Aaptamine Derivatives from the Indonesian Sponge Aaptos suberitoides

Four new aaptamine derivatives (1-4) along with aaptamine (5) and three related compounds (6-8) were isolated from the ethanol extract of the sponge Aaptos suberitoides collected in Indonesia. The structures of the new compounds were unambiguously determined by one- and two-dimensional NMR and by HRESIMS measurements. Compounds 3, 5, and 6 showed cytotoxic activity against the murine lymphoma L5178Y cell line, with IC(50) values ranging from 0.9 to 8.3 μM.