Isothiocyanate Sesquiterpenes from a sponge of the genus Axinyssa

The chemical study of a sponge of the genus Axinyssa collected in the Gulf of California has led to the isolation of the new bicyclic sesquiterpenes axinisothiocyanates A-L (1-12) together with the known compounds (1R,6S,7S,10S)-10-isothiocyanato-4-amorphene (13), (4R*,5R*,7S*,IOR*)-4-isocyanoeudesm-11-ene, (-)-epipolasin A, and (+)-aristolone. The structures of the new metabolites have been established by spectroscopic techniques, including the analysis of pyridine-induced H-1 NMR chemical shifts. The cytotoxic activity has been tested against three human tumor cell lines.