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1.
建立了醋酸锌在线衍生高效液相色谱法同时测定血浆中色氨酸(Trp)、犬尿氨酸(Kyn)、5-羟吲哚乙酸(5-Hiaa)和犬尿喹啉酸(Kyna)的方法。以3-硝基酪氨酸为内标(IS),采用Hypersil C-18柱(250 mm×4.0 mm, 5 μ m),以250 mmol/L醋酸锌溶液(pH 5.5)-乙腈(95:5, v/v)为流动相,流速为0.8 mL/min,柱温30℃。荧光检测波长设定:5-Hiaa为278 nm(λex)/343 nm(λem), Kyna为244 nm(λex)/400 nm(λem);紫外检测波长设定:Kyn和IS为360 nm, Trp为302 nm。4种物质的回收率在91.62%~114.17%之间;线性范围分别为2.50~320.00 μ mol/L(Trp), 0.32~15.36 μ mol/L(Kyn), 3.27~104.60 nmol/L(5-Hiaa), 14.00~464.80 nmol/L(Kyna);检出限分别为0.078 μ mol/L(Trp), 0.056 μ mol/L(Kyn), 0.690 nmol/L(5-Hiaa), 1.290 nmol/L(Kyna)。利用该方法对30例正常孕妇和28例女性健康志愿者的血浆进行测定,结果表明两组间Trp, Kyn和Kyna含量有显著性差异。该方法操作简便,重复性好,灵敏度高,适合于临床检测。 相似文献
2.
We studied nanocarbon film electrodes with the aim of detecting tryptophan metabolites via the kynurenine pathway. The nanocarbon films were formed by using unbalanced magnetron sputtering, and they exhibited superior electrode properties including a wide potential window and a low background current as a result of the sp3-containing structure and ultraflat surface. These properties allowed us to detect certain tryptophan metabolites such as kynurenic acid (KYNA), which has a relatively high oxidation potential. We also investigated the effect of the sp2/sp3 ratio of the nanocarbon film as regards the electrode activity in relation to target molecules. We found that the sp2/sp3 ratio played important roles in both widening the potential window and obtaining superior electrode performance for the metabolites. The nanocarbon film with a high sp3 content was beneficial as regards the electrode performance with respect to the detection limit and sensitivity. Compared with conventional carbon-based electrodes, the nanocarbon film electrode with a high sp3 content exhibited higher electrode activity against KYNA while maintaining a low background current. Computational experiments revealed that the theoretical oxidation potential (Eox) value for some targets coincided with that obtained in electrochemical experiments using our nanocarbon film electrode. 相似文献
3.
建立了在线衍生、双波长高效液相色谱-荧光检测器同时检测血清中犬尿氨酸(kynurenine, Kyn)和犬尿喹啉酸(kynurenic acid, KYNA)含量的方法。血清标本经5%高氯酸溶液去除蛋白质后,上清液直接进样分析测定。采用的色谱柱为Hypersil C8柱;流动相为0.25 mol/L醋酸锌-50 mmol/L醋酸溶液(含3%乙腈),流速为1.5 mL/min。在0～10 min时间段,在激发波长和发射波长分别为365 nm和480 nm时检测Kyn;10 min后,在激发波长和发射波长分别变换为344 nm和404 nm时检测KYNA。Kyn的保留时间约为8.1 min,线性范围为98～19600 nmol/L,最低检出浓度为50 nmol/L,平均回收率为94.88%,日内、日间测定值的相对标准偏差(RSD)均低于4%。KYNA的保留时间约为13.0 min,线性范围为2.62～1047 nmol/L,最低检出浓度为0.11 nmol/L,平均回收率为102.72%,日内、日间测定的RSD均低于4%。苯丙氨酸、酪氨酸、色氨酸和5-羟色胺等物质对目标物的检测无干扰。71例健康成人血清中,Kyn和KYNA含量分别为(1.40±0.34) μmol/L和(24.22±8.67) nmol/L。该方法简便、快速、灵敏、特异,适于临床和科研应用。 相似文献
4.
