Journal of Lipid Research, Vol 29, 1039-1054, Copyright © 1988 by Lipid Research, Inc.
5 alpha-cholest-8(14)-en-3 beta-ol-15-one, a potent regulator of cholesterol metabolism: occurrence in rat skin
GT Emmons, J St. Pyrek, R Dam, M Martin, K Kudo and GJ Schroepfer Jr
Department of Biochemistry, Rice University, Houston, TX 77251.
5 alpha-Cholest-8(14)-en-3 beta-ol-15-one is a potent inhibitor of
cholesterol biosynthesis which has significant hypocholesterolemic activity
upon oral administration to animals. Described herein are the results of
experiments that indicate the presence of the 15-ketosterol in rat skin.
The 15-ketosterol was, after purification by medium pressure liquid
chromatography on Lichroprep RP-8 columns, thin-layer chromatography on
silica gel G, and reverse phase high performance liquid chromatography,
characterized by gas-liquid chromatography-mass spectrometry in the form of
its trimethylsilyl ether derivative. The use of an internal standard
containing both tritium and deuterium permitted the determination of the
levels of the 15-ketosterol by mass fragmentography. The results of five
separate analyses of portions of the skin of a male Sprague Dawley rat
showed a mean value of 84.5 +/- 4.1 (SEM) ng per g. Analyses of hair
samples of ten male Sprague Dawley rats indicated a mean level of 143 +/-
19 (SEM) ng per g of hair. Most (approximately 72%) of the 15-ketosterol in
hair was esterified. This report constitutes the first isolation of the
15-ketosterol from animal tissues.