2H-pyranone and isocoumarin derivatives from the endophytic fungus Pestalotiopsis microspora SC3082 derived from Scaevola taccada (Gaertn.) Roxb

Two new 2H-pyranones (1 and 2), two new isocoumarins (4 and 5), and two known compounds (3 and 6) were obtained from solid cultures of the endophytic fungus Pestalotiopsis microspora SC3082. Their structures and revision of the absolute stereochemistry of 6 were established by spectroscopic analyses and computational calculations. Compounds 2, 4 and 6 displayed moderate antifungal activities against Candida albicans ATCC 10321 with MIC values of 25.0, 25.0, and 12.5 μg/mL, respectively.