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Journal articles on the topic 'Quinone'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

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1

Weiss, Sophie A., and Lars J. C. Jeuken. "Electrodes modified with lipid membranes to study quinone oxidoreductases." Biochemical Society Transactions 37, no. 4 (2009): 707–12. http://dx.doi.org/10.1042/bst0370707.

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Quinone oxidoreductases are a class of membrane enzymes that catalyse the oxidation or reduction of membrane-bound quinols/quinones. The conversion of quinone/quinol by these enzymes is difficult to study because of the hydrophobic nature of the enzymes and their substrates. We describe some biochemical properties of quinones and quinone oxidoreductases and then look in more detail at two model membranes that can be used to study quinone oxidoreductases in a native-like membrane environment with their native lipophilic quinone substrates. The results obtained with these model membranes are com

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2

Wang, Zhen-Hua, Xiao-Hui Fu, Qun Li, et al. "Recent Advances in the Domino Annulation Reaction of Quinone Imines." Molecules 29, no. 11 (2024): 2481. http://dx.doi.org/10.3390/molecules29112481.

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Quinone imines are important derivatives of quinones with a wide range of applications in organic synthesis and the pharmaceutical industry. The attack of nucleophilic reagents on quinone imines tends to lead to aromatization of the quinone skeleton, resulting in both the high reactivity and the unique reactivity of quinone imines. The extreme value of quinone imines in the construction of nitrogen- or oxygen-containing heterocycles has attracted widespread attention, and remarkable advances have been reported recently. This review provides an overview of the application of quinone imines in t

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3

Jensen,, Kenneth A., Zachary C. Ryan, Amber Vanden Wymelenberg, Daniel Cullen, and Kenneth E. Hammel. "An NADH:Quinone Oxidoreductase Active during Biodegradation by the Brown-Rot Basidiomycete Gloeophyllum trabeum." Applied and Environmental Microbiology 68, no. 6 (2002): 2699–703. http://dx.doi.org/10.1128/aem.68.6.2699-2703.2002.

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ABSTRACT The brown-rot basidiomycete Gloeophyllum trabeum uses a quinone redox cycle to generate extracellular Fenton reagent, a key component of the biodegradative system expressed by this highly destructive wood decay fungus. The hitherto uncharacterized quinone reductase that drives this cycle is a potential target for inhibitors of wood decay. We have identified the major quinone reductase expressed by G. trabeum under conditions that elicit high levels of quinone redox cycling. The enzyme comprises two identical 22-kDa subunits, each with one molecule of flavin mononucleotide. It is speci

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4

Armendáriz-Vidales, Georgina, Fidel Hernandez-Perez, Felipe J. González-Bravo та Carlos Frontana. "Hydrogen Bonding Processes During Self-protonation of Natural α-hydroxyquinones". Journal of the Mexican Chemical Society 69, № 1 (2025): 48–59. https://doi.org/10.29356/jmcs.v69i1.2316.

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The passage from non-substituted quinone to hydroquinone moieties involves the exchange of two-electron and two-protons, however, the presence of hydroxyl groups in the α position to the carbonyl group of the quinone induce a mechanistic change in which the quinone plays the role of electron acceptor and proton donor. This feature promotes a self-protonation mechanism which can be characterized in the framework of the ECE-DISP theory. However, when additional hydroxyl groups are contained in the quinone structure, hydrogen bonding becomes an additional competition factor that was studied in th

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5

Miseviciene, Lina, Zilvinas Anusevicius, Jonas Sarlauskas, Richard J. Harris, Nigel S. Scrutton, and Narimantas Cenas. "Two-electron reduction of quinones by Enterobacter cloacae PB2 pentaerythritol tetranitrate reductase: quantitative structure-activity relationships." Acta Biochimica Polonica 54, no. 2 (2007): 379–85. http://dx.doi.org/10.18388/abp.2007_3260.

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In order to clarify the poorly understood mechanisms of two-electron reduction of quinones by flavoenzymes, we examined the quinone reductase reactions of a member of a structurally distinct old yellow enzyme family, Enterobacter cloacae PB2 pentaerythritol tetranitrate reductase (PETNR). PETNR catalyzes two-electron reduction of quinones according to a 'ping-pong' scheme. A multiparameter analysis shows that the reactivity of quinones increases with an increase in their single-electron reduction potential and pK(a) of their semiquinones (a three-step (e(-),H(+),e(-)) hydride transfer scheme),

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6

Vienozinskis, J., A. Butkus, N. Cenas, and J. Kulys. "The mechanism of the quinone reductase reaction of pig heart lipoamide dehydrogenase." Biochemical Journal 269, no. 1 (1990): 101–5. http://dx.doi.org/10.1042/bj2690101.

