Mass spectrometry investigation of nucleoside adducts of fatty acid hydroperoxides from oxidation of linolenic and linoleic acids

• HPLC-ESI-MS was applied for characterization of two fatty acid hydroperoxides. • In-source fragmentation occurred in the detection of fatty acid hydroperoxides. • Nucleoside adducts were formed from the reactions of fatty acid hydroperoxides. • Reductive cyclization reaction was responsible for generation of nucleoside adducts. The widespread presence of lipid hydroperoxides in foodstuffs and biological samples has aroused great attentions in recent years, while it remains challenging for analysis of the fragility of O − O bond linkage of peroxides. In this present study, we explored the utility of electrospray ionization mass spectrometry (ESI-MS) for characterization of two fatty acid hydroperoxides from oxidation of linoleic acid and α-linolenic acid, which are the essential fatty acids abundant in many seeds and vegetable oils. The results indicated that in-source fragmentation occurred in the detection of the two fatty acid hydroperoxides in both positive and negative ion modes, which yielded characteristic fragments for ESI-MS analysis. In addition, the genotoxicity of fatty acid hydroperoxides for generation of nucleoside adducts was investigated. It was found that a variety of nucleoside adducts were formed from the reactions of fatty acid hydroperoxides and nucleosides. Furthermore, the decomposition products of the fatty acid hydroperoxides were determined, which provided evidence to elucidate the reaction mechanism for formation of nucleoside adducts.