45 results about "Glycosyl acceptor" patented technology

The invention discloses a method for improving the water solubility of dye lignin by utilizing cyclodextrin glucosyltransferase transglycosylation reaction, and belongs to the field of enzyme engineering. A gene (GenBank accession no.JX412224), which is derived from P.macerans strain JFB05-01 (CCTCC NO:M208063) and optimized by a cyclodextrin glucosyltransferase codon, is connected to pET20b(+) plasmid and is transferred to an E.coli BL21(DE3) cell to establish gene engineering bacteria for producing the cyclodextrin glucosyltransferase. The pure cyclodextrin glucosyltransferase, which is obtained through fermentation enzyme production and purification, is applied to catalytic transglycosylation reaction, alpha-cyclodextrin serves as a glycosyl donor, the dye lignin serves as glycosyl receptor, and at least four dye lignin glycosylated derivatives (Glc)n-genistein (n is equal to 1, 2, 3 and 4) are finally obtained, wherein Glc-genistein and (Glc)2-genistein are main products, in particular the water solubility of the (Glc)2-genistein is greatly improved compared with that of the dye lignin.

The invention discloses cyclodextrin glucosyltransferase mutants and application thereof, and belongs to the technical field of enzyme engineering and microbial engineering. The CGTase mutants have high specificity to long-chain glycosylated genistein products. The yield of long-chain glycosylated genistein prepared from CGTase mutants A156V/L174P, A156V/L174P/A166Y, A156V/L174P/A166V, A156V/L174P/A166G and A156V/L174P/A166K by using maltodextrin as a glycosyl donor and genistein as a glycosyl receptor is increased by 62.5%, 165%, 112.5%, 112.5% and 59.4% respectively, compared with the yieldof long-chain glycosylated genistein prepared from wild type cyclodextrin glucosyltransferase by taking maltodextrin as a glycosyl donor and genistein as a glycosyl receptor.

The invention discloses a synthesis method of glucoside based on an indoxyl derivative and a 2-(benzothiazol-2'-yl)phenol derivative. The general formula of a synthetic equation of the synthesis method is as shown in the description; the Ar-OH represents aromatic phenol or a ketonic compound thereof, and is used as a glycosyl receptor in a glycosylation reaction; the G-X represents halogenated sugar, and is used as a glycosyl donor in the glycosylation reaction. According to the synthesis method of the glucoside based on the indoxyl derivative and the 2-(benzothiazol-2'-yl)phenol derivative, a 1-acetylindolin-3-one derivative is selected and used as an intermediate; a novel synthesis method is researched and developed to prepare the glucoside based on the indoxyl derivative; a novel glycosidase fluorescence probe based on a BTP ((2-benzothiazol-2'-yl)phenyl) derivative is synthesized by applying the method; meanwhile, the application effects of the glucoside based on the indoxyl derivative and the glycosidase fluorescence probe are investigated. The glucoside based on the indoxyl derivative and the 2-(benzothiazol-2'-yl)phenol derivative can be used as glycosidase substrates, and is used for the positioning analytic detection and screening on the corresponding glycosidase, a microorganism using the corresponding glycosidase as a characteristic target, and the like.

The invention discloses a method for preparing glucose-based stevioside by enzymatic variable temperature and high-flux, and belongs to the technical field of sweetener biosynthesis. According to themethod for preparing the glucose-based stevioside by the enzymatic variable temperature and high-flux, cyclodextrin glucosyltransferase derived from geobacillus sp. is used as a catalyst, stevioside is used as a glycosyl acceptor, dextrin or oligosaccharide is used as a glycosyl donor, and a calcium barium ion salt bridge is used as a main stabilizer, and glycerol is combined with to adjust the conformation and binding domain opening degree of enzyme, the variable temperature utilizes the transesterification and hydrolysis activity of amylase by stages to prepare the glucose-based stevioside by enzymatic variable temperature and high-flux. The technology disclosed by the invention can improve the utilization rate of the enzyme, and obtain the glucose-based stevioside with excellent sweetness and good taste.

