Bioassay-guided isolation of bioactive compounds from a plant-derived endophytic fungus Talaromyces funiculosus TF37

The bioassay-guided isolation of an endophytic fungus Talaromyces funiculosus TF37 yielded a total of eleven compounds (1-11), including three undescribed compounds, a bicyclic tetralone named tanicutone D (1) and two prenylated indole alkaloids named mangrovamides L (4) and M (5). The undescribed structures were elucidated by comprehensive spectroscopic analyses of HR-ESI-MS, 1D and 2D NMR, as well as ECD calculations. All isolates were evaluated by the antimicrobial assay against Staphylococcus aureus, Saccharomyces cerevisiae, Candida albicans, and MRSA. Compounds 1-3 were found to have significant antimicrobial activities toward four tested microbials, and especially 2 exhibited potent inhibition with the MIC of 0.5-1.0 μg/mL against S. aureus. Furthermore, 1 and 2 also showed moderate cytotoxic activities (IC₅₀ 16.0-25.5 μM) against four kinds of tumor cell lines. The biosynthetic pathway of compound 5 was proposed.