Ilona Sadok Andrzej Gamian Magdalena Maria Staniszewska 《Journal of separation science》2017,40(15):3020-3045
The kynurenine pathway generates multiple tryptophan metabolites called collectively kynurenines and leads to formation of the enzyme cofactor nicotinamide adenine dinucleotide. The first step in this pathway is tryptophan degradation, initiated by the rate‐limiting enzymes indoleamine 2,3‐dioxygenase, or tryptophan 2,3‐dioxygenase, depending on the tissue. The balanced kynurenine metabolism, which has been a subject of multiple studies in last decades, plays an important role in several physiological and pathological conditions such as infections, autoimmunity, neurological disorders, cancer, cataracts, as well as pregnancy. Understanding the regulation of tryptophan depletion provide novel diagnostic and treatment opportunities, however it requires reliable methods for quantification of kynurenines in biological samples with complex composition (body fluids, tissues, or cells). Trace concentrations, interference of sample components, and instability of some tryptophan metabolites need to be addressed using analytical methods. The novel separation approaches and optimized extraction protocols help to overcome difficulties in analyzing kynurenines within the complex tissue material. Recent developments in chromatography coupled with mass spectrometry provide new opportunity for quantification of tryptophan and its degradation products in various biological samples. In this review, we present current accomplishments in the chromatographic methodologies proposed for detection of tryptophan metabolites and provide a guide for choosing the optimal approach. 相似文献
5.
Tamera D. Hughes Osman F. Güner Emma Carine Iradukunda Robert S. Phillips J. Phillip Bowen 《Molecules (Basel, Switzerland)》2022,27(1)
Under normal physiological conditions, the kynurenine pathway (KP) plays a critical role in generating cellular energy and catabolizing tryptophan. Under inflammatory conditions, however, there is an upregulation of the KP enzymes, particularly kynurenine 3-monooxygenase (KMO). KMO has garnered much attention due to its production of toxic metabolites that have been implicated in many diseases and disorders. With many of these illnesses having an inadequate or modest treatment, there exists a need to develop KMO inhibitors that reduce the production of these toxic metabolites. Though prior efforts to find an appropriate KMO inhibitor were unpromising, the development of a KMO crystal structure has provided the opportunity for a rational structure-based design in the development of inhibitors. Therefore, the purpose of this review is to describe the kynurenine pathway, the kynurenine 3-monooxygenase enzyme, and KMO inhibitors and their potential candidacy for clinical use. 相似文献
6.
Gozde Girgin;Sonia Sanajou;Sinem Meric-Deliveli;Terken Baydar; 《Biomedical chromatography : BMC》2024,38(2):e5791
Colostrum, the first breast fluid produced by mammals after giving birth, is followed by breast milk, which serves as the sole source of nutrients for breastfed newborns and infants. Tryptophan, an essential amino acid, plays a crucial role in the development and maturation of the central nervous system in infants. Tryptophan is primarily degraded through the kynurenine pathway. Owing to its sensitivity to dietary intake, immune-mediated tryptophan degradation is assessed by the kynurenine-to-tryptophan ratio, with a focus on one of the rate-limiting enzymes in the pathway. This study involved the validation of the simultaneous determination of tryptophan and kynurenine using HPLC. The validated method was then used to detect levels of tryptophan and kynurenine, as well as to calculate the kynurenine-to-tryptophan ratio in colostrum samples. Simultaneously, these results were compared with colostrum neopterin levels measured using commercial enzyme-linked immunosorbent assay kits. The mean levels for tryptophan, kynurenine, and neopterin were 17.3 ± 62.4 μM, 0.45 ± 0.03 μM, and 28.9 ± 2.6 nM, respectively. This study is among the few that have evaluated these parameters in colostrum samples. Neopterin levels secreted by the mammary gland were found not to be correlated with tryptophan degradation, a process influenced by the mother’s nutritional status. 相似文献
7.
Jianxing Zhao 《Biomedical chromatography : BMC》2015,29(3):410-415
A high‐performance liquid chromatography with ultraviolet detection method has been developed for the simultaneous determination of a set of reliable markers of renal function, including creatinine, uric acid, kynurenine and tryptophan in plasma. Separation was achieved by an Agilent HC‐C18 (2) analytical column. Gradient elution and programmed wavelength detection allowed the method to be used to analyze these compounds by just one injection. The total run time was 25 min with all peaks of interest being eluted within 13 min. Good linear responses were found with correlation coefficient >0.999 for all analytes within the concentration range of the relevant levels. The recovery was: creatinine, 101 ± 1%; uric acid, 94.9 ± 3.7%; kynurenine, 100 ± 2%; and tryptophan, 92.6 ± 2.9%. Coefficients of variation within‐run and between‐run of all analytes were ≤2.4%. The limit of detection of the method was: creatinine, 0.1 µmol/L; uric acid, 0.05 µmol/L; kynurenine, 0.02 µmol/L; and tryptophan, 1 µmol/L. The developed method could be employed as a useful tool for the detection of chronic kidney disease, even at an early stage. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
8.
