Nonenzymatic glycation reaction of folate with reducing sugars: A case study on [6S]-5-methyltetrahydrofolate and fructose

In the Maillard reaction, free amino groups react with reducing sugars to form nonenzymatic glycation products. It has recently been shown that in the presence of reducing sugars (i.e. fructose) folic acid is subjected to a non-enzymatic glycation reaction, which may represent an important pathway of folate degradation besides the established oxidative degradation pathways. In the current study, the thermal stability of [6S]-5-methyltetrahydrofolic acid ([6S]-5-CH3H4PteGlu, 0.4µM), the predominant naturally occuring folate derivate, was investigated on a qualitative and kinetic basis in the presence of different fructose concentrations (0-3M) in milliQ water (8.11ppm O2). Samples were isoth…