• Bulletin of the Korean Chemical Society
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• 제20권5호
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• pp.531-534
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• 1999

Irradiation (300 nm UV light) of dibenzoylmethane and 1,4-naphthoquinone in dichloromethane gave 1,5-dike-tone as the major product, along with β-hydroxyketone as the minor product. Anthraquinone and anthrone also added photochemically to dibenzoylmethane to give 1,5-diketones as the major products. In contrast, tetrahalo-1,4-benzoquinones added to dibenzoylmethane to give two types of 1,5-diketones via oxetane and cyclobutane intermediates. Comparison of the potential energy values of the photoproducts reveals that the 1,5-diketones are more stable than the corresponding oxetanes or cyclobutanes due to the ring-strain of the bicyclic compounds.

• 약학회지
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• 제41권6호
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• pp.829-836
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• 1997

Studies on the effect of quinones on cardiac function has been conducted with normal hearts. But not with injured hearts, I.e. ischemia/reperfusion-injured heart. Quinone compounds are known to produce oxygen free radicals during metabolism, and for this reason, quinones are implicated in the aggravation of ischemia/reperfusion injury or cardioprotection, as in the case of ischemic preconditioning depending on the experimental conditions. The present study was carried out to examine the effect of 2-chloro-3-(4-cyanophenylamino)-1.4-naphthoquinone (NQ-Y15) on cardiac function of ischemic/reperfused and normal rat hearts. In isolated perfused hearts, various functional parameters such as left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (EDP) and maximum positive and negative dP/dt ($[\pm}dP/dt_{max}$), time to contracture, heart rate (HR) and coronary flow rate (CFR) were measured before and 30 min after dosing and following 25 min ischemia/30min reperfusion. NQ-Y15 increased LVDP, +dP/$d_{max}$and -dP/$dt_{min}$ by 18%. 30%, and 40%, respectively. There were no significant changes in other haemodynamic parameters. After ischemia/reperfusion injury, pretreatment with NQ-Y15 induced a significant decrease in LVDP and $[\pm}dP/dt_{max}$, but an increase in EDP. LDH-release was not significantly increased. These results suggested that NQ-Y15 may augment the ventricular contractility but it makes hearts more vulnerable to ischemia/reperfusion injury.

• 생명과학회지
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• 제16권1호
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• pp.148-155
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• 2006

창원시 주요하천의 미생물군집의 다양성을 quinone profile 방법을 이용하여 분석하였다. 그리고 온도, pH, 용존산소(DO), 용존탄소(DOC)와 화학적 산소 요구량(BOD)등 물리화학적 성상도 조사하였다. Ubiquinone UQ-8, UQ-9, UQ-10은 모든 조사 하천에서 관찰되었다. UQ-8은 가을의 남천하류, 토월천, 가음정천을 제외한 모든 하천에서 주요 퀴논 분자종이었으며, 겨울철에는 하남천, 토월천, 가음정천과 남산천을 제외한 하천에서 역시 주요 퀴논 분자종임이 확인되었다. DOC가 높을수록 가을철에는 plastoquinone(PQ-9)의 농도가 높았으며, 겨울에는 total quinone의 농도가 높았다. 상관분석 결과 BOD도 하천의 PQ농도를 좌우하는 주요 요인으로 확인되었다.

• BMB Reports
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• 제32권4호
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• pp.321-325
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• 1999

NAD(P)H-quinone oxidoreductase (EC 1. 6. 99. 2) was purified form S. cerevisiae. The enzyme readily reduced 2,6-dichlorophenolindophenol, a quinonoid redox dye, as well as substituted benzo- and naphthoquinones, and could accept electrons from either NADH or NADPH. The purified NAD(P)H-quinone oxidoreductase turned out to be capable of reducing nitrosoarenes as well as a variety of quinones. A chemical-trapping technique using 4-chloro-1-naphthol was used to show that the N,N-dimethyl-p-benzoquinonediiminium cation was produced in the reduction of 4-nitroso-N,N-dimethylaniline catalyzed by NAD(P)H-quinone oxidoreductase.

