Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Toho University, Chiba, Japan.
Biomed Chromatogr. 2022 May;36(5):e5308. doi: 10.1002/bmc.5308. Epub 2022 Mar 31.
Kynurenine (KYN) is synthesized from an essential amino acid, tryptophan, by tryptophan 2,3-dioxygenase or indoleamine 2,3-dioxygenase via N-formyl-KYN in vivo. Subsequently, KYN acts as a precursor of some neuroactive metabolites such as kynurenic acid, quinolinic acid, and an important enzyme co-factor, nicotine adenine dinucleotide. These metabolites of tryptophan are a part of the 'kynurenine pathway.' In addition, KYN functions as an endogenous ligand for the aryl hydrocarbon receptor, which acts as a transcription factor. The levels of tryptophan metabolites are important for the assessment of the stage of neurological disorders, and therefore have garnered significant interest for clinical diagnosis. In this review, the detection of kynurenine, kynurenic acid, quinolinic acid, and other tryptophan metabolites performed via chromatographic methods such as HPLC using UV absorbance, fluorescence, and chromatographic-mass spectrometric detection is summarized.
犬尿氨酸（KYN）由色氨酸通过色氨酸 2,3-加双氧酶或吲哚胺 2,3-加双氧酶在体内由必需氨基酸色氨酸合成，通过 N-甲酰基-KYN 生成。随后，KYN 作为一些神经活性代谢物的前体，如犬尿氨酸、喹啉酸和重要的酶辅助因子烟酰胺腺嘌呤二核苷酸。这些色氨酸的代谢物是‘犬尿氨酸途径’的一部分。此外，KYN 作为芳烃受体的内源性配体发挥作用，芳烃受体作为转录因子。色氨酸代谢物的水平对于评估神经紊乱的阶段很重要，因此在临床诊断中引起了极大的关注。在这篇综述中，总结了使用 HPLC 结合紫外吸收、荧光和色谱-质谱检测等色谱方法对犬尿氨酸、犬尿氨酸酸、喹啉酸和其他色氨酸代谢物进行检测。
