysis, and after 3d, freeze-drying the dialysate in the dialysis bag to obtain the modified chitosan.
The reducing solution is prepared by mixing 30 parts by weight of formic acid and 180 parts by weight of water.
Example 3
A preparation method of modified chitosan comprises the following steps:
1) adding 10 parts by weight of chitosan into 200 parts by weight of reducing solution, heating at 70 ℃ and stirring at 800rpm for 30min, then adding 40 parts by weight of salicylaldehyde, continuously stirring at 70 ℃ for 5d, after the reaction is finished, adjusting the pH value to 11 by using a 1mol/L sodium hydroxide aqueous solution, filtering, washing the product, dispersing the product into hydrochloric acid with the pH value of 4, putting the hydrochloric acid into a dialysis bag for dialysis, and after 3d, freeze-drying the dialysate in the dialysis bag to obtain pre-modified chitosan;
the reducing solution is prepared by mixing 30 parts by weight of formic acid and 180 parts by weight of water;
2) adding 3 parts by weight of the pre-modified chitosan obtained in the step 1) into a mixed solution consisting of 80 parts by weight of N-methyl pyrrolidone and 20 parts by weight of water, heating at 60 ℃, stirring at the rotating speed of 1000rpm for 60min, then adding 2 parts by weight of 1, 3-propane sultone, continuing heating and stirring for 6h, cooling to room temperature after the stirring is finished, adding 60 parts by weight of acetone, uniformly mixing, centrifuging, taking a bottom precipitate, washing, and drying to obtain the modified chitosan.
Example 4
A preparation method of modified chitosan comprises the following steps:
1) adding 10 parts by weight of chitosan into 200 parts by weight of reducing solution, heating at 70 ℃ and stirring at 800rpm for 30min, then adding 40 parts by weight of salicylaldehyde, continuously stirring at 70 ℃ for 5d, after the reaction is finished, adjusting the pH value to 11 by using a 1mol/L sodium hydroxide aqueous solution, filtering, washing the product, dispersing the product into hydrochloric acid with the pH value of 4, putting the hydrochloric acid into a dialysis bag for dialysis, and after 3d, freeze-drying the dialysate in the dialysis bag to obtain pre-modified chitosan;
the reducing solution is prepared by mixing 30 parts by weight of formic acid and 180 parts by weight of water;
2) adding 3 parts by weight of the pre-modified chitosan obtained in the step 1) into a mixed solution composed of 80 parts by weight of N-methyl pyrrolidone and 20 parts by weight of water, heating at 60 ℃, stirring at the rotating speed of 1000rpm for 60min, then adding 2 parts by weight of chlorosulfonic acid, continuing heating and stirring for 6h, cooling to room temperature after the completion, then adding 60 parts by weight of acetone, uniformly mixing, centrifuging, taking a bottom precipitate, washing, and drying to obtain the modified chitosan.
Example 5
A preparation method of modified chitosan comprises the following steps:
1) adding 10 parts by weight of chitosan into 200 parts by weight of reducing solution, heating at 70 ℃ and stirring at 800rpm for 30min, then adding 40 parts by weight of salicylaldehyde, continuously stirring at 70 ℃ for 5d, after the reaction is finished, adjusting the pH value to 11 by using a 1mol/L sodium hydroxide aqueous solution, filtering, washing the product, then dispersing the product into 1mol/L hydrochloric acid with the pH value of 4, filling the product into a dialysis bag for dialysis, and after 3d, freeze-drying the dialysate in the dialysis bag to obtain pre-modified chitosan;
the reducing solution is prepared by mixing 30 parts by weight of formic acid and 180 parts by weight of water;
2) adding 3 parts by weight of the pre-modified chitosan obtained in the step 1) into a mixed solution composed of 80 parts by weight of N-methylpyrrolidone and 20 parts by weight of water, heating at 60 ℃, stirring at 1000rpm for 60min, then adding 2 parts by weight of a functional substance, continuing to heat and stir for 6h, cooling to room temperature after the completion, adding 60 parts by weight of acetone, uniformly mixing, centrifuging, taking a bottom precipitate, washing, and drying to obtain the modified chitosan.
The functional substance is a mixture of chlorosulfonic acid and 1, 3-propane sultone, wherein the mass ratio of chlorosulfonic acid to 1, 3-propane sultone is 1: 2.
