Pregnanes with antiproliferative activity from the gorgonian Eunicella cavolini

Four new natural products (1-4), along with three previously reported metabolites (5-7), all belonging to the pregnane class of steroids were isolated from the organic extract of the gorgonian Eunicella cavolini. The structures and relative configurations of the isolated compounds were determined through NMR spectroscopic techniques and chemical interconversions, while their absolute stereochemistry was determined using the modified Mosher's method. Activity evaluation of 1-7 towards MCF-7 human breast cancer cells showed partial growth inhibitory effects for all metabolites bearing an 11α-acetoxy moiety.