• Title/Summary/Keyword: Hydrogen radical

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The Antioxidant Activity of Cnidii Fructus and Torilis Fructus in Leydig cells (Leydig Cell의 항산화에 미치는 벌사상자와 사상자의 비교연구)

  • Oh, Ji Hoon;Kim, Do Rim;Park, Soo Yeon;Chang, Mun Seog;Park, Seong Kyu
    • The Korea Journal of Herbology
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    • v.29 no.6
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    • pp.111-116
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    • 2014
  • Objectives : The purpose of this study was to estimate the antioxidant activity of water extract of Cnidii Fructus (CF) and Torilis Fructus (TF) in Leydig cells. Methods : Free radical scavenging activity of CF and TF against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was determined spectrophotometrically. We investigated the effect of CF and TF in Leydig cells by MTT assay. The protective effects of CF and TF against hydrogen peroxide-induced oxidative stress in Leydig cells. Superoxide dismutase (SOD), and catalase activity assays were performed in Leydig cells. Results : The results showed that CF scavenged DPPH radical in a dose-dependent manner by up to 81.2%, TF scavenged DPPH radical in a dose-dependent manner by up to 63.8%. CF showed cell viability as 121.0, 132.7, 126.6% in 5, 10, $100{\mu}g/ml$ concentrations. TF showed cell viability as 127.5, 111.8% in 5, $100{\mu}g/ml$ concentraions, respectively. The hydrogen peroxide-induced cytotoxicity of Leydig cells were protected to 86.3% by CF at concentration of $10{\mu}g/ml$ and protected to 83.5% by TF at concentration of $100{\mu}g/ml$. Both CF and TF at all concentrations, SOD activity was not significantly changed. Catalase activity was significantly increased at 10, $100{\mu}g/ml$ concentrations of CF, respectively. TF's catalase activity showed no significant difference from that of the control. Conclusions : These results suggest that CF, as an antioxidant, protects Leydig cells in hydrogen peroxide-induced oxidative stress. know that "Kwangjebikeup" played a role in settlement and spreading of foreign knowledge to civilians.

A Crossed Beam Study of Atom-Radical Reaction Dynamics (원자-라디칼 반응 동력학의 교차 빔 연구)

  • Ju Seon-Gyu;Gwon Lee-Gyeong;Lee Ho-Jae;Choe Jong-Ho
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.163-164
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    • 2003
  • Reaction dynamics plays an essential role in understanding the microscopic mechanism of elementary chemical processes at the molecular level. Detailed studies of the reactions of atomic species such as hydrogen and second-row atoms with small closed-shell molecules have provided important insights into hydrocarbon synthesis, combustion, interstellar space and atmospheric chemistry. Despite its mechanistic significance, however, the investigations of atom-radical reaction dynamics are quite scarce in comparison to the extensive studies of atom-molecule reactions. (omitted)

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Free radical scavenging phenolic compounds of the leaves of Juglans sinensis

  • Kim, Mi-Hee;Ko, Eun-Kyung;Jun, Jung-Yang;Li-Xun;Oh, Myung-Hun;An, Nyeon-Hyoung;Kim, Youn-Chul
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.381.3-382
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    • 2002
  • Free radical-mediated cell damage and free radical attack on polyunsaturated fatty acids result in the formation of lipid radicals. These lipid radicals react readily with molecular oxygen to produce peroxy radicals responsible for initiating lipid peroxidation. The peroxidation of cellular membrane lipid can lead to cell necrosis and considered to be implicated in a number of pathophysiological conditions as well as in the toxicity of many xenobiotics. DPPH is known to abstract labile hydrogen and the ability to scavenge the DPPH radical is related to the inhibition of lipid peroxidation. (omitted)

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The Changes in the Chemical Components and Antioxidant Activities in Ecklonia Cava According to the Drying Methods (건조방법에 따른 해조류(감태)의 주요성분 및 항산화 활성의 변화)

  • 김진아;이종미
    • Journal of the Korean Home Economics Association
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    • v.42 no.5
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    • pp.193-203
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    • 2004
  • This study examined the changes in the chemical components and antioxidant activity of Ecklonia cava according to the drying methods. As chemical components, the concentrations of minerals(K, Ca, Na, Mg, Fe, Cu, Mn and Zn), vitamins(vitamin C, ${\beta}$-carotene and ${\alpha}$-tocopherol) and the total polyphenols were analyzed. In additions, the antioxidant activity was determined by measuring the free radical(DPPH radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide) scavenging activity and the linoleic acid peroxidation inhibitory activity. The mineral content was not affected by the drying methods. However, more vitamins were lost and the total polyphenol concentration was reduced as a result of sun-drying than by the other drying methods used. More of the total polyphenol was preserved by freezing-drying than by any of the other drying methods, which meant that there was a higher antioxidant activity after freeze drying.

