Inhibition of glycosylation processes: the reaction between pyridoxamine and glucose

Abstract

[eng] Glycosylation of proteins by glucose produces toxic and immunogenic compounds called −advanced glyclosylation end products× (AGEs), which are the origin of pathological symptoms in various chronic diseases. In this work, a kinetic study of the reaction between glucose (2) and pyridoxamine (1) ± a potent inhibitor of AGEs formation both in vivo and in vitro ± was conducted. The NH2 group of pyridoxamine was found to react with the C O group of glucose to form the Schiff base 9 (Scheme 2). Subsequently, the Schiff base gives rise to other products, including compound 3, pyridoxal, pyridoxine, and 4-pyridoxic acid. Compound 3 inhibits the Amadori rearrangement, and prevents the formation of other C O groups capable of triggering glycosylation processes. Pyridoxal and pyridoxine can also inhibit protein glycosylation via other previously reported mechanisms.