345319-75-7

Upstream product

• 2106-10-7 1-deoxy-1-fluoro-α-D-glucose 
• 154-23-4 catechin 
• 1980-14-9 maltoheptaose 
• 1184-46-9 Maltohexaose 
• 1668-09-3 Maltopentaose 
• 1263-76-9 Maltotetraose 
• 6401-81-6 maltotriose 
• 17465-86-0 cyclomaltooctaose 

Relevant academic research and scientific papers

pH-promoted O-α-glucosylation of flavonoids using an engineered α-glucosidase mutant

Retaining glycosidase mutants lacking its general acid/base catalytic residue are originally termed thioglycoligases which synthesize thio-linked disaccharides using sugar acceptor bearing a nucleophilic thiol group. A few thioglycoligases derived from retaining α-glycosidases have been classified into a new class of catalysts, O-glycoligases which transfer sugar moiety to a hydroxy group of sugar acceptors, resulting in the formation of O-linked glycosides or oligosaccharides. In this study, an efficient O-α-glucosylation of flavonoids was developed using an O-α-glycoligase derived from a thermostable α-glucosidase from Sulfolobus solfataricus (MalA-D416A). The O-glycoligase exhibited efficient transglycosylation activity with a broad substrate spectrum for all kinds of tested flavonoids including flavone, flavonol, flavanone, flavanonol, flavanol and isoflavone classes in yields of higher than 90%. The glucosylation by MalA-D416A preferred alkaline conditions, suggesting that pH-promoted deprotonation of hydroxyl groups of the flavonoids would accelerate turnover of covalent enzyme intermediate via transglucosylation. More importantly, the glucosylation of flavonoids by MalA-D416A was exclusively regioselective, resulting in the synthesis of flavonoid 7-O-α-glucosides as the sole product. Kinetic analysis and molecular dynamics simulations provided insights into the acceptor specificity and the regiospecificity of O-α-glucosylation by MalA-D416A. This pH promoted transglycosylation using O-α-glycoligases may prove to be a general synthesis route to flavonoid O-α-glycosides.

METHOD FOR GLYCOSYLATION OF FLAVONOID COMPOUNDS

The present invention provides a method for preparing a glycoside of a flavonoid compound, which comprises the step of treating flavonoid and a glycosyl donor with an enzymatic agent having glycosylation activity and being derived from the genus Trichoderma (preferably Trichoderma viride or Trichoderma reesei). Such a flavonoid compound includes a catechin compound or a methylated derivative thereof, and the glycosyl donor includes a carbohydrate containing a maltotriose residue (preferably maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose, dextrin, γ-cyclodextrin or soluble starch). Glycosides obtained by the present invention have higher water solubility, improved taste, and increased stability. The present invention also provides novel glycosides of catechin compounds, which are obtained by the method of the present invention.