CRDS Study of Tropospheric Ozone Production Kinetics : Isoprene Oxidation by Hydroxyl Radical

  • Park, Ji-Ho
    • Journal of Environmental Health Sciences
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    • v.35 no.6
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    • pp.532-537
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    • 2009
  • The tropospheric ozone production mechanism for the gas phase additive oxidation reaction of hydroxyl radical (OH) with isoprene (2-methyl-1,3-butadiene) has been studied using cavity ring-down spectroscopy (CRDS) at total pressure of 50 Torr and 298 K. The applicability of CRDS was confirmed by monitoring the shorter (~4%) ringdown time in the presence of hydroxyl radical than the ring-down time without the photolysis of hydrogen peroxide. The reaction rate constant, $(9.8{\pm}0.1){\times}10^{-11}molecule^{-1}cm^3s^{-1}$, for the addition of OH to isoprene is in good agreement with previous studies. In the presence of $O_2$ and NO, hydroxyl radical cycling has been monitored and the simulation using the recommended elementary reaction rate constants as the basis to OH cycling curve gives reasonable fit to the data.

Antioxidaitve and Antibacterial Activities of Endemic Plants Extracts in Korea (국내 자생 식물 추출물의 항산화 활성 및 항균효과)

  • Han, Seung-Ho;Woo, Na-Ri-Yah;Lee, Song-Deuk;Kang, Myung-Hwa
    • Korean Journal of Medicinal Crop Science
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    • v.14 no.1
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    • pp.49-55
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    • 2006
  • Antioxidative and antibacterial activities of endemic plants extracts in Korea were investigated. Hydrogen radical scavenging activity was 99.72% in an elm tree, 99.725 in a Job's tears, 99.575 in an eggplant, and 94.025 in a barrenwort. Antibacterial activity of ethanol extract from 23 different species of wild plants were determined. The gull nut was showed the strongest antibacterial activities (16.0-19.0 mm) and also showed high antibacterial activities in a pine neddles, a gulmyungja, a wild ginger plants, a ginko (9.5-11.5 mm). Only extracts of Saurrranceae extract showed the antibacterial activity in Bacillus subtilus, Stapylococcus aureus, Escherichia coli, Samonella entetotidis. An antibacterial activities were showed weakly in an esungcho and an eggplant. A ground ivy showed Antibacterial activity on Stapylococcus aureus. A barren wort showed in antibacterial activity on Stapylococcus aureus, and E. coli. This results were suggested that many edemic plants resources contains antioxidative and antibacterial substances.

Superoxide and Hydrogen Peroxide Scavenging Action of Ocimum Sanctum Extracts and their Fractions

  • Geetha, S.;Kedlaya, R.;Vasudevan, D.M.
    • Natural Product Sciences
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    • v.9 no.4
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    • pp.223-225
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    • 2003
  • Ocimum sanctum, the Indian holy basil has significant abilities to scavenge highly reactive free radicals. Shade dried leaf powder of plant has extracted with water and alcohol, fractionated with different solvents. Both extracts and their fractions were found to be good scavengers of Superoxide and hydrogen peroxide. Free radical scavenging action of these compared with ascorbic acid, a known antioxidant.

Photocatalytic Decompositions of Carboxylic Acid Derivatives by Semiconductors

  • Koon Ha Park;Jung Hae Kim
    • Bulletin of the Korean Chemical Society
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    • v.12 no.4
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    • pp.438-440
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    • 1991
  • Each aqueous solution (pH = 1) of acetic acid, acetamide, and acetonitrile produces carbon dioxide and hydrogen at 300 K when irradiated in the presence of semiconductors such as titanium dioxide, platinized titanium dioxide, etc. Similar results were obtained for each of benzoic acid, benzamide, and benzonitrile. Based on the relative amount of carbon dioxide, nitrile is believed to be transformed into carboxylic acid through the intermediacy of amide. A mechanism in which hydrogen atom and hydroxyl radical are involved is presented.

