• 제목/요약/키워드: kynurenic acid

검색결과 13건 처리시간 0.035초

4-Substituted-kynurenic Acid Derivatives:A Novel Class of NMDA Receptor Glycine Site Antagonists

  • Kim, Ran-Hee;Chung, Yong-Jun;Lee, Chang-Woo;Jae, Yang-Kong;Young, Sik-Jung;Seong, Churl-Min;Park, No-Sang
    • Archives of Pharmacal Research
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    • 제20권4호
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    • pp.351-357
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    • 1997
  • A series of 4-substituted-kynurenic acid derivatives possessing several different substituents at C4-position which are consisted of both a flexible propyloxy chain and an adjunct several type of carbonyl groups has been synthesized and evaluated for their in vitro antagonist activity at the glycine site on the NMDA receptor. Of them, N-benzoylthiourea 15c and N-phenylthiourea 15a were found to have the best in vitro binding affinity with $IC_{50}$ of 3.95 and $6.04{\mu}M$, respectively. On the other hand, in compounds 12a-c and 13 the displacement of a thiourea group to an amide or a carbamate caused a significant decrease of the in vitro binding affinity. In the SAR study of the 4-substituted kynurenic acid derivatives, it was realized that the terminal substitution pattern on a flexible C4-propyloxy chain of kynurenic acid nucleus significantly influences on the binding affinity for glycine site; the binding affinity to the NMDA receptor might be increased by the introduction of a suitable electron rich substituent at C4 of kynurenic acid nucleus.

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Serum Kynurenic Acid: Possible Association with Invasiveness of Non-small Cell Lung Cancer

  • Sagan, Dariusz;Kocki, Tomasz;Kocki, Janusz;Szumilo, Justyna
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권9호
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    • pp.4241-4244
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    • 2012
  • The lung adenocarcinoma is considered more aggressive than other types of non-small cell lung cancer. As metabolites of tryptophan degradation along the kynurenine pathway, including kynurenic acid, have been shown to induce immunosuppression and facilitate escape of tumor cells from immune surveillance, a hypothesis was set up that differences in biological behavior between types of lung cancer may be associated with altered activity of the kynurenine metabolic pathway. The aim of the study was to determine kynurenic acid levels in the serum of patients with bronchial adenocarcinoma for comparison with other types of non-small cell lung cancer. A total of 227 patients with non-small cell lung cancer were enrolled in the study, including 71 with adenocarcinoma and 96 with squamous cell carcinoma. Serum kynurenic acid concentration was determined with use of high performance liquid chromatography and fluorometry. The level of kynurenic acid in the serum of patients with adenocarcinoma was significantly higher than in those with squamous cell lung cancer ($107.1{\pm}62.8$ pmol/ml; 95%CI: 92.4 to 132.3 pmol/ml versus $82.1{\pm}47.6$ pmol/ml; 95%CI: 78.5 to 91.2 pmol/ml, respectively; p = 0.027). Differences between other histological types of lung cancer were insignificant. We conclude that increased activity of kynurenine metabolic pathway manifested by elevated serum kynurenic acid level may be one of the factors associated with clinically distinct biological behavior of adenocarcinoma, in particular high invasiveness and rapid progression.

Effects of Glutamate Receptor Antagonists and Protein Synthesis Inhibitor on Delayed Neuronal Death Induced by Transient Global Ischemia in Rat Brain

  • Ko, Jun-Seog;Bae, Choon-Sang;Kim, Jong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권3호
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    • pp.279-286
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    • 1998
  • It has been well documented that transient forebrain global ischemia causes selective neuronal degeneration in hippocampal CA1 pyramidal neurons with a delay of a few days. The mechanism of this delayed hippocampal CA1 pyramidal neuronal death (DND) is still controversial. To delineate the mechanisms of the DND, the effects of treatment with MK-801, an NMDA receptor antagonist, kynurenic acid, a NMDA/non-NMDA receptor antagonist, and/or cycloheximide, a protein synthesis inhibitor, on the DND were investigated in male Wistar rats. To examine the participation of apoptotic neuronal death in the DND, TUNEL staining was performed in ischemic brain section. Global ischemia was induced by 4-vessel occlusion for 20 min. All animals in this study showed the DND 3 and 7 days after the ischemic insult. The DND that occured 3 days and 7 days after the ischemia were not affected by pretreatment with MK-801 (1 mg/kg), but markedly attenuated by the pretreatment with kynurenic acid (500 mg/kg). Treatment with cycloheximide (1 mg/kg) also markedly inhibited the DND. The magnitudes of attenuation by the two drugs were similar. The magnitude of attenuation by co-treatments with kynurenic acid and cycloheximide was not greater than that with any single treatment. TUNEL staining was negative in the sections obtained 1 or 2 days after the ischemic insults, but it was positive at hippocampal CA1 pyramidal cells in sections collected 3 days after the ischemia. These results suggested that the DND should be mediated by the activation of non-NMDA receptor, not by the activation of NMDA receptor and that the activation of AMPA receptor should induce the apoptotic process in the DND.

