Microbial deglycosylation and ketonization of ginsenosides Rg₁ and Rb₁ by Fusarium oxysporum

Abstract

Two major ginsenosides, ginsenoside-Rg₁ (1) and ginsenoside-Rb₁ (2), were transformed by the fungus Fusarium oxysporum f. sp. Lycopersici (Z-001). 1 was converted into five metabolites, ginsenoside-F₁ (3), 6α,12β-dihydroxydammar-3-one-20(S)-O-β-d-glucopyranoside (4), 3a-oxa-3a-homo-6α,12β-dihydroxydammar-3-one-20(S)-O-β-d-glucopyranoside (5), 20(S)-protopanaxatriol (6), and 3-oxo-20(S)-protopanaxatriol (7). 2 was converted into four metabolites, ginsenoside-Rd (8), ginsenoside-F₂ (9), compound K (10), and 12β-hydroxydammar-3-one-20(S)-O-β-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.

Keywords:

• ginsenosides
• Fusarium oxysporum
• deglycosylation
• ketonization

Acknowledgements

This work was financially supported by the National Science & Technology Major Project ‘Key New Drug Creation and Manufacturing’, China (No. 2009ZX09301-003-4-1), and the Program for New Century Excellent Talents in University (NCET-06-0155).