Electrochemical method of purifying chondroitin sulphate
SUBSTANCE: invention relates to a method of purifying chondroitin sulphate and can be used in food and cosmetic industry and in medicine. The method involves electrochemical deposition to obtain a hydrogel of chondroitin sulphate, stabilisation, removal from the electrode, washing and drying. The chondroitin sulphate is dissolved in a 0.01-0.1 n alkali solution in ratio of 1:50-1:200 and deposited in an alkaline medium with constant cooling and stirring. The solution is stirred at a rate of 10-20 rpm. Current density is equal to 1-10 A/m2. Voltage is preferably not lower than 2.7 V. The hydrogel of chondroitin sulphate is stabilised in a 0.05-0.5 n HCl solution.
EFFECT: invention enables to obtain chondroitin sulphate with high weight ratio of the basic substance and increases output of the end product.
5 cl, 1 ex
The invention relates to methods of producing, or rather the purification of chondroitin sulfate derived from the tissues of marine organisms, such as cartilage fish, muscle-muscular bag molluscs etc, and can be used in food, cosmetic industry, medicine.
The basic properties of chondroitin sulfate that are crucial for its successful application in various fields such as high bioavailability, biocompatibility, low toxicity, ability to selective accumulation in cartilage (Kofuji K, Ito T., Murata Y., Kawashima S. Effect of chondroitin sulfate on the biodegradation and drug release of chitosan gel beads in the subcutaneous air pouches of mice // Biological and Pharmaceutical Bulletin. - 2002. - Vol.25, No.2. - P.268-271). These properties are determined by the chemical structure of the molecules of chondroitin sulfate, namely, molecular weight, degree and location of sulfation. (Michelacci Y.M., Dietrich S.R. Structure of chondroitin sulphate from whale cartilage: distribution of 6 - and 4-sulphated oligosaccharides in the polymer chains // International Journal of Biological Macromolecules. - 1986. - Vol.8, No.2. - P.108-113. Toida T., Amomrut C., Linhardt R.J., Structure and bioactivity of sulfated polysaccharides // Trends in Glycoscience and Glycotechnology. - 2003. - Vol.15, No.81. - P.29-46).
A known method of purification of chondroitin sulfate (CS), providing for the dissolution of chondroitin sulfate in an alkaline environment, the enzymatic hydrolysis of proteins, separation of high molecular weight carbohydrate fraction by precipitation from low molecular weight is of Reducto protein hydrolysis, remaining in the solution, washing the obtained precipitate and drying the finished product (Takai M., Kono H. Salmon-origin chondroitin sulfate: European Patent EP 1270599. IPC AC 31/737. - Appl. 15.12.2000; No. EP 20000981747; Publ. 02.01.2003).
This conventional technology is implemented by different authors in different ways: changing the sequence, the number of operations, temperature, nature and concentration of reagents used.
Known isolation and purification of cholesterol, which consists in the hydrolysis of the feedstock and subsequent precipitation of cholesterol from the hydrolysate by adding ethyl alcohol (U.S. Pat. Of the Russian Federation. No. 2056851, publ. 27.03.1996; Pat the Russian Federation No. 2061485, publ. 10.06.1998; U.S. Pat. Of the Russian Federation No.. 2383351, publ. 10.03.2010). The disadvantages of the method are the following. Requires a large consumption of ethyl alcohol, and the necessity of regeneration. In addition, the precipitation is not complete, so a considerable part of the cholesterol remains in solution.
A known method of purification of polysaccharide based on the electrochemical deposition of the polysaccharide from the solution (U.S. Pat. U.S. No. 7883615, publ. 08.02.2011). In the discharge of negatively charged molecules of the polysaccharide, in particular chitosan, occurs at the anode deposition of the polysaccharide in the form of a hydrogel. The resulting product is subsequently removed from the electrode, washed in distilled water and dried. This method is most similar to that proposed and adopted for the prototype. Spoopendyke to obtain films of polysaccharide for further use as cards in the production of biosensors. Electrochemical deposition method prototype is carried out in an acidic environment (PH=5.0-5.5, the current density is high and ranges from 20 to 100 a/m2the duration of the electrochemical deposition is 2-30 minutes Stabilization hydrogel of a polysaccharide is carried out in an alkaline environment (rather basic solution).
