Sterols from Thai Marine Sponge Petrosia (Strongylophora) sp. and Their Cytotoxicity

Eight new sterols (1–5 and 11–13), together with eight known compounds (6–10 and 14–16) were isolated from marine sponge Petrosia sp. The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis. The cytotoxicity of some compounds against a panel of human cancer cell lines is also reported.