Metabolites with cytotoxic activity from the Formosan soft coral Cladiella australis

The metabolites, (24S)-3 beta-acetoxyergost-5-en-21-oic acid (2), 5'-O-acetylthymidine (3), 3'-O-acetylthymidine (4), and p-vinylbenzy] alcohol (5), along with a known steroid (1) were isolated from the EtOAc extract of the Formosan soft coral Caldiella australis. The structures of new metabolites were determined on the basis of spectroscopic (including 1D and 2D NMR) analyses and by comparison of their NMR spectral data with those of related compounds. Except for 3, all compounds exhibited cytotoxic activity of various degrees of potency against a limited panel of human liver and breast cancer cell lines.