Hypothesis: Glyoxal Is an Unavoidable Byproduct of the Activity of Transketolase in the Pentose Phosphate Pathway

Diabetes mellitus and its consequent pathological complications continue to pose serious and growing health care challenges across the world. One promising mechanism for linking hyperglycemia and diabetic complications is the process of spontaneous, nonenzymatic reactions between glucose and its catabolites with amino groups in macromolecules (a.k.a. Maillard reactions). The most reactive sugars in this process are two low-molecular-weight α-dicarbonyls: methylglyoxal and glyoxal (GO). While the origins of methylglyoxal are well documented, little is known about the origins of the equally important GO. This article postulates that GO is produced as an unavoidable byproduct of the transketolase reaction in the pentose-phosphate pathway.