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The relationship between the NADH:lipoamide reductase and NADH:quinone reductase reactions of pig heart lipoamide dehydrogenase (EC 1.6.4.3) was investigated. At pH 7.0 the catalytic constant of the quinone reductase reaction (kcat.) is 70 s-1 and the rate constant of the active-centre reduction by NADH (kcat./Km) is 9.2 x 10(5) M-1.s-1. These constants are almost an order lower than those for the lipoamide reductase reaction. The maximal quinone reductase activity is observed at pH 6.0-5.5. The use of [4(S)-2H]NADH as substrate decreases kcat./Km for the lipoamide reductase reaction and both

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7

Giulivi, C., and E. Cadenas. "One- and two-electron reduction of 2-methyl-1,4-naphthoquinone bioreductive alkylating agents: kinetic studies, free-radical production, thiol oxidation and DNA-strand-break formation." Biochemical Journal 301, no. 1 (1994): 21–30. http://dx.doi.org/10.1042/bj3010021.

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The one- and two-electron enzymic reduction of the bioreductive alkylating agents 2-methylmethoxynaphthoquinone (quinone I) and 2-chloromethylnaphthoquinone (quinone II) was studied with purified NADPH-cytochrome P-450 reductase and DT-diaphorase respectively, and characterized in terms of kinetic constants, oxyradical production, thiol oxidation and DNA-strand-break formation. The catalytic-centre activity values indicated that DT-diaphorase catalysed the reduction of quinone I far more efficiently than NADPH-cytochrome P-450 reductase, although the Km values of the two enzymes for this quino

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8

Breker, Johannes, Reinhard Schmutzler, Bernd Dorbath та Markus Wieber. "Reaktionen von unsymmetrischen λ5P – λ3P-Diphosphorverbindungen und von Diphosphinen (λ3P – λ3P) mit o-Chinonen / Reactions of Unsymmetrical λ5Ρ – λ3Ρ Diphosphorus Compounds and of Diphosphines (λ3P – λ3P) with o-Quinones". Zeitschrift für Naturforschung B 45, № 8 (1990): 1177–86. http://dx.doi.org/10.1515/znb-1990-0812.

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The reaction of λ5Ρ – λ3Ρ diphosphorus compounds with o-quinones, e.g. tetrachloro-o-benzoquinone or 2,5-di-tert-butyl-o-benzoquinone, led not only to oxidative addition of the o-quinone to λ3Ρ but also to insertion of a further molecule of o-quinone into the P–P bond (i.e. λ5Ρ – λ3Ρ diphosphorus compound and o-quinone reacted in a molar ratio 1:2). In the course of these oxidative addition and insertion reactions the o-quinones were converted into the corresponding hydroquinones (i.e. catechols). The products of these reactions were characterized by NMR and mass spectrometric methods, and by

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9

Flynn, Noah R., Michael D. Ward, Mary A. Schleiff, et al. "Bioactivation of Isoxazole-Containing Bromodomain and Extra-Terminal Domain (BET) Inhibitors." Metabolites 11, no. 6 (2021): 390. http://dx.doi.org/10.3390/metabo11060390.

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The 3,5-dimethylisoxazole motif has become a useful and popular acetyl-lysine mimic employed in isoxazole-containing bromodomain and extra-terminal (BET) inhibitors but may introduce the potential for bioactivations into toxic reactive metabolites. As a test, we coupled deep neural models for quinone formation, metabolite structures, and biomolecule reactivity to predict bioactivation pathways for 32 BET inhibitors and validate the bioactivation of select inhibitors experimentally. Based on model predictions, inhibitors were more likely to undergo bioactivation than reported non-bioactivated m

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10

Gready, JE, K. Hata, S. Sternhell, and CW Tansey. "N.M.R.-Study of Bond Orders in o- and p-Quinone." Australian Journal of Chemistry 43, no. 3 (1990): 593. http://dx.doi.org/10.1071/ch9900593.

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The 4J(Me-CC-H) coupling constant, previously established as a probe of bond order,1-3 was used to examine bond orders in a number of quinones. It was found that the presence of a quinone moiety does not cause bond localization in aromatic rings adjacent to the quinone ring.

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11

Monks, Terrence, and Douglas Jones. "The Metabolism and Toxicity of Quinones, Quinonimines, Quinone Methides, and Quinone-Thioethers." Current Drug Metabolism 3, no. 4 (2002): 425–38. http://dx.doi.org/10.2174/1389200023337388.

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12

Li, Jin, Kattesh V. Katti, Ronald G. Cavell, A. Alan Pinkerton, and Herbert Nar. "Synthesis and characterization of phosphinimine-substituted trifluoro- or trichloro-p-benzoquinones and their cationic Rh(I) complexes. The crystal and molecular structure of 3,5,6-trichloro-2-(triphenylphosphinimino)-p-benzoquinone." Canadian Journal of Chemistry 74, no. 11 (1996): 2378–85. http://dx.doi.org/10.1139/v96-265.

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Reaction of tetrafluoro- or tetrachloro-p-benzoquinone with silylated phosphoranimines R2R′P=NSiMe3 (R = Ph, Me) yields very highly colored monosubstituted derivatives of the p-quinone that act as two-electron acceptors showing clean, reversible CV traces. The molar absorptivity values are typical of dyes. These ligands also form chelate complexes with Rh(I) precursors using the quinone oxygen and the imine nitrogen donor sites. One of the quinone derivatives, 3,5,6-trichloro-2-(triphenylphosphinimino)-p-benzoquinone, has been structurally characterized. The iminated quinone shows a normal P=N

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13

Xu, Wei, William R. Dolbier, Jian-Xin Duan, et al. "Octafluoro[2.2]paracyclophane (AF4) Quinone." Collection of Czechoslovak Chemical Communications 73, no. 12 (2008): 1764–76. http://dx.doi.org/10.1135/cccc20081764.

