Mechanochemical and mass spectral approach for the analysis of maltosylated glycylglycine

The interaction of maltose with glycylglycine was studied under ball milling condition to generate the Amadori product. Although single step milling (30 Hz, 30 min) has been shown to be efficient in the generation of Amadori products of monosaccharides with amino acids, however with disaccharides and dipeptides, single step process showed a significant intensity of unreacted disaccharide peak, prompting us to develop a multistep process where the more consumed reactant was replenished in the subsequent milling steps. Under multistep milling conditions, the Amadori compound was the main product. The fragmentation patterns of protonated and sodiated Amadori products were studied aided by isotope labeling technique. Formation of the other products in the ball-milled maltose and glycylglycine was rationalized through glycosidic and peptidyl bond cleavage reactions. Degradation of the Amadori product of maltose and glycylglycine through such cleavage reactions, generated three other Amadori products corresponding to dipeptide/monosaccharide, amino acid/monosaccharide and amino acid/disaccharide interactions.