The Amadori rearrangement is an

organic reaction Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, mechanistic organ ...

describing the acid or base catalyzed

isomerization In chemistry, isomerization or isomerisation is the process in which a molecule, polyatomic ion or molecular fragment is transformed into an isomer with a different chemical structure. Enolization is an example of isomerization, as is tautomer ...

rearrangement reaction In organic chemistry, a rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. Often a substituent moves from one atom to another at ...

of the ''N''-

glycoside In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. ...

of an

aldose An aldose is a monosaccharide (a simple sugar) with a carbon backbone chain with a carbonyl group on the endmost carbon atom, making it an aldehyde, and hydroxyl groups connected to all the other carbon atoms. Aldoses can be distinguished from ket ...

or the

glycosylamine Glycosylamines are a class of biochemical compounds consisting of a glycosyl group attached to an amino group, -NR2. They are also known as N-glycosides,. as they are a type of glycoside. Glycosyl groups can be derived from carbohydrates. The gl ...

to the corresponding 1-

amino In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

-1-

deoxy Deoxygenation is a chemical reaction involving the removal of oxygen atoms from a molecule. The term also refers to the removal of molecular oxygen (O2) from gases and solvents, a step in air-free technique and Hydrogen purifier#Catalytic recombi ...

ketose In organic chemistry, a ketose is a monosaccharide containing one ketone () group per molecule. The simplest ketose is dihydroxyacetone (), which has only three carbon atoms. It is the only ketose with no optical activity. All monosaccharide keto ...

. The reaction is important in

carbohydrate chemistry A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ma ...

, specifically the glycation of hemoglobin (as measured by the

HbA1c Glycated hemoglobin, also called glycohemoglobin, is a form of hemoglobin (Hb) that is chemically linked to a sugar. Most monosaccharides, including glucose, galactose, and fructose, spontaneously (that is, non-enzymatically) bond with hemoglob ...

test). 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: : Amadori-rearrangement

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-product Advanced glycation end-products (AGEs) are proteins or lipids that become Glycation, glycated as a result of exposure to sugars. They are a bio-marker implicated in aging and the development, or worsening, of many degenerative diseases, such as dia ...

s (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) in which the reagents are naturally occurring sugars and

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s. One study demonstrated the possibility of Amadori rearrangement during interaction between oxidized dextran and gelatine.

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.''Strategic Applications of Named Reactions in Organic Synthesis (Paperback)'' by Laszlo Kurti, BN 0-12-429785-4

References

External links

Amadori Rearrangement
PowerPoint presentation detailing the reaction mechanism {{Organic reactions Rearrangement reactions Post-translational modification Name reactions

Food chemistry

History

See also

References

External links