49 results about "Polymannuronic acid" patented technology

The invention discloses an alginate lyase (Alg509) derived from marine bacteria and a gene thereof, and also disclosed a method for recombinant expression and preparation of the alginate lyase. According to the method, the alg509 gene is cloned into an E. coli expression vector, and the vector is transformed into an E. coli host strain to obtain a recombinant engineering strain which can heterologously express the enzyme. The alginate lyase Alg509 disclosed in the invention has high enzyme activity, the specific enzyme activity can reach up to 48000 U/mg and above, the optimum reaction pH is 10, the optimum reaction temperature is 55 DEG C, and the enzyme activity has no dependence on various metal ions. The enzyme is active to sodium alginate, poly-guluronic acid (polyG) and ploymannuronic acid (polyM), and can completely degrade sodium alginate to produce alginate oligomers such as alginate disaccharide, alginate trisaccharide, alginate tetrasccharide, etc. The enzyme exhibits strongbasophilia, has certain tolerance to high pH, has certain potential of industrial applications, and can be widely applied in the fields of agriculture, food, feed additive, medicine and the like.

The invention belongs to the field of marine drugs and particularly relates to the application of mannan-oligosaccharide aldehyde acid salt in preparing a medicine for preventing and curing liver damage, various hepatitis, liver fibrosis or cirrhosis. The mannan-oligosaccharide aldehyde acid salt is used for preparing the medicine for protecting livers and curing various hepatitis, liver fibrosis or cirrhosis. The mannan-oligosaccharide aldehyde acid salt takes algin as a raw material, through a chemical degradation method or a physical degradation method, or the combination of the two degradation methods, mannan-oligosaccharide aldehyde acid with different molecular weights can be obtained; the mannan-oligosaccharide aldehyde acid is prepared through neutralization into lithium salt, sodium salt, kali salt, calcium salt or magnesium salt of the mannan-oligosaccharide aldehyde acid with different molecular weights, the molecular skeleton of the mannan-oligosaccharide aldehyde acid adopts a linear oligosaccharide compound formed by connecting D-mannuronic acid (M) through a Beta-1, 4 glucosidic bond. The product in the invention is derived from algal polysaccharides, has the advantages of rich resources, easiness in industrialization, safety, effectiveness and the like, and has a wide development and application prospect in preventing and curing liver damage, and various hepatitis, liver fibrosis and cirrhosis.

The invention provides application of mannuronic acid oligomers in preparing medicines, health products or dietary supplements for preventing and treating alcoholic liver injury. Mannuronic acid oligomers with different molecular weights, which are obtained by degrading polymannuronic acid graded and purified from algin, can lower the hepatosomatic index increase caused by alcoholic injury, resist triglyceride and cholesterol increase caused by alcohol, effectively lower glutamic-pyruvic transaminase and glutamic oxaloacetic transaminase increase in serum caused by alcohol, enhance the total oxidation resistance and glutathione level of the serum, lower the mouse drunkenness rate, prolong the mouse drunkenness time, and shorten the sober-up time, thereby implementing the protective action and hangover alleviating function on alcoholic hepatic injury. The products provided by the invention are derived from marine natural products, have the advantages of abundant resources, high industrialization tendency, high safety, high effectiveness and the like, and have wide development and application prospects in the aspects of prevention and treatment of alcoholic hepatic injury, hangover alleviation and liver protection.

The invention provides a method for preparing alginate oligosaccharide monomers by using microwave radiation. The method comprises the following steps of: preparing polymannuronic acid or polyguluronic acid in algin, subjected to graded purification, into solutions or suspensions with different concentrations; performing microwave radiation in a microwave reaction system for degradation for 5 to 30 minutes; then cooling, filtering and freeze-drying the degradation product to obtain an oligosaccharide mixture; and separating and purifying the oligosaccharide mixture by using a gel column chromatography to obtain oligosaccharide monomers with different polymerization degrees. The method has the advantages that the degradation efficiency is high, the yield of oligosaccharide is high, acid or a buffer salt is not added during the degradation, few byproducts are generated, the after-treatment is simple and convenient, the product is easy to separate and purify, clean and environment-friendly effects are achieved, the cost is low, oligosaccharide mixtures with different molecular weight distributions and oligosaccharide monomers with different polymerization degrees can be prepared according to different aims and purposes, and the product is applied to various fields of foods, medicaments, chemical industry and the like.

The invention provides oligomerization mannuronic acid and application of medicinal salts of oligomerization mannuronic acid in leucopenia prevention medicine. In in-vitro cell experiments, oligomerization mannuronic acid can obviously promote forming of colony-forming unit-granulocyte macrophage (CFU-GM), simultaneously can promote marrow stroma cells to breed and secrete CFU-GM and promote splenic lymphocytes to secrete interleukin-3. In vivo experiments further indicates that oligomerization mannuronic acid can obviously restrain reduction of white blood cells in mice caused by cyclophosphamide, increase the number marrow nucleated cell of the mice and promote forming of CFU-GM. Experiment results indicate that oligomerization mannuronic acid can be developed to be a clinical medicine capable of effectively preventing leucopenia.

