Enzymatic transformation of the major ginsenoside Rb2 to minor compound Y and compound K by a ginsenoside-hydrolyzing β-glycosidase from Microbacterium esteraromaticum.
The ginsenoside-hydrolyzing β-glycosidase (Bgp3) derived from Microbacterium esteraromaticum transformed the major ginsenoside Rb2 to more pharmacologically active minor ginsenosides including compounds Y and K. The bgp3 gene consists of 2,271 bp encoding 756 amino acids which have homology to the glycosyl hydrolase family 3 protein domain. Bgp3 is capable of hydrolyzing beta-glucose links and arabinose links. HPLC analysis of the time course of ginsenoside Rb2 hydrolysis by Bgp3 (0.1 mg enzyme ml(-1) in 20 mM sodium phosphate buffer at 40 °C and pH 7.0) showed that the glycosidase first hydrolyzed the inner glucose moiety attached to the C-3 position and then the arabinopyranose moiety attached to the C-20 position. Thus, Bgp3 hydrolyzed the ginsenoside Rb2 via the following pathway: Rb2 → compound Y → compound K.
Department of Oriental Medicinal Material and Processing, College of Life Science, Korean Ginseng Center Most Valuable Products and Ginseng Genetic Resource Bank, Kyung Hee University, Seocheon-dong, Giheung-gu, Gyeonggi-do 446-701, Republic of Korea.
Lin-Hu
LH
Quan
Yan
Y
Jin
Chao
C
Wang
Jin-Woo
JW
Min
Yeon-Ju
YJ
Kim
Deok-Chun
DC
Yang
D000192:Actinomycetales / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D036145:Ginsenosides / Q000737:chemistry / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D013379:Substrate Specificity; D013997:Time Factors
D036145:Ginsenosides; C048026:ginsenoside Rb2; D006026:Glycoside Hydrolases