Transformation of ginsenosides Rb2 and Rc from Panax ginseng by food microorganisms.

Protopanaxadiol ginsenosides Rb2 and Rc were transformed using cell-free extracts from various edible food microorganisms and then analyzed by TLC and HPLC. Rb2 and Rc were transformed into compound K via Rd and F2 by Bifidobacterium sp. Int57 and Bifidobacterium sp. SJ32. Lactobacillus delbrueckii transformed Rb2 and Rc into ginsenoside Rh2. Bifidobacterium sp. SH5 transformed Rb2 and Rc into F2. Aspergillus niger transformed Rb2 into compound K via compound O and compound Y, whereas it transformed Rc into compound K via Mc. Taken together, these processes would allow a specific bioconversion process to obtain specific ginsenosides using an appropriate combination of ginsenoside substrates and specific microbial enzymes.