Three new highly oxygenated sterols and one new dihydroisocoumarin from the marine sponge-derived fungus Cladosporium sp. SCSIO41007

Three new highly oxygenated sterols (1-3) and a new dihydroisocoumarin (7) together with six known compounds were isolated from the extracts of the culture of a sponge-derived fungus Cladosporium sp. SCSIO41007. The structures of all new compounds (1-3, 7) were determined by the extensive spectroscopic analysis including NMR, MS, IR, and UV. Their absolute configurations were determined by X-ray single-crystal and CD data analysis. Compound 2 exhibited weak inhibitory activity against H3N2 with the IC50 value of 16.2 μM.