Lipids of human atheroma. 8. Oxidised derivatives of cholesteryl linoleate.

Abstract

Abstract Cholesterol linoleate hydroperoxides, isolated from the lipids of advanced atherosclerotic plaques of human aortas obtained during post mortem examination, have been shown to comprise a mixture of 9- and 13-hydroperoxides similar to those produced by autoxidation. Corresponding 9- and 13-keto-octadecadienoates, found in variable amounts in plaque lipids, may be satisfactorily separated by preparative thin-layer chromatography after selective reduction of the accompanying hydroperoxides with SnCl 2 . The two classes of oxidised linoleate were characterised in the form of the diols produced by reduction with LiA1 2 H 4 , using combined gas chromatography-mass spectrometry. Gas-liquid chromatography of the drimanoate esters of methyl 13-hydroxystearate derived from arterial hydroxycholesterol esters indicated a 1:1 ratio of the 13−( S )- and 13−( R )-derivatives.