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Octafluoro[2.2]paracyclophane (AF4) has been oxidized by treatment with HIO3 in CF3CO2H to form the corresponding p-quinone along with a unique triketone. This quinone undergoes reduction to the respective hydroquinone as well as a Diels-Alder reaction with 1,3-cyclohexadiene. Its reduction potential was obtained by cyclic voltammetry and is discussed in the context of other quinones.

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14

Begleiter, Asher. "The contribution of alkylation to the activity of quinone antitumor agents." Canadian Journal of Physiology and Pharmacology 64, no. 5 (1986): 581–85. http://dx.doi.org/10.1139/y86-096.

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Studies have shown that the quinone group can produce tumor cell kill by a mechanism involving active oxygen species. This cytotoxic activity can be correlated with the induction of DNA double strand breaks and is enhanced by the ability of the quinone compound to bind to DNA by alkylation. The cytotoxic activity and the production of DNA damage by model quinone antitumor agents were compared in L5178Y cells, sensitive and resistant to alkylating agents, to assess the contribution of alkylation to the activity of these agents. The resistant L5178Y/HN2 cells were found to be two fold and six fo

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15

Ellis, Jessie, Xueyan Fu, J. Philip Karl, et al. "Investigation of Vitamin K Quinone Metabolism by Human Gut Bacteria." Current Developments in Nutrition 4, Supplement_2 (2020): 392. http://dx.doi.org/10.1093/cdn/nzaa045_025.

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Abstract Objectives Vitamin K (VK) is a family of structurally-related quinones, phylloquinone (PK) and menaquinones (MKn, n = prenyl units in side chain), that share a common napthoquinone ring (menadione, MD). VK quinones function as an essential dietary nutrient for humans. MD is considered a pro-vitamin form of VK. Plants and bacteria that produce VK quinones (PK and MKn, respectively) use them as an electron carrier in energy production. Little is known about the interaction of dietary VK quinones with gut bacteria, which may be bi-directional. The objective of this study was to investiga

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16

Lima, Larissa S., Luiz Cláudio de A. Barbosa, Elson S. de Alvarenga, Antônio J. Demuner, and Antônio A. da Silva. "Synthesis and Phytotoxicity Evaluation of Substituted para-Benzoquinones." Australian Journal of Chemistry 56, no. 6 (2003): 625. http://dx.doi.org/10.1071/ch02032.

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Sorgoleone (1) is one of the major constituents of sorghum root exudates. Sorgoleone is an allelochemical that reduces the growth of broad-leaf plants. The 3,5-dimethoxybenzylic alcohol (3) was used as starting material for the synthesis of 2-methoxy-6-(non-1-yl)benzo-1,4-quinone (9) in 69% yield. Acetylation of (9) with acetic anhydride gave the triacetate (10) in 82% yield. The triacetate (10) was then converted in two steps in 2-hydroxy-5-methoxy-3-(non-1-yl)benzo-1,4-quinone (11) and 2-acetoxy-5-methoxy-3-(non-1-yl)benzo-1,4-quinone (12) in 8% and 37% yield, respectively. Quinone (11) was

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17

Russell, RA, BA Pilley, RW Irvine, and RN Warrener. "Anthracyclines. XVI. Further Comments Concerning the Phthalide Anion Annelation of Quinone Monoacetals." Australian Journal of Chemistry 40, no. 2 (1987): 311. http://dx.doi.org/10.1071/ch9870311.

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.Yields of tricyclic and tetracyclic quinones prepared by annelation of quinone monoacetals with the anion of 3-phenylsulfonylphthalides are shown to be sensitive to the substituent on both the phthalide and the quinone monoacetal partner. In contrast, reactions with the anions of 3-cyanophthalides afford high yields of condensed products in all cases examined.

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18

Juliasih, Ni Luh Gede Ratna, Lee Chang Yuan, Yuki Sago, Yoichi Atsuta, and Hiroyuki Daimon. "Supercritical Fluid Extraction of Quinones from Compost for Microbial Community Analysis." Journal of Chemistry 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/717616.

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Supercritical fluid extraction (SFE) was used to extract quinones from compost to monitor the microbial community dynamics during composting. The 0.3 g of dried compost was extracted using 3 mL min−1of carbon dioxide (90%) and methanol (10%) at 45°C and 25 MPa for a 30 min extraction time. The extracted quinones were analysed using ultra performance liquid chromatography (UPLC) with 0.3 mL min−1of methanol mobile phase for a 50 min chromatographic run time. A comparable detected amount of quinones was obtained using the developed method and an organic solvent extraction method, being 36.06 μmo

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19

Ito, Shosuke, Manickam Sugumaran, and Kazumasa Wakamatsu. "Chemical Reactivities of ortho-Quinones Produced in Living Organisms: Fate of Quinonoid Products Formed by Tyrosinase and Phenoloxidase Action on Phenols and Catechols." International Journal of Molecular Sciences 21, no. 17 (2020): 6080. http://dx.doi.org/10.3390/ijms21176080.

