Enzymatic preparation of ginsenosides Rg2, Rh1, and F11)

During investigation of the hydrolysis of a protopanaxatriol-type saponin mixture by various glycoside hydrolases, crude preparations of beta-galactosidase from Aspergillus oryzae and lactase from Penicillium sp. were found to produce two minor saponins, ginsenoside Rg(2) [6-O-(alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl)-20(S)-protopanaxatriol] and ginsenoside Rh-1 (6-O-beta-D-glucopyranosyl-20(S)-protopanaxatriol), respectively, in high yields. Moreover, a naringinase preparation from Penicillium decumbens readily gave an intestinal bacterial metabolite, ginsenoside F-1 (20-O-beta-D-glucopyranosyl-20(S)-protopanaxatriol), as the main product, with a small amount of 20(S)-protopanaxatriol from a protopanaxatriol-type saponin mixture. Also, a hesperidinase from Penicillium sp. selectively hydrolyzed ginsenoside Re into ginsenoside Rg(1). This is the first report on the enzymatic preparation of minor saponins, ginsenosides Rg(2) and Rh-1, and of an intestinal bacterial metabolite, ginsenoside F-1, with high efficiency from a protopanaxatriol-type saponin mixture.