51 results about "GalP" patented technology

The present invention provides a genetically engineered bacterium for synthesizing N-acetylglucosamine, a preparation method thereof, and an application thereof. The genetically engineered bacterium uses Escherichia coli as an initial bacterium, and related genes for the catabolism of N-acetylglucosamine are knocked out on the genome of the initial bacterium, and related genes for the metabolic synthesis of N-acetylglucosamine are overexpressed, so as to improve the production level of N-acetylglucosamine. Among them, the related genes for the catabolism of N-acetylglucosamine include any one or a combination of at least two of nagB, nagA, manX, nagE, nagK, or ptsG, and the related genes for the metabolic synthesis of N-acetylglucosamine include any one or a combination of at least two of glmS, gna1, glnA, yqaB, icaC, galP, or glk.

The invention relates to the technical field of natural compounds, in particular to ganoderma leukemia polysaccharide and a preparation method thereof. The ganoderma leukemia polysaccharide comprises galactose, glucose and mannose, and the molar ratio of the galactose to the mannose to the glucose is (1.5-3.5): (15-30): (65-85); the ganoderma leukemia polysaccharide comprises:-> 6)-Glcp-(1-> dominant residues; (-> 6)-Manp-(1->,-> 4)-Glcp-(1-> residue; and-> 4, 6)-Manp-(1->,-> 3, 6)-Galp-(1->. The ganoderma leukemia polysaccharide has anti-oxidation and detoxification capabilities, can avoid neurodegenerative diseases, reduce lipid accumulation and prolong the service life, and also has high-temperature resistance.

The invention provides a method for synthesizing D-psicose through fermentation of escherichia coli by using D-glucose and D-xylose. The method comprises the following steps: by taking escherichia coli as a host cell, over-expressing a galactose permease gene galP, a glucokinase gene glk, a 6-phosphate glucose isomerase gene pgi, a D-psicose-6-phosphate epimerase gene alsE with an SUMO tag and a D-psicose-6-phosphate phosphatase gene a6PP, and constructing a path for synthesizing D-psicose by taking D-glucose and D-xylose as substrates; the synthetic route of D-psicose is optimized by knocking out a D-glucose phosphorylation transport pathway gene ptsG, knocking out D-fructose-6-phosphokinase genes pfkA and pfkB, silencing a glucose-6-phosphate dehydrogenase gene zwf, overexpressing glutamate transhydrogenase genes gdh1 and gdh2, knocking out a UDP-glucose-4-epimerase gene galE and knocking out a transport protein key gene fryA in D-psicose; and finally, the optimal proportion of mixed sugar fermentation is explored, so that efficient synthesis of D-psicose from escherichia coli through mixed sugar fermentation of D-glucose and D-xylose is realized.

The invention belongs to the technical field of biomedicine, and discloses a structure of linear chaetoceros alkali extraction polysaccharide and an application method in anti-T2DM, methyl GC-MS and NMR are adopted to research the structure of polysaccharide CBS2, and the result shows that CBS2 is mainly composed of [-> 4)-beta-L-Arap-(1->] and contains a small amount of [-> 4)-beta-D-Galp-(1->] and [-> 2)-alpha-L-Rhap-(1->], and the CBS2 has the advantages that the structure of the polysaccharide CBS2 is improved; and a sulfuric acid group is located at a C-3 / C-2 position of [-> 4)-beta-L-Arap-(1->]. The research on the anti-diabetic activity of the polysaccharide CBS2 shows that the CBS2 can inhibit the aggregation of hIAPP, can play a role in protecting pancreatic beta cells by improving the oxidative stress caused by hIAPP and protecting the mitochondrial function, has better anti-diabetic activity, and is a potential compound of anti-diabetic drugs.