ESR-Spin Trapping Detection of Radical Center Formed on the Reaction of Metmyoglobin with Hydrogen Peroxide

  • Jeong, Sang-Hyeon;Hong, Sun-Joo
    • BMB Reports
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    • v.28 no.4
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    • pp.293-300
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    • 1995
  • The radical centers detected in the reaction of metmyoglobin (MetMb) with hydrogen peroxide ($H_2O_2$) have been studied by using a spin trapping technique. A broad 5-line asymmetric electron spin resonance (ESR) spectrum, with $2A_{max}=4.07\;mT$ and $2A_{min}=2.97\;mT$, obtained after incubation of MetMb with $H_2O_2$ in the presence of a spin trap, 5,5-dimethyl pyrroline-N-oxide (DMPO) was gradually weakened with time and disappeared completely by 6 min after addition of guanidine-HCl (14 M). When a higher concentration (6 M) of the agent was added, the signal disappeared within 40 see and the DMPO/OH signal appeared immediately. Then, a new 8-line signal with similar intensities grew gradually and was fixed by 45 min, coexisting with the DMPO/OH signal. This new signal was found to be composite, consisting of two different radical species. One of the 6-line signals, with $a_N$ 1.49 mT and $a_H$ 0.988 mT, was assigned to the DMPO/phenoxyl radical adduct. The second 6-line signal with $a_N$ 1.55 mT and $a_H$ 2.22 mT was assigned to carbon-centered radical adduct. When 3,3,5,5-tetramethylpyrrolin-N-oxide (TMPO), was employed in the place of DMPO, another broad asymmetric 5-line signal was detected with $2A_{max}=3.99\;mT$ and $2A_{min}=3.04\;mT$, which is virtually identical to that obtained from the DMPO system The shape of the spectrum of the TMPO adduct changed drastically, with lapse of time resulting in a broad singlet after 40 min. The broad singlet was assigned to the porphyrin radical adduct. Incubation of globin with Fenton reagent in the presence of DMPO initially gave a DMPO/OH signal. Then, a new 12-line signal began to grow after one minute and fixed after 15 min. coexisting with the DMPO/OH signal, This 12-line signal was assigned to DMPO/phenoxyl with $a_N$ 1.47 mT, $a_{{\beta}H}$ 0.99 mT and $a_{{\gamma}H}$ 0.13 mT. A minor concentration of carbon-centered radical adduct was also detected. This radical composition is identical to that of guanidine HCl treated MetMb/DMPO/$H_2O_2$ system, indicating that the radical producing conditions are somehow common in both systems. Heme iron can be released by excess $H_2O_2$ in the MetMb/$H_2O_2$ system, providing for Fenton reagent. When MetMb was pretreated with tyrosine blocking agent, $KI_3$ the broad 5.line MetMb-derived signal was not detected in the MetMb/DMPO/$H_2O_2$ system, whereas no such effect was detected on such system of Hb in which the radical center was assigned to cysteine residue not tyrosine, indicating that tyrosine residue is a main radical center produced in the MetMb/$H_2O_2$ system Thus, the present data strongly support the previous indication that the apomyoglobin-derived radical center formed in the reaction of MetMb with $H_2O_2$ is a tyrosine residue.

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The Effect of Gamma-Irradiation on Aqueous Solutions of Triglycine 3. Mechanism for Gamma-ray Induced Degradation Products (Triglycine 수용액에 미치는 감마선의 영향 3. 감마선에 의한 분해산물에 관하여)

  • ;LEONE, Charles A
    • The Korean Journal of Zoology
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    • v.7 no.2
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    • pp.1-5
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    • 1964
  • Carbonyl compounds, glycine, ammonia, carbon dioxide and hydrogen have been identified in gamma-irradiated oxygenated aqueous solutions of triglycine. The reactions occurring in this system are postulated only by representing the initial process and the final products. The triglycine molecule undergoes a reaction to form an intermediate giving rise to carbonyl compounds and acid amides. These compounds are decomposed to acetamide, glycine, glyoxylic acid, formic acid, oxalic acid, ammonia, and carbon dioxide by free radical attack in the primary and/or secondary reactions. It is also possible that the unrecognized reactions may give rise to products formed by radical-radical combinations. Satisfactory material balance for all the products have to wait until the completion of a study now in progress.ogress.

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