Sterols of the oyster,Crassostrea virginica

Abstract
A commericial sample of the oyster,Crassostrea virginica, obtained from Maryland waters of the Chesapeake Bay, contained 31 desmethylesterols and at least eight 4‐monomethylsterols. The combined gas liquid chromatography‐mass spectra of the minor components showed the presence of 6 unusual sterols, 24‐ethylcholest‐22‐en‐3β ol, 4α‐methyl‐24‐ethylcholestan‐3β‐ol, occelasterol, (24E)‐24‐propylidene‐cholest‐5‐en‐3β‐ol, (24ZO‐24‐propylidene‐cholest‐5‐en‐3β‐ol, and 24‐methylene‐cholestanol. The C‐24 configuration of 24‐ethylcholest‐5‐enol, 24‐methyl‐cholesta‐5,22‐dienol, and 24‐ethylcholesta‐5,22 dienol were elucidated by 220 MHz nuclear magnetic resonance spectrometry.