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Tyrosinase catalyzes the oxidation of phenols and catechols (o-diphenols) to o-quinones. The reactivities of o-quinones thus generated are responsible for oxidative browning of plant products, sclerotization of insect cuticle, defense reaction in arthropods, tunichrome biochemistry in tunicates, production of mussel glue, and most importantly melanin biosynthesis in all organisms. These reactions also form a set of major reactions that are of nonenzymatic origin in nature. In this review, we summarized the chemical fates of o-quinones. Many of the reactions of o-quinones proceed extremely fast

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20

Khetan, Abhishek. "High-Throughput Virtual Screening of Quinones for Aqueous Redox Flow Batteries: Status and Perspectives." Batteries 9, no. 1 (2022): 24. http://dx.doi.org/10.3390/batteries9010024.

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Quinones are one of the most promising and widely investigated classes of redox active materials for organic aqueous redox flow batteries. However, quinone-based flow batteries still lack the necessary performance in terms of metrics, such as specific capacity, power density, and long-term stability, to achieve mass market adoption. These performance metrics are directly related to the physicochemical properties of the quinone molecules, including their equilibrium redox potential, aqueous solubility, and chemical stability. Given the enormous chemical and configurational space of possible qui

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21

Norkov, Sergey V., Anton V. Cherkasov, Andrey S. Shavyrin, Maxim V. Arsenyev, Viacheslav A. Kuropatov, and Vladimir K. Cherkasov. "Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands." Beilstein Journal of Organic Chemistry 17 (January 27, 2021): 273–82. http://dx.doi.org/10.3762/bjoc.17.26.

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The fused 1,3-dithiole spacer seems to be very suitable for the functionalization of sterically hindered o-quinones with additional groups capable of coordination of metal ions and/or possessing a redox activity. An effective method for the synthesis of sterically hindered o-quinones containing 1,3-diketonate, dinitrile and p-quinone-methide functional groups at the periphery of the ligand has been developed. The novel compounds have rigid and conjugated structures and exhibit properties typical of o-quinones. A study of their monoreduced semiquinone derivatives reveal that the spin density is

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22

Wiraswati, Hesti L., Fida M. Warganegara, Akhmaloka Akhmaloka, and Muhamad A. Martoprawiro. "Molecular Docking Studies of ROS Agent from Quinone Family to Reductase Enzymes:Implication in Finding Anticancer Drug Candidate." Biomedical and Pharmacology Journal 14, no. 02 (2021): 681–89. http://dx.doi.org/10.13005/bpj/2170.

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Understanding the metabolism of cytotoxic compounds of quinone family is importance in cancer therapy because they have been successfully explored for their anti-tumor activity. Quinone which form radical semiquinone (by reductase enzymes) to generate Reactive Oxygen Species (ROS) is associated to be anticancer drug candidate. However, molecular mechanism of those compounds to reductase enzymes has not yet clearly understood.This study aimed to understand molecular interaction of quinones to oxidoreductase enzymes such as cytochrome P450 reductase or ubiquinone reductase (NQO1), or apoptosis i

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23

Kass, G. E., S. K. Duddy, and S. Orrenius. "Activation of hepatocyte protein kinase C by redox-cycling quinones." Biochemical Journal 260, no. 2 (1989): 499–507. http://dx.doi.org/10.1042/bj2600499.

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The effects of quinone-generated active oxygen species on rat hepatocyte protein kinase C were investigated. The specific activity of cytosolic protein kinase C was increased 2-3-fold in hepatocytes incubated with the redox-cycling quinones, menadione, duroquinone or 2,3-dimethoxy-1,4-naphthoquinone, without alterations in particulate protein kinase C specific activity or Ca2+- and lipid-independent kinase activities. Redox-cycling quinones did not stimulate translocation of protein kinase C; however, activated protein kinase C was redistributed from cytosol to the particulate fraction when qu

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24

Luo, Yu Jiao, Ling Feng Qiu, Yi Ming Chen, and Jian Zhang. "Preliminary Discussion on the Activity of Denitrifying Phosphorus-Removing Bacteria in Sequencing Batch Reactors by Quinone Profile Analysis." Advanced Materials Research 518-523 (May 2012): 440–43. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.440.

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Based on DPBs (Denitrifying Phosphorus-removing Bacteria) obtained from a lab-scale SBR, a quinone profile system had been established to analyze quinones in sludge samples. There existed a positive correlation between the contents of UQ-8 extracted from the sludge samples and the denitrifying and phosphorus removal efficiency of the treating system. With quinone profiles taken as a new important index, it was evidently feasible to determine the removal effect.

