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

• Three new highly oxygenated sterols were isolated from Cladosporium sp. SCSIO41007. • All compounds were elucidated by spectroscopic methods. • Absolute configurations were determined by X-ray single-crystal and CD methods. • Compound 2 exhibited weak antiviral activity against H3N2.