Induced production of zinniol analogues by co-cultivation of two endophytic fungi in the same ecological niche

Three zinniol analogues, pleoniols A-C (1-3), together with a known compound (4), were isolated from a mixed fermentation of two endophytic fungi, Pleosporales sp. F46 and Acremonium pilosum F47, both of which are found the pedicel of the medicinal plant Mahonia fortunei. High-performance liquid chromatography analysis showed that none of compounds 1-4 were detected when either one of the two fungi was cultured alone. The structures of compounds 1-4, including the absolute configurations, were deduced based on the interpretation of HRMS, NMR, and optical rotation data. Compounds 1-3 exhibited no antimicrobial efficacies against four Gram-positive or Gram-negative bacteria and two plant pathogenic fungi. Moreover, they demonstrated no obvious cytotoxic activities against four cancer cell lines, A549, MDA-MB-231, CT-26 and MCF-7. Our work indicates that the coculture of endophytes in the same ecological niche is an effective approach for promoting interspecies interaction and enriching chemical diversity.