Novel enzymatic approach to the synthesis of flavonoid glycosides and their esters

• Published in: Biotechnology and bioengineering Vol. 71; no. 3; pp. 235 - 243
• Main Authors: Gao, Chunli, Mayon, Patrick, MacManus, David A., Vulfson, Evgeny N.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 2000; Wiley
• Subjects: Acrylic Resins - chemistry; Alcohols; Bioconversions. Hemisynthesis; Biological and medical sciences; Biotechnology; catechin; Catechin - chemical synthesis; Catechin - chemistry; Enzymes, Immobilized; Esters - chemical synthesis; flavonoid; flavonoid glycosides; Flavonoids - chemistry; Fundamental and applied biological sciences. Psychology; glycosidase; glycosides; Glycosides - chemical synthesis; glycosylation; lipase; Lipase - metabolism; Methods. Procedures. Technologies; supersaturated solutions; transesterification; Enzymatic synthesis; Catechin; Enzyme; Triacylglycerol lipase; Esterases; Transesterification; Flavonoid; Carboxylic ester hydrolases; Ester; Supersaturated solution; Glycosidases; Hydrolases; Glycoside
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/1097-0290(2000)71:3<235::AID-BIT1013>3.0.CO;2-M

Flavonoids such as (+)catechin can be efficiently solubilised in supersaturated solutions prepared with donor glycosides, e.g., p‐nitrophenyl glycosides, di‐ and higher oligosaccharides, and poly(ethylene glycol) dimethyl ether in sufficiently high concentration for their efficient enzymatic glycosylation. Under these conditions several glycosidases readily accept (+)catechin as substrate and the target glycosides were prepared in one step in up to 26% yields. The regioselectivity of the reaction depends on the enzyme and substrate combination used; three positions, 5, 7, and 4′, in the flavonoid can be glycosylated. The resulting and similar flavonoid glycosides were further modified by regioselective acylation with vinyl esters of arylpropenoic acids using lipases as biocatalyst. The efficiency of acylation was found to diminish in the order of vinyl cinnamate > vinyl ferulate > vinyl coumarate. This work demonstrates the feasibility of assembling complex flavonoid glycoside esters in just two steps by sequential use of commercially available glycosidases and lipases. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 71: 235–243, 2000/2001.