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Oliveira, Joyce C., Renato L. de Carvalho, Hugo G. S. Sampaio, et al. "It Takes Two to Tango, Part II: Synthesis of A-Ring Functionalised Quinones Containing Two Redox-Active Centres with Antitumour Activities." Molecules 28, no. 5 (2023): 2222. http://dx.doi.org/10.3390/molecules28052222.

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In 2021, our research group published the prominent anticancer activity achieved through the successful combination of two redox centres (ortho-quinone/para-quinone or quinone/selenium-containing triazole) through a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The combination of two naphthoquinoidal substrates towards a synergetic product was indicated, but not fully explored. Herein, we report the synthesis of 15 new quinone-based derivatives prepared from click chemistry reactions and their subsequent evaluation against nine cancer cell lines and the murine fibroblast line L

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26

MacDonald, Michael J. "Stimulation of insulin release from pancreatic islets by quinones." Bioscience Reports 11, no. 3 (1991): 165–70. http://dx.doi.org/10.1007/bf01182485.

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Coenzyme Q (CoQ0) and other quinones were shown to be potent insulin secretagogues in the isolated pancreatic islet. The order of potency was CoQ0≅benzoquinone≅hydroquinonemenadione. CoQ6 and CoQ10 (ubiquinone), duroquinone and durohydroquinone did not stimulate insulin release. CoQ0's insulinotropism was enhanced in calcium-free medium and CoQ0 appeared to stimulate only the second phase of insulin release. CoQ0 inhibited inositol mono-, bis- and trisphosphate formation. Inhibitors of mitochondrial respiration (rotenone, antimycin A, FCCP and cyanide) and the calcium channel blocker verapamil

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Lian, Xiao-Lei, Alafate Adili, Bin Liu, Zhong-Lin Tao, and Zhi-Yong Han. "Enantioselective [4 + 1] cycloaddition of ortho-quinone methides and bromomalonates under phase-transfer catalysis." Organic & Biomolecular Chemistry 15, no. 17 (2017): 3670–73. http://dx.doi.org/10.1039/c7ob00484b.

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28

Casertano, Marcello, Anna Aiello, Marialuisa Menna, and Concetta Imperatore. "The Effects of Ceric Ammonium Nitrate in the Oxidation of 2-Benzyl-1,4-dimethoxybenzene Derivatives." Molbank 2024, no. 3 (2024): M1882. http://dx.doi.org/10.3390/m1882.

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The one- or two-electron reduction in quinone compounds gives rise to semiquinones and hydroquinones, respectively, which, in turn, can be oxidized back to quinones, generating a cyclic redox system with the production of reactive oxygen species (ROS). For these reasons, quinone derivatives participate in various biological processes in metabolic pathways, such as oxidative reactions and electron transport. In addition, natural quinone compounds as well as their semisynthetic and/or synthetically produced derivatives are of great pharmacological interest for the discovery and design of new dru

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29

Webster, Richard David. "Utilizing Redox Transformations of Quinones to Modulate Weak Donor and Acceptor Bonding Interactions with H₂o and CO₂ in Organic Solvents." ECS Meeting Abstracts MA2023-01, no. 41 (2023): 2335. http://dx.doi.org/10.1149/ma2023-01412335mtgabs.

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Redox chemical transformations can be used to modulate supramolecular interactions between reduced quinones and acceptor molecules, with the application of an electric potential enabling the interactions to be switched on and off. The supramolecular interactions targeted include weak solution phase processes involving H-bonding with water molecules, and interactions between dissolved molecular gases such as CO2 and solution phase electroactive species. The advantage of this approach is that it enables the supramolecular complexing abilities of one molecule to be improved and tuned simply by ch

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30

Laatsch, Hartmut. "Methylierung 3,3′-dihydroxylierter 2,2′-Binaphthyl-1,4;1′,4′-dichinone / Methylation of 3,3′-Dihydroxylated 2,2′-Binaphtho-1,4;1′,4′-quinones." Zeitschrift für Naturforschung B 45, no. 3 (1990): 393–400. http://dx.doi.org/10.1515/znb-1990-0316.

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Monomeric hydroxy-p-quinones (1) are in equilibrium with the corresponding o-quinones (2) and on methylation, a mixture of both isomeric ethers is obtained. In contrast, dimeric hydroxynaphthoquinones with the 3 a-skeleton in treatment with diazomethane are yielding only p-quinone ethers of type 3b.

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31

Tsou, Yun-Jie, Ren-You Guan, and Jeng-Liang Han. "Enantioselective organocatalytic vinylogous aldol-cyclization cascade reaction of 3-alkylidene oxindoles with o-quinones." Organic & Biomolecular Chemistry 19, no. 26 (2021): 5836–43. http://dx.doi.org/10.1039/d1ob00888a.

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A enantioselective organocatalytic vinylogous aldol-cyclization cascade reaction of 3-alkylidene oxindoles to o-quinones afforded chiral spirocyclic o-quinone analogues in good to excellent yields with high enantioselectivities.

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Jovanovic, S. V., K. Kónya, and J. C. Scaiano. "Redox reactions of 3,5-di-tert-butyl-1,2-benzoquinone. Implications for reversal of paper yellowing." Canadian Journal of Chemistry 73, no. 11 (1995): 1803–10. http://dx.doi.org/10.1139/v95-222.

