Résumé : Lobosterol [(24S)-24-methylcholestane-3β,4β,5β,25tetrol-6-one 25 monoacetate] has been isolated from the Alcyonacean Lobophytum pauciflorum. The structural elucidation of this novel polyoxygenated sterol was achieved by chemical and spectroscopic evidence, and by X-ray diffraction analysis. © 1976.