Reverse Amadori

U. Hommel, M. Eberhard, and K. Kirsehner, Phosphoribosyl anthranilate isomerase eafalyzes a reversible Amadori reaction. Biochemistry, 34 (1995) 5429-5439. 

Carson 66) induced a reverse Amadori rearrangement with the conversion of V-alkylfructosylamines to aldose derivatives. By the reaction of primary alkylamines with fructose under anhydrous conditions, crystalline monoamino condensation products were obtained. V-Ethylfructosyl-amine was the only fructosylamine isolated. Usually the products were 2-amino-2-deoxyaldoses, probably of glucose configuration. Presumably. 

When 15 mM /Va-formyl-/Ve-fructosyl-lysine (fFL) in 0.2 M phosphate buffer, pH 7.4, was incubated in air for 15 d at 37 °C, not only was CML formed, but a substantial amount of lysine was recovered, which N. Ahmed el al.50 and M.U. Ahmed el al.51 interpreted as due to reversal of the Amadori rearrangement. The reduction of the reaction mixture with NaBH4 and subsequent identification of both glucitol and mannitol supports the interpretation. 

The Amadori product from D-glucose 33 and L-proline decomposes at 130 °C in DMF to afford 33 and D-Mannose 54, indicating the reversibility of the Amadori reaction. A kinetic study using 33 and phenylalanine indicates that the Schiff s base formation is the rate-determining step of the Maillard reaction [275,276]. 

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