• 제목/요약/키워드: oxidation inhibitor

검색결과 109건 처리시간 0.024초

Pseudotsuga menziesii의 Monoterpenoid가 질화작용에 미치는 효과 (The Effects of Pseudotsuga menziesii Monoterpenoids on Nitrification)

  • 김종희
    • The Korean Journal of Ecology
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    • 제17권3호
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    • pp.251-260
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    • 1994
  • Pseudotsuga menziesii 임상에서 질화작용의 억제제로서의 monoterpenoids의 역할을 연구하고자 토양에서의 질화작용과 식물체잎, 낙엽 및 무기토양에서의 monoterpenoids의 함량을 분석하였다. Pseudotsuga menziesii잎이나 임상에서 분석된 monoterpenoids는 대략 16종 이었으며, 그 중 ${\alpha}$-pinene, ${\beta}$-pinene, ${\gamma}$-terpinene 그리고 terpenolene이 대표적인 것들이었다. 임상에 있는 monoterpenoids의 양은 무기토양층에 비해 항상 많았으며, 계절적 변이가 있었으나 토양층은 항상 일정하였다. 질화작용 과정 중 ammonium oxidation 과정은 낙엽층이 보다 더 많은 저해를 받았으나, nitrite oxidation 과정은 두층별간 별 차이가 없었다. 또한 4가지 monoterpenoids(${\alpha}$-pinene, ${\beta}$-pinene, ${\gamma}$-terpinene, terpenolene)를 인위적으로 첨가한 토양에서의 질화작용에 역시 am-monium oxidation 과정은 심히 저해를 받는 반면 nitrite oxidation 과정은 저해를 받지 않는 것으로 나타났다. 이 같은 모든 결과들은 Pseudotsuga menziesii 임상에 있는 monoterpenoids의 영향으로 질화작용에 관여하는 미생물, 특히 Nitrosomonas europaes의 증식이 억제되어 am-monium oxidation 과정이 저해되었음을 시사한다.

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Electrodeposition of Conducting Polymers on Copper in Nonaqueous Media by Corrosion Inhibition

  • Lee, Seonha;Lee, Hochun
    • Journal of Electrochemical Science and Technology
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    • 제3권2호
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    • pp.85-89
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    • 2012
  • This study demonstrates the direct anodic electrodeposition of polypyrrole (PPy), poly(3,4-ethyl-enedioxythiophene) (PEDOT), and polythiophene (PTh) on Cu electrodes by employing a corrosion inhibitor, succinonitrile (SN). SN was found to suppress anodic Cu dissolution beyond the oxidation potential of the polymer monomers. It is also revealed that the Cu surface passivated by SN is still adequately conductive to allow the redox reaction of 1,4-difluoro-2,5-dimethoxybenzene (FMB) and the oxidation of the polymer monomers. Through both cyclic voltammetry and galvanostatic techniques, PPy, PEDOT, and PTh films were successfully synthesized on Cu electrodes in the presence of SN, and the redox behaviors of the films were evaluated.

에탄올아민화합물 첨가에 대한 니켈의 전기화학적 특성 (Electrochemistry Characterization of Nickel Using Ethanolamine Compound Additives)

  • 박근호
    • 한국응용과학기술학회지
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    • 제27권4호
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    • pp.531-538
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    • 2010
  • The electrochemistry characterization of metal is important in many industrial applications. In this study, we investigated the C-V diagrams related to the electrochemistry characterization of nickel. We determined electrochemical measurement by using cyclic voltammetry with a three electrode system. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650mV and measured to the initial point. The scan rate were 100, 150, 200 and 200mV/s. As a result, the C-V characterization of nickel using ethanolamine and ethylethanolamine inhibitor appeared irreversible process caused by the oxidation current from the cyclic voltammogram. After adding ethanolamine compound additive, adsorption film constituted, and the passive phenomena happened. According to the results by cyclic voltammetry method, it was revealed that the effect of the electrochemistry characterization of nickel depends on ethanolamine structure interaction to adsorption complex.

Antioxidant Activity of major protein from Panax Ginseng C.A. Meyer.

  • Kim, Min-Jung;Sok, Dai-Eun
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.146.1-146.1
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    • 2003
  • A major protein was isolated from ginseng root (Panax ginseng C.A. Meyer) using a combination of ammonium sulfate fractionation, gel filtration chromatography, ion-exchange FPLC. Electrophoretic and gel permeation chromatographic studies revealed that the major protein, GMP, is composed of two subunits of approximately 28 kDa. In this, investigated the ability of GMP to inhibit the oxidation of low-density lipoprotein (LDL). GMP inhibited $Cu^{2+}$ (5$\mu$M)-promoted oxidation of LDL (125$\mu$g protein/mL) in a dose-dependent mamer (0~5 $\mu$M), with a maximal inhibitor at GMP/copper ratio of 1:10 and an $IC_{50}$ value of 0.2 $\mu$M, as determined by measurement TBARS. (omitted)

