Syntheses of 1-O-benzyl-alpha-glucoside and 1-O-benzyl-alpha-maltoside by transglycosylation of alpha-amylase from soluble starch in aqueous solution

Glycosides, 1-O-benzyl-alpha-glucoside (BG) and 1-O-benzyl-alpha-maltoside (BM), were synthesized from soluble starch and benzyl alcohol by transglyco sylation with an alpha-amylase in a water system. BG was mostly obtained in a reaction mixture of pH 5.0, while BM was synthesized in pH 8.0. The synt hesized glycosides had alpha-configuration linkage between sugar and benzyl alcohol. The BG was rapidly hydrolyzed to benzyl alcohol and glucose by al pha-glucosidase. The BM was hydrolyzed to BG and glucose below pH 5.0 by th e alpha-amylase used for its synthesis but it was not hydrolyzed above pH 8 .0.