CHOLESTEROL AUTOXIDATION IDENTIFICATION OF THE VOLATILE FRAGMENTS 胆固醇自氧化挥发性碎片的鉴定.pdf

Chemistry and Physzcs of Llpzds 14 (1975) 327-335 © North-Holland Pubhshlng Company CHOLESTEROL AUTOXIDATION IDENTIFICATION OF THE VOLATILE FRAGMENTS Johan E VAN LIER*, Arnold L DA COSTA and Leland L SMITH Btochemzstry Laboratories, Department of Nuclear Medtcme and Radlobzology Centre Hospttaher Umversttatre, Sherbrooke, Quebec, Canada and Dtvtszon of Bzochemlstry, Department of Human Btologtcal Chemistry and Genetws Umverstty of Texas, Medtcal Branch, Galveston, Texas, USA Recewed April 5, 1975 accepted May 15, 1975 The volatile fragments of air-aged cholesterol were analysed by means of gas chromatography- mass spectrometry The foUowmg fourteen compounds were identified ethanol, acetic acid, ate- tone, 2-methylpropene, 2-methyl-l-propanol, 2-methyl-2-propanol, 2-butanone, 2-methylpropl- omc acid, 2-methyl-2-butanol, 2-pentanone, 3-methyl-2-butanone, 2-methyl-l-pentene, 2-methyl- 2-pentanol, and 2-methyl-4-penten-2-ol Thetr formation wa decomposition of lmtmlly formed sterol hydroperoxldes Is discussed I Introduction In previous studles we have shown that the autoxldatxon of cholesterol may pro- ceed both via hydroperoxlde formation xn the A/B-ring system as well as m various positions of the hydrocarbon side-chain Hydroperoxldes which have been obtained from oxidized cholesterol as crystalline products include 5ct-hydroperoxy-6-cho- lesten-3/3-ol together with the 7a- and 7/~-hydroperoxy-5-cholesten-3~-ols, 6/3-hydro- peroxy-4-cholesten-3-one, the 20ct-, 24-, 25- and 26-hydroperoxy derlvatwes of cho- lesterol [2, 4, 6] and the secondartly formed 20~- and 20/3-hydroperoxy-5-pregnen- 3/3-ols [3] Decomposmon of these hydroperoxldes accounts for the presence of a vartety of C19-, C21-, C24-, and C27-sterolds in a~r-aged chole