MARINE STEROLS - SIDE-CHAIN-OXYGENATED STEROLS, POSSIBLY OF ABIOTIC ORIGIN, FROM THE NEW CALEDONIAN SPONGE STELODORYX-CHLOROPHYLLA

The steroidal composition of the sponge Stelodoryx chlorophylla was examined, and twenty-two components were identified. The sponge contains ''conventional'' C27-C29, DELTA5-mono and diunsaturated sterols, sterols with oxygenated side chains, e.g., (22E)-3beta-hydroxycholesta-5,22-dien-24-one [5], and sterols with short oxygenated side chains, e.g., 3beta-hydroxy-17beta-pregn-5-en-20-one [6] and (22E)-3beta-hydroxy-26,27-bisnorcholesta-5,22-dien-24-one [7]. In addition, the extracts of the sponge contain the epimeric steroidal DELTA(5)3beta-7-diols and the steroidal 3beta-hydroxy-5-en-7-ones, well recognized autoxidation products of DELTA5-sterols. The origin of the oxidized side chains is discussed.