THE SYNTHESES OF CATECHIN-GLUCOSIDES BY TRANSGLYCOSYLATION WITH LEUCONOSTOC-MESENTEROIDES SUCROSE PHOSPHORYLASE

Sucrose phosphorylase from Leuconostoc mesenteroides was found to cata lyze transglycosylation from sucrose to catechins. All catechins were efficient glycosyl acceptors and their transfer ratios were more than 40%. The acceptor specificity of the enzyme decreased in the following order: (-)-epicatechin =(+)-catechin>(-)-epicatechin>(-)-epigallocate chin gallate>(-)-epigallocatechin. About 150 mg of the purified transf er product was obtained from 100 mg of (+)-catechin. Its structure was identified as (+)-catechin 3'-O-alpha-D-glucopyranoside (C-G) on the bases of the secondary ion mass spectrometry analysis, the component a nalyses of its enzymatic hydrolyzates, and the nulcear magnetic resona nce analysis. The browning resistance of C-G to light irradiation was greatly increased compared to that of (+)-catechin. The solubility of C-G in water was 50-fold higher than that of (+)-catechin. The antioxi dative activity of C-G in the aqueous system with riboflavin was almos t equal to that of (+)-catechin. In addition, C-G strongly inhibited t yrosinase, in contrast with (+)-catechin, which is the substrate of ty rosinase. The inhibitory pattern of C-G was competitive using L-beta-3 ,4-dihydroxyphenylalanine as a substrate.