Amphidinolide V, novel 14-membered macrolide from marine dinoflagellate Amphidinium sp.

A novel 14-membered polyene macrolide, amphidinolide V (1), has been isolated from a marine dinoflagellate Amphidinium sp., and the structure was elucidated by spectroscopic data. The relative stereochemistry of C-8, C-9, C-10, and C-13 was elucidated by NOESY correlations. Amphidinolide V (1) possessing five exo-methylenes and one epoxide exhibited cytotoxicity against tumor cell lines.