Isolation and Identification of Two Tetrahydroxylated Sterols with Cytotoxic Activity

Two cytotoxic activity sterols 23-nor-ergost-24(28)-ene-3 beta,5 alpha,6 beta,7 beta-tetrol (1) and ergost-24(28)-ene-3 beta,6 beta,9 alpha,19 beta-tetrol (2) from Dendronephthya sp. collected from Naozhou Islands of the South China Sea have been reported. Their structures were defined by spectroscopic and chemical methods. Sterol 1 is a new compound, which exhibited cytotoxicity against BEL-7402, MCG, MCF, LOVO and HepG-2 cells (IC(50) 32.2, 20.5, 2.0, 5.5 and 18.6 mu g/mL, respectively). Sterol 2 also showed significant cytotoxicity against MCG and LOVO cells (IC(50) 22.0 and 13.8 mu g/mL, respectively).