Four new steroids from the marine soft coral-derived fungus Penicillium sp. SCSIO41201

Penicildiones A−D ( 1 − 4 ), four new steroids derivatives together with three known compounds including 16α-methylpregna-17α,19-dihydroxy-(9,11)-epoxy-4-ene-3,18-dione-20-acetoxy ( 5 ), stachybotrylactone B ( 6 ) and stachybotrin ( 7 ) were isolated from the soft coral-derived fungus Penicillium sp. SCSIO41201, cultured in the 1% NaCl PDB substrate. Their structures were determined through spectroscopic methods and X-ray crystallography. Biological evaluation results revealed that 6 exhibited significant cytotoxic activity against HL-60, K562, MOLT-4, ACHN, 786-O, and OS-RC-2 cell lines with IC₅₀ values of 5.23, 4.12, 4.31, 23.55, 7.65 and 10.81 μmol·L⁻¹, respectively, while other compounds showed weak or no cytotoxicity at 50 μmol·L⁻¹.