New cytotoxic and anti-inflammatory steroids from the soft coral Klyxum flaccidum.

Four new steroids, namely klyflaccisteroids G-J (1-4) were isolated from the Formosan soft coral Klyxum flaccidum. The structures of compounds 1-4 were established by spectral data analysis (IR, MS, 1D and 2D NMR) and comparison of spectral data with those of the related known compounds. Cytotoxicity assay revealed that 4 exhibited inhibition activity against the growth of HT-29, P388 and K562 cancer cell lines, whereas 2 showed selective cytotoxicity toward P388 cells. Compound 4 was also found to display significant anti-inflammatory activity for suppressing superoxide anion generation (O2(-)) and elastase release.