Stellettazole D, a Cytotoxic Imidazole Alkaloid from the Marine Sponge Jaspis duoaster

A new cytotoxic imidazole alkaloid, stellettazole D, containing norsesquiterpene and aminopropylimidazolium units, has been isolated from the marine sponge Jaspis duoaster. The structure of stellettazole D was assigned on the basis of NMR, mass spectrometry, and IR spectral data. Stellettazole D has moderate cytotoxicity against a limited number of tumor cells.