Antifeedant and antiphytopathogenic metabolites from co-culture of endophyte Irpex lacteus, phytopathogen Nigrospora oryzae, and entomopathogen Beauveria bassiana.

Five new tremulane sesquiterpenoids were isolated from co-culture of endophyte Irpex lacteus, phytopathogen Nigrospora oryzae, and entomopathogen Beauveria bassiana. All compounds showed obvious antifeedant activities against silkworm with inhibition percentages of 73-99%, at concentrations of 50 µg/cm2. Compound 11 indicated notable antifeedant activity with inhibition percentage of 93% at concentration of 6.25 µg/cm2 among them. Compounds 2, 3, 4, 8, 9, 15 and 16 indicated anti-fungal activities against I. lacteus with MIC values ≤8 µg/mL, compounds 11, 12, 16-18 showed significant anti-fungal activity against N. oryzae with MICs ≤ 4 µg/mL, and compounds 2, 5, 12 and 18 indicated significant anti-fungal activity against B. bassiana with MICs ≤ 8 µg/mL. In addition, the I. lacteus should unite B. bassiana to inhibit the production of phytotoxins from N. oryzae in the ternary culture.

Biotransformation of natural polyacetylene in red ginseng by Chaetomium globosum.

BACKGROUND: Fermentation has been shown to improve the biological properties of plants and herbs. Specifically, fermentation causes decomposition and/or biotransformation of active metabolites into high-value products. Polyacetylenes are a class of polyketides with a pleiotropic profile of bioactivity. METHODS: Column chromatography was used to isolate compounds, and extensive NMR experiments were used to determine their structures. The transformation of polyacetylene in red ginseng (RG) and the production of cazaldehyde B induced by the extract of RG were identified by TLC and HPLC analyses. RESULTS: A new metabolite was isolated from RG fermented by Chaetomium globosum, and this new metabolite can be obtained by the biotransformation of polyacetylene in RG. Panaxytriol was found to exhibit the highest antifungal activity against C. globosum compared with other major ingredients in RG. The fungus C. globosum cultured in RG extract can metabolize panaxytriol to Metabolite A to survive, with no antifungal activity against itself. Metabolites A and B showed obvious inhibition against NO production, with ratios of 42.75 ± 1.60 and 63.95 ± 1.45% at 50 µM, respectively. A higher inhibitory rate on NO production was observed for Metabolite B than for a positive drug. CONCLUSION: Metabolite A is a rare example of natural polyacetylene biotransformation by microbial fermentation. This biotransformation only occurred in fermented RG. The extract of RG also stimulated the production of a new natural product, cazaldehyde B, from C. globosum. The lactone in Metabolite A can decrease the cytotoxicity, which was deemed to be the intrinsic activity of polyacetylene in ginseng.

New Bisabosquals from Stachybotrys sp. PH30583 Elicited on Solid Media.

Stachybotrys sp. PH30583 cultured in liquid medium only led to one structure type of novel isochroman dimers. Using the one strain-many compounds strategy, the reinvestigation of the metabolites from Stachybotrys sp. PH30583 cultured in rice solid medium led to the isolation of four triprenyl phenols, including two new bisabosquals and two known phenylspirodrimanes. Nitrobisabosquals A and B (1 and 2) are the first case of pyrrolidone-bisabosquals reported in literature. Totally different compounds were isolated using rice solid medium, compared with those isolated using liquid medium, so that rice solid medium presents a key factor in the production of triprenyl phenols. Compound 1 exhibited cytotoxicity against tumor cells, A-549, HL-60, MCF-7 SMMC-7721, and SW480, as well as weak anticoagulant activity with activated partial thromboplastin time (APTT) of 32.1 ± 0.17 s (p < 0.05 vs. Con.) at a concentration of 5 mM. Triprenyl phenol metabolites could be used as chemotaxonomic markers for Stachybotrys.

Potential antihyperlipidemic polyketones from endophytic Diaporthe sp. JC-J7 in Dendrobium nobile.

Eleven new polyketones named diaporthsins A-K (1-11) were isolated from the fermentation of Diaporthe sp. JC-J7. The chemical structures of compounds (1-11) were elucidated by spectroscopic methods including HRESIMS, 2DNMR, NMR and chemical methods. Compound 11 features an unusual acyclic polyketone-phenolic polyketone hybrid structure that integrates the characteristics of different fungal metabolites (cytosporone and multiplolide). Compound 3 was the only C12-polyketone obtained in this research. These new polyketones showed inhibitory activity on triglycerides (TG) in steatosis hepatocyte L-02 cells. Among them, compound 5 and (4E)-6,7,9-trihydroxydec-4-enoic acid displayed inhibitory activities on TG in steatotic L-02 cells with inhibition ratios of 26% and 21% at concentration of 5 µg mL-1; also, inhibition ratios of 8-O-acetylmultiplolide A and phomopsisporone A at concentration of 5 µg mL-1 were calculated to be about 24% and 16%, respectively, which were equivalent to the antihyperlipidemic activity of lovastatin. The preliminary structure-activity relationship indicated that acetyl at C-8 can increase the antihyperlipidemic activity of multiplolide A and the glycol ester and hydroxyl at C-6 can also increase the corresponding activity of diaporthsin B.