Products of the reaction of cholesterol with hypochlorite anion.

Products of the reaction of cholesterol with hypochlorite (OCI) in various systems (egg phosphatidylcholine liposomes, low-density lipoproteins, and aqueous colloidal dispersion of cholesterol) were separated and analyzed by TLC, HPLC, and gas chromatography-mass spectrometry. The reactions of hypochlorite with cholesterol result in the same reaction products in all treated systems. Eighteen fractions were isolated from the reaction mixture by normal-phase HPLC in hexane-isopropanol (95:5 v/v); these were then examined by gas chromatography-mass spectrometry. Six products less polar than cholesterol were isolated from the reaction mixture; two of them were identified as 4,6-cholesten-3-one and 4-cholesten-3,6-dione. Among the oxidation products more polar than cholesterol, nine compounds were identified; they are 5,7-cholestadien-3 beta-ol,3,5-cholestadien-7-one, 4-cholesten-3 beta, 6 beta-diol, 5-cholesten-3 beta, 7 beta-diol, cholestan-3 beta, 5 alpha, 6 beta-triol, 5 alpha-cholestan-3 beta-ol-6-one, 5-cholesten-3 beta-ol-7-one, 5 alpha, 6 alpha-epoxycholestan-3 beta-ol, and 5 alpha-cholesten-3,6-dione.