Minor and trace sterols in marine invertebrates XVI. 3 epsilon-hydroxymethyl-A-nor-5 alpha-gorgostane, a novel sponge sterol.

The free sterol mixture of the sponge Stylotella agminata contained a series of 3-hydroxymethyl-A-nor sterols of 5 alpha-cholestane, 5 alpha-cholest-22-ene, 24-methyl-5 alpha-cholestane, 24-ethyl-5 alpha-cholestane, and 24-ethyl-5 alpha-cholest-22-ene. A new cyclopropane-containing sterol was isolated and shown to be 3 epsilon-hydroxymethyl-A-nor-5 alpha-gorgostane. Sterols with conventional nuclei were also present as minor constituents;