Rg. Kerr et al., A NOVEL BIOSYNTHETIC ROUTE TO PREGNANES IN THE MARINE SPONGE AMPHIMEDON COMPRESSA, Journal of natural products, 58(7), 1995, pp. 1077-1080
A novel degradative route to pregnanes has been elucidated in the mari
ne sponge Amphimedon compressa, 22-Dehydrosterols, common in the diet
of sponges, are the precursors to pregnanes and apparently are degrade
d by a mechanism analogous to the dealkylation of phytosterols to chol
esterol.