L-Kynurenine-d4 [4-(2-aminophenyl-3,5-d2); 3,3-d2] is a useful isotopically labeled compound of L-Kynurenine (K661005); which is a precursor of kynurenic acid (K660500) and an antagonist of N-methyl-aspartate receptor.
L-Kynurenine-d4 is intended for use as an internal standard for the quantification of kynurenine by GC- or LC-MS. L-Kynurenine is an active metabolite of tryptophan .1 It is formed from tryptophan via tryptophan 2,3-dioxygenase (TDO) or indoleamine 2,3-dioxygenase (IDO). L-Kynurenine binds to the aryl hydrocarbon receptor (AhR; Kd = ~4 μM) and increases the activity of ethoxyresorufin-O-deethylase (EROD) in H-4-II-E rat hepatoma cells (EC50 = 12.3 μM).2 It decreases intracellular concentrations of NAD+ in, and increases lactate dehydrogenase (LDH) activity in the supernatant of, primary human astrocytes and neurons in a concentration-dependent manner.3 L-Kynurenine in combination with IFN-γ reduces lung injury induced by A. fumigatus infection in the p47phox-/- mouse model of chronic granulomatous disease.4
1.Stone, T.W., Forrest, C.M., and Darlington, L.G.Kynurenine pathway inhibition as a therapeutic strategy for neuroprotectionFEBS J.279(8)1386-1397(2012)
2.Opitz, C.A., Litzenburger, U.M., Sahm, F., et al.An endogenous tumour-promoting ligand of the human aryl hydrocarbon receptorNature478(7368)197-203(2011)
3.Braidy, N., Grant, R., Brew, B.J., et al.Effects of kynurenine pathway metabolites on intracellular NAD+ synthesis and cell death in human primary astrocytes and neuronsInt. J. Tryptophan Res.261-69(2009)
4.Romani, L., Fallarino, F., De Luca, A., et al.Defective tryptophan catabolism underlies inflammation in mouse chronic granulomatous diseaseNature451(7175)211-215(2008)