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One- and two-electron transfer reactions of 3,5-di-tert-butylcatechol and the corresponding quinone were studied by fast kinetic spectroscopy coupled with laser photolysis and pulse radiolysis, and by cyclic voltammetry in aqueous solutions. Photoionization of catechol yields the same semiquinone radical as the formate-radical-induced quinone reduction in the pulse radiolysis experiment. The neutral semiquinone radical deprotonates at pKr = 6.0 ± 0.1, as deduced from the pH induced changes in the radical spectra. The two-electron reduction potentials of quinone and catechol were measured by cy

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Field, J. A., F. J. Cervantes, F. P. van der Zee, and G. Lettinga. "Role of quinones in the biodegradation of priority pollutants: a review." Water Science and Technology 42, no. 5-6 (2000): 215–22. http://dx.doi.org/10.2166/wst.2000.0516.

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Evidence is accumulating that inert humic substances can play important roles in the anaerobic degradation of priority pollutants by shuttling electrons. This paper reviews the roles of humus and quinone analogues as electron acceptors, redox mediators and electron donors for microbial and abiotic degradation processes. An eventual technology based on pumping quinones as terminal electron acceptors into aquifers and sediments to stimulate xenobiotic degradation offers promising potential. Also quinone redox mediators can be considered to accelerate reductive transformations (e.g. dechlorinatio

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Sekulic, Tatjana, Lj V. Vujisic, B. P. M. Curcic, et al. "Quinones and non-quinones from the defensive secretion of Unciger transsilvanicus (Verhoeff, 1899) (Diplopoda, Julida, Julidae), from Serbia." Archives of Biological Sciences 66, no. 1 (2014): 385–90. http://dx.doi.org/10.2298/abs1401385s.

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A complex mixture of compounds was identified from the secretion of specimens of Unciger transsilvanicus. Phenol and p-cresol were detected for the first time in the family Julidae, and for the second time in the order Julida. Thirteen quinones were identified, with a great relative abundance of toloquinone and 2-methoxy-3-methyl-1,4-benzoquinone. Hydroquinone was detected for the first time in the order Julida. Besides these compounds, isopentyl hexacosatetraenoate and isopentyl esters of saturated and unsaturated fatty acids with chain lengths from C14 to C20were identified. The most abundan

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35

Elgawish, Mohamed Saleh, Naoya Kishikawa, Mohamed A. Helal, Kaname Ohyama, and Naotaka Kuroda. "Molecular modeling and spectroscopic study of quinone–protein adducts: insight into toxicity, selectivity, and reversibility." Toxicology Research 4, no. 4 (2015): 843–47. http://dx.doi.org/10.1039/c5tx00098j.

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The toxicity, reversibility and selectivity of quinone–protein adducts were studied using molecular modeling and molecular spectroscopy. Adduction of quinones with proteins could affect their redox potential, bioavailability, and intracellular distribution.

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36

Hu, H. Y., B. R. Lim, N. Goto, V. K. Bhupathiraju, and K. Fujie. "Characterization of microbial community in an activated sludge process treating domestic wastewater using quinone profiles." Water Science and Technology 43, no. 1 (2001): 99–106. http://dx.doi.org/10.2166/wst.2001.0024.

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The dynamics of microbial community structure of activated sludges in a small-scale domestic wastewater treatment process were examined using a novel approach of quinone profiles. The composition and content of quinones in the activated sludges were analyzed monthly over a period of one year. More than 4 types of ubiquinones and 12 types of menaquinones were observed in the activated sludges, with the dominant quinones being ubiquinone (UQ) -8, menaquinone (MK) -7, followed by UQ-10, MK-8 and MK-6. The total quinone contents in the activated sludges varied from 0.93 to 2.28μmol per gram of par

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37

Nozawa, Mamie, Hong-Ying Hu, Koichi Fujie, Tomohiko Tsuchida, and Kohei Urano. "Population dynamics of chromate reducing bacteria in a bioreactor system developed for the treatment of chromate wastewater." Water Science and Technology 37, no. 4-5 (1998): 109–12. http://dx.doi.org/10.2166/wst.1998.0595.

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The population dynamics of microbes was investigated in a bioreactor system for the treatment of chromate wastewater supplemented with chromate reducing bacteria Enterobacter cloacae strain HO-1. In this study, respiratory quinone profile and PCR techniques were used to analyse the microbial population. The change in microbial community structure and density was observed on the basis of the respiratory quinone profile since the predominant quinone of HO-1 is ubiquinone-8 (Q-8) and the amount of quinone is proportional to the cell mass. the quantity of microbes and the Q-8 fraction of the total

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38

Fujie, Koichi, Hong-Ying Hu, Hajime Tanaka, and Kohei Urano. "Ecological Studies of Aerobic Submerged Biofilter on the Basis of Respiratory Quinone Profiles." Water Science and Technology 29, no. 7 (1994): 373–76. http://dx.doi.org/10.2166/wst.1994.0364.

