492-27-3

A product of L-Tryptophan metabolism, possessing neruoactive activity having antiexcitotoxic and anticonvulsant properties.

An antagonist of NMDA and AMPA/kainate receptors

ChEBI: Kynurenic acid is a quinolinemonocarboxylic acid that is quinoline-2-carboxylic acid substituted by a hydroxy group at C-4. It has a role as a G-protein-coupled receptor agonist, a NMDA receptor antagonist, a nicotinic antagonist, a neuroprotective agent, a human metabolite and a Saccharomyces cerevisiae metabolite. It is a monohydroxyquinoline and a quinolinemonocarboxylic acid. It is a conjugate acid of a kynurenate.

Broad spectrum EAA antagonist.

Kynurenic acid (KynA) is a non-selective antagonist of N-methyl-d-aspartate (NMDA), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate receptors. It blocks kainic acid neurotoxicity. Kynurenic acid also blocks nicotinic acetylcholine receptors. It is a by-product of tryptophan catabolic pathway. Kynurenic acid is a neuromodulator and controls the levels of glutamate, dopamine, acetylcholine and α-aminobutyric acid (GABA). KynA controls neuroendocrine functions and altered levels of KynA is a potential marker in depression, schizophrenia Alzheimer′s and Huntington′s diseases. Normal levels of KynA in the brain is crucial for the cognitive function.

Room temperature

Crystallise the acid from absolute EtOH. The methyl ester crystallises from MeOH with m 224-226o. [Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p2723 1961, Beilstein 22 II 174, 22 III/IV 2245, 22/6 V 280.]