Method for hydrophobic modification of exopolysaccharides. RU patent 2463353.

FIELD: chemistry.

SUBSTANCE: disclosed is a method for hydrophobic modification of exopolysaccharides selected from xanthan and ritizan. The H⁺ form of exopolysaccharide is obtained. The obtained H⁺ form of exopolysaccharide then reacts with a primary alkyl amine in an aprotic solvent in the presence of dicyclohexyl carbodiimide. The aprotic solvent used is 1-methyl-2-pyrrolidone, dimethyl formamide and dimethylsulphoxide. The modified exopolysaccharide is separated by multiple precipitation.

EFFECT: method enables to obtain modified xanthan and ritizan with high output.

2 cl, 6 ex

IPC classes for russian patent Method for hydrophobic modification of exopolysaccharides. RU patent 2463353. (RU 2463353):

C12P19/06 - Xanthan, i.e. Xanthomonas-type heteropolysaccharides

C12P19/04 - Polysaccharides, i.e. compounds containing more than five saccharide radicals attached to each other by glycosidic bonds

C08B37 - Preparation of polysaccharides not provided for in groups ; C08B0001000000-C08B0035000000; Derivatives thereof (cellulose D21)

Another patents in same IPC classes:

Method for preparing xanthane thickening agent "saraksan" or "saraksan-t" / 2323005
Invention relates to a method for preparing the xanthane thickening agent for drugs and for technical aims. Method involves culturing strain-producers Xanthomonas campestris on nutrient medium comprising carbon nutrition source, mineral salts and growth factors under aeration condition. Culturing process is carried out in fermenters preliminary washed out with 0.01-0.05% of β-lactam antibiotic or antibiotic from tetracycline order, water followed by sterilization. Method provides improving quality of xanthane thickening agent.

Method for production of xanthan thickening agent / 2252033
Target xanthan thickening agent is produced by cultivation of producer strain Xanthomonas campestris on nutrient medium containing carbon source, mineral salts and growth factors under aeration condition followed by sterilization, Cultivation is carried out in enzymes from synthesis of beta-lactam antibiotic drug.

Method for forming cellulose film applicable on skin and tissue damages / 2462514
Cellulose film for coating, regeneration, recovery and healing for such skin and tissue damages as ulcers, burns, wounds and similar is produced by cultivation of microorganisms including Acetobacter xylinum species and at least one microorganism of Leuconostoc oenos species in a culture medium containing nitrogen and carbon sources. The cultivation is conducted at temperature 20°C to 36°C and the pH value 1 to 6. The formed film contains crystalline cellulose in the form of microfibrils having an average degree of polymerisation 250 to 400, a degree of crystallinity 65% to 90% with the film being insoluble in concentrated acid.

Method for enzyme production of penta-n-acetylchitopentaose / 2460800
Method involves biosynthesis of penta-N-acetylchitopentaose in vivo from N-acetylglucosamine precursor in the high-density bacterial culture Escherichia coli DH5α with the use of recombinant enzyme of N-acetylglucosaminyl transferase Mesorhizobium loti 1803 expressed in cells of said bacteria. The biosynthesis in vivo is enabled by recovery, cloning and expression in Escherichia coli DH5αa of the gene NodC Mesorhizobium loti 1803 coding N-acetylglucosaminyl transferase; the gene NodC is amplified with the use of specific primers and Pfu-polymerase; a matrix for amplification of the gene NodC is presented by DNA recovered from the strain Mesorhizobium loti 1803 deposited in the collection of All-Russian Research Institute for Agricultural Microbiology; it results in preparing an amplification product sized 1300 base pairs; the amplified gene NodC Mesorhizobium loti 1803 (NodC) is cloned in the vector pUC19 in sites BamH EcoRl with preserving a reading frame so that to produce the plasmid pUC19-NodC that is used for expression of the gene NodC in the bacteria Escherichia coli DH5α; N-acetylglucosaminyl transferase (NodC) is expressed in the strain Escherichia coli DH5a after induction by isopropyl-β-D-thiogalactoside in cultivation of the bacteria Escherichia coli DH5α bearing the plasmid pUC19-NodC with the built-in gene NodC Mesorhizobium loti 1803; neHTa-N-acetylpentachitopentaose is synthesised in the presence of the N-acetylglucosamine precursor; the amount of neHTa-N-acetylpentachitopentaose synthesised by the enzyme N-acetylglucosaminyl transferase Mesorhizobium loti 1803 makes about 0.1-0.5 gram per one litre of the bacterial culture; the synthesised substance is analysed by mass spectrometry to prove that the synthesised substance is penta-N-acetylchitopentaose.