Test example 1
Evaluation of antibacterial property:
(1) adding the modified chitosan prepared in each example into water to prepare a modified chitosan solution with the concentration of 1 wt%, and sterilizing at 120 ℃ for 20 min;
(2) respectively adding Escherichia coli and Staphylococcus aureus into culture medium containing peptone 1g, yeast extract 0.5g, NaCl 1g, and water 100mL with pH 7.5, sterilizing at 120 deg.C for 20min, and keeping the concentration of the bacteria liquid in the culture medium at 106CFU/mL；
(3) Selecting filter paper with strong water absorbability, punching into a plurality of circular filter paper sheets with the diameter of 6mm by using a puncher, and sterilizing for 2h by using an ultraviolet sterilizing lamp;
(4) and (3) respectively soaking the sterilized filter paper sheets in the modified chitosan solution prepared in each example in the step (1), then pasting the filter paper sheets in the culture medium prepared in the step (2), finally culturing at 36 ℃ for 24h, taking out the filter paper sheets, and measuring the diameter of the inhibition zone.
Each set of samples was tested in parallel five times and the test results averaged.
TABLE 1 results of the bacteriostatic properties test
From the above results, it can be seen that the antibacterial performance of the modified chitosan prepared in example 2 is significantly increased compared to that of example 1, probably because the reducibility of formic acid is mild, so that the alkylation modification mainly occurs on N in the amino group at C2, the O-methylation at C6 is avoided, the chain scission of the grafted N-acetyl group is prevented, and the alkylated modified chitosan which does not contain O-methylated groups and has high grafting ratio is generated, which is beneficial to the increase of antibacterial performance. The antibacterial performance of example 3 is obviously better than that of example 2, and the main possibility is that 1) the modified chitosan molecule contains a large number of sulfonic acid groups (RSO) with negative charges3 -) It can be combined with metal ions (such as Ca) necessary for growth of thallus2+) Chelation, which causes the thallus to be unable to synthesize some metalloenzyme necessary for growth, thereby inhibiting the growth of the thallus; 2) because the dimethyl group is introduced to the chitosan structure, the positive charge density on the amino group can be increased, and the chitosan can be combined with the negative charge on the cell membrane surface of the thallus, so that the chitosan can be better absorbedAttached to the surface of the thallus to form a compact film, which blocks the transportation of nutrient substances and causes thallus metabolism disorder, thereby achieving the effect of inhibiting the growth of the thallus and promoting the promotion of antibacterial performance.
Compared with the method in which chlorosulfonic acid and 1, 3-propane sultone are adopted separately in examples 3 and 4, the antibacterial performance of example 5 is further increased, and chlorosulfonic acid and 1, 3-propane sultone are both used as sulfonation reagents, so that sulfonation modification can be further realized on the pre-modified chitosan, chlorosulfonic acid has strong oxidizing property, hydroxyl groups at positions C3 and C6 on a chitosan molecule can be used as sulfonation sites, and sulfonic acid groups are introduced, while 1, 3-propane sultone can perform sulfonation reaction with secondary amine at position C2 on the pre-modified chitosan molecule, and the sulfonic acid groups are introduced, so that the sulfonation rate of the chitosan is effectively improved, and the improvement of the antibacterial performance of the chitosan is promoted under the combined action of the chlorosulfonic acid and the 1, 3-propane sultone.
Test example 2
Evaluation of solubility: the modified chitosan prepared in each example was dispersed in 2mL of water until precipitation ceased, and the weight of the added modified chitosan was recorded as m0Centrifuging at 4000rpm at room temperature for 10min, collecting the bottom precipitate, freeze drying, and recording the weight as m1. The solubility was evaluated by the solubility, the greater the solubility, the better the solubility. The solubility was calculated using the following formula:
solubility (mg/mL) ═ m0-m1)/2
Each set of samples was tested in parallel five times and the test results averaged.
