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A new pentacyclic steroid, xestobergsterol C [1], possessing a cis C/D ring junction, has been isolated together with two known compounds, xestobergsterols A [2] and B [3], from the Okinawan marine sponge Ircinia sp., and the structure determined on the basis of spectral data. Reexamination of the nmr data of xestobergsterols A [2] and B [3] resulted in revision of the configuration at C-23 and of the conformation of ring D in 2 and 3. The absolute stereochemistry of xestobergsterol A [2] was established by the cd exciton chirality method.

A new bromopyrrole alkaloid (1) along with (+/-)-2 and (+/-)-longamide (3) has been isolated from the Japanese marine sponge Homaxinella sp. The structures of the compounds were proposed on the basis of spectroscopic data. The optical resolution of (+/-)-2 by chiral HPLC was successful and afforded the two enantiomers, (+)-2 and (-)-2.