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

Sucrose phosphorylase from Leuconostoc mesenteroides was found to catalyze 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 gallate=(+)-catechin>(-)-epicatechin>(-)-epigallocatechin gallate>(-)-epigallocatechin. About 150 mg of the purified transfer 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 analyses of its enzymatic hydrolyzates, and the nulcear magnetic resonance 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 antioxidative activity of C-G in the aqueous system with riboflavin was almost equal to that of (+)-catechin. In addition, C-G strongly inhibited tyrosinase, in contrast with (+)-catechin, which is the substrate of tyrosinase. The inhibitory pattern of C-G was competitive using L-beta-3,4-dihydroxyphenylalanine as a substrate.