Role of hydroxyl radicals and singlet oxygen in the formation of primary radicals in unsaturated lipids: A solid state Electron Paramagnetic Resonance study

Article Article scientifique Article Role of hydroxyl radicals and singlet oxygen in the formation of primary radicals in unsaturated lipids: A solid state Electron Paramagnetic Resonance study eng 2000 author Geoffroy Michel 25153 author Lambelet Pierre author Richert Pascal 25894 974-978 10.1021/jf990684y 0021-8561 Primary radicals were generated by UV photolysis of samples of trilinolein, at 77 K and under a controlled atmosphere. The resulting EPR spectra clearly show that the amount of radicals is dependent on the purity of the lipid, the exposure to visible light in the presence of a photosensitizer and oxygen, and, finally, the presence of an antioxidant. These solid state EPR experiments indicate that if all of the elements for the production of singlet oxygen (Rose Bengal, molecular oxygen, and visible light) are not present, primary radicals are practically not generated. They also point out the various steps of the oxidation mechanism: formation of singlet oxygen, which reacts with the lipid to form a hydroperoxide; and photolytic formation of the hydroxyl radical, which reacts with the frozen lipid to generate primary lipidic radicals. This constitutes a new method for investigating lipid oxidation and studying the influence of photosensitizers and molecules that are likely to react with singlet oxygen. Radicals EPR Lipids Hydroxyl radicals Singlet oxygen Dewey 540 38 Département de chimie physique 142 false 688 Groupe Geoffroy Journal of agricultural and food chemistry 48 4 05f0a1e1-9fa5-4632-86b8-4c1db5f5ecfb Article (Published version) Restricted jf990684y.pdf 58739 application/pdf restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie physique

Title	Published in	Access level	OA Policy	Year	Views	Downloads

Role of hydroxyl radicals and singlet oxygen in the formation of primary radicals in unsaturated lipids: A solid state Electron Paramagnetic Resonance study	Journal of agricultural and food chemistry			2000	638	0

Archive ouverte UNIGE

Richert, Pascal