The invention relates to the technical field of biological analysis and detection, in particular to a method for determining the activity of O-linked N-acetylglucosamine transferase and application ofthe method. The method comprises the following steps: firstly, modifying a glycosyl receptor of OGT by utilizing a fluorescent group, transferring azide-modified glycosyl to polypeptide through an enzyme reaction catalyzed by OGT, and then connecting the glycosyl receptor to macromolecular bovine serum albumin modified by dibenzocyclooctyne through a click reaction. The property that bovine serumalbumin is a macromolecule is utilized, and the bovine serum albumin is used as an 'FP tag 'capable of causing polarization signal enhancement, so that the enzyme activity of OGT is visually displayed. According to the invention, the problem of low catalytic activity of OGT on a complex modified substrate is solved, meanwhile, the correlation between the enzyme activity and the fluorescence polarization signal size is realized, and the method can be used for determining the enzyme activity of OGT, and can also be used for high-throughput screening of an OGT inhibitor and determination of theinhibitory activity of the OGT inhibitor.

The invention relates to microbes having a high-efficiency transglycosylation activity and application thereof. The microbes are Arthrobacter sp.DL001. Strains or broth of Arthrobacter sp.DL001 can realize high-efficiency transglycosylation to glycosyl acceptors in the presence of glycosyl donors and thus a novel effective method for preparing carbohydrates and glycosides by biotransformation reactions is provided. The novel effective method can realize high-efficiency, cheap and eco-friendly preparation of carbohydrates and glycosides and is an effective approach of industrial production of carbohydrates and glycosides.

The invention relates to a fluorine label and a preparation method thereof, and a method for synthesizing an oligosaccharide chain by adopting an assisted enzyme method. The structural formula of the fluorine label is G-R(I) as shown in the formula I. G represents monosaccharide or oligosaccharide; and R is one of the following formulas II and III, wherein R1 is one of C6H13 and C8H17. When G represents lactose and R represents a C8F17 difluoro chain, the formula II is shown in the specification. The fluorine label has the advantages of being easy to remove and recycle. The glycosyl receptor is used for synthesizing various different oligosaccharide chains, so that the oligosaccharide chain with a determined structure is quickly and efficiently synthesized.

The invention discloses a magnetic nanoparticle-glycosyl transferase-amorphous metal organic framework composite catalytic material as well as a preparation method and application thereof. The composite catalytic material is formed by wrapping glycosyl transferase and magnetic nanoparticles in an amorphous metal organic framework as a novel immobilized enzyme material. After the composite catalytic material is prepared, the composite catalytic material is added into a mixed solution of a glycosyl donor and a glycosyl acceptor, and a heparin disaccharide product is obtained through a catalytic glycosylation reaction. The amorphous metal organic framework material has a larger aperture than a common metal organic framework, reduces mass transfer resistance, improves enzymatic efficiency, is hollow inside, and is more beneficial to maintenance of enzyme molecule activity. The composite catalytic material can be used for efficiently catalyzing the glycosylation reaction of monosaccharide, not only has good thermal stability and chemical stability, but also can improve the enzymatic reaction rate, can be recycled for multiple times, keeps higher catalytic activity and simplifies the separation step.

The invention discloses a synthetic method for 3,6-branched glucosepolyheptasaccharide, and belongs to the technical field of natural product synthesis. The method comprises the following steps: glucose trichloroacetimidate is used as a glycosyl donor, tert-butyldimethylsilyl-alpha-D-glucopyranose is used as a glycosyl acceptor, coupling is performed, acid hydrolysis is performed, activation is performed to obtain a glucose trisaccharide donor, glucose trichloroacetimidate and 4,6-phenylmethylene-2,3-di-O-benzoylglucose trichloroacetimidate are used as glycosyl donors, tert-butyldimethylsilyl-alpha-D-glucopyranose is used as a glycosyl acceptor, coupling is performed, hydrolysis is performed, the obtained material is used as a glycosyl acceptor, 4,6-phenylmethylene-2,3-di-O-benzoylglucosetrichloroacetimidate is used as a glycosyl donor, coupling is performed, hydrolysis is performed to obtain a glucose tetrasaccharide acceptor, the glucose trisaccharide donor is coupled with the glucose tetrasaccharide acceptor to obtain heptasaccharide, deprotection is performed, and therefore the target product 3,6-branched glucosepolyheptasaccharide is obtained. The synthesis disclosed by the invention is convenient to operate, has a high utilization rate of the raw materials, and is a high-efficiency synthetic method.

