• BMB Reports
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• v.33 no.4
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• pp.321-325
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• 2000

Quinone reductase was purified to homogeneity from bovine liver by using ammonium sulfate fractionation, ionexchange chromatography, and gel filtration chromatography. The enzyme utilized either NADH or NADPH as the electron donor. The enzyme catalyzed the reduction of several quinones and other artificial electron acceptors. Furthermore, the enzyme catalyzed NAD(P)H-dependent reduction of azobenzene. The apparent Km for 1,4-benzoquinone and azobenzene was 1.64 mM and 0.524 mM, respectively. The reduction of azobenzene by quinone reductase was almost entirely inhibited by dicumarol or Cibacron blue 3GA, potent inhibitors of the mammalian quinone reductase. In the presence of 1.0${\mu}M$ Cibacron blue 3GA, azoreductase activity was lowered by 45%, and almost complete inhibition was seen above 2.0 ${\mu}M$ Cibacron blue 3GA.

• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.48-50
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• 2000

The energetics at the succinate:quinone oxidoreductase segment of V. alginolyticus was studied using a fluorescence quenching technique with inside-out membrane vesicles. A transient generation of the membrane potential (inside-positive) and ${\Delta}pH$ (inside-acidic) occurred in the presence of KCN and succinate when ubiquinone-1 (Q1) was added. The membrane potential (\Delta\psi$) generated by the succinate; quinone oxidoreductase segment was completely collapsed by the protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP) and the membrane permeable anion $SCN^{-}$, whereas the ${\Delta}pH$ was completely collapsed by CCCP and $(NH_4)_2SO_4$. From these results, it was concluded that the succinate: quinone oxidoreductase segment as well as quinol oxidase [1] in the respiratory chain of V. alginolyticus generated $H^{+}$ electrochemical potential.

• Proceedings of the Microbiological Society of Korea Conference
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• 2003.05a
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• pp.111-114
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• 2003

The dynamics of microbial community structure of the various domestic wastewater treatment processes were examined using a novel approach of quinone profiles. The compositions of microbial quinone of 5 sites fer plant and lab-scale activated sludge were analyzed. More than 14 kinds of quinones were observed in the activated sludges tested in this study. The microbial community structure of the plant activated sludge processes a little differed from that of the lab-scale submerged MBR systems. The dominant quinones were UQ-8, UQ-10 followed $MK-8(H_4)$, MK-7 and MK-6. The molar ratio of ubiquinones to menaquinones (UQ/MK) changed from 0.81 to 1.9, indicating that aerobic bacteria dominated the microbial community of the activated sludge examined. The microbial diversity of the activated sludges calculated from the all quinone compositions was 9.5-11.9 and the microbial equability of the activated sludges was 0.64-0.79.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3143-3155
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• 2014

This tutorial review provides a general account of the electrochemical behavior of quinones and their various applications. Quinone electrochemistry has been investigated for a long time due to its complexity. A simple point of view is developed that considers the relative stability of the reduced quinone species and the values of the first and second reduction potentials. The 9-membered square scheme in buffered aqueous solutions is explained and semiquinone radical stability is discussed in this context. Quinone redox reaction has also been employed in various studies. Diverse examples are presented under three broad categories defined by the roles of quinone: molecular tool for physical chemistry, versatile electron mediator, and charge storage for energy conversion devices.

• Natural Product Sciences
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• v.7 no.2
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• pp.38-44
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• 2001

NAD(P)H:quinone reductase (QR), known as DT-diaphorase, is a kind of detoxifying phase II metabolic enzyme catalyzing hydroquinone formation by two electron reduction pathway from quinone type compounds, and thus facilitating excretion of quinoids from human body. With the usefulness of QR induction activity assay system for the modulation of toxicants, in the course of searching for cancer chemopreventive agents from natural products, the methanolic extracts of approximately two hundreds of oriental medicines were primarily evaluated using the induction potential of quinone reductase (QR) activity in cultured murine Hepa1c1c7 cells. As a result, several extracts including Hordeum vulgare, Momordica cochinchinensis, Strychnos ignatii, Houttuynia cordata, and Polygala japonica were found to significantly induce QR activity. In addition, the methylene chloride fraction of H. vulgare, one major dietary food source, showed potent induction of QR activity $(CD=6.4{\mu}g/ml)$. Further study for isolation of active principles from these lead extracts is warranted for the discovery of novel cancer chemopreventive agents.

