The basic biochemical steps leading to the generation of AGEs are shown in Fig. 1. The initial reaction between reducing sugars and a protein proceeds through the formation of a labile Schiff's base, a rapid and easily reversible reaction that may halt at this point. The reaction product, however, may eventually continue to isomerize while slowly forming a ketoamine adduct termed the Amadori product. A typical Amadori compound, for instance, is hemoglobin A1c being used as a classic long-term marker for glycemia in diabetes mellitus. Such early products can undergo further complex oxidative decomposition, condensation, and additional molecular rearrangements that ultimately lead to stable, irreversible late AGEs, a process that may take weeks or months to accomplish. To fuel this process, glucose is an ubiquitous and predominant substrate, but other sugar molecules such as fructose, threose, glucose 6-phosphate, and glyceraldehyde 3 phosphate may also react similarly with proteins and produce chemically distinct AGEs according to the reaction partners, respectively