TheAmadori rearrangement is anorganic reaction describing theacid or base catalyzedisomerization orrearrangement reaction of theN-glycoside of analdose or theglycosylamine to the corresponding 1-amino-1-deoxy-ketose.[1] The reaction is important incarbohydrate chemistry, specifically the glycation of hemoglobin (as measured by theHbA1c 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 ofadvanced glycation end-products (AGE)s. The formation of an advanced glycation end-product involves the oxidation of the Amadori product.
The reaction is associated with the amino-carbonyl reactions (also called glycation reaction, orMaillard reaction)[3] in which the reagents are naturally occurring sugars andamino acids. One study demonstrated the possibility of Amadori rearrangement during interaction between oxidized dextran and gelatine.[4]
The Amadori rearrangement was discovered by the organic chemist Mario Amadori (1886–1941), who in 1925 reported this reaction while studying theMaillard reaction.[5][6]