Isolation and identification of antitrypanosomal and antimycobacterial active steroids from the sponge Haliclona simulans.

The marine sponge Haliclona simulans collected from the Irish Sea yielded two new steroids: 24-vinyl-cholest-9-ene-3β,24-diol and 20-methyl-pregn-6-en-3β-ol,5a,8a-epidioxy, along with the widely distributed 24-methylenecholesterol. One of the steroids possesses an unusually short hydrocarbon side chain. The structures were elucidated using nuclear magnetic resonance spectroscopy and confirmed using electron impact- and high resolution electrospray-mass spectrometry.