The invention discloses stropharia rugoso-annulata polysaccharide as well as a preparation method and application thereof. The monosaccharide of the stropharia rugoso-annulata polysaccharide disclosed by the invention comprises glucose, galactose, mannose and galacturonic acid; the weight-average molecular weight of the stropharia rugoso-annulata polysaccharide is 1.4712 * 10 < 4 > to 1.623 * 10 < 4 > Da; the main chain of the stropharia rugoso-annulata polysaccharide contains-> 6)-alpha-D-(O-Me)-Galp-(1->, 1, 6-Glc, 1, 3-Man and 1.3-Gal exist in the main chain or a side chain, and terminal residues contain T-Glc and T-Gal. According to the invention, by constructing a DSS induced UC mouse model, the influence of Stropharia rugosoannulata polysaccharide (SRP1) on UC mice is investigated. Results show that the stropharia rugoso-annulata polysaccharide has a certain treatment effect on ulcerative colitis. In-vivo experiments show that the stropharia rugoso-annulata polysaccharide disclosed by the invention can increase abundance of bacteroides and thick-wall funguses and reduce abundance of proteobacteria and deferribacterium funguses; in-vitro experiments show that the stropharia rugoso-annulata polysaccharide can increase the abundance of beneficial bacteria bacteroides, reduce the abundance of harmful bacteria Escherichia-Shigella and Enterococcus, and increase the content of short-chain fatty acids.

The invention belongs to the technical field of biosynthesis, and particularly relates to a method for regulating and controlling stevioside production by improving the utilization rate of a carbon source. According to the invention, a high-efficiency stevioside biosynthesis system is constructed through systematic engineering modification: in the aspect of chassis cell optimization, transcription factors (AtWRKY18, AtWRKY40 and AtMYC2) for regulating and controlling MEP pathway and key genes (dxs and / or dxr) of the MEP pathway are over-expressed, so that supply of terpene precursors is enhanced; and a heterologous MVA pathway (over-expression T7-atoB-mvaS-mvaE-mvK / mvKmut-pmK-mvaD-idi) with a modular design is introduced, so that sufficient supply of the terpenoid precursor is realized. Meanwhile, by knocking out related genes and bypass metabolism genes (mgsA, iclR, menA or adhE) synthesized by organic acid, a glucose transport and utilization system (fnr, fadR, ppc, zwf or pgi is knocked out, and ACS, fbaA, tpiA, glf, galP or ptsG is overexpressed, so that the utilization rate of a carbon source is further improved, and the production capacity of stevioside is remarkably improved.

The invention belongs to the technical field of ocean, and particularly relates to sea cucumber polysaccharide and application thereof in preparation of products for treating diabetic nephropathy. The invention discloses a novel holothuria leucospilota PS, which is a sulfated polysaccharide with a fucosylated glycosaminoglycan (FGs)-like structure, and the main chain structure of the novel holothuria leucospilota PS is-> 3)-beta-D-Galp NAc-(1-> 4)-beta-D-Glcp UA-(1->. Results show that after the H.leucospilota PS is intervened, the contents of SCr, BUN and UA in serum of a DKD rat can be reduced, and kidney injury and fibrosis of the DKD rat are improved. The compound can be used for developing functional foods or medicines for treating diabetic nephropathy.

The invention discloses a double promoter sequence for balancing galP and glk gene expression and an application of the double promoter sequence in an L-tryptophan synthesis process. According to the promoter combination, double-gene expression vectors of Ptac-galP and Pj23119-glk are constructed, basic groups are designed and merged, so that the-35 to-10 regions of the promoters for regulating and controlling the two genes are subjected to random replacement of the basic groups, and a pair of promoter combinations with relatively good expression balance is obtained by combining fluorescence high-throughput screening. Compared with an initial promoter combination, the combination can remarkably improve the sugar transport efficiency of escherichia coli, so that the efficiency of producing L-tryptophan by PTS defective escherichia coli is improved. The technology has important social and economic values.

The application discloses application of an extract of Epiphyllum crenatum in preparation of a medicine for treating and improving intestinal diseases, relates to the fields of phytochemistry and microbiological technology, and the extract of the Epiphyllum crenatum is type I arabinogalactan. 6 The average molecular weight of the extract of the Epiphyllum crenatum extracted from petals of the Epiphyllum crenatum is 5.767*10 6 Da, and the backbone structure is a polysaccharide of β-Galp connected through (1→4) bonds, which expands the application potential of the Epiphyllum crenatum, improves the value of the Epiphyllum crenatum, and provides a new raw material for the field of the medicine for treating and improving intestinal diseases.

