Microbial deglycosylation and ketonization of ginsenosides Rg_1 and Rb_1 by Fusarium oxysporum

摘要

Two major ginsenosides, ginsenoside-Rgi (1) and ginsenoside-Rbj (2), were transformed by the fungus Fusarium oxysporum f. sp. Lycopersici (Z-001). 1 was converted into five metabolites, ginsenoside-Fi (3), 6a,12P-dihydroxydammar-3-one-20(S)-O-beta-D-gluco-pyranoside (4), 3a-oxa-3a-homo-6a,12P-dihydroxydammar-3-one-20(5)-O-p-D-glucx)-pyranoside (5), 20(S)-protopanaxatriol (6), and 3-oxo-20(S)-protopanaxatriol (7). 2 was converted into four metabolites, ginsenoside-Rd (8), ginsenoside-F_2 (9), compound K (10), and 12 beta-hydroxydammar-3-one-20(S)-O-beta-D-glucopyranoside (11). The structures of these metabolites were determined by the analysis of extensive spectroscopic data. Among them, 4 and 5 were two new compounds. Deglycosylation and ketonization at C-3 were recognized as the characteristic reactions of this strain.