The Amadori rearrangement is an organic reaction describing the acid or base catalyzed isomerization or rearrangement reaction of the N-glycoside of an aldose or the glycosylamine to the corresponding 1-amino-1-deoxy-ketose.^[1] The reaction is important in carbohydrate chemistry, specifically the glycation of hemoglobin (as measured by the HbA1c test).^[2]

The rearrangement is usually preceded by formation of a α-hydroxyimine by condensation of an amine with an aldose sugar. The rearrangement itself entails intramolecular redox reaction, converting this α-hydroxyimine to an α-ketoamine:

The formation of imines is generally reversible, but subsequent to conversion to the keto-amine, the attached amine is fixed irreversibly. This Amadori product is an intermediate in the production of advanced glycation end-products (AGE)s. The formation of an advanced glycation end-product involves the oxidation of the Amadori product.

Food chemistry

The reaction is associated with the amino-carbonyl reactions (also called glycation reaction, or Maillard reaction)^[3] in which the reagents are naturally occurring sugars and amino acids. One study demonstrated the possibility of Amadori rearrangement during interaction between oxidized dextran and gelatine.^[4]

History

The Amadori rearrangement was discovered by the organic chemist Mario Amadori (1886–1941), who in 1925 reported this reaction while studying the Maillard reaction.^[5][6]