This invention discloses a novel structural polysaccharide SYQE3-F derived from the roots of *Tripterygium wilfordii*, its preparation method, pharmaceutical composition, and applications, belonging to the field of biomedical technology. This invention is the first to isolate and purify a homogeneous polysaccharide SYQE3-F from the roots of *Tripterygium wilfordii*, with an average molecular weight of 13.174 kDa. Its main chain consists of →4)-β-D-GlcpA-(1→) and →2)-α-D-Manp-(1→), and its side chains include t-Galp and t-Araf. This invention also discloses a pharmaceutical composition containing this polysaccharide and vitamin E. In vitro and in vivo experiments show that this polysaccharide can effectively break down choroidal occlusion barriers and significantly promote the transport of vitamin E to the target retinal tissue, providing a novel natural drug combination for the clinical treatment of DR.

The invention discloses an escherichia coli system for synthesizing D-lactic acid as well as a preparation method and application of the escherichia coli system. The escherichia coli system comprises a strain GL10 and a strain XL15; the bacterial strain GL10 is obtained by deleting genes of ppsA, mgsA, dld, pta, poxB, pflB, adhE, frdA, frdB and frdC in an escherichia coli BL21 bacterial strain; the bacterial strain XL15 is obtained by deleting genes of glk, ptsI, ptsG, mglB and galP in a bacterial strain GL10. The strain GL10 efficiently utilizes glucose, and the strain XL15 utilizes xylose, so that the CCR effect is effectively relieved, efficient synergistic utilization of a mixed carbon source is realized, the yield and purity of D-lactic acid are improved, and the production cost is reduced.

The present application belongs to the technical field of application of fungal polysaccharides, and particularly relates to a Boletus edulis fruiting body polysaccharide as well as a preparation method and application thereof. Polysaccharides in Boletus edulis fruiting bodies are extracted, and the chemical structure of BDP-F is characterized by ultraviolet-visible light, Fourier transform infrared spectroscopy, one-dimensional nuclear magnetic resonance and two-dimensional nuclear magnetic resonance. The research results show that BDP-F is mainly composed of mannose, glucose, galactose and fucose. Methylation and nuclear magnetic resonance analysis show that the glycosidic bond of BDP-F is (1→6)-alpha-d-galactose, the main chain is composed of ->6)-alpha-d-galp-(1→ residues, and the O-2 position is branched by alpha-L-Fucp-(1→ and alpha-D-Manp-(1→ residues. Through DPPH free radical, hydroxyl radical and superoxide anion radical scavenging experiments, it is shown that BDP-F has the ability to serve as a natural antioxidant, and BDP-F can also reduce alcohol-induced GES-1 cell damage through antioxidant and anti-inflammatory effects within the experimental concentration range.

The present application provides a kind of Pseudostellaria heterophylla non-starch uniform polysaccharide and its preparation method and application, belong to natural substance extraction technical field.The Pseudostellaria heterophylla non-starch uniform polysaccharide is divided into five kinds, molecular weight is 2124Da, 85900Da, 72970Da, 35820Da and 20300Da respectively, all have three spiral structures.The Pseudostellaria heterophylla non-starch uniform polysaccharide with molecular weight of 2124Da includes the following molar ratio of glucose, galactose and mannose: 95.47:2.15:2.37, and its repeatable primary structure unit includes the following sugar residues: T-Glcp, 1,3-Glcp, 1,2-Galp, 1,3,6-Manp, 1,4,6-Glcp.The Pseudostellaria heterophylla non-starch uniform polysaccharide of the present application has excellent prebiotic activity and simple preparation method, and the obtained Pseudostellaria heterophylla non-starch uniform polysaccharide has stable yield, high purity and stable structure, and is suitable for industrial scale production.

The invention belongs to the technical field of traditional Chinese pharmacology and veterinary medicine, and relates to prepared rhizoma polygonati polysaccharide as well as a preparation method and application thereof. The prepared rhizoma polygonati polysaccharide is mainly composed of galactose, the main chain is-4)-beta-D-Galp-[(1-4) / beta-D-Galp] 7-(1->, a beta-D-Galp-group is connected to the position 6 of an intermediate galactose molecule, the prepared rhizoma polygonati polysaccharide is further connected to-4)-beta-D-Manp-(1-4)-beta-D-Manp-(1-> residue, and mannose is substituted by acetyl. The prepared rhizoma polygonati polysaccharide provided by the invention has various effects of relieving ulcerative colitis, relieving intestinal injury induced by LPS (lipopolysaccharide), protecting intestinal mucosal barrier, regulating intestinal flora, improving antioxidant capacity and in-vitro antioxidant activity and the like.

