41 results about "Glycosidic bond" patented technology

This invention discloses a pullulanase mutant with enhanced catalytic activity against highly branched dextrin substrates, its construction method, and its applications, belonging to the fields of enzyme engineering and biotechnology. This invention obtains two mutants, D139A and D139E, by site-directed mutagenesis of the pullulanase derived from Klebsiella pneumoniae at position 139 aspartic acid residue. Compared with the wild-type enzyme, both mutants maintain high hydrolytic activity against pullulan polysaccharides while significantly improving hydrolytic activity against dextrin substrates with high α-1,6 glycosidic bond content. Specifically, the hydrolytic activity against dextrin substrates with 6% and 10% α-1,6 bond content is increased by up to 242% and 110%, respectively. The pullulanase mutants obtained in this invention exhibit excellent catalytic performance in the enzymatic debranching reaction of highly branched dextrin substrates, showing promising application prospects in starch deep processing and related biomanufacturing fields.

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.

This invention provides an extract of *Hedyotis diffusa*, its preparation method, and its uses. When the extract is measured under reversed-phase high-performance liquid chromatography, the peak area A of 6''-malonyl *Hedyotis diffusa* I is... M Peak area A with cypermethrin I B The ratio is less than 0.1, and the peak area A of free kaempferol is... K With A B The ratio shall not exceed 0.15. The preparation method includes: adjusting the pH of the aqueous extract of *Kaempferia galanga* to 11-13.5, and performing alkaline hydrolysis at 25-65°C for 20-60 minutes. This invention utilizes the difference in stability of malonyl bonds and glycosidic bonds under alkaline conditions to achieve the selective conversion of 6''-malonylkaempferol I to kaempferol I, increasing the content of kaempferol I while maintaining the integrity of the glycosidic bonds and inhibiting or controlling the formation of free kaempferol. The resulting extract can be used to prepare anti-inflammatory and antioxidant drugs or health foods.

This invention relates to the field of gene vector technology, and more particularly to an ionizable comb-like polymer, its preparation method, and its applications. This comb-like polymer is a block polymer, comprising at least one block unit. Each block unit includes a first block, a second block, and a third block linked by covalent bonds. It exhibits high molecular flexibility and readily binds to nucleic acid-like substances to form polymer / nucleic acid complexes. Due to the presence of easily degradable intracellular glycosidic bonds in its structure, the polymer demonstrates high transfection efficiency. Furthermore, cell experiments show that the polymer / nucleic acid complex exhibits low toxicity to cells and significantly improves cell survival compared to the positive control. Therefore, it holds promise for widespread application in cell transfection. The preparation method provided by this invention utilizes a redox amination tandem reaction to directly prepare the target product, eliminating the need for intermediate product purification processes. This simple process facilitates large-scale production.

The present application relates to the field of enzyme engineering, and in particular to a mutanase and application thereof. At present, mutan is mostly prepared by bacterial extraction, and there are problems such as low product yield and many impurities. The present application provides a mutanase, a MutI gene fragment of the mutanase is obtained by cloning a genome of Leuconostoc pseudomesenteroides G496, and a genetically engineered bacterium is constructed. The mutanase provided by the present application is subjected to enzymatic property analysis, and it is found that the mutanase has good stability under acidic conditions, and the optimal induction expression temperature and reaction temperature are close to room temperature, and the production energy consumption is low and the raw material conversion rate is high. The catalytic product of the mutant enzyme is linear mutan with a high polymerization degree, the molecular weight of the linear mutan is as high as 650 kDa, the linear mutan contains 90% of alpha-1,3 glycosidic bonds, and the structure is relatively dense, and the linear mutan has a good application prospect in the field of biological base materials.

