CHEMICAL ECOLOGY OF SHALLOW WATER OCTOCORALS. OCCURRENCE OF CEMBRANOLIDES IN PSEUDOPLEXAURA AND EUNICEA

Gorgonians of the genus Pseudoplexaura, from a variety of geographical locations, yield crassin acetate as the major cembranolide. The cembranolides found in Eunicea collected at different locations vary. Eunicin is found in Eunicea mammosa from Bimini, and from a number of other locations. Its position isomer Jeunicin, has been found in the Eunicea from Jamaica. Eunicea from Curacao yields an epimer ot eunicin, Cueunicin, while that from Puerto Rico yields Eupalmerin acetate, and Peunicin occurs in Eunicea collected off Panama. The cembranolides are toxic to various aquatic organisms. They inhibit ciliary action in the ciliate Tetrahymena pyriformis, and in the larvae of the nudibranch Phestilla sibogae.

Isolation and structures of the uprolides. I. Thirteen new cytotoxic cembranolides from the Caribbean gorgonian Euniceamammosa

Thirteen new cembranolide diterpenoids, uprolides 3–15, have been isolated from the Caribbean gorgonian Euniceamammosa collected off the West coast of Puerto Rico. Several known metabolites, such as eupalmerin acetate (1) and eupalmerin (2), were also isolated from the same organism. The structures of the new compounds, which also showed modest in vitro cytotoxic activity, were assigned on the basis of extensive nuclear magnetic resonance analysis, chemical correlation studies, and by comparison with analogous spectral data from known cembranolide diterpenoids. One structure (3) was confirmed by X-ray diffraction analysis. Keywords: uprolides, Euniceamammosa, cytotoxicity, Caribbean, gorgonian.