Results 161 to 170 of about 5,596 (203)
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A new fluorimetric method for the determination of 3-hydroxykynurenine
Clinica Chimica Acta, 1970Abstract A new fluorimetric assay for the determination of 3-hydroxykynurenine has been developed, which is based on the reaction of the compound with p -toluenesulfonyl chloride in basic condition to yield a fluorescent product. In combination with the thin-layer chromatographic technique this assay has been used to estimate the urinary excretion ...
M, Watanabe, Y, Watanabe, M, Okada
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Determination of endogenous 3-hydroxykynurenine in plasma
Microchemical Journal, 1984Abstract A method is described which permits determination of 3-hydroxykynurenine ( l -3-(2-amino-3-hydroxybenzoyl)-alanine), a metabolite of tryptophan, in plasma with a limit of detection of less than 0.1 pmol. This compound can be extracted by means of adsorption onto a strong anion-exchange resin at pH 9.5 in the presence of an antioxidant ...
Stig Allenmark +3 more
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3-Hydroxykynurenine in human urine
Clinica Chimica Acta, 1960Abstract An investigation has been made into the determination of 3-hydroxykynurenine in urine. Urine was passed through an ion-exchange resin and 3-hydroxykynurenine determined in the 5N hydrochloric acid eluate by means of the molybdate-phosphate reaction.
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Oxidation of 3‐hydroxykynurenine. An EPR investigation
Journal of Heterocyclic Chemistry, 1990AbstractA weak alkaline solution of 3‐hydroxykynurenine was oxidized using potassium ferricyanide. A stable epr signal was recorded, probably arising from a phenoxazine intermediate. A plausible radical mechanism for this reaction is presented.
A. BOLOGNESE +3 more
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Biphotonic ionization of kynurenine and 3-hydroxykynurenine
Journal of Photochemistry and Photobiology A: Chemistry, 2007Abstract The photoionization of kynurenine (KN) and 3-hydroxykynurenine (3OHKN) in aqueous solutions proceeds via a biphotonic mechanism. The precursors for ionization are the triplet states TKN and T3OHKN, absorbing the second light quantum. The addition of solvated electrons to the parent molecules with the rate constant 2.0 × 1010 M−1 s−1 results ...
O.A. Snytnikova +2 more
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The role of hydrogen peroxide in the in vitro cytotoxicity of 3-hydroxykynurenine
Neurochemical Research, 1990Previous studies have indicated that the generation of H2O2 may be a key step in the mechanism mediating the in vitro cytotoxicity of 3-hydroxykynurenine (3HK). An exposure protocol resulting in a delayed toxicity was utilized in order to further examine the role of H2O2 in the in vitro toxicity of 3HK in a neural hybrid cell line.
Eastman, Clifford L., Guilarte, Tomas R.
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Formation of hydroxanthommatin-derived radical in the oxidation of 3-hydroxykynurenine
Archives of Biochemistry and Biophysics, 1992Using ESR, a radical (g = 2.004) was detected in the reaction mixture of 3-hydroxykynurenine (3-HKY), H2O2, and horseradish peroxidase. The radical was stable and was detected even after 5 h. On HPLC analysis of the reaction mixture, two radical peaks (Peak-1 and Peak-2) were detected using ESR.
T, Ishii +3 more
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3-hydroxykynurenine as O2⨪ scavenger in the blowfly, Aldrichina grahami
Biochemical and Biophysical Research Communications, 1986We studied the distribution of O2-.-scavenging activity in 6-day-old larvae of Aldrichina grahami. Total activity was highest in the muscle. The specific activity per milligram of protein in the Malpighian tubules was highest, 10 times the highest elsewhere. Most of the O2-. scavenging activity in muscle depended on superoxide dismutase.
N, Goshima, A, Wadano, K, Miura
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Oxidation of 3-hydroxykynurenine catalyzed by methemoglobin with hydrogen peroxide
Free Radical Biology and Medicine, 1992Methemoglobin (metHb) with H2O2 catalyzed the oxidation of 3-hydroxykynurenine (3-HKY) in the reaction mixture of metHb, 3-HKY, and H2O2. The spectrophotometric experiments suggest the following mechanism for the 3-HKY oxidation by metHb with H2O2. MetHb first reacts with H2O2 to form the ferryl complex of Hb. This species then oxidizes 3-HKY, while it
T, Ishii +3 more
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Journal of Liquid Chromatography & Related Technologies, 1998
Abstract Identification of 3-hydroxykynurenine and xanthurenic acid and determination of 3-hydroxykynurenine transaminase activity using HPLC with electrochemical detection (HPLC-ED) are described using mosquito larval samples as testing materials.
J. Li, G. Li
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Abstract Identification of 3-hydroxykynurenine and xanthurenic acid and determination of 3-hydroxykynurenine transaminase activity using HPLC with electrochemical detection (HPLC-ED) are described using mosquito larval samples as testing materials.
J. Li, G. Li
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