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Respiratory quinone profiles were applied as tools for identifying different bacterial populations in the aerobic submerged biofilter along with the change of environment such as the temperature and the loading of hard-biodegradable chemicals. To begin with, a novel and simplified analytical operation of respiratory quinones was developed. A diversity in microbial population was observed in the film cultivated at the higher temperature. The change of microbial population in the course of acclimation to hard-biodegradable chemicals such as dimethylformamide(DMF, hereafter) was clarified on the

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Sladic, Dusan, Irena Novakovic, Zoran Vujcic, et al. "Protein covalent modification of biologically active quinones." Journal of the Serbian Chemical Society 69, no. 11 (2004): 901–7. http://dx.doi.org/10.2298/jsc0411901s.

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The avarone/avarol quinone/hydroquinone couple shows considerable antitumor activity. In this work, covalent modification of ?-lactoglobulin by avarone and its derivatives as well as by the synthetic steroidal quinone 2,5(10)-estradiene- 1,4,17-trione and its derivatives were studied. The techniques for studying chemical modification of ?-lactoglobulin by quinones were: UV/Vis spectrophotometry, SDS PAGE and isoelectrofocusing. SDS PAGE results suggest that polymerization of the protein occurs. It could be seen that the protein of 18 kD gives the bands of 20 kD, 36 kD, 40 kD, 45 kD, 64 kD and

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40

Gutiérrez, Isela, Sonia G. Bertolotti, M. A. Biasutti, Arnaldo T. Soltermann, and Norman A. García. "Quinones and hydroxyquinones as generators and quenchers of singlet molecular oxygen." Canadian Journal of Chemistry 75, no. 4 (1997): 423–28. http://dx.doi.org/10.1139/v97-048.

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The role of quinones and hydroxyquinones as sensitizers and as quenchers in Type II photooxygenations has been examined. The second aspect is discussed here, through a systematic study, for the first time in the open literature. Quinonic compounds are excellent generators of O2(1Δg) in aprotic solvents (excluding those quinones possessing substituents in positions adjacent to the carbonyl groups, in the case of anthraquinone derivatives). Benzoquinones, anthraquinones, and hydroxy derivatives are good O2(1Δg) quenchers upon dye-sensitized photoirradiation. The excited oxygen species is deactiv

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Baxter, Ryan, Akil Hamsath, and Jordan Galloway. "Quinone C–H Alkylations via Oxidative Radical Processes." Synthesis 50, no. 15 (2018): 2915–23. http://dx.doi.org/10.1055/s-0037-1610005.

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A brief survey of radical additions to quinones is reported. Carboxylic acids, aldehydes, and unprotected amino acids are compared as alkyl radical precursors for the mono- or bis- C–H alkylation of several quinones. Two methods for radical initiation are discussed comparing inorganic persulfates and Selectfluor as stoichiometric oxidants. Kinetic analysis reveals dramatic differences in the rate of radical initiation depending on the identity of the radical precursor and oxidant. Synthetic strategies for efficiently producing alkyl-quinones are discussed in the context of selecting optimum ra

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42

Kianmehr, Ebrahim, Mehran Rezazadeh Khalkhali, Masoud Rezaeefard, Khalid Mohammed Khan, and Seik Weng Ng. "Pd-Catalyzed Dehydrogenative Cross-Coupling of 1,4-Quinones with N,N′-Dialkyluracils." Australian Journal of Chemistry 68, no. 1 (2015): 165. http://dx.doi.org/10.1071/ch14412.

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A straightforward and efficient method for the palladium-catalyzed direct cross-coupling of quinones with N,N′-dialkyluracils via 2-fold C–H activation has been developed to rapidly construct uracil substituted quinone structural motifs.

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Sugumaran, M., H. Dali, and V. Semensi. "Mechanistic studies on tyrosinase-catalysed oxidative decarboxylation of 3,4-dihydroxymandelic acid." Biochemical Journal 281, no. 2 (1992): 353–57. http://dx.doi.org/10.1042/bj2810353.

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Mushroom tyrosinase, which is known to convert a variety of o-diphenols into o-benzoquinones, has been shown to catalyse an unusual oxidative decarboxylation of 3,4-dihydroxymandelic acid to 3,4-dihydroxybenzaldehyde [Sugumaran (1986) Biochemistry 25, 4489-4492]. The mechanism of this reaction was re-investigated. Although visible-region spectral studies of the reaction mixture containing 3,4-dihydroxymandelic acid and tyrosinase failed to generate the spectrum of a quinone product during the steady state of the reaction, both trapping experiments and non-steady-state kinetic experiments provi

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Hui, Pan, Mathieu Branca, Benoît Limoges, and François Mavré. "An autocatalytic organic reaction network based on cross-catalysis." Chemical Communications 57, no. 86 (2021): 11374–77. http://dx.doi.org/10.1039/d1cc05121k.

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A simple autocatalytic organic reaction network based on cross-catalysis is here illustrated. It involves the redox chemistry of quinones and reactive oxygen species, requiring only an pro-quinone boronate probe and ascorbate in an aerated solution.

