A new gorgostane derivative from the Egyptian Red Sea soft coral Heteroxenia ghardaqensis.

Chemical investigation of the chloroform extract of the Egyptian Red Sea soft coral, Heteroxenia ghardaqensis (Family Xeniidae), led to the isolation of three gorgostane derivatives, namely gorgosten-5(E)-3β-ol (1), gorgostan-3β,5α,6β, 11α-tetraol (sarcoaldosterol A) (2) and gorgostan-3β,5α,6β-triol-11α-acetate (3). To our knowledge, sterol 3 is reported in this article for the first time. The structure elucidation of these compounds was deduced by 1-D and 2-D NMR as well as ESIMS. Sterol 1 showed moderate activity as growth inhibitor of human colon tumour cell lines.