The invention relates to a marine oligosaccharide compound with type II diabetes resisting activity, which is a compound which is formed by following steps: taking D-polymannose aldehydic oligosaccharide which comes from sea and contains carboxyl in each oligosaccharide ring, reacting with dilute alkali and chromium salt solution and introducing trivalent chromium ions which is closely relative tothe generation and the development of diabetes into oligosaccharide molecules. A pharmacological experiment proves that the product has remarkable effect on accelerating insulin secretion, is not influenced by amylin and has effects on lightening glucose load, improving blood-lipoid metabolism, insulin sensitivity and certain kidney protection and lightening pancreatic injury for type II diabetesrats and mouse. The product of the invention comes from marine natural species, has the advantages of good security, unique structure, low molecular weight, high chromium binding ratio, good oral absorption effect, and the like, can play a hypoglycemic role in a plurality of links and has favorable market application prospect on the aspect of preventing and treating type II diabetes.

The invention provides application of oligomeric mannuronic acid to preparation of a medicine for resisting influenza A virus subtype H1N1. Through experiment, the oligomeric mannuronic acid (OM) has a good function of protecting madin-darby canine kidney cells which are infected by influenza A virus subtype H1N1 in vitro, can effectively reduce virus reproduction, and has an effect equal to thatof a positive control medicine ribavirin. Moreover, OM can also reduce the death of mice which is caused by infection of influenza A virus subtype H1N1 obviously, and prolong the survival time. The oligomeric mannuronic acid (OM) has the advantages of high water solubility and stability, and safety and low toxicity and the like; and in an in vivo-in vitro experiment, the OM can resist influenza Avirus subtype H1N1 well, and the oligomeric mannuronic acid can be expected to be developed to the medicine for resisting influenza A virus.

A process for preparing algin lyase includes such steps as preparing culture medium, sterilizing, cooling, inoculating Vibro sp QY101, shake fermenting culture at constant temp. removing bacteria from fermented liquid, ultrafiltering supernatant and concentrating. Its advantages are short fermenting time, high output and activity and high temp stability. It can be used to prepare alginic oligose.

The invention relates to incision difunctional alginate lyase Aly2 generating various monosaccharide products, an encoding gene of the Aly2 and an application of the Aly2. The amino acid sequence of the Aly2 is as shown in SEQ ID NO. 2, and the nucleotide sequence of the encoded Aly2 is as shown in SEQ ID NO. 1. The specific activity of prepared gene engineering recombinant protein rAly2 for alginate, polyguluronic acid and polymannuronic acid is 2025U/mg, 3672U/mg and 1324U/mg, so that the gene engineering recombinant protein rAly2 is a difunctional enzyme. The enzyme is an incision enzyme, and final main products are unsaturated disaccharide and unsaturated trisaccharide when an alginate polysaccharide substrate is thoroughly degraded. When different oligosaccharide substrates are degraded, various monosaccharide products such as saturated M and G or unsaturated delta can be generated. Besides, the rAly2 is stable in biochemical property, is a potential tool enzyme, can be applied tothe field of medicines, food and the like and has a wide application prospect.

The invention relates to the technical field of selenylation polysaccharide and provides a method for preparing selenylation poly mannuronic acid. The method comprises steps of suspending poly mannuronic acid in an anhydrous organic solvent; adding a sulfur trioxide-pyridine compound dissolved by the anhydrous organic solvent with stirring; conducting reaction for 1-10 hours at the constant temperature from 20 DEG C to 100 DEG C; adding ethanol; centrifugalizing a reaction product; cleaning by using the ethanol; adding water and dissolving; adjusting the Potential of Hydrogen (PH) value to the neuter by using alkali; conducting dialysis; conducting filtering; conducting freezing and drying; obtaining sulfonated poly mannuronic acid; subjecting the sulfonated poly mannuronic acid and selenite to the reaction in the acid solution at the catalysis of Ba2+; adding sulphate; extracting supernatant fluid through centrifugation; adjusting the Potential of Hydrogen (PH) value to the neuter by using the alkali; conducting dialysis; conducting filtering; conducting freezing and drying; and obtaining the selenylation poly mannuronic acid. The invention also provides application of the selenylation poly mannuronic acid which is prepared through the method in medicines and health products for prevention and curing of Alzheimer's disease.

The invention discloses an alginate lyase SHA-3 gene with a nucleotide sequence as shown in SEQ ID NO:1. The invention establishes a prokaryotic expression vector of the alginate lyase SHA-3 gene. The vector can obtain an expression product, namely alginate lyase SHA-3 within relatively-short time, has wide substrate specificity, can take polymannuronic acid PolyM or polyguluronic acid PolyG as a substrate, and has the enzyme activity of 12U/mg so as to be a difunctional enzyme with a wide application prospect. The prokaryotic expression vector and a whole expression system are easily operated and are conveniently used for realizing industrial production.