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산지별 밤꿀에 함유된 Kynurenic Acid의 정량 분석과 분석법 검증 (Quantitative Analysis of Kynurenic Acid in Chestnut Honey from Different Regions and Method Validation)

  • 김주리;김도윤;이상현
    • 생약학회지
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    • 제53권2호
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    • pp.111-118
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    • 2022
  • Chestnut honey is a sweet dark-colored honey with a distinct bitter aftertaste. It contains numerous phenolic compounds and alkaloids and is noted for its antioxidant and anti-inflammatory activities. However, it has been established that there are differences in the composition and activity of chestnut honey constituents depending on the region of origin, the sources of which warrant further research. In this study, we analyzed the kynurenic acid (KA) contents in chestnut honey produced in nine different regions in Korea, using high-performance liquid chromatography in conjunction with ultraviolet detection, and validated the analytical method developed. Use of a reverse-phase column and detection at a wavelength of 240 nm were found to be optimal for the detection of KA. Similar evaluation of an optimal method for extracting KA from chestnut honey revealed that extraction using 10% EtOH at 20 times the sample volume over a 6 h period was the most suitable for obtaining a high content of KA. Among the nine regional chestnut honeys assessed, KA content was found to be highest in the "Gongju" sample (1.14 mg/g), followed by that in the "Cheongdo" and "Damyang" samples. Validation of the KA analytical method revealed a good analyte linearity, with a correlation coefficient (r2) of 0.9995, an accuracy of between 92.37% and 107.35%, and good precision (RSD ≤ 1.05%). Our findings in this study, based on a validated quantitative analytical method for KA, could make an important contribution to establishing a data profiling procedure for characterizing chestnut honeys produced in different regions, and may also provide basic data for the identification of functional honey.

Changes in Vestibular Nerve Activity Following Acute Hypotension in Rats

  • Park, Byung-Rim;Kim, Min-Sun;Yee, Gue-Hyun;Moon, Myoung-Jin;Kim, Jae-Hyo;Jin, Yuan-Zhe;Kim, Yo-Sik
    • The Korean Journal of Physiology and Pharmacology
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    • 제7권2호
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    • pp.85-89
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    • 2003
  • The basic mechanism for the excitation of the peripheral vestibular receptors following acute hypotension induced by sodium nitroprusside (SNP) or hemorrhage was investigated in anesthetized rats. Electrical activity of the afferent vestibular nerve was measured after pretreatment with kynurenic acid, an NMDA receptor antagonist. The activity of the vestibular nerve at rest following acute hypotension induced by SNP or simulating hemorrhage was a greater increase than in control animals. The gain of the vestibular nerve with sinusoidal rotation following acute hypotension increased significantly compared to control animals. The acute hypotension induced by SNP or hemorrhage did not change the activity of the afferent vestibular nerve after kynurenic acid injection. These results suggest that acute hypotension produced excitation of the vestibular hair cells via glutamate excitotoxicity in response to ischemia.

Kynurenic Acid (KYNA) Attenuates Oxidative Stress and Mitochondrial damage in 6-OHDA-induced Dopaminergic Neuronal Cell Death

  • Lee, Hyun-Jung;Joo, Wan-Seok;Yeo, Joo-Hong;Lee, Kwang-Gill;Chae, Hee-Sun;Kang, Yong-Koo;Lee, In-Sook;Kweon, Hae-Yong;Lee, Ang-Hyung;Kim, Sung-Su
    • 한국잠사학회:학술대회논문집
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    • 한국잠사학회 2003년도 International Symposium of Silkworm/Insect Biotechnology and Annual Meeting of Korea Society of Sericultural Science
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    • pp.112-113
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    • 2003
  • Kynurenic acid (KYNA), tryptophan metabolite is known to have cell protective effect against various insults in the brain. But so far, the protective mechanism is largely unknown. In this study, we investigated how the KYNA exerts protective effect against 6-OHDA, a causative molecule of Parkinsonian syndrome, using SH-SY5Y cells. (omitted)