The invention belongs to the technical field of medical health food and medicines, and relates to pleurotus eryngii polysaccharide, a preparation method thereof and application of the pleurotus eryngii polysaccharide in prevention and treatment of mastitis and / or intestinal flora disorder. The pleurotus eryngii polysaccharide is neutral polysaccharide and is at least composed of galactose, glucose, mannose and fucose, residues of-> 2, 6)-alpha-D-Galp-(1->,-> 6)-alpha-D-Galp-(1-> form a main chain, branch sites are located at C-2 of-> 2, 6)-alpha-D-Galp-(1->, and residues of-> 6)-alpha-3-O-Me-D-Galp-(1->,-> 6)-3-OMe-alpha-D-Galp-(1-> exist; and the molecular weight at the peak position is 15800 to 15900 Da. The pleurotus eryngii polysaccharide provided by the invention has the pharmacological activity of protecting mastitis and regulating the abundance of intestinal flora.

The invention discloses recombinant escherichia coli, a construction method thereof and application of the recombinant escherichia coli in production of 3-dehydroshikimic acid, and belongs to the technical field of bioengineering. According to the recombinant escherichia coli, escherichia coli FMME-DHS03 is used as an original strain, pyruvate kinase gene pykA is knocked out, excessive 3-dehydroquinic acid synthase gene aroB, transketolase gene tktA and galactose permease gene galP are added, the finally obtained recombinant strain is fermented for 40 h, the yield of 3-dehydroshikimic acid reaches 130.9 g / L, and the yield of glucose reaches 0.55 g / g. The process for producing the 3-dehydroshikimic acid through fermentation is simple and easy to operate, free of additional antibiotics, short in period, high in yield, low in culture medium cost and suitable for industrial production.

The invention discloses a preparation method of high-purity sugarcane leaf polysaccharide, which comprises the following steps: separating sugarcane leaf crude polysaccharide by using an alkaline H2O2 method, and then separating and purifying by using a DEAE-Sepharose Fast Flow anion exchange column to obtain the high-purity sugarcane leaf polysaccharide SLP-2. The monosaccharide composition of the high-purity sugarcane leaf polysaccharide SLP-2 is mainly Xyl, Ara and Gal, and the main chain structure of the high-purity sugarcane leaf polysaccharide SLP-2 is composed of glycosidic bonds such as Araf-(1-), Xylp-(1-),-> 3, 4)-Galp-(1-),-> 5)-Araf-(1-),-> 4)-Xylp-(1-),-> 4)-Glcp-(1-),-> 3, 4)-Xylp-(1-) and the like. The research on the efficacy of a diabetic cardiomyopathy rat model induced by feeding with streptozotocin combined with high-sugar and high-fat feed finds that the high-purity sugarcane leaf polysaccharide SLP-2 has the effects of reducing the blood sugar of the diabetic cardiomyopathy rat and improving the heart function of the diabetic cardiomyopathy rat. In conclusion, the preparation process is simple, the polysaccharide composition and structure are clear, and the SLP-2 has good effects of reducing blood sugar and improving diabetic cardiomyopathy and heart injury, has a certain application prospect in the field of medicines, and is worthy of further research.

The invention belongs to the technical field of medicine development, and particularly discloses GGAGG polysaccharide, a preparation method of the GGAGG polysaccharide and application of the GGAGG polysaccharide in preparation of a medicine for treating osteoporosis. Branched chains beta-D-Manp-(1-> 4)-beta-L-Arp-(1-> [2, 6]-alpha-D-Galp-(1-> 6)-alpha-D-Galp-(1-> 2, 4)-beta-L-Arp-(1-> [2, 6]-alpha-D-Galp-(1-> 6)-alpha-D-Galp-(1-> 4)-beta-L-Arp-(1-> [2, 6]-alpha-D-Galp-(1-> 2, 4)-beta-L-Arp-(1-> [2, 6]-alpha-D-Galp-(1-> 1)-beta-D-Manp-(1-> 1)-beta-D- The research shows that the GGAGG polysaccharide has lower molecular weight, so that the GGAGG polysaccharide has good biological adaptability and excellent treatment activity.

