NOR-STEROLS IN AXINELLA PROLIFERANS, SPONGE FROM THE INDIAN-OCEAN

An examination of the sterol mixture of the sponge Axinella proliferan s collected in the Indian Ocean led to the isolation of nine A-nor-ste rols, including two rare nor-sterols with a D-ring unsaturation. The k nown 3 beta-(hydroxymethyl)-A-nor-5 alpha-cholest-15-ene has been iden tified by a comparison with mass spectrum and H-1 and C-13 nuclear mag netic resonance (NMR) data of the sterol isolated from Homoaxinella tr achys, a marine sponge collected in the Indian Ocean. A new sterol, 3 beta-(hydroxymethyl)-A-nor-5 alpha-cholest-14-ene-16 alpha-ol, has bee n identified by their mass and two-dimensional NMR spectra compared wi th those of the D-ring unsaturated sterol, 5 alpha-cholest-14-ene-3 be ta, 16 alpha-diol isolated from the Mediterannean sponge Topsentia aur antiaca.