Exopolysaccharide producer / 2460780
Strain is deposited in the Russian National Collection of Microorganisms, No. B-2680D. The strain is able to produce exopolysaccharide in the amount of 25 g/l. Kinematic viscosity of 0.1% and 0.25% aqueous exopolysaccharides makes 1.90 CS and 5.45 CS respectively.

Method for type 3 streptococcus pneumoniae polysaccharide purification (versions) / 2460539
Group of inventions refers to biotechnology and biochemistry. The serotype 3 Streptococcus pneumoniae polysaccharides are purified from protein impurities. According to the first version of the method, the Streptococcus pneumoniae cell lysate is heated to 60°C for 30 min for protein aggregation and deposition. The deposited substances are separated by filtration through membrane and depth filter of the pore diameter of 0.45 mcm and centrifuged to produce the purified lysate. According to the second version of the method, the pH value of the lysate or the centrifugate is increased to 8.0 to 8.4 and filtered. According to the third version of the method, the Streptococcus pneumoniae cell lysate is heated to 60°C - 70°C for 30 - 50 min. It is followed by lysate centrifugation and increase of the pH value to 8.0 - 8.4, and filtration. According to the fourth version of the method, the pH value is decreased to 3.0 - 5.0 and heated to 60°C - 70°C for 30 - 50 min. It is followed by centrifugation and increase of the pH value of the lysate and the centrifugation to 8.4, and filtration.

Method for noncovalent immobilisation of lipopolysaccharide shigella flexneri 2a on solid hydrophobic carrier / 2447153
Method involves passing a solution of lipopolysaccharide Shigella flexneri 2a in a 0.05 M triethylammonium acetate buffer at pH 4.7, which contains 10% n-propanol, through a column with a hydrophobic carrier which is Octyl Sepharose CL-4B, and then washing the column with the same buffer solution.

Method of preparing composition with improved rheological properties (versions) and composition obtained using said methods / 2428482
Methods involve obtaining a bacterial cellulose product through fermentation, possible lysis of bacterial cells from the bacterial cellulose product, mixing it with at least one polymeric thickener or precipitating agent and coprecipitation of the obtained mixture with alcohol. The bacterial cell lysis step can be performed after mixing with the precipitating agent. The polymeric thickener used can be at least one charged cellulose ester, at least one precipitating agent or combination thereof. The composition obtained using said method, having improved rheological properties and containing bacterial cellulose, has viscosity of at least 300 cP (300 mPa·s) and tensile yield 1.0 dine/cm2 (0.1 N/m) when more than 0.36 wt % of it is put into a 500 ml water sample and after application of not more than two passages in an extensional homogeniser at pressure 1500 lb/in2 (10342.5 kPa).

Method of making construct containing crystal cellulose / 2427647
What is offered is a method of making a construct containing crystal cellulose. Cellulose-forming organisms are grown at least partially in a hollow template made by means of a three-dimensional printer. What is offered is a method of making the hollow template by means of the three-dimensional printer which grows portions of the hollow template in layers from a modelling material.

Method of producing low-molecular chitosan in salt-free medium via enzymatic polymerisation / 2425844
Starting high-molecular chitosan is dissolved in acid solution. The chitosan dissolved in the acid is then precipitated by adding alkali solution. The re-precipitated high-molecular chitosan is washed from the formed salt and excess alkali using a coarse-porous filter. The re-precipitated chitosan is dissolved in acid solution until achieving pH 5.5. An enzyme preparation is then added and hydrolysis is carried out. The reaction is stopped after formation of low-molecular chitosan.

Polysaccharide produced by microorganism, belonging to genus bifidobacterium / 2418857
Polysaccharide contains galactose, glucose, ramnose as monosaccharide components and pyruvic acid bound with any of the monosaccaride components. Molar content of galactose, glucose and ramnose in polysaccharide is in ratio 4:2:1, quantity of pyruvic acid being from 4 to 7% in weight. Said polysaccharide has structure, represented by formula (I): Polysaccharide is obtained by cultivation in anaerobic conditions of strain Bifidobacterium longum JBL05 (NITE BP-82) - polysaccharide producent. Also claimed are immunostimulator and moisturising means representing said polypeptide.

Method of preparing wood raw material to obtain sugars, installation for realising said method and product / 2405832
According to the method, wood raw material undergoes coarse grinding first and resinous substances are then extracted, after which the obtained product undergoes fine grinding and mechanical activation. The installation has for coarse grinding wood raw material, apparatus for extracting resinous substances and apparatus for fine grinding and mechanical activation arranged in series.