The invention provides construction and application of a detection and quality standard evaluation system of ulva polysaccharide in an ulva polysaccharide biological compound product, and aims to solve the problem of activity fluctuation caused by lack of structural standards of ulva polysaccharide, core quality control indexes are determined for the first time: total sugar is greater than or equal to 70% (preferably 74% + / -2%), protein is less than or equal to 0.1% (preferably 0.04% + / -0.01%), and sulfate group is greater than or equal to 15% (preferably 15.47% + / -0.5%); the molecular weight is 5 * 10 < 4 >-7 * 10 < 4 > Da (the typical value is 6.41 * 10 < 4 > Da), the HPGPC spectrum is in unimodal distribution within 35-45 minutes, and the main chain structure is beta-D-Xylp-(1-> 3)-beta-D-Arp-(1-> 6)-beta-D-Galp-(1-> 6)-beta-D-Glcp. According to the detection method, a phenol-sulfuric acid method is adopted for detecting total sugar, a BCA method is adopted for detecting protein, an improved gelatin-barium chloride turbidimetric method is adopted for detecting sulfate groups, and the purity is judged through HPGPC unimodal distribution. According to the method, by limiting polysaccharide structure core parameters and establishing a detection process capable of realizing quantitative reproduction, the biological activity and batch consistency of the raw materials are ensured, and a core technical support is provided for standardized production of ulva polysaccharide in functional foods.

The present invention discloses a Qihong polysaccharide KBPW1 with anti-tumor activity and its application in the preparation of anti-tumor drugs, relating to the technical field of plant polysaccharide active substances and their applications. The Qihong polysaccharide KBPW1 has a repeatable primary structural unit containing eight glycosidic bonds: →4)-β-D-Glcp-(1→, α-L-Araf-(1→, →3)-β-D-Galp-(1→, →5)-α-L-Araf-(1→, →3,5)-β-L-Araf-(1→, β-D-Glcp-(1→, →4,6)-β-D-Glcp-(1→, →6)-β-D-Glcp-(1→), and is composed of arabinose, galactose, and glucose. The molar ratio of arabinose, galactose, and glucose is 2.62:1.02:6.36; the relative molecular mass is 3.8×10 3 Da. Beneficial Effects: As an active anticancer ingredient, it can significantly inhibit the growth, proliferation, migration and invasion of colorectal cancer CT26WT cells, reduce the tumor volume and weight of CT26WT tumor-bearing mice, and has minimal toxicity and side effects on the body. It has good biocompatibility, strong specificity, and low toxicity and side effects. It can make up for the shortcomings of traditional cancer treatments and can be used in the development of new anticancer drugs.

The invention relates to the technical field of biochemical engineering, and particularly discloses a recombinant microorganism for producing L-histidine and application of the recombinant microorganism. Compared with an original strain, the recombinant microorganism has the advantages that the expression of a ptsG gene is reduced while galactose transporter protein galP and glucokinase glk are overexpressed, and / or one or more of transketolase tktA, transketolase tktB, transaldolase talA or transaldolase talB are overexpressed, and the original strain is escherichia coli capable of producing histidine. The recombinant microorganism provided by the invention can improve the production efficiency of histidine and reduce the cost of industrial production of histidine.

The invention discloses an ulcerative colitis resisting astragalus membranaceus and angelica sinensis homogeneous polysaccharide and a preparation method thereof, and the homogeneous polysaccharide is composed of 1, 6-alpha-D-Glcp, T-alpha-D-Glcp, 1, 3-beta-D-Galp, 1, 4-alpha-D-Manp and 1, 2-alpha-D-Galp according to a molar ratio of 3.9: 1.2: 1.6: 1.0: 61.3. On the cellular level, it is found through ELISA detection that compared with a model group, AAPS-4a (10 mg. L <-1 >) remarkably inhibits LPS-induced TNF-alpha, IFN-beta and NO level rising. In an in-vivo experiment, compared with a normal group, the DAI score and spleen index of a model group mouse are remarkably improved, the colon length is remarkably shortened, and the levels of inflammatory factors TNF-alpha and IL-6 are remarkably improved. Compared with a model group, the AAPS-4a has the advantages that the DAI score, the spleen index, the TNF-alpha level and the IL-6 level are obviously reduced, and the colonic atrophy is improved. HE staining shows that AAPS-4a obviously inhibits infiltration of colitis sexual cells and relieves pathological damage of the colitis sexual cells. The separated AAPS-4a neutral homogeneous polysaccharide is a key active component playing an anti-UC role in the astragalus membranaceus-angelica sinensis medicine pair, and has potential clinical application value.

