Highly selective hydrolysis for the outer glucose at the C-20 position in ginsenosides by β-glucosidase from Thermus thermophilus and its application to the production of ginsenoside F2 from gypenoside XVII

Abstract

β-Glucosidase from Thermus thermophilus has specific hydrolytic activity for the outer glucose at the C-20 position in protopanaxadiol-type ginsenosides without hydrolysis of the inner glucose. The hydrolytic activity of the enzyme for gypenoside XVII was optimal at pH 6.5 and 90°C, with a half-life of 1h with 3genzymel(-1) and 4g gypenoside XVIIl(-1). Under the optimized conditions, the enzyme converted the substrate gypenoside XVII to ginsenoside F2 with a molar yield of 100% and a productivity of 4gl(-1)h(-1). The conversion yield and productivity of ginsenoside F2 are the highest reported thus far among enzymatic transformations.