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Li, Zhi, and Xiao-Long Xu. "Deciphering the Redox Chain Mechanism in the Catalytic Alkylation of Quinones." Synlett 29, no. 14 (2018): 1807–13. http://dx.doi.org/10.1055/s-0037-1610125.

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Alkylation of p-quinones with allylic and benzylic esters is achieved by using a strong Lewis acid as the catalyst. This transformation likely follows an unusual redox chain mechanism. In this mechanism, quinone undergoes a sequence of reactions: it is reduced to hydroquinone (HQ), functionalized in a Lewis acid-catalyzed Friedel–Crafts alkylation, and then oxidized back to quinone. The last step is concurrent with the first step of a second quinone molecule, which is reduced to new HQ and functionalized, and thus propagates the redox chain reaction. The autoinitiation mechanism of the redox

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Caldwell, Sharon L., Joe B. Gilroy, Rajsapan Jain, Evan Crawford, Brian O. Patrick, and Robin G. Hicks. "Synthesis and redox properties of a phosphine-subsituted para-dioxolene and its bimetallic palladium complex." Canadian Journal of Chemistry 86, no. 10 (2008): 976–81. http://dx.doi.org/10.1139/v08-127.

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Oxidation of 2,5-bis(diphenylphosphino)-1,4-hydroquinone (8) with iodobenzene diacetate produces the corresponding bis(phosphine) substituted benzoquinone (9), the first phosphine-substitued quinone. Cyclic voltammetry studies reveal that the redox functionality of the quinone unit in 9 is retained, and the reduction potentials render this compound slightly more easily reduced than the parent p-benzoquinone. Reaction of the precursor hydroquinone 8 with Pd(hfac)2 affords a binuclear complex 10 with the hydroquinonate ligand bridging two Pd(hfac) substrates. The redox activity of the bridging d

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47

Fujisawa, Takuma, Seiji Tsuzuki, Masayoshi Watanabe, and Kazuhide Ueno. "Redox Behavior of Quinones Bearing Ionic Liquid Moiety for Electrochemical CO₂ Capture." ECS Meeting Abstracts MA2024-02, no. 56 (2024): 3749. https://doi.org/10.1149/ma2024-02563749mtgabs.

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CCUS (Carbon dioxide Capture, Utilization and Storage), is attracting attention as an effective method for reducing carbon dioxide (CO2) emissions toward carbon neutrality by 2050. Currently, chemical absorption followed by thermal desorption using liquid amine is employed as the CO2 capture and concentration technology. However, low energy efficiency and high cost of the thermal swing process remain to be addressed. CO2 capture driven by renewable electricity represents a promising alternative approach to mitigate CO2 emissions and address climate change. Electrochemically mediated carbon cap

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Hiraishi, Akira, Taichi Umezawa, Hiroyuki Yamamoto, Kenji Kato, and Yonosuke Maki. "Changes in Quinone Profiles of Hot Spring Microbial Mats with a Thermal Gradient." Applied and Environmental Microbiology 65, no. 1 (1999): 198–205. http://dx.doi.org/10.1128/aem.65.1.198-205.1999.

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ABSTRACT The respiratory and photosynthetic quinones of microbial mats which occurred in Japanese sulfide-containing neutral-pH hot springs at different temperatures were analyzed by spectrochromatography and mass spectrometry. All of the microbial mats that developed at high temperatures (temperatures above 68°C) were so-called sulfur-turf bacterial mats and produced methionaquinones (MTKs) as the major quinones. A 78°C hot spring sediment had a similar quinone profile.Chloroflexus-mixed mats occurred at temperatures of 61 to 65°C and contained menaquinone 10 (MK-10) as the major component to

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Silva, Raquel L., Daniel P. Demarque, Renata G. Dusi, João Paulo B. Sousa, Lorena C. Albernaz, and Laila S. Espindola. "Residual Larvicidal Activity of Quinones against Aedes aegypti." Molecules 25, no. 17 (2020): 3978. http://dx.doi.org/10.3390/molecules25173978.

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The number of documented dengue cases has increased dramatically in recent years due to transmission through the Aedes aegypti mosquito bite. Vector control remains the most effective measure to protect against this and other arboviral diseases including Zika, chikungunya and (urban) yellow fever, with an established vaccine only available for yellow fever. Although the quinone class shows potential as leading compounds for larvicide development, limited information restricts the development of optimized structures and/or formulations. Thus, in this contribution we investigated the larvicidal

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Becker, James Y. "Electrochemistry of Diquinonyl Amines with an Internal Proton Source." ECS Meeting Abstracts MA2024-01, no. 41 (2024): 2340. http://dx.doi.org/10.1149/ma2024-01412340mtgabs.

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It is well established that quinones play an important role in various biological systems. Studying electrochemical properties of quinones affords fundamental knowledge of semi-quinone radicals formation in vivo and in vitro in different media. Following our previous work on electrochemical properties of various quinonyl amines [1], Scheme 1 below describes seven diquinonyl amines. Noteworthy that six of them (1-6) contain an internal proton donor (‘NH’) except for the seventh one (7), in which both quinone moieties are attached to ‘NMe’ group. Their redox potentials were measured by cyclic vo

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