Megumi Iwasaki Yoshiyuki Kashiwaguma Chihiro Nagashima Mao Izumi Ayano Uekusa Sumiko Iwasa Mayu Onozato Hideaki Ichiba Takeshi Fukushima 《Biomedical chromatography : BMC》2016,30(3):384-389
Elution profiles of kynurenic acid (KYNA) and 7‐chlorokynurenic acid (Cl‐KYNA) were examined by high‐performance liquid chromatography (HPLC) using a triazole‐bonded stationary phase column (Cosmosil® HILIC) under isocratic elution of a mobile phase consisting of CH3CN–aqueous 10 mm ammonium formate between pH 3.0 and 6.0. The capacity factors of KYNA and Cl‐KYNA varied with both the CH3CN content and the pH of the mobile phase. The elution order of KYNA and Cl‐KYNA was reversed between the CH3CN‐ and H2O‐rich mobile phases, suggesting that hydrophilic interactions and anion‐exchange interactions caused retention of KYNA and Cl‐KYNA in the CH3CN‐ and H2O‐rich mobile phases, respectively. The present HPLC method using a triazole‐bonded column and fluorescence detection (excitation 250 nm, emission 398 nm) was applied to monitor in vitro production of KYNA from d ‐kynurenine (d ‐KYN) by d ‐amino acid oxidase (DAO) using Cl‐KYNA as an internal standard. A single KYNA peak was clearly observed after enzymatic reaction of d ‐KYN with DAO. Production of KYNA from d ‐KYN was suppressed by the addition of commercial DAO inhibitors. The present HPLC method can be used to evaluate DAO activity and DAO inhibitory effects in candidate drugs for the treatment of schizophrenia. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
9.
The term reactive oxygen species refers to small molecules that can oxidize, for example, nearby proteins, especially cysteine, methionine, tryptophan, and tyrosine residues. Tryptophan oxidation is always irreversible in the cell and can yield several oxidation products, such as 5-hydroxy-tryptophan (5-HTP), oxindolylalanine (Oia), kynurenine (Kyn), and N-formyl-kynurenine (NFK). Because of the severe effects that oxidized tryptophan residues can have on proteins, there is a great need to develop generally applicable and highly sensitive techniques to identify the oxidized residue and the oxidation product. Here, the fragmentation behavior of synthetic peptides corresponding to sequences recently identified in three skeletal muscle proteins as containing oxidized tryptophan residues were studied using postsource decay and collision-induced dissociation (CID) in matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF)/TOF mass spectrometry (MS) and CID in an electrospray ionization (ESI) double quadrupole TOF-MS. For each sequence, a panel of five different peptides containing Trp, 5-HTP, Kyn, NFK, or Oia residue was studied. It was always possible to identify the modified positions by the y-series and also to distinguish the different oxidation products by characteristic fragment ions in the lower mass range by tandem MS. NFK- and Kyn-containing peptides displayed an intense signal at m/z 174.1, which could be useful in identifying accordingly modified peptides by a sensitive precursor ion scan. Most importantly, it was always possible to distinguish isomeric 5-HTP and Oia residues. In ESI- and MALDI-MS/MS, this was achieved by the signal intensity ratios of two signals obtained at m/z 130.1 and 146.1. In addition, high collision energy CID in the MALDI-TOF/TOF-MS also permitted the identification of these two isomeric residues by their v- and w-ions, respectively. 相似文献
10.
11.
Giangiacomo Beretta Giulio Vistoli Enrico Caneva Cecila Anselmi Roberto Maffei Facino 《Magnetic resonance in chemistry : MRC》2009,47(5):456-459
The complete 1H, 13C and 15N NMR spectral assignments of two new alkaloids isolated from chestnut honey and structurally related to kynurenic acid have been made using 1‐D and 2‐D NMR techniques, including COSY, HMQC and HMBC experiments. The new compounds have been identified as 3‐(2′‐pyrrolidinyl)‐kynurenic acid and its γ‐lactam derivative. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
12.
