Isolation and Cytotoxicity of Isocoumarins from the Entomogenous Fungus Setosphaeria sp.

A new isocoumarin compound named setosphacohol A (1), together with six known ones, alternariol (2), isoaltenuene (3), phomasatin (4), alternariol 5-O-methyl ether (5), 1-deoxyrubralactone (6), and rubralactone (7), was isolated from the entomogenous fungus Setosphaeria sp. The structure of the new compound was elucidated by analysis of the 1D and 2D spectroscopic data as well as MS. Compounds 2, 5, 6 showed moderate cytotoxicity against six human tumor cell lines MCF-7, MGC-803, H1975, Huh-7, A549, and HeLa with IC₅₀ values ranging from 23.04 to 96.91 μg·mL^–1. [ABSTRACT FROM AUTHOR]