The application discloses a kind of Russula nigra polysaccharides and its preparation method and application.The Russula nigra polysaccharides is composed of glucose, galactose heteropolysaccharide, which includes 1,6-connected galactose residue, 1,4-connected D-glucose residue, 1,4-connected D-galactose residue, 1,4,6-connected glucose residue and 1-connected galactose residue, and the molar ratio of 1-Galp, 1,6-Galp, 1,4,6-Glcp, 1,4-D-Galp and 1,4-D-Glcp residue is about 2:1:2:1:4.The Russula nigra polysaccharides is obtained by hot water extraction, ethanol precipitation, protein removal, ion exchange column chromatography, dialysis and concentration.The Russula nigra polysaccharides has significant immunomodulatory activity and antitumor activity, and can be applied in medicine, health care products or food.

The invention discloses a construction method of a recombinant microorganism, the recombinant microorganism and a fermentation process thereof, and belongs to the technical field of genetic engineering. In order to solve the technical problems of low conversion rate and poor fermentation performance of L-tryptophan, L-threonine and L-valine in the prior art, the invention provides a construction method of a recombinant microorganism, and the recombinant microorganism is obtained by respectively inserting glf, glk and galp genes subjected to point mutation treatment into escherichia coli of original strains CGMCC NO.11073, CGMCC NO.16144 and CGMCC NO.29960 and knocking out ptsI and crr genes. The recombinant microorganisms WB-B, TH-B and VB-B provided by the invention are respectively combined with fermentation processes thereof, so that the yields and conversion rates of L-tryptophan, L-threonine and L-valine are respectively improved, the production efficiency is improved, and the requirements of large-scale industrial production are met.

The invention discloses an engineering strain for efficiently producing Ectoine through polysaccharide co-utilization and a fermentation process, and belongs to the technical field of gene recombination and metabolic engineering. According to the invention, crr, ptsG and overexpression genes of lysC, glk, galp, xylA, xylB, xylR, ectA, ectB and ectC are knocked out, so that recombinant escherichia coli is obtained. According to the escherichia coli disclosed by the invention, glucose and xylose can be efficiently metabolized at the same time, the yield of Ectocaine can reach 162.2 g / L when cellulose hydrolysate from straw is used, the yield reaches 0.37 g / g carbon source, and xylose is efficiently utilized. The engineering Escherichia coli constructed by the invention provides a powerful basis for producing Ectoin by efficiently utilizing cheap carbon sources such as cellulose hydrolysate and the like.

The invention discloses an N-acetylglucosamine transferase mutant and application thereof in production of L-tryptophan, and belongs to the technical field of genetic engineering. In order to solve the problems of yield limitation and the like caused by excessive consumption of phosphoenolpyruvic acid in the production of L-tryptophan, the invention weakens a phosphoprotein coding gene crr on escherichia coli; meanwhile, a uridine diphosphate galactose pyranose mutase gene glf and a glucokinase gene glk of the pseudomonas mobilis and an endogenous galactose H (+) transporter enzyme gene galP of escherichia coli are integrated at a pflB site, and a genetically engineered bacterium is obtained; mutagenesis is carried out on the basis to obtain a mutant strain with improved L-tryptophan yield; and the N-acetylglucosamine transferase mutants nagC and nagE are obtained by virtue of sequencing. Fermentation proves that overexpression of the mutant nagC or nagE or simultaneous overexpression of the mutants nagC and nagE in the genetically engineered bacteria can improve the yield of L-tryptophan.

The invention provides a Kunlun chrysanthemum bud polysaccharide with sugar controlling and lipid lowering effects and a preparation method thereof, and relates to the technical field of biological medicine, the main chain of the Kunlun chrysanthemum bud polysaccharide is formed by alternation of-> 4)-beta-D-Galp-(1-> and-> 4)-beta-D-Glcp-(1->; a side chain of the Kunlun chrysanthemum bud polysaccharide is composed of-> 5)-alpha-L-Araf-(1->,-> 3, 6)-beta-D-Galp, alpha-L-Araf, beta-D-Glcp / Galp and alpha-D-Rhap. The technical problems that the Kunlun chrysanthemum bud polysaccharide prepared in the prior art is complex in component and low in purity, and application of the Kunlun chrysanthemum bud polysaccharide in the field of sugar control and lipid reduction is seriously limited are solved, the effects of reducing blood sugar and blood lipid are achieved, the use dosage of a blood sugar reducing medicine metformin is reduced, and the sugar control and lipid reduction effects are enhanced.

