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Seeking a strategy for triggering the cryptic natural product biosynthesis to yield novel compounds in the plant-associated fungus Xylaria sp., the effect of culture conditions on metabolite production was investigated. A shift in the production of five known cytochalasin-type analogues 1-5 to six new α-pyrone derivatives, xylapyrones A-F (compounds 6-11), from a solid to a liquid medium was observed. These compounds were identified by analysis of 1D and 2D NMR and HRMS data. Compounds 1-3 showed moderate cytotoxicity against HepG2 and Caski cancer cell lines with IC50 values ranging from 25 to 63 μM and compounds 4-11 were found to be inactive, with ICY50 values >100 μM. [ABSTRACT FROM AUTHOR]

Five new 2(5H)-furanone-type derivatives, pestalafuranones F-J (compounds 3-7), together with two known compounds, pestalafuranones A (1) and B (2), were isolated from the ethyl acetate extract from the fermentation broth of the endophytic fungus Nigrospora sp. BM-2 in a hypersaline medium. The structures of these metabolites were elucidated by EIMS, HREIMS and NMR spectroscopic data. Compounds 1-7 exhibited no cytotoxic activities against the MDA-MB-231 and Caski cancer cell lines. [ABSTRACT FROM AUTHOR]

A new isoflavipucine derivative, (8S, 9R)-dihydroisoflavipucine (1), is isolated from an ethyl acetate extract of endophytic fungi Botryosphaeria dothidea (D4-2) derived from Taxus mairei. The structure of 1 is elucidated based on nuclear magnetic resonance, circular dichroism, and mass spectrometry. The antiproliferative activity of the isolates against breast cancer cells MDA-MB-231, MCF7 and 4T1 are evaluated. [ABSTRACT FROM AUTHOR]

A new α-pyrone derivative 1, along with four known congeners 2, 3, 4 and 5, were isolated from the solid-substrate fermentation medium of the endophytic fungus Pestalotiopsis microspore isolated from the branch of Taxus chinensis. Their structures and relative configurations were elucidated by extensive spectroscopic analysis. The cytotoxic activities of the isolated α-pyrone derivatives against two tumor cell lines as well as compound 1's antimicrobial activity against three bacteria and three plant-pathogenic strains were evaluated. No antimicrobial activity was observed for compound 1. The cytotoxicity against Caski and HeLa tumor cell lines was insignificant. To our surprise, the known compound 4 showed significant gibberellin synergistic activity towards Distylium chinense seeds. [ABSTRACT FROM AUTHOR]