Chemotaxonomic study of the demosponge Cinachyrella cavernosa (Lamarck)

•We compared Sterols of Cinachyrella cavernosa with literature reports for genus Cinachyrella.•No ketoxime was found in C. cavernosa suggesting C. tarentina and C.cavernosa as two distinct species.•Absence of oxime also indicated that it is not a biomarker of genus Cinachyrellabut of C. tarentina.•First report of 16-dehydropregnenolone from a marine source and 4α-methyl gorgostanol in a sponge.

Sterols as acetates and phthalate esters were identified by GC–MS in demosponge Cinachyrella cavernosa. The sponge contained mainly C27, C28 and C29 Δ5 conventional sterols and minor amounts of C27 and C28 Δ0 analogues. This study also reports the presence of an ester, clionasterol oleate, 16-dehydropregnenolone (DPA), relatively rare cyclopropane containing sterols such as gorgosterol, 4α-methyl gorgostanol, phthalate esters, and nucleoside, 9β-D-ribofuranosyl adenine in C. cavernosa. 4α-Methyl gorgostanol, DPA, phthalate esters: 1,2 benzene dicarboxylic acid bis-(2-methyl propyl) ester and nucleoside, adenosine, are described for the first time from this genus. Dibutyl phthalate and 1,2 benzene dicarboxylic acid bis 2-ethyl hexyl ester have previously been identified in Cinachyrella australiensis. To our knowledge, this is the first report of 4α-methyl gorgostanol from a sponge and DPA from a marine source. The probable origin and chemotaxonomic importance of some of the metabolites is discussed.