A new steroid with long cross-conjugation structure from the marine-derived fungus Aspergillus aculeatus.

A new steroid with a long cross-conjugation structure, 15a-hydroxy-(22E, 24R)-ergosta-3, 5, 8 (14), 22-tetraen-7-one (1), was isolated from the marine-derived fungus Aspergillus aculeatus. Its structure was established by the extensive spectroscopic analyses, and its cytotoxicities against P388, HL-60, and PC-3 cell lines were measured in vitro.