title: Occurrence and seasonal variation of 19-norcholest-4-en-3-one and 3 beta-monohydroxy sterols in the Californian gorgonian, Muricea californica.
abstract: The first natural occurrence of 19-norcholestenone is reported, together with 17 sterols and one other delta 4-3-ketone in the extracts of the Californian gorgonian, Muricea californica (Aurivillius). Six additional demethyl sterols and five additional 4-monomethyl sterols which remain unidentified were also detected. Lipid extracts of M. californica from a winter and summer collection were split by various chromatographic methods into free sterol, steryl ester, and steryl conjugate fractions. Sterol compositions (determined by CG and CG-MS)  of each fraction, subsequent to hydrolysis, are tabulated and discussed with respect to plausible origins of observed variations. The possible relationship of the Muricea 19-nor-steroidal ketone to other naturally occurring 19-nor-steroids is discussed.
mesh_terms: D000818:Animals; D002782:Cholestenes / Q000032:analysis*; D002783:Cholestenones / Q000032:analysis*; D002850:Chromatography, Gel; D008974:Mollusca / Q000502:physiology*; D012621:Seasons; D013261:Sterols / Q000032:analysis*; D013329:Structure-Activity Relationship
chemical_list: D002782:Cholestenes; D002783:Cholestenones; D013261:Sterols; C040169:19-norcholest-4-en-3-one