Heptaketides from the endophytic fungus Pleosporales sp. F46 and their antifungal and cytotoxic activities.

Six new heptaketides, pleosporalins A-F (1-5, and 7), and a new heptaketide derivative, pleosporalin G (9), together with four biosynthetically related known compounds (6, 8, 10, and 11), were isolated from an endophytic fungus, Pleosporales sp. F46, found in the medicinal plant Mahonia fortunei . The structures and stereochemistry of these compounds were established by extensive spectroscopic analyses including LC-HRMS, NMR spectroscopy, optical rotations, ECD calculations, and single-crystal X-ray diffraction. The antifungal activities of isolated compounds 1-11 were investigated against Candida albicans , and their cytotoxic activities were evaluated against A549, SMMC-721, and MDA-MB-231 cancer cell lines. Compound 1 was active against C. albicans with an MIC 80 of 128 μg mL -1 , and compound 7 showed moderate cytotoxicity against MDA-MB-231 with an IC 50 of 22.4 ± 1.1 μM. By comparing compounds 1 and 7 with structurally related metabolites, it was revealed that alterations to their C-1 or C-2 substitutions could significantly influence their antifungal or cytotoxic efficacies.