VERRUCOSIN-A AND VERRUCOSIN-B, ICHTHYOTOXIC DITERPENOIC ACID GLYCERIDES WITH A NEW CARBON SKELETON FROM THE DORID NUDIBRANCH DORIS-VERRUCOSA

The dorid nudibranch Doris verrucosa contains in its skin extracts two glycerides (2-3) linked to diterpenoid acid residues. The terpenoids show a rearranged tricyclic skeleton. The structures, inferred from spectral and chemical evidence, were unambiguously determined by X-ray diffraction analysis of 3. Both 2 and 3 are highly ichthyotoxic.