The invention provides an antithrombotic medicament for intravenous injection. The medicament is a modified acidic polysaccharide consisting of only one monosaccharide and has a structural general formula, wherein R is -CH3 or -CH2-CH(OH)-CH3; R' is -H or -SO3Na; each sugar ring has at least one R' which is -SO3Na; n is equal to 2 to 6; when R is -CH3, the compound represented by the structural general formula is an oligomannuronicacid methyl acetate sulfate sodium salt; and when R is -CH2-CH(OH)-CH3, the compound represented by the structural general formula is an oligomannuronicacid proply acetate sulfate sodium salt. The medicament for intravenous injection has obvious anticoagulation, wherein the anticoagulation titer is 17 to 23; rabbit collagen induced platelet aggregation and platelet adhesion are obviously inhibited; and local ischemic brain damage caused by formation of cerebral thrombosis is lessened by inhibiting the formation of cerebral thrombosis and ischemic brain tissues are obviously protected.

The invention discloses an alginic acid lyase SHA-5 gene. The nucleotide sequence of the alginic acid lyase SHA-5 gene is shown as SEQ ID NO:1. A prokaryotic expression vector of the alginic acid lyase SHA-5 gene is structured, the expression product alginic acid lyase SHA-5 can be obtained in a short time through the vector, and the vector has wide substrate specificity; both polymannuronic acid PolyM and polyguluronic acid PolyG can be used as a substrate, the enzyme activity reaches 17 U/mg, and the alginic acid lyase SHA-5 is difunctional and has wide application prospects. The prokaryotic expression vector and an integral expression system are easy to operate, and industrial production is convenient.

The invention discloses endo-alginate lyase and a coding gene and application thereof. A primer is designed and synthesized by taking genome DNA of a Vibriosp.MCCC 1A13243 as a template, an endo-alginate lyase gene is amplified through PCR, the gene is cloned into a pET-22b expression vector, induced expression is carried out in escherichia coli E.coli BL21, and affinity chromatography purification is carried out by adopting Ni-Sepharose to obtain the recombinant endo-alginate lyase protein with higher purity. The optimum temperature of the enzyme is 35 DEG C, the optimum pH of the enzyme is 8.5, and the enzyme has good stability in the ranges of 0-65 DEG C and pH 4.5-10.5; co<2+>, Cu<2+>, Mn<2+> and Fe<3+> can obviously promote the enzyme activity; and the enzyme has the highest degradation effect on sodium alginate and can further degrade polyguluronic acid and polymannuronic acid, and a main product for degrading the three substrates is disaccharide. The endo-alginate lyase has advantages in the aspect of producing alginate oligosaccharide, especially brown algae disaccharide.

The main object of the present invention is to provide polysaccharide-coated antigens derivatized with lectins for pharmaceutical use. In said vaccines, polysaccharides are preferably selected from the group consisting of chitosan, low-molecular-weight and high-deacetylation-degree chitosan, methyl glycol chitosan, alginic acid, polymannuronic acid and salts or derivatives thereof. In the vaccines of the invention, antigens are microorganisms, infectious agents or constituents thereof, hormones, enzymes, proenzymes, narcotics, bioactive peptides, metabolites, biological precursors, cell constituents, allergens, and the lectins are of vegetable origin.

The invention relates to a recombinant alginate lyase AlyL7 and application thereof. The amino acid sequence of the alginate lyase is shown as SEQ ID NO.1, and the nucleotide sequence of a coding gene of the alginate lyase is shown as SEQ ID NO.2. The recombinant alginate lyase belongs to bifunctional alginate lyase, the optimum reaction temperature of the recombinant alginate lyase is 40 DEG C, the optimum reaction pH of the recombinant alginate lyase is 9.0, the recombinant alginate lyase is stable under the conditions that the temperature is 0-25 DEG C and the pH is 5.0-10.0, and the recombinant alginate lyase has degradation activity on sodium alginate, polyguluronic acid and polymannuronic acid. The recombinant alginate lyase also belongs to an incision enzyme, and a final product obtained by enzymolysis of sodium alginate by the recombinant alginate lyase comprises unsaturated 1-5 sugars and mainly comprises unsaturated 2-3 sugars. The alginate lyase is high in reaction speed and high in efficiency, and has good industrial application potential.

A polymannuronic acid sulfate with anti-AIDS activity contains the primary molecular skeletons: the mannuronic acid linked with beta-D (1-4) and the guluronic acid linked with beta-L (1-4). The SO3Na is introduced to the hydroxy position on C2 and C3 of carbon ring. Its preparing process includes dewatering sodium alginate, dissolving, centrifugal separation, classifying with alcohol, dissolving the classified and degradated alginic acid, neutralizing with alkali, separating out solid, dewatering with alcohol, sulforating with chlorosulfonic acid, neutralizing with alkali, dewatering with alcohol and drying. It can be used to prepare anti-AIDS medicines.