Table 2 dissolution property test results
| Solubility (mg/mL) | |
| Example 1 | 12.48 |
| Example 2 | 13.65 |
| Example 3 | 15.81 |
| Example 4 | 15.74 |
| Example 5 | 16.93 |
From the results, the solubility of the modified chitosan prepared by using formic acid as a reducing agent in example 2 is superior to that of example 1, and the formic acid can allow the chitosan to be dissolved in an aqueous solution without using an acetate buffer solution on one hand, so that the raw material cost is saved, and the experimental steps are reduced; on the other hand, the reducibility of formic acid is mild, so that alkylation modification can be promoted to mainly occur on N in C2 amino, O-methylation at C6 position is avoided, chain scission of grafted N-acetyl is prevented, the alkylation modified chitosan which does not contain O-methylation groups and has high grafting rate is generated, hydrogen bonds among chitosan molecules are weakened, the regular arrangement of the chitosan molecules is influenced, the rigidity of the chitosan is reduced, and the solubility of the chitosan is promoted to be increased. Compared with the example 2, the dissolution performance of the example 3 is obviously improved, mainly probably because the original crystal structure of the chitosan is damaged due to the introduction of the sulfonic acid group, the hydrogen bond acting force among C2, C3 and C6 is weakened, and the regular arrangement of chitosan molecules is damaged, so that the rigidity of the chitosan is reduced, and the dissolution performance of the chitosan is greatly improved. The solubility of the chitosan in the embodiment 5 is better than that of the embodiment 3 and 4, and mainly, chlorosulfonic acid and 1, 3-propane sultone are used as functional substances together, a large amount of hydrophilic groups, namely sulfonic groups, are continuously grafted on the surface of the pre-modified chitosan, chlorosulfonic acid can introduce sulfonic groups into the positions of C3 and C6 on chitosan molecules, 1, 3-propane sultone can introduce sulfonic groups into the position of C2 on the chitosan molecules, and the sulfonation rate of the chitosan is effectively improved under the combined action of the chlorosulfonic acid and the sulfonic groups, so that the degree of molecular aggregates formed by intermolecular hydrogen bonds of the chitosan molecules in the solution is reduced, and the solubility of the chitosan is effectively improved.
Claims (9)
1. The preparation method of the modified chitosan is characterized by comprising the following steps:
adding 8-15 parts by weight of chitosan into 220 parts by weight of reducing solution 180-40 min, heating and stirring for 15-40min, then adding 30-50 parts by weight of aldehyde, continuing stirring, adjusting the pH value to 10-12 after the reaction is finished, filtering, washing the product, then dispersing the product into hydrochloric acid with the pH value of 3-5, filling the hydrochloric acid into a dialysis bag for dialysis, and freeze-drying the dialysate in the dialysis bag to obtain the modified chitosan.
2. The method for preparing modified chitosan according to claim 1, comprising the steps of:
1) adding 8-15 parts by weight of chitosan into 220 parts by weight of reducing solution 180-180 parts by weight, heating and stirring for 15-40min, then adding 30-50 parts by weight of aldehyde, continuing stirring, after the reaction is finished, adjusting the pH value to 10-12, filtering, washing the product, then dispersing the product into hydrochloric acid with the pH value of 3-5, filling the hydrochloric acid into a dialysis bag for dialysis, and freeze-drying the dialysate in the dialysis bag; obtaining pre-modified chitosan;
2) adding 2-5 parts by weight of the pre-modified chitosan obtained in the step 1) into the mixed solution, heating and stirring, then adding 1-3 parts by weight of the functional substance, continuing to heat and stir, cooling to room temperature after the heating and stirring are finished, then adding 50-90 parts by weight of acetone, uniformly mixing, centrifuging, taking the bottom precipitate, washing, and drying to obtain the modified chitosan.
3. The method of claim 2, wherein the mixture solution comprises 70 to 100 parts by weight of N-methylpyrrolidone and 15 to 30 parts by weight of water.
4. The method of claim 1 or 2, wherein the reducing solution is prepared by mixing 20-40 parts by weight of reducing agent and 150-200 parts by weight of water.
5. The method of claim 4, wherein the reducing agent is any one of sodium borohydride, sodium cyanoborohydride, or formic acid.
6. The method of claim 1 or 2, wherein the aldehyde is any one of formaldehyde, benzaldehyde, or salicylaldehyde.
7. The method of claim 2, wherein the functionalized compound is one or more of chlorosulfonic acid, 1, 3-propane sultone, and trimethylamine sulfur trioxide.
8. A modified chitosan obtained by the production method as claimed in any one of claims 1 to 7.
9. The application of the modified chitosan is characterized by being applied to the fields of food preservation, water body purification, textile antibiosis and the like.
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| CN101230109A (en) * | 2007-12-24 | 2008-07-30 | 河北科技师范学院 | Sulfonated acylation 6-carboxyl chitosan as well as salt and preparation method thereof |
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| CN101230109A (en) * | 2007-12-24 | 2008-07-30 | 河北科技师范学院 | Sulfonated acylation 6-carboxyl chitosan as well as salt and preparation method thereof |
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