The invention relates to the technical field of oligosaccharide preparation, and discloses pyruvate-containing fucotetraose with an intestinal barrier enhancing function and a preparation method of the pyruvate-containing fucotetraose, the structural main chain of the pyruvate-containing fucotetraose is alpha-L-Fucp-(1-> 3)-alpha-L-Fucp-(1-> 3)-beta-D-Glcp, and the side chain of the pyruvate-containing fucotetraose is formed by introducing 1, 2-D-Galp of which the 4 and 6 sites are substituted by pyruvate into a reaction kettle through a reaction between 1, 2-D-Galp and 1, 2-D-Galp. The second alpha-L-Fucp of the main chain is substituted in a 2, 4 connection mode, and the molecular formula is C27H44O21. The pyruvate-containing fucotetraose provided by the invention can promote intestinal goblet cell-like cells Ls174T to generate mucoprotein and enhance the barrier function of the intestinal tract; the safe concentration of the pyruvate-containing fucotetraose to Ls174T cells is 1 mg / mL, and after the pyruvate-containing fucotetraose with the concentration of 1 mg / mL acts on the Ls174T cells, the output of mucoprotein in a mucous layer is increased by 1.5 times or above.

This invention discloses a kelp fucoidan, its preparation method, and its application. The kelp fucoidan includes LF3-1 and / or LF4-1. The main chain of LF3-1 is composed of alternating →3)-α-L-Fucp-(1→ and →3)-β-D-Galp-(1→). The fucose residues on the main chain of LF3-1 are sulfated at the C-4 position or connected to a first branch, which is composed of →4)-α-L-Fucp-(1→. The galactose residues on the main chain of LF3-1 are sulfated at the C-6 position or connected to a second branch, which is composed of →2,3)-β-D-Manp-(1→ and β-D-Galp-(1→). The sulfate content of LF3-1 is 26.3%, and the weight-average molecular weight of LF3-1 is 305. LF4-1 has a molecular weight of 32.7% and a weight-average molecular weight of 182.1 kDa. Its main chain consists of alternating links of →3)-α-L-Fucp-(1→ and →6)-β-D-Galp-(1→). The fucose in the main chain of LF4-1 is sulfated at C-4 or has a third branch, which is composed of →4)-α-L-Fucp-(1→. The galactose in the main chain of LF4-1 is sulfated at C-3 or has a fourth branch, which is composed of →2,4)-β-D-Manp-(1→ and β-D-Galp-(1→). LF4-1 effectively improves blood lipids and insulin resistance, promotes lipid oxidation and glucose metabolism gene expression, and thus plays a role in weight loss and lipid reduction.

The invention discloses a preparation method of Bupleurum marginatum polysaccharide (BMP-1), and relates to a process method for extracting, separating and purifying plant polysaccharide. The method comprises the following steps: firstly, obtaining a crude extract from bupleurum chinense through a petroleum ether, 90% ethanol and hot water reflux extraction method; then, deproteinizing and decolorizing the extract, and removing impurities; then, carrying out primary separation by adopting DEAE-52 cellulose column chromatography so as to enrich polysaccharide components; and finally, carrying out further purification by using Sephadex G-200 gel, so as to obtain the high-purity Bupleurum marginatum polysaccharide BMP-1. Further, methylation analysis is combined with a gas chromatography-mass spectrometry method, and it is shown that a main chain structure in the bupleurum marginatum polysaccharide contains fragments alpha-D-GalpA-6OMe-(1-> 4)-beta-D-Glcp-(1->, alpha-D-Galp-(1-> 4)-alpha-D-Galp-(1-> and-> 4)-alpha-L-Rhap-(1-> 3)-alpha-L-Rhap-(1->. In-vitro DPPH, ABTS and hydroxyl radical scavenging activity results show that the Bupleurum marginatum polysaccharide BMP-1 has certain antioxidant activity.