Object of the present invention to provide CHS with increased mass fraction of the primary substance, i.e. increasing the degree of purification of the target product.
It is solved in an electrochemical method of purification of chondroitin sulfate, which provides for electrochemical deposition of obtaining hydrogel XC, stabilization, removal from the electrode, rinse and drying, XC is dissolved in a solution of 0.01-0.1 n alkali in the ratio of 1:50-1:200 and conduct electrochemical deposition in an alkaline medium at a constant cooling and stirring the solution with a speed of 10-20 rpm, current density of 1-10 a/m2, the voltage required to precipitation, stabilization hydrogel XC is carried out in a solution of 0.05-0.5 n Hcl. The voltage of electrochemical deposition is not less than 2.7 V, and the deposition time from 2 to 60 min, depending on the purity of the original CS, the drying of the hydrogel XC carried out first in air and then in a drying Cabinet at a temperature not exceeding 60°C. the Cooled reaction mixture is performed proto is Noah water with a temperature of 4°C-15°C.
Electrochemical deposition is carried out in an alkaline medium, pre-dissolved source CS in 0,01-0,10 n solution of alkali, such as NaOH or another. Dissolution of cholesterol in alkali and conducting electrochemical deposition in an alkaline environment due to the fact that it dissolves much better in alkaline than in acidic or neutral media, therefore the cleanup process will be more complete. The mass ratio chondrotin sulfate and alkali solution is from 1:50 to 1:200 (concentration of cholesterol in the solution is from 0.5 to 2.0%). The resulting solution is poured into the electrolytic cell.
The cell consists of a container (glass or plastic Cup), which houses the electrodes and mixing device. The anode is made in the form of a cylinder, located at the side walls of the container, the cathode is in the form of a Central rod. Between the cathode and the anode is rotating mixer, which is made either in the form of frames or blades, the axis of which is inclined at an angle to the horizontal plane of the vessel.
For cooling the reaction mixture, the tank is provided with a cooling device in the form of the external jacket in which cooling water is supplied. For cooling capacity may be immersed in a vessel with a flowing cooling water or liquid thermostat. The cooling water temperature from 4 to 15°C. Cooling is necessary for more than the full deposition of hydrogel XC pole.
The electrodes serves a DC voltage of not less than 2.7 V, when the voltage is lower than 2.7 In deposition on the electrode will not occur. The current density is from 1 to 10 a/m2this density is quite enough for the process. High current density causes a significant release of heat that will not contribute to a more complete cholesterol deposition on the electrode.
The electrolysis is carried out at constant slow 10-20 rpm stirring of the solution between the electrodes during the whole process of electrochemical deposition, i.e. 2-60 minutes of Slow mixing helps to include in the electrochemical deposition of the entire volume of the solution in the cell, mixing the same with a speed of more than 20 rpm will break deposited on the electrode hydrogel XC.
At the end of the electrolysis, the voltage from the electrodes are removed, a cylindrical electrode with the deposited hydrogel XC transferred into the vessel with distilled water and wash out within 1-5 minutes
Then the electrode with the deposited hydrogel XC transferred into the vessel from 0.05-0.5 n Hcl for the final formation of the precipitate, i.e. they perform the stabilization of the formed hydrogel is then washed with distilled water.
The wet gel is cut from the surface of the electrode is dried first in air and then in a drying Cabinet at a temperature not exceeding 60°C.
Obtained the product is crushed in the device of any design.
A portion of the original XC 5.0 g was dissolved in 500 ml of 0.05 n NaOH solution (or other alkali) and filled in the electrolytic cell.
The electrolytic cell consisted of a glass, which is a cylindrical anode and a cathode in the form of a Central rod. The electrodes are made of stainless steel. Between the cathode and the anode is placed a rotating anchor agitator.
For cooling the reaction mixture, the cell was placed in a tank with running water. The cooling water temperature was 8°C.
