Characterization of Oxidized Glycerophosphoethanolamines via Radical-Directed Dissociation Tandem Mass Spectrometry and the Paterno-Buchi Derivatization

Oxidized glycerophosphoethanolamines (oxPEs) represent a subclass of bioactive lipids that have intricate roles in various physiological and pathological events. Conventional mass spectrometric methods cannot provide unambiguous information to locate the OH group and the sites of unsaturation. Herein, we report a combined strategy for in-depth structural characterization of oxPEs, including radical-directed dissociation tandem mass spectrometry (RDD-MS/MS) for localizing the OH group and the Paterno-Buchi derivatization coupled with tandem mass spectrometry for pinpointing carbon-carbon double-bond locations. The RDD-MS/MS method has been integrated on a reversed-phase liquid chromatography-mass spectrometry workflow. It enables the profiling of 24 distinct oxPE molecules with unequivocal assignment of the OH sites at nM sensitivity in bovine liver lipid extract treated by soybean 15-lipoxygenase. These findings showcase that the developed method has a good potential in analyzing biological systems where oxPEs may play important roles.

Automated summary

Oxidized glycerophosphoethanolamines (oxPEs) are a subclass of bioactive lipids that play intricate roles in various physiological and pathological events. A combined strategy using radical-directed dissociation tandem mass spectrometry (RDD-MS/MS) and Paterno-Buchi derivatization coupled with tandem mass spectrometry has been developed for structural characterization of oxPEs. The RDD-MS/MS method integrated into a reversed-phase liquid chromatography-mass spectrometry workflow enables the profiling of 24 distinct oxPE molecules with unequivocal assignment of the OH sites at nM sensitivity. These findings demonstrate the potential of the developed method in analyzing biological systems where oxPEs may play important roles.