Reaction: ginsenoside Rb1 + 2 H2O = ginsenoside Rg3 + 2 D-glucopyranose (overall reaction)
(1a) ginsenoside Rb1 + H2O = ginsenoside Rd + D-glucopyranose
(1b) ginsenoside Rd + H2O = ginsenoside Rg3 + D-glucopyranose
For diagram of reaction click here.
Glossary: ginsenoside Rb1 = 3β-[β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyloxy]-20-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyloxy]dammar-24-en-12β-ol
ginsenoside Rd = 3β-[β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyloxy]-20-(β-D-glucopyranosyloxy)dammar-24-en-12β-ol
ginsenoside F2 = 3β,20-bis(β-D-glucopyranosyloxy)dammar-24-en-12β-ol
Systematic name: ginsenoside Rb1 glucohydrolase
Comments: Ginsenosidases catalyse the hydrolysis of glycosyl moieties attached to the C-3, C-6 or C-20 position of ginsenosides. They are specific with respect to the nature of the glycosidic linkage, the position and the order in which the linkages are cleaved. Ginsenoside Rb1 β-glucosidase specifically and sequentially hydrolyses the 20-[β-D-glucopyranosyl-(1→6)-β-D glucopyranosyloxy] residues attached to position 20 by first hydrolysing the (1→6)-glucosidic bond to generate ginsenoside Rd as an intermediate, followed by hydrolysis of the remaining 20-O-β-D-glucosidic bond.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Yan, Q., Zhou, W., Li, X., Feng, M. and Zhou, P. Purification method improvement and characterization of a novel ginsenoside-hydrolyzing β-glucosidase from Paecilomyces Bainier sp. 229. Biosci. Biotechnol. Biochem. 72 (2008) 352-359. [PMID: 18256474]