45 results about "Glycosyl acceptor" patented technology

The invention relates to a new unnatural ginsenoside Rd12 (3-O-β-D-glucopyranosyl (1-2)-β-D-glucopyranosyl-12-O-β-D-glucopyranosyl-protopanaxadiol) and a preparation method thereof and application, the present invention uses cheap sucrose as glucose glycosyl donor, utilizes glycosyltransferase and sucrose synthase as coupling catalyst, uses ginsenoside Rg3 as glycosyl acceptor, and uses cheap sucrose as glycosyl donor, Efficiently catalyze the C12 hydroxyl glycosylation of ginsenoside Rg3 to produce unnatural ginsenoside Rd12, which has the characteristics of good specificity, high catalytic efficiency, and simple product purification. In addition, the unnatural ginsenoside Rd12 prepared by the invention can be used as an antitumor drug, and the unnatural ginsenoside Rd12 has significant inhibitory effects on colon cancer cells, liver cancer cells, lung cancer cells and gastric cancer cells.

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 synthesizing various glucosides on a basis of 4-methylumbelliferone. According to the invention, a glycosyl donor peracetyl saccharide and a glycosyl acceptor 4-methylumbelliferone are subjected to a glycosylation reaction under room temperature or under heating with dichloromethane or 1,2-dichloroethane as a solvent and with the combined effect of Lewis acid boron trifluoride ethyl ether and organic alkali triethylamine or pyridine; and protecting groups are removed, such that various glucosides based on 4-methylumbelliferone can be obtained. The glucosides include 4-methylumbelliferone-beta-D-glucopyranosiduronide, 4-methylumbelliferone-beta-D-glucopyranoside, 4-methylumbelliferone-beta-D-xylopyranoside, 4-methylumbelliferone-beta-D-ribofuranoside, 4-methylumbelliferone-alpha-D-galactopyranoside, and 4-methylumbelliferone-alpha-D-mannopyranoside. The method is simple, and can produce a beta or alpha single-configuration target. A glycosylation reaction yield can reach 17-93%.

The invention relates to beta-galactosidase, and in particular relates to beta-galactosidase capable of glycosylating resveratrol, and belongs to the technical field of zymoprotein engineering. The enzyme is a mutant enzyme by directionally evoluting natural beta-galactosidase, has novel substrate specificity of a transglycosylation acceptor, can glycosylate resveratrol molecules which cannot be glycosylated, and can be used as a tool enzyme for glycosylated modification of galactose. The beta-galactosidase has wide application prospect in processing phenolic compound, molecular modification of medicines and the like.

The invention discloses a method for synthesizing a β-glucuronidase precipitation-type fluorescent substrate based on 2-(benzothiazole-2'-yl)-4-bromophenol. The synthesis method comprises the following three-step reactions: 1) glycosylation reaction; 2) aromatic ring reaction; 3) deprotection group reaction. In the synthesis method, the reaction yield of each step can reach above the middle level, the highest is more than 90%, the reaction conversion rate of the material with relatively high price or preparation cost is relatively high, and the total yield of the three steps can reach 37%, and the reaction conditions are mild. Easy to implement. At the same time, the glycosylation reaction step and the deprotection group reaction step in the synthesis method can be applied to the synthesis of common fluorescent substrates 4-methylumbelliferyl-β-D with 4-methylumbelliferone as a glycosyl acceptor ‑Glucuronide, the two-step reaction yields can reach 51%, 89%, respectively, and the total yield can reach about 45%.

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 cyclodextrin glucosyltransferase mutant and application thereof, belonging to the technical fields of enzyme engineering and microorganism engineering. The CGTase mutant of the present invention has high product specificity for long-chain glycosylated genistein; use the CGTase mutants A156V / L174P, A156V / L174P / A166Y, A156V / L174P / A166V, A156V / L174P / A166G and A156V of the present invention / L174P / A166K using maltodextrin as a glycosyl donor and genistein as a glycosyl acceptor to produce long-chain glycosylated genistein has a higher yield than wild-type cyclodextrin glucosyltransferase As a glycosyl donor, the production of long-chain glycosylated genistein with genistein as a glycosyl acceptor increased by 62.5%, 165%, 112.5%, 112.5% ​​and 59.4%, respectively.