IRIOMOTEOLIDES-4A AND-5A, HYDROPHILIC MACROLIDES FROM MARINE DINOFLAGELLATE AMPHIDINIUM SPECIES

摘要

-Two new macrolides, iriomoteolides-4a (1) and-5a (2), have been isolated from a marine benthic dinoflagellate Amphidinium sp. (strain HYA024), and the structures were assigned by detailed analyses of 2D NMR data. Iriomotelide-4a (1) is a 16-membered macrolide with five hydroxyl groups on the lactone ring and an isoprenoid-like side chain, while iriomoteloide-5a (2) is a 20-membered macrolide with five hydroxyl groups and three vicinally-Iocated Cj branches. Iriomoteolides-4a (1) and-5a (2) exhibited moderate cytotoxic activity against antitumor cells.