The present application belongs to the field of computational chemistry and molecular simulation technology, and relates to a kind of aromatic eutectic solvent multiscale molecular simulation screening method and system based on multi-objective collaborative scoring model.Establish target molecule model library and eutectic solvent candidate component library;Quantum chemistry calculation is carried out on target molecules and eutectic solvent candidate system, and quantum chemistry descriptors are extracted;Molecular dynamics simulation system is constructed, and molecular dynamics descriptors such as aromatic space enrichment coefficient Kπ, glycosidic bond interaction index Ggly and lignin bond type affinity index Lβ are extracted;Multi-scale feature vectors are obtained by normalization processing, input into multi-objective collaborative scoring model, calculate and extract score SE, grading score SF, and judge and output active ingredient extraction priority, lignocellulose grading priority or segmented collaborative processing mode.The present application is suitable for eutectic solvent calculation screening and application mode discrimination when there is a target conflict between plant aromatic active ingredient extraction and lignocellulose grading treatment.

The application provides a high-stability gastrodin production process, which takes gastrodin tetraacetate as a starting material, and sequentially undergoes pentaacetylation reaction, centrifugation and drying to obtain a gastrodin pentaacetate intermediate; then gradient saponification refining is adopted, that is, preliminary hydrolysis is first carried out by using a low-concentration lye, and then deep saponification is carried out by using a high-concentration lye; after saponification, the product is subjected to centrifugation, drying and crushing to obtain a finished product; an ultrasonic-assisted crystallization step is added after saponification, and an inert gas atmosphere coating is carried out after crushing. The glycosidic bond breakage caused by strong alkali is effectively avoided through gradient saponification, and the key problems of low product purity and poor stability in the existing process are solved in combination with ultrasonic crystallization and inert gas protection. The obtained gastrodin product has the remarkable characteristics of high purity, few impurities and excellent stability, and has the following indexes: purity ≥ 99.1%, related substances ≤ 0.45%, and content decrease rate ≤ 0.8% after 18 months of accelerated test.

The application provides a synthesis method of chondroitin polysaccharide ABW90-1 and / or chondroitin polysaccharide ABW50-1, and relates to the technical field of polysaccharide preparation.The synthesis method provided by the application adopts a fructose 6-position picoloyl group as a guiding group, highly stereoselectively constructs beta-(2 to 6)-D-furan fructose and internal beta-(2 to 1)-D-furan fructose glycosidic bonds through a glycoside unit transfer strategy mediated by hydrogen bonds, and efficiently prepares chondroitin polysaccharide ABW90-1 and chondroitin polysaccharide ABW50-1.The synthesis method provided by the application has the advantages of simplicity, high efficiency, high target product yield and high purity, and has reference significance for the synthesis of other types of sucrose oligosaccharides.

This invention relates to a method for producing an aqueous polymer dispersion by free radical-initiated aqueous emulsion polymerization of a monomer composition comprising 50% to 99.9% by weight of at least one (meth)acrylic acid C1 to C2. 10 Alkyl esters and / or vinyl aromatic compounds (Class I), or at least one vinyl aromatic compound and conjugated aliphatic diene by weight of 50% to 99.9% (Class II), or vinyl acetate, vinyl propionate, vinyl tert-carbonate, long-chain fatty acid vinyl esters and / or ethylene by weight of 50% to 99.9% (Class III), these amounts being based on total monomers in each case, the method being carried out by polymerizing the composition in the presence of an oligosaccharide having 1.5 to 10 β-1,4-glycosidic bonds linking pyranose units; relating to the dispersion obtained accordingly; and relating to the use of the dispersion as a binder, adhesive, sizing agent for fibers, for the production of coatings or for the production of paper coating formulations.

