Formation of α-amino-acid amides and α-hydroxy-acid amides by degradation of sugars with primary amines

Reactions of glucose and ribose with an excess of propylamine in phosphate buffered nearly neutral solution lead to the formation of N-propylalanine propylamide, N-propylglycine propylamide, lactic acid propylamide, and glycolic acid propylamide. The production of these amides is favoured by alkaline conditions. These model reactions represent a new mechanism for cross-linking of proteins, through lysine side chains by sugars.