The electrodes were applied constant voltage of 2.7 Century, the Current in the electrolyte was 2.5 a/m2.
The electrolysis is carried out at constant slow 20 rpm stirring of the solution between the electrodes for 10 minutes
At the end of the electrolysis the voltage from the electrodes are removed. A cylindrical electrode with the deposited gel chondroitin transferred into the vessel with distilled water and wash out within 1-5 minutes
Then a cylindrical electrode with the deposited gel XC is transferred into a vessel with 0.1 n Hcl for the final formation of the precipitate (stabilization), then washed with distilled water.
The wet gel is cut from the surface of the electrode and dried in air and then in a drying Cabinet at a temperature not exceeding 60°C.
The resulting product is pulverized in a mortar.
Output XC was 4.3 g, i.e. 86%.
The image is a buy allows you to get the drug chondroitin sulfate with increased mass fractions of the basic substance, and to increase the yield of the target product.
1. Electrochemical method of purification of chondroitin sulfate, including electrochemical deposition with obtaining hydrogel chondroitin sulfate (CS), stabilization, removal from the electrode, washing, drying, wherein XC is dissolved in a solution of 0.01-0.1 n alkali in the ratio of 1:50-1:200 and conduct electrochemical deposition in an alkaline medium at a constant cooling and stirring the solution with a speed of 10-20 rpm, current density of 1-10 a/m2, the voltage required for the deposition of cholesterol, stabilize the hydrogel XC is carried out in a solution of 0.05-0.5 n Hcl.
2. The method according to claim 1, characterized in that the voltage of electrochemical deposition is not less than 2.7 Century
3. The method according to claim 1, characterized in that the dried hydrogel XC first in air and then in a drying Cabinet at a temperature not exceeding 60°C.
4. The method according to claim 1, characterized in that the time of electrochemical deposition ranges from 2 to 60 min, depending on the initial purity XC.
5. The method according to claim 1, characterized in that the cooling is carried out by flowing water with temperatures ranging from 4°C to 15°C.
SUBSTANCE: present invention relates to a method of producing a N,S-cyclo-containing chitosan derivative. Described is a method of producing a chitosan-based N,S-cyclo-containing polymer (I) which contains in the macrochain 1-oxa-6-thia-4,8-diazocycloundecane fragments: I, by reacting chitosan with formaldehyde and a S-containing compound, characterised by that the S-containing compound used is hydrogen sulphide, the formaldehyde solution is pre-saturated with H2S and the reaction is carried out with molar ratio chitosan: formaldehyde: hydrogen sulphide of 1:2:1, at temperature of 0-60°C in a chloride medium for 24 hours.
EFFECT: obtaining modified chitosan which exhibits properties of a highly efficient heavy metal sorbent for waste water treatment, an extractant for separating rare, noble and precious metals and a complexing agent for biological molecules.
1 tbl, 3 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to biochemistry. What is presented is a conjugate of hyaluronic acid and novocaine of a structure as defined in the patent claim containing 20-50% residues of novocaine.
EFFECT: conjugate is water-soluble; it possess the amphoteric properties and contains no side O-acylisourea.
3 tbl, 3 ex
SUBSTANCE: disclosed are versions of a method of producing cross-linked polysaccharides, involving reaction of at least one polysaccharide selected from amino-polysaccharide, amino-functionalised polysaccharide containing one or more amino groups which can be cross-linked by reducing sugar, and combinations thereof, with at least one reducing sugar. The invention also discloses polysaccharides obtained using the disclosed method, a method of producing cross-linked matrices based on polysaccharides and matrices obtained using this method. The obtained matrices may include polysaccharide matrices and composite cross-linked matrices, including polysaccharides cross-linked with proteins and/or polypeptides.
EFFECT: obtained polysaccharides have satisfactory resistance to enzymatic degradation coupled with rheological properties of the preparation for injection, obtained matrices exhibit various physical, chemical and biological properties.
