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.