Identification of the Modified Structure of Arginine Residues in Proteins with 3-Deoxyglucosone, a Maillard Reaction Intermediate

Abstract

The major compounds formed from the N^α-benzoylarginine amide (BzArgNH₂) and 3-deoxyglucosone (3DG) reaction system were purified by reversed-phase HPLC. The major product was identified as R-4-imidazolone (I) ; R=2-(4-benzoylamino-5-pentamide)amino-5-(2, 3, 4-trihydroxybutyl) as described in a previous paper (ref. 10). Intermediate products to the formation of compound I were identified as R-4(5H)-imidazolone (II), R-4(5-hydroxy)-imidazolone (III), and R-4-dihydroxyl-2-imidazoline (IV). Periodical changes in the amounts of compounds I, II, III, and IV suggest the formation of compound I via compound II by dehydration and oxidation from the BzArgNH₂-3DG reaction system to be the major pathway, the formation of compound I via compound III being the other pathway.