Inducing Intermediates in Biotransformation of Natural Polyacetylene and A Novel Spiro-γ-Lactone from Red Ginseng by Solid Co-Culture of Two Gut and The Potential Bioactivity Modification by Oxidative Metabolism.

The ω-hydroxyl-panaxytriol () and ω-hydroxyl-dihydropanaxytriol ()-are rare examples of polyacetylene metabolism by microbial transformation, and these new metabolites (, ) from fermented red ginseng (FRG) by solid co-culture induction of two should be the intermediates of biotransformation of panaxylactone (metabolite ). The metabolic pathway of panaxylactone was also exhibited. The ingredients of red ginseng (RG) also induced the production of rare 6/5/5 tricyclic ring spiro-γ-lactone skeleton (). The ω-hydroxylation of new intermediates (, ) decreases cytotoxicity and antifungal activity against compared with that of its bioprecursor panaxytriol. Additionally, compounds and indicated obvious inhibition against nitric oxide (NO) production, with ratios of 44.80 ± 1.37 and 23.10 ± 1.00% at 50 μM. has an equivalent inhibition of NO production compared with the positive drug. So, the microbial biotransformation that occurred in FRG fermented by gut can change the original bioactivity of polyacetylene, which gave a basis about the metabolic modification of red ginseng by intestinal fungus fermentation.