Hirsutane sesquiterpenoids from the marine-derived fungus Chondrostereum sp.

A new hirsutane sesquiterpenoid, hirsutanol E (1), together with the known compounds hirsutanol A (2) and hirsutanol F (3; gloeosteretriol) were obtained from AcOEt extract of the marine fungus Chondrostereum sp., which was isolated from the soft coral Sarcophyton tortuosum. The structures were elucidated mainly on the basis of the NMR, MS, and X-ray single-crystal diffraction data. Hirsutanol A (2) exhibited potent cytotoxic activities against various cancer cell lines.