Homoquinolinic acid

Homoquinolinic acid (HQA) is a potent excitotoxin^[1] which is a conformationally-restricted analogue of N-methyl-D-aspartate (NMDA) and a partial agonist of the main/glutamate site of the NMDA receptor, with some selectivity for NR2B subunit-containing receptors.^[2][3][4] It is approximately equipotent to NMDA and about five times more potent than quinolinic acid as an agonist of the NMDA receptor.^[5] HQA has also been found to label a novel, yet uncharacterized binding site, which can be distinguished from the NMDA receptor with the use of 2-carboxy-3-carboxymethylquinoline (CCMQ), a selective ligand of the uncharacterized site.^[6]

Homoquinolinic acid

Clinical data
Other names	Homoquinolinate
ATC code	None
Identifiers
IUPAC name 3-(Carboxymethyl)-2-pyridinecarboxylic acid
CAS Number	490-75-5
PubChem CID	3080554
ChemSpider	2338312
PDB ligand	QM1 (PDBe, RCSB PDB)
CompTox Dashboard (EPA)	DTXSID70197658
ECHA InfoCard	100.164.902
Chemical and physical data
Formula	C8H7NO4
Molar mass	181.147 g·mol^−1
3D model (JSmol)	Interactive image
SMILES c1cc(c(nc1)C(=O)O)CC(=O)O
InChI InChI=1S/C8H7NO4/c10-6(11)4-5-2-1-3-9-7(5)8(12)13/h1-3H,4H2,(H,10,11)(H,12,13) Key:HQPMJFFEXJELOQ-UHFFFAOYSA-N

See also

• Aspartate
• Ibotenic acid
• Tetrazolylglycine

References

1. Stone TW (1989). Quinolinic acid and the kynurenines. CRC Press. ISBN 978-0-8493-6592-8.
2. Stolerman IP (31 July 2010). Encyclopedia of Psychopharmacology. Springer Science & Business Media. pp. 511–. ISBN 978-3-540-68698-9.
3. de Carvalho LP, Bochet P, Rossier J (April 1996). "The endogenous agonist quinolinic acid and the non endogenous homoquinolinic acid discriminate between NMDAR2 receptor subunits". Neurochemistry International. 28 (4): 445–52. doi:10.1016/0197-0186(95)00091-7. PMID 8740453. S2CID 19395334.
4. Lemke TL, Williams DA (24 January 2012). Foye's Principles of Medicinal Chemistry. Lippincott Williams & Wilkins. pp. 404–. ISBN 978-1-60913-345-0.
5. C.S.A. Neurosciences Abstracts. Cambridge Scientific Abstracts. 1984.
6. Egebjerg J, Schousboe A, Krogsgaard-Larsen P (4 October 2001). Glutamate and GABA Receptors and Transporters: Structure, Function and Pharmacology. CRC Press. pp. 73–. ISBN 978-0-203-29938-8.