Record Information
Creation date2018-05-02 12:35:03 UTC
Update date2018-05-04 14:22:35 UTC
FoodComEx IDPC001201
FoodDB RecordFDB022200
Chemical Information
NameKynurenic acid
DescriptionKynurenic acid (KYNA) is a well-known endogenous antagonist of the glutamate ionotropic excitatory amino acid receptors N-methyl-D-aspartate (NMDA), alphaamino-3-hydroxy-5-methylisoxazole-4-propionic acid and kainate receptors and of the nicotine cholinergic subtype alpha 7 receptors. KYNA neuroprotective and anticonvulsive activities have been demonstrated in animal models of neurodegenerative diseases. Because of KYNA's neuromodulatory character, its involvement has been speculatively linked to the pathogenesis of a number of neurological conditions including those in the ageing process. Different patterns of abnormalities in various stages of KYNA metabolism in the CNS have been reported in Alzheimer's disease, Parkinson's disease and Huntington's disease. In HIV-1-infected patients and in patients with Lyme neuroborreliosis a marked rise of KYNA metabolism was seen. In the ageing process KYNA metabolism in the CNS of rats shows a characteristic pattern of changes throughout the life span. A marked increase of the KYNA content in the CNS occurs before the birth, followed by a dramatic decline on the day of birth. A low activity was seen during ontogenesis, and a slow and progressive enhancement occurs during maturation and ageing. This remarkable profile of KYNA metabolism alterations in the mammalian brain has been suggested to result from the development of the organisation of neuronal connections and synaptic plasticity, development of receptor recognition sites, maturation and ageing. There is significant evidence that KYNA can improve cognition and memory, but it has also been demonstrated that it interferes with working memory. Impairment of cognitive function in various neurodegenerative disorders is accompanied by profound reduction and/or elevation of KYNA metabolism. The view that enhancement of CNS KYNA levels could underlie cognitive decline is supported by the increased KYNA metabolism in Alzheimer's disease, by the increased KYNA metabolism in down's syndrome and the enhancement of KYNA function during the early stage of Huntington's disease. Kynurenic acid is the only endogenous N-methyl-D-aspartate (NMDA) receptor antagonist identified up to now, that mediates glutamatergic hypofunction. Schizophrenia is a disorder of dopaminergic neurotransmission, but modulation of the dopaminergic system by glutamatergic neurotransmission seems to play a key role. Despite the NMDA receptor antagonism, kynurenic acid also blocks, in lower doses, the nicotinergic acetycholine receptor, i.e., increased kynurenic acid levels can explain psychotic symptoms and cognitive deterioration. Kynurenic acid levels are described to be higher in the cerebrospinal fluid (CSF) and in critical central nervous system (CNS) regions of schizophrenics as compared to controls. (PMID: 17062375, 16088227) [HMDB]
CAS Number492-27-3
4-hydroxy-2-Quinolinecarboxylic acidhmdb
4-hydroxy-Quinaldic acidhmdb
4-Hydroxyquinaldic acidhmdb
4-Hydroxyquinaldinic acidhmdb
4-Hydroxyquinoline-2-carboxylic acidhmdb
Kynurenic acidhmdb
Quinurenic acidhmdb
Chemical FormulaC10H7NO3
IUPAC name4-oxo-1,4-dihydroquinoline-2-carboxylic acid
InChI IdentifierInChI=1S/C10H7NO3/c12-9-5-8(10(13)14)11-7-4-2-1-3-6(7)9/h1-5H,(H,11,12)(H,13,14)
Isomeric SMILESOC(=O)C1=CC(=O)C2=CC=CC=C2N1
Average Molecular Weight189.1675
Monoisotopic Molecular Weight189.042593095
Chemical Taxonomy
Description Belongs to the class of organic compounds known as quinoline carboxylic acids. These are quinolines in which the quinoline ring system is substituted by a carboxyl group at one or more positions.
KingdomOrganic compounds
Super ClassOrganoheterocyclic compounds
ClassQuinolines and derivatives
Sub ClassQuinoline carboxylic acids
Direct ParentQuinoline carboxylic acids
Alternative Parents
  • Quinoline-2-carboxylic acid
  • Dihydroquinolone
  • Dihydroquinoline
  • Pyridine carboxylic acid
  • Pyridine carboxylic acid or derivatives
  • Pyridine
  • Benzenoid
  • Heteroaromatic compound
  • Vinylogous amide
  • Monocarboxylic acid or derivatives
  • Carboxylic acid
  • Azacycle
  • Carboxylic acid derivative
  • Hydrocarbon derivative
  • Organic oxide
  • Organopnictogen compound
  • Organooxygen compound
  • Organonitrogen compound
  • Organic oxygen compound
  • Organic nitrogen compound
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External Descriptors
Physico-Chemical Properties - Experimental
Experimental logPNot Available
Experimental Water SolubilityNot Available
Melting PointNot Available
Foods of Origin
FoodContent Range AverageReference
Production Data
Production Methodcommercial
Production Method ReferenceNot Available
Production Method Reference FileNot Available
Quantity Available1 to 2 mg
Delivery Time2 weeks
Storage Formpowder
Storage ConditionsRT
StabilityNot Available
Spectral Data Upon RequestNot Available
Provider Information
Contact NameContact InstitutionContact Email
Augustin ScalbertInternational Agency for Research on Cancer (IARC), Biomarkers Group, 150 cours Albert Thomas, Lyon, FR,
Commercial Vendors
AKSci W6496
MetaSci HMDB0000715
Sigma-Aldrich HMDB0000715
Toronto Research Chemicals K660500