Nakiterpiosin, a Novel Cytotoxic C‐nor‐D‐Homosteroid from the Okinawan Sponge Terpios hoshinota.

A novel cytotoxic compound, nakiterpiosin (1), was isolated from the Okinawan sponge Terpios hoshinota. Its structure was determined by spectroscopic analysis. The absolute stereostructure of 1 was also determined by a modified Mosher's method. Nakiterpiosin showed potent cytotoxicity against P388 cells.