Characterization of the lipoidal derivatives of pregnenolone prepared by incubation of the steroid with adrenal mitochondria.

Using mass spectrometric, radioisotopic, chromatographic and chemical techniques, five fatty acid esters of 3 beta-hydroxy-5-pregnen-20-one (pregnenolone) have been identified as components of the lipoidal derivatives biosynthesized in vitro with bovine adrenal mitochondria. The five compounds are: pregnenolone arachidonate, pregnenolone linoleate, pregnenolone oleate, pregnenolone palmitate, and pregnenolone stearate. The distribution of the fatty acids among these five esters is different from the previously reported (Cmelik, S.H.W., and Ley, H. (1977) Comp. Biochem. Physiol. 56B, 267-270) fatty acid composition of these organelles.