A New Sesterterpene from the Korean Sarcotragus sp. Sponge

Sarcotragin C (1), a new sesterterpene metabolite was isolated from a Sarcotragus sp. sponge collected from Chuja Island, Korea. On the basis of the combined spectroscopic analyses, the structure of this compound was determined to be a linear norsesterterpene containing a leucine-derived gamma-lactam moiety. This compound exhibited moderate cytotoxicity against K562 and A549 cell-lines.