Method for forming chitosan film coating and chitosan film coating / 2461575
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%.

Ballast substance / 2460312
Inventions group relates to biotechnology. The ballast substance as a food additive for the human and animals with a monolocular stomach contains a fibre composition including the following components: lignocellulose, a fermentable fibre ingredient (bark material of soft wood, hardwood or their mixtures) and a marginally fermentable or non-fermentable fibre ingredient (fibres of soft wood, hardwood and their mixtures) at a ratio of 1:100 - 100:1, isoquinoline alkaloids. The ballast substance is produced and purified; impurities are removed at stage (a). The components are dried till dry substances content is equal to 3-12% at stage (b), milled, strained at stage (c) and mixed. The mixture is pressed at stage (d) and milled into desired size particles and mixed at stage (e). One adds a vegetable material containing isoquinoline alkaloids before pressing at stage d) and before mixing the ground components at stage (e). According to the second version of the method isoquinoline alkaloids are added at the stages of mixing (iv) or pressing and grinding at stage (v). The ballast substance is included in the composition of a fodder (in an amount of 0.01 - 50 % of the total fodder weight) and a fodder premix (up to >99%). The ballast substance is applied as a food additive in human alimentation, as a fodder or food additive for weight reduction.

Method of producing chondroitin sulphate from sea hydrobiont tissue / 2458134
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.

Cross-linked hyaluronic acid and production method thereof / 2456299
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.

Method for producing gel-forming dextrane phosphates / 2455007
Invention refers to chemical-pharmaceutical industry, medicine, biotechnology, and concerns a method for producing dextrane phosphate hydrogels which can find application in preparing prolonged preparations for treating oncological diseases, infectious diseases, immune disorders. The declared invention describes the method for producing polysaccharide phosphate hydrogels, involving processing of an initial polysaccharide in mixed orthophosphoric acid and phosphorus oxide (V) in an organic solvent medium in the presence of trialkylphosphate at temperature 30-70°C that is followed by washing of the prepared products, drying and processing in an aqueous solution of a mineral compound with the etherification process of dextrane conducted in a non-polar organic solvent medium of the low boiling point specified in hydrocarbons and their derivatives and processing of the prepared product in 0.005-0.5 M aqueous solutions of sodium carbonate, or sodium hydrocarbonate, or sodium hydroxide, or their mixtures to the value pH 3.0-8.0 to be set down in ethanol and dried at temperature 20-50°C.

Method of producing arabinogalactan / 2454429
Invention relates to methods of producing arabinogalactan. The method involves aqueous extraction of arabinogalactan from resin-free larchwood while heating. The obtained arabinogalactan extract is purified from high-molecular weight impurities by ultra filtration on hydrophobic membranes with pore size 0.03; 0.05; 0.08 mcm. Further, the extract is concentrated and purified from low-molecular weight impurities on a hydrophilic ultra filtration membrane. The extract then undergoes diafiltration with demineralised water on the same membrane. The end product is extracted via spray drying.

Clatrate complex of cyclodextrine or arabinogalactane with 9-phenyl-symm-octahydroselenoxantene, its production method (versions), pharmaceutical composition and medication / 2451680
Invention relates to a new clatrate complex of α-, β-, γ- or hydroxipropyl-β-cyclodextrine or arabinogalactane with 9-phenyl-symm-octahydroselenoxantene with formula (1) possibly - in α-crystalline form. The weight ratio of 9-phenyl-symm-octahydroselenoxantene to Cyclodextrine is from 1:3 to 1:30 or the weight ratio of 9-phenyl-symm-octahydroselenoxantene to arabinogalactane is from 1:10 to 1:20. Additionally proposed are a liquid phase method of the complex production, a solid phase method of the complex production, a pharmaceutical composition and a medication.

Method of determining antibacterial activity of chitosan / 2450022
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.

Kefiran production method / 2450021
Kefiran production method involves kefiran extraction from kefir fungi in boiling water, the produced solution cooling, kefiran precipitation with an equivalent quantity of ethanol, the solution maintenance, the product drying, extraction is performed (while stirring) in boiling water at a ratio of kefir fungi to water equal to approximately 1:10 during 5-10 minutes till homogeneous mass production. In the process of cooling one adds a proteolytic enzyme and maintains the product at a temperature and pH optimal for the proteolytic enzyme used during no less than 1 hour; the extract cooled to 20°C is filtered through a fine filter; after ethanol precipitation the sediment is filtered, washed with distilled water and repeatedly filtered several times.