Visible-light-activated aziridination reaction enables simultaneous resolving of C = C bond location and the sn -position isomers in lipids

There is a close relationship between the biological functions of lipids and their structures, and various isomers greatly increases the complexity of lipid structures. The C = C bond location and sn -position are two of the essential attributes that determine the structures of unsaturated lipids. However, simultaneous identification of both attributes remains challenging. Here, we develop a visible-light-activated aziridination reaction system, which enables the dual-resolving of the C = C bond location and sn -position isomerism of in lipids when combines with liquid chromatography-mass spectrometry (LC-MS). Based on the derivatization of C = C bonds with PhI = NTs, their location in lipids could be easily identified by tandem MS. Especially, the sn -position isomers of unsaturated phosphatidylcholine (PC) can be separated and quantified by LC-MS after the derivatization. By using the proposed method, the significant changes of the sn -position isomers ratios of PC in mouse brain ischemia were revealed. This study offers a powerful tool for deep lipid structural biology. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.