Decarboxylation

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Decarboxylation

Decarboxylation is any chemical reaction in which a carboxyl group (-COOH) is split off from a compound as carbon dioxide (CO₂).

In biochemistry

Common biosynthetic decarboxylations of amino acids to amines are:

• tryptophan to tryptamine
• phenylalanine to phenylethylamine
• tyrosine to tyramine
• histidine to histamine
• serine to ethanolamine
• glutamic acid to GABA
• lysine to cadaverine
• arginine to agmatine
• ornithine to putrescine
• 5-HTP to serotonin
• L-DOPA to dopamine

Other decarboxylation reactions from the citric acid cycle include:

• pyruvate to acetyl-CoA
• oxalosuccinate to α-ketoglutarate
• α-ketoglutarate to succinyl-CoA.

Enzymes that catalyze decarboxylations are called decarboxylases or, more formally, carboxy-lyases (EC number 4.1.1).

In organic chemistry

Chemical decarboxylations reactions often require extensive heating in high-boiling solvents. Copper salts are often added as catalysts. Also the addition of catalytic amounts of cyclohexen-2-one has been reported to catalyze the decarboxylation of amino acids. Decarboxylations are especially easy for beta-keto acids due to the formation of a cyclic transition state for instance in Knoevenagel condensations. The Barton decarboxylation and Hunsdiecker reaction are radical reactions.

See also

• Oxidative decarboxylationde:Decarboxylierungit:Decarbossilazione