This invention discloses a method for separating and purifying inulin, belonging to the field of natural plant powder separation and purification technology. The method includes: S1. Adding ethanol to an aqueous solution of natural inulin, performing a first alcohol precipitation at 2-5°C, separating to obtain a first supernatant and a precipitate; S2. Preparing the precipitate into an aqueous solution, preheating, subjecting to ultra-high pressure treatment, and freeze-drying to obtain medium- and long-chain inulin; S3. Freeze-drying the first supernatant to obtain a solid, redissolving the solid into an aqueous solution, adding ethanol, performing a second alcohol precipitation at -22 to -18°C, separating to obtain a second supernatant; S4. Freeze-drying the second supernatant, preparing an aqueous solution, ultrasonically treating at less than 40°C, and low-temperature drying to obtain short-chain inulin. The short-chain inulin of this invention employs graded alcohol precipitation assisted by temperature-controlled ultrasound to precisely break glycosidic bonds, resulting in a purity of 80.04%~92.55% and a yield of 42.90%~54.24%. The medium- and long-chain inulin employs graded alcohol precipitation combined with low-temperature preheating and ultra-high pressure coupling to improve its degree of polymerization and uniformity, resulting in a purity of 80.15%~87.84% and a yield of 31.53%~48.06%.

The application discloses a nanowire-nanotube hybrid sensor and a preparation method and application thereof. The nanowire-nanotube hybrid sensor has two regions of a nanochannel and a nanowire electrode by using a conical double-channel microcapillary. A substrate solution is precisely released to a specific site of a single cell through the nanochannel. After a to-be-measured glycosidase recognizes the substrate molecules, the glycosidic bond is cut to release active substances of the electrode. The nanowire electrode is used for real-time quantitative detection of the active substances, so that quantitative detection of glycosidase substances at a single / subcellular level is realized. The application constructs an efficient and universal detection strategy of non-electrochemical active glycosidase by using the nanowire-nanotube hybrid sensor and an electrical signal conversion method of the reaction of specific glycosidase and a substrate, widens the detection range of electrochemical target objects, and provides a promising method for high-time-space-resolution quantitative monitoring of hydrolytic enzymes at a single / subcellular level.

The application discloses a kind of double-enzyme modified starch with high freeze-thaw stability and its preparation method and application, for the serious problem of gel structure deterioration and water separation of starch-based frozen food caused by ice crystal damage in repeated freeze-thaw process, the method utilizes malt alpha-amylase and starch branching enzyme to catalyze different crystal form starch particles in sequence, and realizes the directional regulation of starch branching topological structure by the synergistic mediation of glycosidic bond reconstruction. First, the malt alpha-amylase hydrolyzes the starch particles moderately, and the long internal chain connected to the molecular cluster is cracked; then the starch branching enzyme cuts off the alpha-1,4 glycosidic bond, and connects the free malt oligosaccharide to the cluster-shaped molecular residue with alpha-1,6 glycosidic bond, thereby significantly increasing the branching degree of starch. The method disclosed in the application belongs to enzyme modification, and has the characteristics of green safety and simple operation, and has wide application prospect in frozen food, such as instant noodles and instant rice products.

This document discloses a method for producing ester derivatives of α-glucan comprising α-1,6 bonds. Such methods may include esterifying α-glucan in an esterification reaction composition comprising an increased α-glucan to total liquid ratio. Further disclosure includes α-glucan ester compositions produced by the disclosed process, and various applications using these compositions.

This invention provides a microbial preparation for enhancing the aroma and quality of low-grade tobacco leaves and its preparation method, belonging to the interdisciplinary field of microbial engineering and tobacco processing technology. Bacillus subtilis is inoculated into a fermentation medium containing low-grade tobacco leaf powder, using the powder as the core inducer for directional fermentation. Combined with staged fermentation regulation, the metabolic flow of Bacillus subtilis is directionally trained to produce a complex enzyme system highly matched to the degradation needs of tobacco leaves. Compared with conventional fermentation, this invention significantly enhances the activities of protease, amylase, and β-glucosidase. This complex enzyme system can simultaneously degrade proteins and starches in low-grade tobacco leaves and hydrolyze glycosidic bonds to release latent aroma substances. This invention is low-cost, achieves internal circulation within the tobacco industry chain, and is environmentally friendly.