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추황배(Pyrus pyrifolia Nakai cv. Chuhwangbae) 과피로부터 3종의 저분자 화합물의 단리·동정 (Isolation and Identification of 3 Low-molecular Compounds from Pear (Pyrus pyrifolia Nakai cv. Chuhwangbae) Fruit Peel)

  • 이유건;조정용;김찬미;정항연;이동이;김수로;이상현;김월수;박근형;문제학
    • 한국식품과학회지
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    • 제45권2호
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    • pp.174-179
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    • 2013
  • 본 연구에서는 동양배에 함유된 유용성분을 분자수준에서 밝히고자, 우리나라에서 가장 많이 섭취되고 있는 품종 중의 하나인 추황배를 대상으로 배 과피의 MeOH 추출물을 해리성을 이용하여 용매분획하였다. 얻어진 획분들을 대상으로 항산화 활성에 초점을 맞추어 open column chromatography와 high performance liquid chromatography를 행하여 3종의 항산화 화합물을 단리하였다, 그 결과, BuOH 획분으로부터 화합물 1을, EtOAc-산성 획분으로부터 화합물 2를, 그리고 EtOAc-페놀성 획분으로부터 화합물 3을 단리하고, 각각 NMR 및 MS 분석을 행하여 구조해석을 행하였다. 그 결과, 화합물 1-3은 각각 2-carboxyl 4(1H)-quinolinone (kynurenic acid, 화합물 1), cis-coumaric acid (화합물 2), 그리고 vanillin(화합물 3)으로 동정되었다. 이 3종의 화합물 모두 본 연구에 의해 배로부터 처음 동정되었다. 본 연구결과가 배의 유용성 및 기능성 연구를 위한 기초자료로 활용되길 기대한다.

Specific urinary metabolites in canine mammary gland tumors

  • Valko-Rokytovska, Marcela;Ocenas, Peter;Salayova, Aneta;Titkova, Radka;Kostecka, Zuzana
    • Journal of Veterinary Science
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    • 제21권2호
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    • pp.23.1-23.10
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    • 2020
  • The identification of biomarkers that distinguish diseased from healthy individuals is of great interest in human and veterinary fields. In this research area, a metabolomic approach and its related statistical analyses can be useful for biomarker determination and allow non-invasive discrimination of healthy volunteers from breast cancer patients. In this study, we focused on the most common canine neoplasm, mammary gland tumor, and herein, we describe a simple method using ultra-high-performance liquid chromatography to determine the levels of tyrosine and its metabolites (epinephrine, 3,4-dihydroxy-L-phenylalanine, 3,4-dihydroxyphenylacetic acid, and vanillylmandelic acid), tryptophan and its metabolites (5-hydroxyindolacetic acid, indoxyl sulfate, serotonin, and kynurenic acid) in canine mammary cancer urine samples. Our results indicated significantly increased concentrations of three tryptophan metabolites, 5-hydroxyindolacetic acid (p < 0.001), serotonin, indoxyl sulfate (p < 0.01), and kynurenic acid (p < 0.05), and 2 tyrosine metabolites, 3,4-dihydroxy-L-phenylalanine (p < 0.001), and epinephrine (p < 0.05) in urine samples from the mammary gland tumor group compared to concentrations in urine samples from the healthy group. The results indicate that select urinary tyrosine and tryptophan metabolites may be useful as non-invasive diagnostic markers as well as in developing a therapeutic strategy for canine mammary gland tumors.

노란은행잎의 성분분석 (Phytochemical Analysis of Ginkgo biloba Yellow Leaves)

  • 강삼식;고영민;김주선;이명환;이동선
    • 생약학회지
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    • 제26권1호
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    • pp.23-26
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    • 1995
  • 6-Hydroxykynurenic acid and ginkgolide B together with flavonol glycosides and biflavonoids were isolated from the yellow leaves of Ginkgo biloba and identified by means of spectroscopic methods. The correctness of $H{\"{o}}lzl's$ ${13}^C-NMR$ assignments for 6-hydroxykynurenic acid was confirmed by HMQC and HMBC techniques. Based on our present findings, it may be considered that the yellow Ginkgo leaves may contribute to be a source of high medicinal values.

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