Cytotoxic Monocarbocyclic Sesterterpenoids from a Marine Sponge Luffariella sp

Six new monocarbocyclic sesterterpenoids, luffalides A–F 1–6, together with four known sesterterpenes 7–10, were isolated from a marine sponge Luffariella sp. The structures of compounds 1–6 were elucidated on the basis of spectroscopic data analysis (NMR and CD) and comparison of the spectroscopic data with those of known analogues. Among these new metabolites, compounds 1–5 are rarely found in monocarbocyclic sesterterpenoids possessing a 1-isopropenyl-2-methylcyclopentane ring system. Evaluation of the cytotoxicities showed that compound 10 exhibited significant cytotoxicity against HL-60, MOLT-4 and K-562 cell lines, with IC50 values of 0.54, 0.32, and 0.96 µM, respectively. Moreover, compound 9 also showed significant HL-60 and MOLT-4 inhibitory activity, with IC50 values of 1.87 and 1.13 µM.