29 cl, 12 dwg, 6 tbl, 11 ex
SUBSTANCE: chitosan is dissolved in an organic acid: 4-6% citric acid or 2-8% lactic acid in the relation of the ingredients chitosan: the organic acid 1:2-1:4 to prepare a forming solution. Chitosan has molecular weight 80-500 kDa. The forming solution is added with vitamin B1 in the amount of max. 0.5 wt %. The prepared forming solution is applied on a substrate in the amount of 0.2-0.25 ml/cm2 and kept to achieve a film structure. Said method is used to form the chitosan film coating having the thickness of 50-250 mcm and the breaking elongation of 42 to 470%.
EFFECT: group of inventions allows preparing high-elastic chitosan citrate or lactate films possessing bactericidal action.
2 cl, 1 tbl, 13 ex
SUBSTANCE: method involves preparation of material for enzymatic hydrolysis. Alkaline hydrolysis is carried out with proteolytic enzyme preparations with neutralisation of the obtained solution to pH=7. A salt is added to the obtained enzymatic hydrolysate to a value of not less than 0.1 mol/l. Successive ultrafiltration is carried out, first on a membrane with maximum retention of 50 kD with separation of high-molecular weight impurities, and then on a membrane with maximum retention of 5 kD with separation of low-molecular weight substances. The chondroitin sulphate solution retained at the membrane is washed on the same membrane with distilled water until complete removal of salts. Final washing with distilled water is carried out on a membrane with maxim retention of 50 kD.
EFFECT: invention enables to obtain a chondroitin sulphate preparation with weight ratio of the basic substance.
SUBSTANCE: method involves activation of hyaluronic acid using a cross-linking agent and an auxiliary cross-linking agent. The activated hyaluronic acid then reacts with a nucleophilic cross-linking agent. The pH of the reaction medium ranges from 8 to 12. The nucleophilic cross-linking agent contains at least 50 wt % oligopeptide or polypeptide. Further, pH of the reaction medium is regulated to 5-7 and cross-linked hyaluronic acid is precipitated in the organic solvent. The invention also relates to use of the cross-linked hyaluronic acid obtained using this method in plastic surgery to make implants and to a hedrogel containing said cross-linked hyaluronic acid in a buffer aqueous solvent.
EFFECT: invention enables to obtain cross-linked hyaluronic acid in dry form, having high resistance to decomposition factors such as temperature, free radicals and enzymes.
18 cl, 3 tbl, 3 ex
SUBSTANCE: disclosed is a method of determining antibacterial properties of chitosan by estimating its minimum bacteriostatic and/or bactericidal concentration. Complex buffer solutions based on three organic acids MES, ACES and TES with different pH values are prepared. The ready buffer solutions are poured into a vessel. Double dilutions of chitosan are then prepared in vessels with the buffer solutions. Aliquots of a bacterial suspension in a fluid medium are added to the chitosan solutions in the buffer. The solutions are incubated for 24 hours at temperature which is optimum for bacterial growth. The minimum bacteriostatic and/or minimum bactericidal concentration of chitosan is then determined after incubation by determining growth of the culture or a drop in the number of living cells, respectively.
EFFECT: invention enables to determine antibacterial properties of chitosan in a wide pH range from 5,50 to 8,00 without the need to use buffers of different chemical composition.
5 dwg, 2 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to a method for preparing sodium salt of hyaluronic acid modified by boron compounds with no fluid medium added. The method consists in the fact that powdered sodium salt of hyaluronic acid together with a modifying agent and mixed modifying agents is pre-homogenised in a mixer at temperature ranging within 20° to 50°C; thereafter the prepared homogenous powder mixture is simultaneously exposed to pressure and shearing deformation in a mechanochemical reactor at temperature ranging within 20° to 50°C and pressure 5-1000 MPa.
EFFECT: invention provides preparing boron-containing sodium salt of hyaluronic acid applied in boron neutron capture therapy in one-stage process parameters with no fluid medium added which requires low power, labour and water consumptions.
13 cl, 15 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to medicine, more specifically to producing chitosan oligomers possessing biological activity and applicable in food industry and medicine. In a method for producing chitosan oligomers, a chitosan solution is taken in the concentration of 0.025-0.075% (weight/volume) and exposed to low-frequency ultrasound of the intensity of 92-460 Wt/cm2 for 5-30 minutes.
