Plasmalogens and their oxidative degradation products in low and high density lipoprotein

The kinetics of the autoxidation reaction of LDL and HDL with Fe2+/ascorbate was investigated. Aldehydes derived from plasmalogens were determined by conversion to 2-alkyl-1,3-dithiolanes. Their oxidation products, 2-hydroxy-aldehydes, were trapped by reaction with pentafluorobenzylhydroxylamine. After derivatisation, the pentafluorobenzyloximes could be separated from other compounds by thin-layer chromatograpy. They were detected by gas chromatography applying an electron capture detector. LDL plasmalogens are oxidized nearly completely after 180 min while HDL plasmalogens suffer oxidation only to 5%. Oxidation of linoleic and arachidonic acid was investigated by simultaneous determination of 2-hydroxyheptanal.