建立了一种高效液相色谱-程序波长紫外检测法同时测定血浆中色氨酸(Trp)及其主要代谢产物犬尿氨酸(Kyn)和5-羟色胺(5-HT)。以茶碱为内标(IS),采用BDS-Hypersil-C8柱(150 mm×4.6 mm, 5 μm)分离。流动相为10 mmol/L醋酸钠缓冲液(pH 4.5)-乙腈(94:6, v/v),流速为0.6 mL/min;柱温为25 ℃;紫外检测波长设定: Kyn和IS为360 nm, 5-HT为220 nm, Trp为302 nm。3种物质的平均回收率为87%～113%;线性范围分别为3.97～400 μmol/L(Trp), 0.421～20.2 μmol/L(Kyn), 4.36～980 nmol/L(5-HT);检出限分别为0.134 μmol/L(Trp), 0.0160 μmol/L(Kyn), 2.03 nmol/L(5-HT)。利用该方法对15例抑郁症患者和15例健康志愿者的血浆进行测定,结果表明两组间Trp的代谢存在显著的差异。 相似文献
13.
A novel method was developed for the simultaneous determination of kynurenine and tryptophan by high‐performance liquid chromatography with electrochemical detection at multi‐wall carbon nanotube (MWCNT)‐modified glassy carbon electrode. The separation and detection conditions were optimized. The typical HPLC experiments were conducted by using a reversed‐phase ODS column with a mobile phase consisting of stock acetate buffer (pH 5)–methanol (4:1, v/v) using an isocratic elution at the flow rate of 1.0 mL/min. The obtained LODs for kynurenine and tryptophane were 0.5 and 0.4 µmol/L, respectively. The analytical method for human plasma samples was validated and confirmed by LC‐UV and LC‐MS. The recoveries were in the range of 84.8–110%, and the precision was lower than 5.9%. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
14.
建立了一种能同时检测血清中的犬尿氨酸(kynurenine,Kyn)和色氨酸(tryptophan,Trp)的高效液相色谱-紫外检测法。采用的色谱柱为Symmetry Shield RP-C18柱(150 mm×3.9 mm i.d.,5 μm),流动相为15 mmol/L乙酸钠-乙酸溶液(含2.7%乙腈,pH 3.6),流速为1.0 mL/min,紫外检测波长为225 nm。血清标本经5.0%(体积分数)高氯酸溶液去除蛋白质后取上清液直接进样分析测定。研究结果表明,Kyn保留时间为3.5 min,线性范围为0.098~49 μmol/L,最低检出浓度为0.02 μmol/L,回收率为90.82%~93.45%;Trp保留时间为8.1 min,线性范围为4.9~490 μmol/L,最低检出浓度为0.20 μmol/L,回收率为95.51%~98.67%。Kyn和Trp日内、日间测定的相对标准偏差均小于4%,苯丙氨酸、酪氨酸、5-羟色胺和犬尿喹啉酸等物质对该法均无干扰。该方法简便、快速、稳定、可行,可应用于临床和科研工作。 相似文献
15.
Viviane Soares Souza Lima Douglas Oscar Ceolin Mariano Hugo Vigerelli Sabrina Cardoso Janussi Thayz Vanalli Lima Baptista Mrio Angelo Claudino Daniel Carvalho Pimenta Juliana Mozer Sciani 《Molecules (Basel, Switzerland)》2021,26(10)
Kynurenic acid (KYNA) is derived from tryptophan, formed by the kynurenic pathway. KYNA is being widely studied as a biomarker for neurological and cardiovascular diseases, as it is found in ischemic conditions as a protective agent; however, little is known about its effect after ischemia-reperfusion in the vascular system. We induced ischemia for 30 min followed by 5 min reperfusion (I/R) in the rat aorta for KYNA evaluation using functional assays combined with proteomics. KYNA recovered the exacerbated contraction induced by phenylephrine and relaxation induced by acetylcholine or sodium nitroprussiate in the I/R aorta, with vessel responses returning to values observed without I/R. The functional recovery can be related to the antioxidant activity of KYNA, which may be acting on the endothelium-injury prevention, especially during reperfusion, and to proteins that regulate neurotransmission and cell repair/growth, expressed after the KYNA treatment. These proteins interacted in a network, confirming a protein profile expression for endothelium and neuron repair after I/R. Thus, the KYNA treatment had the ability to recover the functionality of injured ischemic-reperfusion aorta, by tissue repairing and control of neurotransmitter release, which reinforces its role in the post-ischemic condition, and can be useful in the treatment of such disease. 相似文献
16.
