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

The ω-hydroxyl-panaxytriol (1) and ω-hydroxyl-dihydropanaxytriol (2)-are rare examples of polyacetylene metabolism by microbial transformation, and these new metabolites (1, 2) from fermented red ginseng (FRG) by solid co-culture induction of two Chaetomium globosum should be the intermediates of biotransformation of panaxylactone (metabolite A). 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 (3). The ω-hydroxylation of new intermediates (1, 2) decreases cytotoxicity and antifungal activity against C. globosum compared with that of its bioprecursor panaxytriol. Additionally, compounds 1 and 2 indicated obvious inhibition against nitric oxide (NO) production, with ratios of 44.80 ± 1.37 and 23.10 ± 1.00% at 50 µM. 1 has an equivalent inhibition of NO production compared with the positive drug. So, the microbial biotransformation that occurred in FRG fermented by gut C. globosum can change the original bioactivity of polyacetylene, which gave a basis about the metabolic modification of red ginseng by intestinal fungus fermentation.

Inducing secondary metabolite production from Daldinia eschscholzii JC-15 by red ginseng medium.

Red ginseng (RG) is one of the most popular herbal medicines and used as a dietary supplement in recent years. The bioactive ingredient in RG can induce the production of novel microbial metabolite from fermented RG. Using the one strain-many compounds strategy, the reinvestigation of the metabolites from Daldinia eschscholzii JC-15 cultured in red ginseng medium led to the isolation of an unprecedented benzopyran-naphthalene hybrid, daldinsin (1) and a new lactone (2). In this research, a new lactone, 8-hydroxylhelicascolide A (2) instead of helicascolide A was produced by the D. eschscholzii JC-15 induced by the red ginseng medium. Compound 1 showed anti-acetylcholinesterase activity with the inhibition ratio of 38.8% at 50 µM. Compound 2 indicated antimicrobial activities against Fusarium Solani, F. oxysporum, and Escherichia coli with MICs at 128 µg/mL. RG is therefore a promising activator in production of novel microbial metabolite.

New azaphilones and tremulane sesquiterpene from endophytic Nigrospora oryzae cocultured with Irpex lacteus.

Five new metabolites belonging to two backbones of pulvilloric acid-type azaphilone and tremulane sesquiterpene were obtained and their structures were determined by spectral analysis. Based on the biogenesis analysis, tremulane sesquiterpenes were obtained from Irpex lacteus by the stimulation of mixed-culture. The antifungal selectivities of metabolites produced by fungus against their co-culture fungus and common pathogens, exhibited competitive interaction of this mix-culture. The tremulane sesquiterpene conocenol B produced by I. lacteus through the induction of Nigrospora oryzae showed selectivity of anti-fungal activity against its co-culture fungus, N. oryzae, with MICs at 16 µg/mL and 128 µg/mL against I. lacteus. The fungus can metabolize these new compounds to inhibit the growth of co-culture fungus while not inhibiting its own growth. Compound 5 was active against acetylcholinesterase (AChE) with a ratio of 35% at the concentration of 50 µM.

Phytotoxic, antibacterial, and antioxidant activities of mycotoxins and other metabolites from Trichoderma sp.

A new natural mycotoxin was isolated from the fermentation broth of Trichoderma sp. Jing-8 and the structure was determined as alternariol 1'-hydroxy-9-methyl ether (1), together with twelve known compounds. The structures were elucidated on the basis of their 1D, 2D NMR spectra and mass spectrometric data. Compounds 1, 8 and 9 indicated inhibitions against germination of the seeds of cabbage with MICs < 3 µg/mL. The compound 1 showed the antibacterial activity against Bacillus subtilis and Staphylococcus aureus with MICs at 64 µg/mL. Compound 1 and 3 showed significant DPPH radical-scavenging activities with IC50 at 12 µg/mL, respectively. The OH at C-1' in compound 1 decreased the cytotoxicity of these mycotoxins. A primary structure-activity relationship about the alternariol derivatives was discussed. Compounds 2-7 and 8 were the first time to be isolated from the Trichoderma.