Discovery of Novel Advanced Glycation End Products by Isotope Labeling-Based Metabolomics and Its Application in Steamed Herbs and High-Temperature Processed Foods

Advanced glycation end products (AGEs), formed through reactions between carbonyl compounds and amino groups, mostly originate from lysine and arginine, with other amino-acid-derived AGEs remaining largely uncharacterized. Here, we developed a comprehensive strategy to annotate novel AGEs. First, a prediction library of 216 AGEs was constructed based on reported formation pathways. Available standards were labeled by dansyl chloride to obtain characteristic fragments via liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using Maillard reaction models of heated amino acid and carbonyl mixtures, combined with LC-MS/MS and high-resolution MS, we identified 20 AGEs, including 7 new structures. A pseudotargeted method covering these AGEs was developed and applied to study their dynamic changes in herbs subjected to varying steam-bask cycles and to investigate differences between free and protein-bound AGEs in high-temperature processed foods. This strategy advances the discovery and understanding of diverse AGEs in food and herbal matrices.