This invention provides RG-I type pectin Lycium barbarum 63 sugar and its fragments, as well as methods for their preparation and uses. Specifically, this invention provides polysaccharide compositions containing polysaccharides as shown in Formula I or II or their salts, pharmaceutical or health product compositions containing the polysaccharide compositions, and uses of the polysaccharide compositions. Furthermore, this invention also provides various intermediates for preparing the polysaccharide compositions, methods for synthesizing the glycosidic bonds required for the preparation of the polysaccharides, and methods for preparing the polysaccharide compositions.

A novel pulp composition having oil resistance and / or water resistance is provided by a pulp composition comprising a liquid-repellent compound and a pulp substrate, wherein the liquid-repellent compound is a compound having a monovalent hydrocarbon group having 6 or more and 40 or less carbon atoms and optionally having a substituent, and is not a fatty acid ester having a glycoside bond, and the pulp substrate comprises bagasse pulp.

The invention relates to a composition based on enzymes of the class of glycosyl hydrolases. The given composition can be used as a dishwashing composition, especially for removal of tough stains and soils based on hemicellulose residues of shells of cereals, plants and fungi even at lower temperatures.

The application discloses a chryseobacterium S1-14 and application thereof in enzymolysis of alpha-1,3-glycosidic bond high-molecular polysaccharide, and belongs to the technical field of food, cosmetics and medicine. Chryseobacterium The chryseobacterium S1-14 is classified as chryseobacterium sp., is preserved in the China General Microbiological Culture Collection Center, has a preservation number of CGMCC No. 37778, a preservation date of February 10, 2026, and a preservation address of No. 3, Xili, Beichen West Road, Chaoyang District, Beijing City. The chryseobacterium S1-14 can be used for degrading macromolecular polysaccharides containing alpha-1,3-glycosidic bonds, has high degradation rate, mild reaction condition, and the advantage that the obtained product has low molecular weight, and can be applied to industrial production.

This invention relates to a disaccharide exoglycosidase β-agarase with both galactosidase and β-galactosidase activities and its applications, belonging to the field of biotechnology. This invention discloses for the first time a method for developing a β-agarase from *Pseudomonas alterniflora* (…). Pseudoalteromonas An enzyme, ORF0276, and its encoding gene, possessing both galactosidase and disaccharide exonuclease activities, were obtained from the genome of strain Q02 (sp.). This enzyme exhibits strong thermostability, high pH tolerance, and stable physicochemical properties, thus possessing potential for industrial applications. When degrading agar polysaccharide substrates, it can act on the β-1,4 glycosidic bonds of the sugar chains to produce a product primarily composed of neo-agarbiose, which can be used for the industrial preparation of neo-agarbiose (NA2). This research provides a molecular template and theoretical reference for the discovery of such multi-functional tool enzymes.

The present application relates to a kind of acid polysaccharide monosaccharide composition determination method.The acid polysaccharide sample is mixed with lysozyme in buffer system and is carried out enzymolysis reaction, after reaction, enzyme is inactivated, and the enzymolysis solution is obtained;Acid liquid is added to the enzymolysis solution, and acid hydrolysis reaction is carried out under heating condition, and the hydrolysis solution containing monosaccharide is obtained, and hydrolysis is completed.The obtained hydrolysis solution is separated and detected, and the monosaccharide composition of the acid polysaccharide sample is determined.Compared with prior art, the present application realizes the complete hydrolysis of enzymolysis oligosaccharide fragment under lower concentration acid and shorter hydrolysis time, so as to realize the complete hydrolysis of polysaccharide chain.Avoid the incomplete hydrolysis of glycosidic bond under the specificity of enzyme hydrolysis and the problem of low hydrolysis rate and monosaccharide easy degradation under extreme acid hydrolysis environment, realize the complete but not excessive hydrolysis of acid polysaccharide, and ensure the accuracy of acid polysaccharide monosaccharide composition analysis.

