Radiolysis of Saturated Phospholipids

Volatile radiolysis products of 1,2-dipalmitoyl-sn-glycerol-3-phosphoethanolamine were recovered by cold-finger distillation and analyzed by gas chromatogrphy and mass spectrometry. They include series of n-alkanes, 1-alkenes, n-alkanals, 2-alkanones, 3-alkanones, 4-alkanones, and methyl and ethyl esters. Quantitative analysis showed that the amounts of products from irradiated 3-sn-phosphatidylethanolamine were strikingly different from those recovered from the acylglycerols. Nonvolatile radiolytic products were separated by thin-layer chromatography. These included palmitic acid, palmitone, lysophosphatidylethanolamine, ethanolamine phosphate, and five unidentified compounds. Possible mechanisms for the formation of these compounds are discussed.