Differential scanning calorimetry of dispersions of products of oxidation of 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine

Abstract

Ultraviolet light was used to promote the autoxidation of 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine (SLPC). The extent of oxidation was monitored by ultraviolet spectroscopy, reaction with thiobarbituric acid, fatty acid analysis, and thin-layer chromatography. Fatty acid analysis and thin-layer chromatography appeared to provide the most consistent estimates of oxidation, especially when extensive oxidation had taken place. The oxidized samples were separated by flash chromatography into fractions enriched in different oxidation products. Differential scanning calorimetry of aqueous dispersions of these fractions indicated that oxidation products had higher transition temperatures than the original SLPC.Key words: lipid peroxidation, ultraviolet light, phase behaviour, transition temperatures.