• BMB Reports
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• 제32권2호
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• pp.127-132
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• 1999

The NAD(P)H-quinone oxidoreductase (EC 1. 6. 99. 2) was purified from S. cerevisiae. The native molecular weight of the enzyme is approximately 111 kDa and is composed of five identical subunits with molecular weights of 22 kDa each. The optimum pH of the enzyme is pH 6.0 with 1,4-benzoquinone as a substrate. The apparent $k_m$ for 1,4-benzoquinone and 1,4- naphthoquinone are 1.3 mM and $14.3\;{\mu}M$, respectively. Its activity is greatly inhibited by $Cu^{2+}$ and $Hg^{2+}$ ions, nitrofurantoin, dicumarol, and Cibacron blue 3GA. The purified NAD(P)H-quinone oxidoreductase was found capable of reducing aromatic nitroso compounds as well as a variety of quinones, and can utilize either NADH or NADPH as a source of reducing equivalents. The nitroso reductase activity of the purified NAD(P)H-quinone oxidoreductase is strongly inhibited by dicumarol.

• BMB Reports
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• 제34권3호
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• pp.225-229
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• 2001

Besides a variety of quinones, purified bovine liver quinone reductase catalyzed the reduction of N,N-p-nitrosoaniline to N,N-dimethyl-p-phenylenediamine. The formation of N,N-dimethyl-p-phenylenediamine was identified by TLC, GC, GC-MS and NMR. Quinone reductase can utilize either NADH or NADPH as a source of reducing equivalents. The apparent Km for 1,4-benzoquinone and N,N-dimethyl-p-nitrosoaniline was 1.64 mM and 0.22 mM, respectively The reduction of N,N-dimethyl-p-nitrosoaniline was almost entirely hampered by dicumarol or Cibacron blue 3GA, potent inhibitors of mammalian quinone reductase. During the bovine liver quinone reductase-catalyzed reduction of N,N-dimethyl-p-nitrosoaniline, benzoquinonediiminium ion was produced.

• BMB Reports
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• 제33권4호
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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 Photoscience
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• 제7권3호
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• pp.111-114
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• 2000

Irradiation of 1,3-cyclohexanedione and p-benzoquinone in methanol gave 3-methoxycyclohex-2-en-1-one. Allyl derivative of the 1,3-diketone was prepared as enol from and irradiated in methanol in the presence of p-benzoquinone to give the same type of photoproduct, i.e., 2-allyl-3-methoxycyclohex-2-en-1-one. Allyldibenzoylmethane was synthesized and irradiated with p-benzoauinone in methanol but no remarkable amount of photoproduct was obtained.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.638-639
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• 2000

Quinone reductase was purified to electrophoretic homogeneity from bovine liver by using ammonium sulfate fractionation, ion-exchange chromatography, and gel filtration chromatography. The enzyme utilized either NADH or NADPH as the electron donor. The optimum pH of the enzyme was pH 8.5, and the activity of the enzyme was greatly inhibited by $Cu^{2+}$ and $Hg^{2+}$ ions, dicumarol and cibacron blue 3GA. The enzyme catalyzed the reduction of several quinones and other artificial electron acceptors. Furthermore, the enzyme catalyzed NAD(P)H-dependent reduction of azobenzene or 4-nitroso-N,N-dimethylaniline. The apparent $K_m$ for 1,4-benzoquinone, azobenzene, and 4-nitroso-N,N-dimethylaniline was 1.64mM, 0.524mM and 0.225mM, respectively. The reduction of azobenzene or 4-nitroso-N,N-dimethylaniline by quinone reductase was strongly inhibited by dicumarol or cibacron blue 3GA, potent inhibitors of quinone reductase.

• Journal of Photoscience
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• 제11권2호
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• pp.61-63
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• 2004

Some quinones such as 1,4-benzoquinone 2, 1,4-naphthoquinone 3 and 1,2-naphthoquinone 4 dissolved in diethylamine were irradiated with 300 nm UV light to afford red aminoquinones 6, 7, and 9 as the major products. Irradiation of a solution of a primary product, i.e., 2,5-bis(diethylamino)-1,4-benzoquinone 6 in benzene gave 2,5-bis (ethylamino)-1,4-benzoquinone 10 in 80% yield, along with an oxazoline 11 in 19% yield via photochemical deethylation. A solution of 2-diethylamino-1,4-naphthoquinone 7 in benzene was also irradiated under the same condition, in which 2-ethylamino-1,4-naphthoquinone 12 was obtained in ca. 100% yield.