A New Antitumor Isoquinoline Alkaloid from the Marine Nudibranch Jorunna funebris

A new dimeric isoquinoline alkaloid, jorumycin (3), has been isolated from the skin and the mucus of the Pacific nudibranch Jorunna funebris. The structure has been fully elucidated on the grounds of ESMS data and of an extensive 2D NMR analysis. The cytotoxicity of 3 was evaluated against various human cancer cell lines and was found to be slightly less potent than Et 743 (2).