Kynurenic acid

Kynurenic acid

Chembox new
Name = Kynurenic acid
ImageFile = KynurenicAcid.png ImageName = Chemical structure of kynurenic acid
IUPACName = 4-oxo-1H-quinoline-2-carboxylic acid
OtherNames = Kinurenic acid, kynuronic acid, quinurenic acid, transtorine
Section1 = Chembox Identifiers
CASNo = 492-27-3
PubChem = 3845
SMILES = C1=CC=C2C(=C1)C(=O)C=C(N2)C(=O)O

Section2 = Chembox Properties
Formula = C10H7N1O3
MolarMass = 189.168 g/mol
Density =
MeltingPt = 282.5°C
BoilingPt =

Kynurenic acid (KYNA) is a product of the normal metabolism of amino acid L-tryptophan. It has been shown that kynurenic acid possesses neuroactive activity. It acts as an antiexcitotoxic and anticonvulsant, most likely through acting as an antagonist at excitatory amino acid receptors. Because of this activity, it may influence important neurophysiologic and neuropathologic processes. As a result, kynurenic acid has been considered for use in therapy in certain neurobiological disorders. Conversely, increased levels of kynurenic acid have also been linked to certain pathological conditions.

Kynurenic acid was discovered in 1853 by the German chemist Justus von Liebig in dog urine.Liebig, J., Uber Kynurensäure, "Justus Liebigs Ann. Chem.", 86: 125-126, 1853.]

It is formed from L-kynurenine in a reaction catalyzed by the enzyme kynurenine—oxoglutarate transaminase.

Mechanism of action

KYNA was found to act on three receptors:

* As a noncompetitive antagonist at glycine site of the NMDA receptor.
* As an antagonist of α7 nicotinic acetylcholine receptor. This action is contrary to another tryptophan metabolite, 5-hydroxyindoleacetic acid. cite journal |author=Grilli M, Raiteri L, Patti L, Parodi M, Robino F, Raiteri M, Marchi M |title=Modulation of the function of presynaptic alpha7 and non-alpha7 nicotinic receptors by the tryptophan metabolites, 5-hydroxyindole and kynurenate in mouse brain |journal=Br. J. Pharmacol. |volume=149 |issue=6 |pages=724–32 |year=2006 |pmid=17016503 |doi=10.1038/sj.bjp.0706914]
* As a ligand for G protein-coupled receptor GPR35. cite journal |author=Wang J, Simonavicius N, Wu X, Swaminath G, Reagan J, Tian H, Ling L |title=Kynurenic acid as a ligand for orphan G protein-coupled receptor GPR35 |journal=J. Biol. Chem. |volume=281 |issue=31 |pages=22021–8 |year=2006 |pmid=16754668 |doi=10.1074/jbc.M603503200]

Role in disease

High levels of kynurenic acid have been identified in patients suffering from tick-borne encephalitis, schizophrenia and HIV-related illnesses. In all these situations increased levels were associated with confusion and psychotic symptoms. Kynurenic acid acts in the brain as a glycine-site NMDAr antagonist, key in glutamatergic neurotransmission system, which is thought to be involved in the pathophysiology and pathogenesis of schizophrenia.

A kynurenic acid hypothesis of schizophrenia has been proposed in 2007,cite journal |author=Erhardt S, Schwieler L, Nilsson L, Linderholm K, Engberg G |title=The kynurenic acid hypothesis of schizophrenia |journal=Physiol. Behav. |volume=92 |issue=1-2 |pages=203–9 |year=2007 |pmid=17573079 |doi=10.1016/j.physbeh.2007.05.025] cite journal |author=Erhardt S, Schwieler L, Engberg G |title=Kynurenic acid and schizophrenia |journal=Adv. Exp. Med. Biol. |volume=527 |issue= |pages=155–65 |year=2003 |pmid=15206728 |doi = ] based on its action on midbrain dopamine activity and NMDArs, thus linking dopamine hypothesis of schizophrenia with the glutamate hypothesis of the disease.

High levels of kynurenic acid have been identified in human urine in certain metabolic disorders, such as marked pyridoxine deficiency and deficiency/absence of kynureninase.

ee also

* Xanthurenic acid

References

External links

* [http://www.thelocal.se/9013/20071106/ Link found between TBE and schizophrenia] - TheLocal.se, Sweden's news in English, 6th November 2007.


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Look at other dictionaries:

  • kynurenic acid — kinureno rūgštis statusas T sritis chemija formulė NC₉H₅(OH)COOH atitikmenys: angl. kynurenic acid rus. кинуреновая кислота ryšiai: sinonimas – 4 hidroksi 2 chinolinkarboksirūgštis …   Chemijos terminų aiškinamasis žodynas

  • kynurenic acid — |ki]nyə|renik , |kī] noun Etymology: kynurenic International Scientific Vocabulary kyn (from Greek kyn , kyōn dog) + uren (irregular from Greek ouron urine) + ic more at hound, urine : a crystalline acid C9H5N(OH)COOH occurring in the urine of… …   Useful english dictionary

  • kynurenic acid — A product of the metabolism of l tryptophan; appears in human urine in states of marked pyridoxine deficiency. * * * kyn·uren·ic acid .kīn yu̇ .ren ik , .kin n a crystalline acid C10H7NO3 that is formed from kynurenine as one of the normal… …   Medical dictionary

  • kynurenic acid — noun A metabolite of tryptophan that has antiexcitotoxic and anticonvulsant activity …   Wiktionary

  • kynurenic — adjective Of or pertaining to kynurenic acid or its derivatives …   Wiktionary

  • Kynurenic — Ky nu*ren ic, a. [Gr. ?, ?, dog + ? urine.] (Physiol. Chem.) Pertaining to, or designating, an acid obtained from the urine of dogs. By decomposition the acid yields a nitrogenous base (called kynurin) and carbonic acid. [Written also {cynurenic} …   The Collaborative International Dictionary of English

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  • N-Methyl-D-aspartic acid — N Methyl D aspartic acid …   Wikipedia

  • xanthurenic acid — |zan(t)th(y)ə|renik noun Etymology: xanth + urenic (as in kynurenic) : a yellow crystalline phenolic acid (HO)2C9H4NCOOH closely related to kynurenic acid and excreted in the urine when tryptophan is added to the diet of experimental animals… …   Useful english dictionary

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