EFFECT: reduction in price of the chitosan oligomers production combined with promotion of higher medium viscosity molecular weight of the product within the range 25 ÷ 120 kDa.
3 tbl, 3 ex
SUBSTANCE: method involves preliminary acetylation of chitin with acetic anhydride, washing and drying the acetylated chitin in order to reduce degree of deacetylation thereof and, as a result, increase output of the desired product - D(+)-glucosamine hydrochloride when obtaining said product through hydrolysis of acetylated chitin with concentrated hydrochloric acid while heating, followed by evaporation, crystallisation, separation, washing and drying the desired product.
EFFECT: high output of the desired product while maintaining its high quality; method is more environmentally friendly since pre-treatment of chitin reduces the amount of processing wastes.
1 cl, 2 ex
FIELD: fish industry.
SUBSTANCE: method involves providing deacetylation of raw material with the use of preliminarily cooled alkaline solution; washing and drying. Deacetylation process is performed in three stages, first stage being performed for 7 days and subsequent two stages being performed for 2 hours each, combined with thermal processing at temperature of 55-590C. Washing process is provided after each deacetylation stage.
EFFECT: provision for producing of chitosan from chitin of cancerous with increased extent of deacetylation, while native properties of natural polymer being kept, without breaking of glycoside binding chain.
FIELD: organic chemistry.
SUBSTANCE: claimed method includes subsequent chitosane-containing raw material with non-polar liquefied gas, water, alkali, water, acid, water, alkali, and water to produce target product in form of solid residue, wherein in at least first extraction step pressure in reaction mixture is periodically released to provide extractant boiling, and than increased up to starting value.
EFFECT: method with reduced energy consumption.
FIELD: chemical technology of natural compounds.
SUBSTANCE: invention describes a method for preparing water-soluble derivatives of chitosan. Method involves treatment of chitosan with acid medium up to its swelling wherein vapor medium water-acid is used as acid medium. Treatment of chitosan is carried out with vapor of monobasic acid aqueous solution taken among the group including hydrochloric acid, formic acid and acetic acid. Method allows simplifying technology in preparing water-soluble derivatives of chitosan.
EFFECT: improved preparing method.
4 cl, 1 tbl, 9 ex
FIELD: chemistry and technology of derivatives of polysaccharides, chemical technology.
SUBSTANCE: invention relates to methods for preparing chitosan esters. Invention describes a method for preparing chitosan polyethylene glycol ester that involves dissolving chitosan in acetic acid followed by alkalization. Then the reaction mixture is subjected for effect of ethylene oxide under pressure 1-3 atm and temperature 60-100°C, and the concentration of reaction mass is corrected by addition of distilled water up to the density value of solution 1.030-1.032 g/cm3. Then the reaction mass is purified by electrodialysis at the rate value of solution in treatment chambers 3.0 cm/s, not less, temperature 20-45°C, the current density value 0.25-0.75 A/dm2 and the constant volume of the reaction mass. Method provides enhancing the effectiveness of purification by electrodialysis due to reducing energy consumptions. Chitosan esters can be used in medicine, cosmetics, food and chemical industry.
EFFECT: improved preparing method.
FIELD: organic chemistry of natural compounds, chemical technology, medicine.
SUBSTANCE: invention relates to the group of chitosan-containing compounds. Invention relates to synthesis of modified chitosan of the following structure: wherein n = 150-1400. The modified chitosan possesses the bactericidal activity, in particular, antituberculosis activity.
EFFECT: valuable medicinal properties of modified chitosan.
1 tbl, 1 dwg, 3 ex
FIELD: natural compounds technology.