Maryam Oudi Kazem Sanchooli Tazeh Nourallah Hazeri Maryam Fatahpour Raheleh Ahmadi 《中国化学会会志》2019,66(12):1721-1728
In the present work, the catalytic activity of quinolinic acid (QUIN) was studied for the synthesis of spirochromene and pyranopyrazole derivatives from readily available materials. The salient features of these one‐pot multicomponent protocols are the clean reaction profile, easy isolation of products, no chromatographic separation techniques, high efficiency, short reaction time, and high yield of products plus using QUIN as a new, inexpensive, commercially available, and efficient organocatalyst. 相似文献
17.
Vignau J Jacquemont MC Lefort A Imbenotte M Lhermitte M 《Biomedical chromatography : BMC》2004,18(10):872-874
Tryptophan metabolism is disturbed in mental depression, and the induction of indoleamine 2,3-dioxygenase increases kynurenine production. In order to determine this disturbance in patients with chronic hepatitis C and receiving interferon-based immunotherapy, a new and specific HPLC protocol was elaborated. For tryptophan, the assay was linear from 6.25 to 100 micromol L(-1), and the limits of detection (LOD) and quantitation (LOQ) for the method were 0.7 and 8.0 micromol L(-1). For kynurenine, the linearity of calibration was from 0.0625 to 6.25 micromol L(-1), with LOD and LOQ of 2 and 3 nmol L(-1). Reproducibility and repeatability were satisfactory. The method allowed study of human blood serum. 相似文献
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19.
Dorota Pogoda Jan Janczak Sylwia Pawlak Michael Zaworotko Veneta Videnova-Adrabinska 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(6):793-805
Kynurenic acid (KYN; systematic name: 4‐hydroxyquinoline‐2‐carboxylic acid, C10H7NO3) displays a therapeutic effect in the treatment of some neurological diseases and is used as a broad‐spectrum neuroprotective agent. However, it is understudied with respect to its solid‐state chemistry and only one crystal form (α‐KYN·H2O) has been reported up to now. Therefore, an attempt to synthesize alternative solid‐state forms of KYN was undertaken and six new species were obtained: five solvates and one salt. One of them is a new polymorph, β‐KYN·H2O, of the already known KYN monohydrate. All crystal species were further studied by single‐crystal and powder X‐ray diffraction, thermal and spectroscopic methods. In addition to the above methods, differential scanning calorimetry (DSC), in‐situ variable‐temperature powder X‐ray diffraction and Raman microscopy were applied to characterize the phase behaviour of the new forms. All the compounds display a zwitterionic form of KYN and two different enol–keto tautomers are observed depending on the crystallization solvent used. 相似文献
20.
Fukushima T Mitsuhashi S Tomiya M Kawai J Hashimoto K Toyo'oka T 《Biomedical chromatography : BMC》2007,21(5):514-519
Kynurenic acid (KYNA), one of the tryptophan metabolites, serves as an endogenous antagonist of N-methyl-d-aspartate and the alpha7 nicotinic receptors in mammalian brains. In the present study, the column-switching high-performance liquid chromatography (HPLC) method we developed for plasma KYNA was extended and validated for the determination of brain KYNA. Rat cerebrum, cerebellum and brainstem homogenates were deproteinized with acetone, and the extracts reconstituted with the mobile phase were injected onto the HPLC. In spite of the facile pretreatment, the fluorescence peak of KYNA in the cerebrum, cerebellum and brainstem was clearly observed with no interfering peaks. Intra- and inter-day precisions [relative standard deviation (%)] and accuracies [relative mean error (%)] were satisfactory (< +/-5.8%). The concentrations of KYNA in rat cerebrum, cerebellum, and brainstem were 224 +/- 65.8, 606 +/- 191, and 323 +/- 114 fmol/mg protein (n = 5), respectively. The proposed HPLC method will be a useful tool for pharmacokinetic and pharmacological researches on brain KYNA. 相似文献