The application discloses a kind of relieving physical fatigue compositions and preparation method thereof, belong to functional food and enzyme engineering technical field;For the technical contradiction that tannic acid astringency is heavy in existing Paraguay tea beverage, and acidic environment is easy to lead to ginsenoside Rb1 hydrolysis inactivation, a kind of step temperature-pH coupling immobilized enzyme catalysis synergistic treatment method is proposed;The method first uses C8-C18 alkyl hydrophobic modification mesoporous silica fixed tannin enzyme, under pH 5.0-6.0, 40-50 DEG C, high-efficiency astringency is removed;Subsequently under the condition that enzyme preparation is not separated, in situ pH is adjusted to 6.5-7.0 and temperature is reduced to 30-35 DEG C, then ginseng extract is added to carry out low-temperature protection reaction, and the destruction of ginsenoside Rb1 glycosidic bond by acid / heat is avoided from the root.The experiment shows that the application can make tannic acid removal rate ≥72.5%, ginsenoside Rb1 retention rate ≥82.5%, and caffeine retention rate ≥86.9%, which is significantly better than traditional process.

This invention discloses a plant-based yogurt rich in phenolic acids from black sweet corn, its preparation method, and its applications. Using black sweet corn juice and soybean flour as a matrix, this invention incorporates *Lactobacillus plantarum* strain BFS1243 into a conventional plant-based yogurt fermentation agent for compound fermentation. The resulting black sweet corn yogurt is a bright pink color, has a delicate texture, low beany odor, and significantly enhanced antioxidant activity. The compound fermentation using strain BFS1243 can cleave the glycosidic bonds on anthocyanin molecules in black sweet corn, directionally degrading and converting large anthocyanin molecules with low absorption rates into small phenolic acids. This solves the problem of easy degradation and low bioavailability of natural anthocyanins in black sweet corn during fermentation and storage. It also shortens fermentation time, improves fermentation efficiency, and significantly improves the flavor and quality of the fermented yogurt, giving it a unique corn aroma and pink appearance, as well as more active substances and better antioxidant activity.

This invention belongs to the field of microbial engineering technology, specifically relating to an Akk bacteria culture method based on the induction and diversion regulation of *Porphyra yezoensis* glycoprotein. The method includes: preparing *Porphyra yezoensis* glycoprotein with high galactose content and high exposure of O-glycosidic bond-related structures using a low-energy pulsed laser-mild alkali treatment synergistic extraction method; inoculating *Akk bacteria* into an induction culture system after pre-culturing, initially adding *Porphyra yezoensis* glycoprotein, and culturing under anaerobic conditions; monitoring butyric acid and / or isobutyric acid content in real-time or at intervals during culture; and initiating a feedback diversion regulation program when the content exceeds a preset threshold to adjust one or more parameters in the input concentration of *Porphyra yezoensis* glycoprotein and the pH of the culture system. Compared with existing technologies, this invention achieves the targeted enrichment of characteristic metabolites such as butyric acid and isobutyric acid, with butyric acid and isobutyric acid contents increasing by approximately 4.4 times and 4.5 times, respectively, compared to the naturally cultured output group.

This application relates to the fields of chemistry and bioengineering, and specifically discloses a preparation process of a Tris salt cap composition and the Tris salt cap composition. The preparation process includes the following steps: (1) preparing a mixed salt form of a cap analog to obtain a mixture, wherein the structure of the cap analog is a compound of formula (I), or its stereoisomer, tautomer, or isotopic variant; (2) eluting the mixture with a Tris-acid aqueous solution, and after desalting and concentration, obtaining a Tris salt cap composition; wherein the pH value of the Tris-acid aqueous solution is 2.5-7.5. In preparing the Tris salt cap composition, this application not only avoids the problem of easy glycosidic bond breakage of the cap analog under strong acid conditions, but also achieves more thorough salt conversion, and can conveniently obtain a Tris salt cap composition with excellent performance.

