Colopsinol A, a Novel Polyhydroxyl Metabolite from Marine Dinoflagellate Amphidinium sp.

: Colopsinol A (1), a novel polyhydroxyl compound, has been isolated from the cultured marine dinoflagellate Amphidinium sp., from which a number of cytotoxic macrolides, amphidinolides, have been obtained to date, and the gross structure of 1 was elucidated on the basis of extensive spectroscopic analyses including recent 2D NMR techniques of CH(2)-selected editing HSQC as well as FABMS/MS experiments and chemical means. Colopsinol A (1), C(71)H(119)O(25)SNa, is the first member of a new class of polyketide natural products possessing a gentiobioside moiety and a sulfate ester. The polyketide aglycon consisted of a C(56)-linear aliphatic chain with one exo-methylene and two methyl branches as well as two ketones, five hydroxyl groups, and a tetrahydropyran and two epoxide rings.