The invention belongs to the technical field of sugar chemistry, and relates to a glycosylation reaction catalyst, a glycosylation method and application. The glycosylation method takes platinum chloride (IV) as a catalyst and is simple to operate, wide in substrate application range and high in reaction regioselectivity and stereoselectivity, and application of the method in glycosylation reaction is disclosed. According to the method, alpha-configuration O-glycosyl trichloroacetimidate is used as a donor, platinum (IV) chloride is used as a catalyst of an acid-base catalysis way, and a product mainly having a beta-configuration is obtained. In the method, a catalyst and a glycosyl acceptor are firstly combined to form a catalyst-acceptor adduct, so that proton acidity and oxygen affinity are increased, donor activation is enhanced, and acceptor transfer is carried out. According to the invention, the ligand binding capacity of platinum (IV) chloride and the characteristic that a diol receptor can be used as a bidentate ligand thereof are fully utilized, so that the method is not only suitable for construction of high-stereoselectivity glycosidic bonds of monohydroxyl receptors, but also can realize glycosidic bond construction with high regioselectivity and stereoselectivity of receptors of 1,3-diol, 1,2-cis-diol, 1,2-trans-diol, and 1,2,3-triol structures.

The present invention relates to a method for chemical synthesis of phillyrin. According to the method, a glycosyl acceptor phillygenin and a glycosyl donor are dissolved in an organic solvent, a glycosylation reaction is performed to prepare tetra acyl phillyrin, the tetra acyl phillyrin is dissolved in an organic solvent, sodium methylate is added, a deacylation reaction is performed, an acidic pH value adjusting agent is added to adjust the pH value of the reaction mixture to achieve a neutral state, and finally a purification treatment is performed to obtain the product. According to the present invention, the advanced and practical characteristics of the production method comprise convenient raw material source, cheap and easily-available catalyst for the glycosylation reaction, significantly-reduced preparation cost, and industrial production achieving.

The invention discloses a synthetic method for 3,6-site branched glucohexaose and belongs to the technical field of natural product synthesis. The synthetic method comprises the following steps: coupling trichloroacetimidate of glucose as a glycosyl donor with tertiary butyl dimethyl silicon-alpha-D-glucopyranose as a glycosyl acceptor to generate trisaccharide; carrying out benzoyl protection andacid hydrolysis to remove end position protecting groups; then carrying out activation to obtain a glucotriose donor; coupling trichloroacetimidate of glucose and 4,6-benzylidenyl-2,3-di-O-benzoyl trichloroacetimidate of glucose as a glycosyl donor with tertiary butyl dimethyl silicon-alpha-D-glucopyranose as a glycosyl acceptor to synthesize trisaccharide; carrying out hydrolysis to remove 4,6-benzylidenyl to obtain the glucotriose acceptor; coupling the trisaccharide donor with the trisaccharide acceptor to obtain hexaose; and then carrying out de-protection to obtain the targeted 3,6-sitebranched glucohexaose. The synthetic method provided by the invention is concise in synthetic route and convenient to operate. In the whole process, the utilization ratio of raw materials is high, andthe method is an efficient synthetic method.

The invention provides thermostable beta galactosidase and a related recombinant engineering strain thereof, and relates to the technical field of recombinase catalysis engineering. The beta galactosidase BtGal42 can be used for synthesizing glycerol galactoside by an enzymatic method at 50 DEG C by taking galactose as a glycosyl donor and taking glycerol as a glycosyl receptor, the enzyme stability is good at the temperature, and compared with the prior art, the use amount of the enzyme is obviously reduced, and the production cost is reduced. When the beta-galactosidase disclosed by the invention is used for a synthetic reaction, the bacterial contamination risk can be reduced and the reaction efficiency of a substrate can be improved by increasing the reaction temperature, so that the production efficiency of glyceryl galactoside is improved, and industrial application requirements can be completely met.

