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

Abstract 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 IC 50 value of 16.2 μM.