• Title/Summary/Keyword: o-Quinone

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Differential Effects of Indole, Indole-3-carbinol and Benzofuran on Several Microsomal and Cytosolic Enzyme Activities in Mouse Liver (Indole, Indole-3-calbinol 및 Benzofuran이 간장 microsome과 cytosol의 약물대사 효소 활성도에 미치는 영향)

  • Cha, Young-Nam;Thompson, David C.;Heine, Henry S.;Chung, Jin-Ho
    • The Korean Journal of Pharmacology
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    • v.21 no.1
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    • pp.1-11
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    • 1985
  • The effects of feeding indole, indole-3-carbinol and benzofuran (all at 5 mmole/kg body wt./day) on various hepatic microsomal and cytosolic enzyme activities involved in xenobiotic metabolism have been compared. Benzofuran was found to elevate the activities of many enzymes both in microsomes (e.g., aniline hydroxylase, 7-ethoxycoumarin O-deethylase, p-nitrophenol UDPGA-transferase and epoxide hydrolase) and in cytosol (e.g., glutathione reductase, glutathione S-transferase, NADH:quinone reductase and UDP-glucose dehydrogenase). The structures of indole and indole-3-carbinol are similar to benzofuran except for the substitution of nitrogen with oxygen atom within the furan ring. Results showed that the activities of UDPGA-transferase and NADH:quinone reductase were not elevated by these indole compounds. While the chemical structure of these two indole compounds are identical except for the presence of the carbinol (methanol) group in indole-3-carbinol, there were marked differences in the types and activities of microsomal enzymes that were enhanced. Among the microsomal enzyme activities determined, indole elevated only the NADPH:cytochrome c reductase, while indole-3-carbinol increased several mixed function oxidase and particularly the epoxide hydrolase activities. Based on the chemical structures of tested compounds and the observed results, possible explanations for the mechanisms involved in elevating epoxide hydrolase activity by benzofuran and indole-3-carbinol are discussed.

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Poly-3,4-dihydroxybenzoic Acid Film Electrodes Modified with Dopamine for Determination of Ti(IV) Ions (도파민으로 수식된 3,4-dihydroxybenzoic acid 고분자 피막전극을 이용한 Ti(IV)이온의 정량)

  • Cha, Seong-Keuck
    • Journal of the Korean Electrochemical Society
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    • v.6 no.2
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    • pp.130-133
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    • 2003
  • 3,4-dihydroxybenzoic acid(3,4-DHBA) was electropolymerized on glassy carbon electrode to give the GC/p-3,4-DHBA type electrode which was modified with dopamine by the help of 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride(EDC) acting as a coupling agent. The carboxylic sites on the polymeric surface of p-3,4-DHBA and mine group at the dopamine gave a QCA(Au)/p-3,4-DHBA-dopamine type of modified electrodes. The o-quinone moieties at the electrode surface exhibited high selectivity to titanium ions in solution. The redox process of the electrode is hydroquinone : quinone +$2H^+2e^-$, which had two strong and two weak pairs of peaks at CV. The modified electrode can deposit Ti(IV) ions as much as $4.13\times10^{-5}gcm^{-2}$. The calibration curve of the electrodes, log of the surface coverage-normalized redox response vs log[Ti], exhibited an excellent correlation$(r{\geq}0.997)$ for titanium concentrations ranging from $5.25\times10^{-4}\;to\;5.25\tiems10^{-8}M.$.

The Effect of Polyphenol Oxidase on Deodorizing Activity of Apple Extract against Methyl Mercaptan (사과 추출물의 구취억제효과에 대한 Polyphenol Oxidase의 영향)

  • 조상원;곽기석;이주항;윤영수;구연숙
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.6
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    • pp.1301-1304
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    • 2001
  • Deodorizing activity of polyphenol cxidase (PPO) extracted from apples was investigated by measuring the changes of methyl mercaptan as an indicator of halitosis in human mouths. In the studies of apple extracts on deodorizing activity, the deodorizing activity was increased with the amount of apple extracts. In the cases of adding PPO to the low molecular fraction of apple extracts, the deodorizing activities were increased with the amount of the law molecular fraction of apple extracts and the reaction time of the extracts with PPO. Deodorizing activities of PPO is thought that o-quinone as an intermidiate produced by an oxidative reaction of PPO during enzymatic browning reactions may react with methyl mercaptan to form a non-volatile and sulfur-containing compound .