This invention provides a method for preparing a bifunctional mesoporous solid acid catalyst and its application in the hydrolysis of cellulose to produce glucose. Using alkali lignin as the carbon source and sucralose as the chlorine source, the bifunctional mesoporous solid acid catalyst is obtained after high-temperature carbonization and concentrated sulfuric acid sulfonation. This catalyst not only possesses a high density of -SO3H groups, enabling efficient cleavage of cellulose glycosidic bonds, but also exhibits -Cl groups that can form hydrogen bonds with cellulose, enhancing the catalyst's adsorption capacity for cellulose polysaccharides. When the prepared catalyst is used for cellulose hydrolysis, it can efficiently convert cellulose into glucose at a temperature of 150–190 °C for 2–6 h. It exhibits advantages such as high catalytic efficiency, few byproducts, and low corrosiveness to equipment, making it an environmentally friendly solid acid catalyst.

The application discloses a method for treating rhizoma polygonati culm and simultaneously extracting total flavones and xylo-oligosaccharides by adopting a steam explosion technology and application, and comprises the following steps: after the rhizoma polygonati culm is crushed and pre-impregnated, the rhizoma polygonati culm is placed into a steam explosion storage tank to be exploded, and after the treatment, alcohol extraction and acid hydrolysis are used to extract alcohol-soluble total flavones and xylo-oligosaccharide crude extract respectively. The application generates strong shearing force by instant pressure release of high-temperature and high-pressure steam, effectively destroys the crystal structure of lignocellulose, promotes the glycosidic bond breakage of the main chain of hemicellulose, reduces the polymerization degree of xylan, generates xylo-oligosaccharides, and forms a loose porous structure and increases the surface area by explosion, thereby promoting the dissolution of flavonoids, avoiding the tediousness of repeated extraction in the traditional method, and being green, efficient and pollution-free. Through the technology, the xylo-oligosaccharides and alcohol-soluble total flavones can reach 47.7 g / kg and 45.4 mg / g respectively; compared with the content of alcohol-soluble total flavones of 0.366% of the rhizoma polygonati culm raw material, the technology is increased by about 10 times.

This invention discloses a *Pneumocystis nigra* strain XMRS204 producing sticky extracellular polysaccharides and its applications. This strain was isolated from the intestine of a deep-sea amphipod in the Mariana Trench and forms milky-white, highly sticky colonies on LB agar. After fermentation, the strain yielded extracellular polymers through centrifugation, ethanol precipitation, dialysis, and freeze-drying; the main component of these polymers was acidic polysaccharides. The infrared spectrum of the polysaccharides purified by agarose gel size exclusion showed the presence of O–H, C–H, and –COO groups. ‑ It contains typical polysaccharide functional groups such as C–O–C glycosidic bonds. In a 2% aqueous solution, this polysaccharide has a viscosity of 1473 mPa·s, approximately three times that of hyaluronic acid (molecular weight 300 kDa) and significantly higher than polyglutamic acid (molecular weight 700,000–1,100,000). The strain and its polysaccharide provided by this invention can be used as biomaterials and thickeners in the food, pharmaceutical, and cosmetic fields.

Anti-SIRPa antibody formulation, suitable for parenteral administration, comprising: an anti-SIRPα antibody that inhibits signaling via the SIRPα-CD47 axis at a concentration between approximately 20 mg / ml and approximately 100 mg / ml; a buffer component selected from the group consisting of approximately 20 mM L-histidine and 20 mM sodium phosphate; a disaccharide comprising an α-glycosidic bond and present at a concentration of approximately 8 wt. / vol.%; approximately 0.01 wt% polysorbate 20; and a pH value of approximately 5.7 to approximately 6.3; which is free of glycine, arginine, carbonate, HEPES, citrate and acetate.

A composition for producing collagen low molecular weight peptides (10,000 Da or less) that utilizes the amylase family of enzymes. The amylases (α-, β-, γ-amylase) are noted for the cleavage of the α-glycosidic bonds of polysaccharides, yielding lower molecular weight carbohydrate / sugar fragments. It has been found that α-amylase is effective in reacting with animal tissues to yield hydrolyzed collagen peptides, which facilitate cell migration and proliferation.