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Ascorbic acid가 에탄올 대사효소에 미치는 영향 (Effect of Ascorbic Acid on the Activities of Ethanol Metabolizing Enzymes)

  • 김용식
    • 대한약리학회지
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    • 제20권1호
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    • pp.47-54
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    • 1984
  • Effect of ascorbic acid on various hepatic ethanol metabolizing enzymes including alcohol dehydrogenase(ADH), the microsomal . ethanol oxidizing system(MEOS), and catalase was quantitatively evaluated in liver microsomal and cytosolic preparation from Sprague-Dowley rats. In present study, ADH activities were no changed significantly by ascorbic acid. The MEOS activity, dependent on NADPH and $O_2$, was affected by azide (inhibitor of catalase) or exogenous catalase. In the presence of ascorbic acid, ethanol oxidation by rat liver microsomal preparation reacted with NADPH-generating system was increased by up to 22.5%, but decreased when liver microsome was reacted with $H_2O_2$ generated by xanthine and xanthine oxidase. Increase in the activity of the MEOS in the presence of ascorbic acid was greater in liver microsomal preparation pretreated with azide. Also ascorbic acid oxidized ethanol nonenzymatically. This ethanol oxidation induced by ascorbic acid was inhibited by OH radical scavengers (thiourea, sodium benzoate), but was not much affected by superoxide dismutase. From these results it was suggested that ascorbic acidcould interact directly with the MEOS, then promote the oxidation of ethanol. And, to some extent, ${\cdot}OH$-radicals or other radicals generated during the spontaneous autooxidation of ascorbic acid may be responsible for the production of acetaldehyde from ethanol.

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Benzothiazine-3-carboxamide 유도체의 합성과 COX-2 저해효과 (Synthesis and COX-2 Inhibitory Activity of Benzothiazine-3-carboxamide Derivatives)

  • 신혜순;최희전;권순경
    • 약학회지
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    • 제46권6호
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    • pp.375-380
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    • 2002
  • In this study, newly designed COX-2 inhibitors, synthetic derivatives of benzothiazine-3-carboxamide, were screened in vitro for selectivity of COX-1 and COX-2 inhibition properties. 7-Bromo-1,2-benzoisothiazine derivatives were obtained from 4-bromotoluene over the chlorosulfonation, amination and oxidation. And benzothiazine ring was synthesized through Gabriel-Colmann rearrangement reaction. To evaluate inhibitory effect of COX-2, synthetic derivatives of benzothiazine-3-carboxamide were tested with accumulation of prostaglandin by lipopolysaccharide in aspirin-treated murine macropharge cell. Some of the synthesized lead compounds have potentially shown the structure-activity relationship for selectivity of COX-2 inhibition activity.

Synthesis of 1,2,3-and 1,2,4-Triazole Isonucleosides as Potential antiviral agents

  • Jeong, Soon-Yong;Kim, Myong-Jung;Chun, Moon-Won
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.181.2-181.2
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    • 2003
  • Inosine monophosphate dehydrogenase(IMPDH) catalyzes the $NAD^+$-dependent oxidation of IMP to XMP, the rate limiting step in the de novo biosynthesis of guanine nucleotide. Its critical role at the metabolic branch point in purine nucleotide biosynthesis makes it a useful target in the development of drugs for antiviral and anticancer chemotherapy and in immunosupressant area. Several compound with antiviral activity have been found to be inhibitors of IMPDH. For example, ribavirin, a competitive inhibitor of IMPDH, has broad spectrum antiviral activities against DNA and RNA viruses. (omitted)

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황화수소 산화세균인 새로운 Thiobacillus sp.의 분리 및 특성 (Isolation and Characterization of a New Hydrogen Sulfide-Oxidizing Bacterium Thiobacillus Sp.)

  • 차진명;이인화
    • 미생물학회지
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    • 제32권4호
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    • pp.252-257
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    • 1994
  • 황화수소 산화세균인 Thiobacillus sp.를 전남 화순의 폐탄광수에서 분리하였다. 분리된 균주는 그람음성의 운동성이 있고, 포자를 형성하는 간균이었으며, 환원된 무기 황화합물을 산화하여 에너지원으로 사용하는 호기성 통성 화학합성 영양균이었다. 분리균주는 thiosulfate를 첨가한 기본배지에서 유기물을 동화하며 성장하였고, 에너지원으로 사용된 thiosulfate는 32mM 이상의 농도에서는 오히려 기질억제 인자로 작용하여 균의 성장을 억제하였다. 최적 thiosulfate 농도는 32mM이었다. DNA의 G+C 함량은 65.0mol%이고, 세포내 주요 지방산중 비순산화 지방산은 16:1+7$_{cyc}$, 16:0과 수산화 지방산은 3-OH 12:0을 가지며, $C_{18}$의 미동정 가지형의 지방산도 포함하고 있었다. Ubiquinone system은 Q-9을 가지고 있었다. 위와 같은 생리생화학적 특성 결과로부터, 본 분리균주는 Thiobacillus sp. iw.의 새로운 종으로 판단하였다.

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