Studies of Australian Ascidians. III. A New Tetrahydrocannabinol Derivative From the Ascidian Synoicum castellatum

Extracts of the colonial ascidian Synoicum castellatum have yielded four compounds derived from prenylated hydroquinones . These included a new tetrahydrocannabinol derivative (6), the first to be isolated from a marine source. Its structure was identified on the basis of one- and two-dimensional n.m.r. experiments at 300 MHz. The known quinone (3), the hydroquinone (4) and the chromene (5) were readily identified by spectral comparison with literature values. Cytotoxicity for (6) against a panel of cultured cell lines is reported.