The invention discloses a batch synthesis method for 4-O-beta-Galactopyranosyl-D-mannopyranoside. The batch synthesis method of 4-O-beta-Galactopyranosyl-D-mannopyranoside comprises the steps of 1) conducting the isopropylidenation of the compound shown in formula II with 2, 3-hydroxy to obtain the compound shown in formula IV; 2) protecting the 6-hydroxy of the compound shown in formula IV through an acylation reaction to obtain the compound shown in formula V; 3) carrying out a coupling reaction between the compound shown in formula V and the compound shown in formula III to obtain the compound shown in formula VI; 4) removing the isopropylidene protection, benzyl protection, R1 protection and R2 protection of the compound shown in formula VI to obtain the compound shown in formula I. The alpha-D-benzyl mannoside (formula II) serves as a starting material, glycosyl acceptor 2, 3-O-isopropylidene-6-O-benzoyl-alpha-D-pyran benzyl mannoside (formula V) intermediate is obtained through a two-steps reaction, the yield and purity in each step of the reaction are very high, accordingly, in a large-scale preparation, the intermediates IV and V do not require purification and can be directly used in the next step of the reaction.

The invention discloses a glycosyl transferase-bimetal organic framework composite catalytic material, a preparation method thereof and application of the glycosyl transferase-bimetal organic framework composite catalytic material in synthesis of disaccharide and polysaccharide, and the composite catalytic material is formed by taking a Zn-based MOFs material as a main body, doping non-Zn metal ions and wrapping glycosyl transferase in the Zn-based MOFs material. According to the composite catalytic material, a metal organic framework doped with bimetal ions serves as a novel immobilized enzyme material, glycosyl transferase is wrapped in the metal organic framework, and the glycosyl transferase-bimetal organic framework composite catalytic material is prepared and added into a glycosyl donor and a glycosyl acceptor, so that the glycosyl transferase-bimetal organic framework composite catalytic material is obtained. And catalyzing glycosylation reaction to obtain heparin disaccharide and polysaccharide. The composite catalytic material disclosed by the invention can efficiently catalyze the glycosylation reaction of monosaccharide, not only has good thermal stability and chemical stability, but also can improve the enzymatic reaction rate of immobilized enzyme compared with a common metal organic framework material, and can be recycled for multiple times while keeping higher catalytic activity.

The invention discloses an oligosaccharide synthesizing method which is characterized in that full-benzyl protection propargyl alcohol glycoside is utilized as a glycosyl donor, 6-site glycosyl intermediate or glycosyl with a -Tr protecting group is utilized as a glycosyl acceptor, and the glycosyl donor and the glycosyl acceptor are dissolved in an organic solvent according to a mole ratio of (1 to 6mmol) to 1mmol to (0.1 to 1mmol) to perform glycosylation reaction under the catalysis of ferric salt. Compared with the prior art, the oligosaccharide synthesizing method achieves the purpose that the glycosyl donor directly perform glycosylation reaction with the 6-site glycosyl intermediate with the -Tr protecting group, oligosaccharide is synthesized through a one-pot method in high yield, a reaction route is shortened, operation steps are simplified, production cost is reduced, and heavy metal ion pollution is effectively avoided. In addition, the oligosaccharide synthesizing method has the advantages of being green, environment-friendly and suitable for industrial production and having larger technological innovation and good application prospect.

The invention discloses curcumin subjected to fructose glycosylation, a preparation method and application, levan sucrase is used as a catalyst, curcumin is used as a glycosylation acceptor, cane sugar is used as a glycosylation donor to carry out enzymatic glycosylation reaction, the curcumin subjected to fructose glycosylation is obtained, the solubility of the curcumin subjected to fructose glycosylation is far higher than that of the curcumin subjected to glucose glycosylation, and the curcumin subjected to fructose glycosylation can be used for preparing the curcumin subjected to fructose glycosylation. Therefore, the better bioavailability is achieved.