• Korean Journal of Acupuncture
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• v.20 no.1
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• pp.39-43
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• 2003

Sophorae Flos aqua-acupuncture solution(SFAS) was prepared and tested for the induction of quinone reductase and glutathione S-transferase activities and glutathione. SFAS significantly induced QR activity at the concentrations of $0.5{\times},\;1{\times}\;and\;3{\times}$ in cell culture. However, GST activity in murine Hepa 1c1c7 cells was slightly increased with SFAS. SFAS increased GSH levels.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.49-53
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• 1993

Arylalkanoic acid derivatives are known as good non-steroidal antiinflamatory and antirheumatic agents. The new arylalkanoic acid derivatives were synthesized when 2-chloro-3-($\alpha$-cyano-$\alpha$-ethoxycarbonyl-methyl)-1, 4-naphthoquinone was reacted with some arylamines.

• Journal of Acupuncture Research
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• v.17 no.1
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• pp.129-142
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• 2000

Gamdutang aqua-acupuncture solution(GAS), Gamdutang water-extracted solution(GWS) and Degamdutang aqua-acupuncture solution(DGAS) were prepared and tested for potential antitumor activities. It was used three biomarkers (quinone reductase, omithine decarboxylase, glutathione) to test chemopreventive potentials of GAS, GWS, DGAS. GAS was potent inducer of quinone reductase activity in Hepalclc7 murine hepatoma cells in culture, whereas GWS is less potent. GAS, GWS and DGAS were significantly induced quinone reductase activity in cultured rat normal liver cell, Ac2F. Glutathione levels were increased about 1.8-fold with GAS, 1.0-1.1 fold with GWS, DGAS in cultured murine hepatoma hepaiclc7 cells. In addition glutathione s-transferase levels were increased with GAS, GWS and DGAS. The effects of GAS, GWS and DGAS were tested on the growth of Acanthamoeba castellanii. Proliferation of Acanthamoeba castellanii was inhibited by GAS, GWS and DGAS at concentradons of $1{\times}$ and $5{\times}$. These results suggest that GAS has chemopreventive potential by inducing quinone reductase and quinone reductase activities, inhibition of ornithine decarboxylase activity, and increasing glutathione levels.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.277-281
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• 1998

There is extensive evidence suggesting the protective role of fruits and vegetables against chemically induced carcinogenesis. We have tested the ability of a representative range of Korean vegetables to act as blocking agents against neoplastic initiation by determining the induction level of quinone reductase , an anticarcinogenci marker enzyme, in hepalclc 7 cells exposed to vegetable extracts. Among thirty vegetables tested, Arcitum lappa(Burdock), Brassica juncea (Mustard leaf), Pteridium aguilinum (Bracken) and Chrysanthemum cornoratium(Crown daisy) caused a significant induction of quinone teductase activity with a limited increase in arylhdrocarbon hydroxylase activity. Combination of crown daisy with burdock had synergistic effect on quinone reductase induction. Quinone reductase-inducing activity was found mostly in hesane and ehtylactate fractions of MeOH extract of crown daisy while it ws not quinone reductase activity in liver, kideny, lung, and small intestine, confirming the presence of potent QR inducer (s) in crown daisy. These sata suggest that some vegetables including crown daisy induced QR merits further investigation as a potential cancer preventive agent in human.

• Korean Journal of Pharmacognosy
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• v.32 no.4 s.127
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• pp.269-273
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• 2001

Ethanol extracts from Xanthii Fructus (XFE) and Prunellae Spica (PSE) were investigated for the effects on the induction of cancer chemoprevention-associated enzymes. The following effects were measured: (a) induction of quinone reductase (QR) (b) induction of glutathione S-transferase (GST) (c) reduced glutathione (GSH) level. XFE and PSE were potent inducers of quinone reductase activity in Hepa1c1c7 murine hepatoma cells. Glutathione levels were increased with XFE and PSE. In addition, glutathione S-transferase activity was increased with XFE. However, GST activity was not increased with PSE. These results suggest that XFE and PSE have chemopreventive potentials by inducing quinone reductase and increasing GSH levels.