Anti-tumor Activity of Lemnalol isolated from the Soft Coral Lemnalia tenuis VERSEVELDT

Abstract

Anti-tumor activities of lemnalol (I), a new ylangene-type sesquiterpenoid isolated from the Japanese soft coral Lemnalia tenuis VERSEVELDT, its stereoisomer (II) and ketone derivative, lemnalone (III), were studied. Lemnalol (I) renders murine peritoneal exudate cells (PEC) cytotoxic, though it has no direct cytotoxicity itself, to syngeneic tumor cells in vitro, while it also inhibits tumor growth in vivo. The stereoisomer (II) does not show PEC-mediated or direct cytotoxicity, while lemnalone (III) exhibits strong direct cytotoxicity in vitro. It is suggested that the 4α-configuration of lemnalol (I) is essential for its anti-tumor activity by PEC activation in vitro.