Studies on the Steroids of Marine Sponge(IV)──Steroids from the Marine Sponge Biemna Sp

eported here is identification of a 7-en-sterol and a 5-en-sterol which containsa cyclopropane ring in its side chain and is separated from the South China Seasponge Biemna sp. . This leads to the isolation and identification of twelve sterols inthis marine sponge by using gas chromatography-mass spectrometry (GC-MS)analysis. The occurrence of 7-en-sterol and 5-en-sterol with a cyclopropane ring inits side chain from the south China Sea sponge was first reported here.