Cytotoxic components from the Xisha sponge .

A new dolabellane diterpenoid, clavirolide H (), together with eleven known compounds, including two dolabellane diterpenoid ( and ), a rare cavernosine-type C -lactone terpenoid (), a diketopiperazine () and seven sterols (-), were isolated from the Xisha sponge . Their structures were elucidated by extensive spectroscopic analysis, and the four types of compounds of the above isolates were reported from the genus for the first time. Selected compounds , - and - were evaluated for cytotoxic activities against K562, HL-60, Hela, HCT-116, A549, L-02 and BEL-7402 cell lines. Compounds - and - showed potent cytotoxicitives against HL-60 with IC values ranging from 8.8 to 12.4 μM. Compounds and exhibited weak cytotoxic activities against HeLa with IC of 20.7 and 27.4 μM, and also has moderate cytotoxicity against HCT-116 with IC of 16.3 μM.[Figure: see text].