Abstract: Soft corals yield a wide variety of terepenes, steroids and glycosides.The soft coral Cladiella krempfi has been studied by Christopher, and Bheemasankara and five cembanoid diterpenes have been obtained.In our continuing search to discover the bioactive substances from Chinese soft coral, a species of the soft coral Cladiella krempfi collected from Weizhou Island, Guangxi Province were investigated.Two steroidal glycosides 1 and 2 were first isolated from the ethanol extract.On the basis of the spectroscopic methods their structures were established as 3-O-[-D-arabinopyranosyl]-pregn-5,20-dien-3β-ol(1) and {4-O-[β-D-arabinopyranosyl]-pregn-20-en-3β,4α-diol(2)}. Steroidal glycosides were first found from this species of soft coral.Compound 1 was a new compound.Compound 2 was obtained from the South China Sea soft coral, Lobophyton sp.Bioassay showed that compound 2 displayed cytotoxic against human Hep-G2 and Cne2 cell lineSIn vitro with IC 50 values 27.9, 14.3 μg/mLrespectively.

Key words: Soft coral Cladiella krempfi, Sterol, Glycoside