Prorocentin, a new polyketide from the marine dinoflagellate Prorocentrum lima.

Prorocentin (1), isolated from an okadaic acid-producing organism, Prorocentrum lima, possessed all-trans trienes, an epoxide, as well as the 6/6/6-trans-fused/spiro-linked polyether ring moieties. The unique structure supports the proposed cyclization mechanism, polyene formation, epoxidation, and cyclization, of marine polyether toxins. The relative stereostructure was determined on the basis of spectral data. [structure: see text]