Citizendia

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. Organic reactions are Chemical reactions involving Organic compounds The basic Organic chemistry reaction types are Addition reactions Elimination In acid catalysis and base catalysis a Chemical reaction is catalyzed by an Acid or a base. In Chemistry isomerisation is the process by which one Molecule is transformed into another molecule which has exactly the same atoms but the atoms are rearranged 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 An aldose is a Monosaccharide (a simple Sugar) containing one Aldehyde group per Molecule and having a Chemical formula of the Glycosylamine is a biochemical compound consisting of an Amine with a β-N-glycosidic bond to a Carbohydrate. Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. A ketose is a Sugar containing one Ketone group per Molecule. [1][2] The reaction is important in carbohydrate chemistry. Carbohydrates (from ' Hydrates of Carbon ' or saccharides ( Greek σάκχαρον meaning " Sugar " are the most

The reaction mechanism is demonstrated starting from the reaction of D-mannose in its closed (1) and open-form (2) with ammonia the 1,1-amino-alcohol 3 which is unstable and loses water to the glycosylamine (again the open imine (5) and the closed form hemiaminal (4)) which is the starting point for the actual Amadori rearrangement. Chemistry, a reaction mechanism is the step by step Sequence of Elementary reactions by which overall Chemical change occurs. Mannose is a Sugar Monomer of the Hexose series of Carbohydrates Metabolism Mannose enters the carbohydrate Metabolism Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor Glycosylamine is a biochemical compound consisting of an Amine with a β-N-glycosidic bond to a Carbohydrate. An imine is a Functional group or Chemical compound containing a Carbon – Nitrogen Double bond. A hemiaminal is a Functional group or type of Chemical compound that has a Hydroxyl group and an Amine attached to the same Carbon [3]

The Amadori Rearrangement

By treatment of the glycosylamine with pyridine and acetic anhydride the imine group rearranges and the intermediate enol in turn rearranges to the ketone. Pyridine is a Chemical compound with the formula C5[[Hydrogen H5]] N. Acetic anhydride is the Chemical compound with the formula (CH3CO2O Enols (also known as alkenols) are Alkenes with a Hydroxyl group affixed to one of the carbon atoms composing the Double bond. A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or In this particular reaction the all alcohol and amino groups are acylated as well. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. In Chemistry, acylation (rarely but more formally alkanoylation) is the process of adding an Acyl group to a compound

The reaction is associated with the Maillard reaction with reagents naturally occurring sugars and amino acids. The Maillard reaction is a Chemical reaction between an Amino acid and a Reducing sugar, usually requiring Heat. In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this


Amadori product

An Amadori product is an intermediate in the production of an advanced glycation end-product (AGE) as a result of glycation. Glycation (sometimes called non-enzymatic Glycosylation) is the result of a sugar molecule such as Fructose or Glucose, bonding to a Protein

The formation of an advanced glycation end-product involves the following steps:

  1. Formation of a Schiff base: For example the aldehyde group of a glucose molecule will combine with the amino group of a lysine molecule (in a protein) to form an imine or Schiff base, which is a double bond between the carbon atom of the glucose and the nitrogen atom of the lysine. Schiff base (or azomethine) named after Hugo Schiff, is a Functional group that contains a Carbon - Nitrogen Double bond An aldehyde is an organic compound containing a terminal Carbonyl group. Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. Lysine (abbreviated as Lys or K) is an α- Amino acid with the Chemical formula HO2CCH(NH2(CH24NH2 Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl An imine is a Functional group or Chemical compound containing a Carbon – Nitrogen Double bond. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14
  2. Formation of an Amadori product: The Amadori product is a re-arrangement from the Schiff base wherein the hydrogen atom from the hydroxyl group adjacent to the carbon-nitrogen double bond moves to bond to the nitrogen, leaving a ketone. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Hydroxyl in Chemistry stands for a molecule consisting of an Oxygen atom and a Hydrogen atom connected by a Covalent bond. A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or
  3. Formation of an advanced glycation end-product (AGE): The Amadori product is oxidized, most often by transition metal catalysis. In Chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings It commonly refers to any element in Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst

The first two steps in this reaction are both reversible, but the last step is irreversible.



External links

References

  1. ^ W. Amadori, Atti. reale accad. nazl. Lincei, [6] 2, 337 (1925); [6] 9, 68, 226 (1929); [6] 13, 72 (1931)
  2. ^ Strategic Applications of Named Reactions in Organic Synthesis (Paperback) by Laszlo Kurti, Barbara Czako ISBN 0-12-429785-4
  3. ^ Mutarotation, Hydrolysis, and Rearrangement Reactions of Glycosylamines HORACE S. ISBELL and HARRIET L. FRUSH J. Org. Chem. 1958, 23(9), 1309 - 1319. The Journal of Organic Chemistry (abbreviated as J Org Chem or JOC) is a Scientific journal for original contributions of fundamental (doi:10.1021/jo01103a019)
A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic