A new isocoumarin from sponge endophytic fungus Aspergillus ochraceopetaliformis with cytotoxic activity

A new isocoumarin, 8-hydroxy-3-methyliscoumarin-6-yl acetate (1), was isolated together with five known compounds from sponge endophytic fungus Aspergillus ochraceopetaliformis. The structure of the new compound was established based on 1D and 2D NMR spectral analysis. Compounds 1–6 were evaluated for their cytotoxic activities and antimicrobial activities. Compounds 1 and 6 display cytotoxic activities against mouse melanoma cells B16 with IC50 values 72.5 ± 2.6 and 1.0 ± 0.5 µM, respectively. Compounds 4 and 5 displayed faint antimicrobial activities of Bacillus subtilis, Micrococcus luteus and Staphylococcus aureus.