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MO Theoretical Studies on Stereoelectronic Control in the Addition Reaction of 1, 4-Benzoquinone-4-(O-methyloxime)$^*$

  • Ik-Choon Lee;Eun-Sook Han
    • Bulletin of the Korean Chemical Society
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    • v.4 no.1
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    • pp.41-44
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    • 1983
  • The chlorine addition and Diels-Alder cycloaddition of cyclopentadiene to 1, 4-benzoquinone-4-(O-methyloxime) have been studied MO theoretically. It has been shown that the reactions occur predominantly to the quinone ring double bond which is oriented anti to the nitrogen lone pair due to an n-${\sigma}^*$ interaction between the nitrogen lone pair, n, and the app. vicinal bond, causing the ${\pi}$ bond to be weakened and destabilized due to the less conjugation from reduced delocalization.

Protective Effect Against Hydroxyl Radical-induced DNA Damage and Antioxidant Mechanism of [6]-gingerol: A Chemical Study

  • Lin, Jing;Li, Xican;Chen, Li;Lu, Weizhao;Chen, Xianwen;Han, Lu;Chen, Dongfeng
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1633-1638
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    • 2014
  • [6]-Gingerol is known as the major bioactive constituent of ginger. In the study, it was observed to effectively protect against ${\bullet}OH$-induced DNA damage ($IC_{50}$ $328.60{\pm}24.41{\mu}M$). Antioxidant assays indicated that [6]-gingerol could efficiently scavenge various free radicals, including ${\bullet}OH$ radical ($IC_{50}$ $70.39{\pm}1.23{\mu}M$), ${\bullet}O_2{^-}$ radical ($IC_{50}$ $228.40{\pm}9.20{\mu}M$), $DPPH{\bullet}$radical ($IC_{50}$ $27.35{\pm}1.44{\mu}M$), and $ABTS{^+}{\bullet}$radical ($IC_{50}$ $2.53{\pm}0.070{\mu}M$), and reduce $Cu^{2+}$ ion ($IC_{50}$ $11.97{\pm}0.68{\mu}M$). In order to investigate the possible mechanism, the reaction product of [6]-gingerol and $DPPH{\bullet}$ radical was further measured using HPLC combined mass spectrometry. The product showed a molecular ion peak at m/z 316 $[M+Na]^+$, and diagnostic fragment loss (m/z 28) for quinone. On this basis, it can be concluded that: (i) [6]-gingerol can effectively protect against ${\bullet}OH$-induced DNA damage; (ii) a possible mechanism for [6]-gingerol to protect against oxidative damage is ${\bullet}OH$ radical scavenging; (iii) [6]-gingerol scavenges ${\bullet}OH$ radical through hydrogen atom ($H{\bullet}$) transfer (HAT) and sequential electron (e) proton transfer (SEPT) mechanisms; and (iv) both mechanisms make [6]-gingerol be oxidized to semi-quinone or quinone forms.

Phenolic Compounds Obtained from Stems of Couepia ulei with the Potential to Induce Quinone Reductase

  • Jang, Dae-Sik;Park, Eun-Jung;Kang, Young-Hwa;Vigo, Jose-Schunke;James-G.Graham;Fernando-Cabieses;Harry-H.S.Fong;John-M.Pezzuto;A.Douglas-Kinghorn
    • Archives of Pharmacal Research
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    • v.27 no.2
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    • pp.169-172
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    • 2004
  • Activity-guided fractionation of the EtOAc-soluble extract of the stems of Couepia ulei, using a bioassay based on the induction of quinone reductase (QR) in cultured Hepa 1c1c7 mouse hepatoma cells led to the isolation of two active compounds, a new natural product, erythro-2,3-bis(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-o1 (1), and a known compound, evofolin-B (2), along with five inactive compounds all of known structure, viz., betulinic acid, oleanolic acid, pomolic acid, ($\pm$)-syringaresinol, and ursolic acid. These isolates were identified by analysis of physical and spectral data. Compounds 1 and 2 exhibited QR inducing activity, with observed CD (concentration required to double induction) values of 16.7 and 16.4 $\mu\textrm{M}$, respectively.