SUBSTANCE: chitosan preparation process comprises breaking naturally occurring chitin-containing material, charging it into reactor, demineralization with 6-7% aqueous hydrochloric acid, deproteination with sodium hydroxide solution at 85-95°C, deacetylation with sodium hydroxide solution on heating, decoloration, and washing with water after each stage to pH 6.5. Process is characterized by that chitin-containing material broken to achieve fraction 0.5-6 mm is fed simultaneously into a number of reactors, wherein demineralization is effected with aqueous hydrochloric acid stream at 85-95°C for 1.5 h while controlling pH in each reactor exit to achieve acid concentration in each reactor exit the same as concentration of the initial acid by way of feeding it in a continuous manner. In addition, deproteination is carried out with 6-7% sodium hydroxide solution stream for 1.5 h followed by discharging treated material into autoclave to perform deacetylation simultaneously with decoloration using 50% sodium hydroxide solution at 130-140°C in inert gas environment and in presence of 3-5% hydrogen peroxide solution used in amount 3-5% of the total volume of mixture.
EFFECT: enhanced process efficiency.
FIELD: chemical technology.
SUBSTANCE: invention relates to methods for preparing water-soluble saline complexes (associates) of hyaluronic acid with d-metals of IV, V and VI periods of Mendeleyev's periodic system of elements that can be used in pharmacology and cosmetology. Invention describes a method for preparing water-soluble saline complexes of hyaluronic acid involving preparing an aqueous solution of salt of d-metal of IV, V and VI periods of periodic system and its mixing with hyaluronic acid sodium salt, holding the mixture, its stirring, dilution with water and isolation of the end product. For mixing method involves using the amount of aqueous salt of abovementioned d-metal that is equivalent to the amount of carboxy-groups of hyaluronic acid sodium salt or in the limit from 0.95 to 1.10. After dilution with water the solution mixture is subjected for ultrafiltration on separating membranes with simultaneous washing out with aqueous salt solution of abovementioned d-metal firstly and then with deionized water followed by concentrating the product. By another variant for mixing the method involves the amount of aqueous solution of d-metal salt lesser of the equivalent amount of carboxy-groups in hyaluronic acid sodium salt. After dilution with water the mixture is subjected for ultrafiltration on separating membranes with simultaneous washing out with deionized water followed by concentrating the product also. Method is characterized by the decreased time of processes and simplicity.
EFFECT: improved preparing method.
2 cl, 1 tbl
FIELD: medicine, food processing industry, in particular production of depolymerized chitosane and products based on the same.
SUBSTANCE: claimed method is based on using of chitosanase in acetic acid medium and spray drying of and depolymerized chitosane and is characterized in that obtained depolymerized chitosane is preliminary converted in non-ionized form by neutralizing of bound acetic acid with ammonium hydroxide followed by precipitation in ethanol and air drying. Further interaction is carried out with ammonium lipoate or glutathione in aqueous medium. Claimed products may be used individually or in combination with other components.
EFFECT: new products for food processing industry and medicine.
4 cl, 2 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for preparing modified glycosaminoglycans possessing analgesic properties. Method involves interaction of glycosaminoglycans with 1-phenyl-2,3-dimethyl-4-aminopyrazolone-5-(4-aminoantipyrine) in aqueous medium at pH = 4.7-4.8 in the presence water-soluble 1-ethyl-3-[3-(dimethlamino)propyl]carbodiimide as a condensing agent at room temperature followed by purification from low-molecular reagents. Method involves a single step that simplifies technology in preparing modified glycosaminoglycans.
EFFECT: improved preparing method.
FIELD: natural substances, chemical technology.
SUBSTANCE: invention relates to a method for preparing chitosan and purification from components of the reaction mixture - low-molecular products of deacetylation and alkali excess. Invention relates to a method for purifying chitosan prepared by solid-state method involving treatment of reaction mass with extractant consisting of 3.3-20.0% of water, 32.2-57.1% of ethyl acetate and 24.6-64.5% of ethanol at the extractant boiling point. Also, invention relates to a method for purifying chitosan prepared by suspension method and involving treatment of the reaction mass with ethyl acetate and the following treatment with extractant consisting of 6.2-25.0% of water, 12.5-62.5% of ethyl acetate and 31.3-62.5% of ethanol at the extractant boiling point.
EFFECT: improved isolating and preparing method.
3 cl, 2 tbl, 1 dwg