Reactivities of D-glucose and D-fructose during glycation of bovine serum albumin

Glycation of bovine serum albumin by D-glucose and D-fructose under dry-hea ting conditions was studied. The reactivities of D-glucose and D-fructose, with respect to their ability to utilize primary amino groups of proteins, to cross-link proteins, to develop Maillard fluorescence, and to reduce pro tein solubility in the presence and absence of air (molecular oxygen) were investigated. D-Glucose showed a higher initial rate of utilization of prim ary amino groups than D-fructose, both in the presence and in the absence o f oxygen. Subsequent reactions of the Amadori and Heyns rearrangement produ cts, cross-linking, development of Maillard fluorescence, oxidation, and fr agmentation, indicated that the alpha-hydroxy carbonyl group of Amadori pro ducts is more reactive than the aldehydo group of Heyns products. D-Fructos e showed a greater sensitivity than D-glucose toward the presence of oxygen at the initial stages of the Maillard reaction. The presence or absence of oxygen in the glycation mixture did not seem to have an influence on the n ature of products generated in the glycation mixtures during the advanced s tages of the Maillard reaction.