Chemopreventive Effect of Protein Extract of Asterina pectinifera in HT-29 Human Colon Adenocarcinoma Cells

  • Shon Yun-Hee;Nam Kyung-Soo
    • Archives of Pharmacal Research
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    • v.29 no.3
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    • pp.209-212
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    • 2006
  • We investigated the effect of protein extract of Asterina pectinifera on the activity of 4 enzymes that may playa role in adenocarcinoma of the colon: quinone reductase (QR), glutathione Stransferase (GST), ornithine decarboxylase (ODC), and cyclooxygenase (COX)-2. QR and GST activity increased in HT-29 human colon adenocarcinoma cells increased that had been exposed to 4 concentrations of the protein extract (80, 160, 200, and $240{\mu}g/mL$). Additionally, 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ODC activity decreased significantly in cells exposed to the extract in concentrations of $160{\mu}g/mL$ (p<0.05), $200{\mu}g/mL$ (p<0.005), and $240{\mu}g/mL$ (p<0.005). TPA-induced COX-2 activity also decreased in cells exposed to extract concentrations of 10, 20, 40, and $60{\mu}g/mL$. COX-2 expression was also inhibited in cells exposed to this extract. These results suggest that this protein extract of A pectinifera has chemopreventive activity in HT-29 human colon adenocarcinoma cells, and therefore, may have the potential to function as a chemopreventive agent in human colorectal cancer.

Anti-inflammatory Effect of Dactyloquinone B and Cyclospongiaquinone-1 Mixture in RAW264.7 Macrophage and ICR Mice

  • Lee, Dong-Sung;Hwang, In Hyun;Im, Nam-Kyung;Jeong, Gil-Saeng;Na, MinKyun
    • Natural Product Sciences
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    • v.21 no.4
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    • pp.268-272
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    • 2015
  • Sesquiterpene-quinone is a class of secondary metabolites frequently encountered from marine sponge. The present study was designed to examine the anti-inflammatory action of sponge-derived dactyloquinone B (DQB) and cyclospongiaquinone-1 (CSQ1) mixture using lipopolysaccharide (LPS)-induced inflammatory responses. We measured the production of nitric oxide (NO), tumor necrosis factor-alpha ($TNF-{\alpha}$), $interleukin-1{\beta}$ ($IL-1{\beta}$), and interleukin-6 (IL-6) and expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein. $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6 production, which increased by treatment with LPS, were significantly inhibited by DQB and CSQ1 mixture. It also decreased the production of NO production, and iNOS and COX-2 expression. Furthermore, it reduced 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ear edema of ICR mice. These results demonstrate that sesquiterpene-quinone, DQB and CSQ1 mixture, might serve as a chemical pipeline for the development of anti-inflammatory agent.

The Characteristics of Microbial Population Community Structure by an Addition of External Carbon Source in BNR Process for Low C/N Ratio Sewage Treatment (낮은 C/N비 하수의 외부 탄소원 주입에 따른 생물학적 질소제거에서 미생물 군집 구조특성)

  • Yoon, Cho-Hee
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.8
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    • pp.831-838
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    • 2008
  • This study investigated the characteristics of nitrogen removal and microbial community in a lab-scale A$_2$O activated sludge process filled with the fluidized media at an aerebic basin. The change of microbial community was monitored based on quinone profiles of activated sludge according to feeding sewage with/without external carbon source. Low C/N ratio(COD$_{Cr}$/T-N of 1.24) sewage was fed. The obtained results from this study were as follows; Ubiquinone(UQ) in the influent was in the descending order of UQ-8, UQ-10 and UQ-9. Menaquinone(MK) was simpler and much less than UQ. The ratio of UQ/MK was less than 0.41 and the dissimilarity was below 0.26. Without an external carbon source, MK-8 was the dominant species and there were 3 kinds of quinone species and low DQ and EQ values in an anaerobic basin. The ratio of UQ/MK increased to 2.3 in an anoxic basin. In an oxic basin, UQ-7 and UQ-8 were the dominant species. UQ-7 was dominating in suspended microorganisms, while UQ-8 was in attached microorganisms. With an external carbon source addition, MK-8 decreased but UQ-8 increased in an anaerobic basin. So did quinone species, DQ and EQ values. There was also a change in an anoxic basin with the improvement of denitrification. UQ-8 decreased instead, MK-7 and MK-8 increased. UQ/MK ratio decreased 2.3 to 1.4. It means that the dominant species change from Pseudomonas sp. to Bacillus and Micrococcus species. etc. In an oxic basin, UQ-8 replaced UQ-7 in suspended microorganisms and UQ-10 replaced UQ-8 in attached microbials. This seemed related with the growth of Nitrosomonas and Nitrobactor species.