Loading AI tools
Chemical compound From Wikipedia, the free encyclopedia
l-Kynurenine is a metabolite of the amino acid l-tryptophan used in the production of niacin.
Names | |
---|---|
Preferred IUPAC name
(2S)-2-Amino-4-(2-aminophenyl)-4-oxo-butanoic acid | |
Other names
(S)-Kynurenine | |
Identifiers | |
| |
3D model (JSmol) |
|
ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
MeSH | Kynurenine |
PubChem CID |
|
UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
Properties | |
C10H12N2O3 | |
Molar mass | 208.217 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Kynurenine is synthesized by the enzyme tryptophan dioxygenase, which is made primarily but not exclusively in the liver, and indoleamine 2,3-dioxygenase, which is made in many tissues in response to immune activation.[1] Kynurenine and its further breakdown products carry out diverse biological functions, including dilating blood vessels during inflammation[2] and regulating the immune response.[3] Some cancers increase kynurenine production, which increases tumor growth.[1]
Kynurenine protects the eye by absorbing UV light, especially in the UVA region (315-400 nm).[4] Kynurenine is present in the lens and retina as one of multiple tryptophan derivatives produced in the eye, including 3-hydroxykynurenine, that together provide UV protection and aid in enhancing visual acuity.[5][6] The use of kynurenine as a UV filter is consistent with its photostability and low photosensitization, owing to its efficient relaxation from the UV-induced excited state.[7] The concentration of this UV filter decreases with age,[8] and this loss of free kynurenine and the concomitant formation of relatively more photosensitizing kynurenine derivatives and kynurenine-protein conjugates may contribute to the formation of cataracts.[9][10][11]
Evidence suggests that increased kynurenine production may precipitate depressive symptoms associated with interferon treatment for hepatitis C.[12] Cognitive deficits in schizophrenia are associated with imbalances in the enzymes that break down kynurenine.[13] Blood levels of kynurenine are reduced in people with bipolar disorder.[14] Kynurenine production is increased in Alzheimer's disease[15] and cardiovascular disease[16] where its metabolites are associated with cognitive deficits[17] and depressive symptoms.[18] Kynurenine is also associated with tics.[19][20]
Kynureninase catabolizes the conversion of kynurenine into anthranilic acid[21] while kynurenine-oxoglutarate transaminase catabolizes its conversion into kynurenic acid. Kynurenine 3-hydroxylase converts kynurenine to 3-hydroxykynurenine.[22]
Kynurenine has also been identified as one of two compounds that makes up the pigment that gives the goldenrod crab spider its yellow color.[23]
Dysfunctional states of distinct steps of the kynurenine pathway (such as kynurenine, kynurenic acid, quinolinic acid, anthranilic acid, 3-hydroxykynurenine) have been described for a number of disorders, including:[25]
Downregulation of kynurenine-3-monooxygenase (KMO) can be caused by genetic polymorphisms, cytokines, or both.[28][29] KMO deficiency leads to an accumulation of kynurenine and to a shift within the tryptophan metabolic pathway towards kynurenine acid and anthranilic acid.[30] Kynurenine-3-monooxygenase deficiency is associated with disorders of the brain (e.g. major depressive disorder, bipolar disorder, schizophrenia, tic disorders) [31] and of the liver.[19][32][33][34][35]
It is hypothesized that the kynurenine pathway is partly responsible for the therapeutic effect of lithium on bipolar disorder. If that is the case, it could be a target of drug discovery.[36][37]
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.