Quinones as Free-radical Fragmentation Inhibitors in Biologically Important Molecules

Шадыро, О. И.; Glushonok, G.K.; Glushonok, T.G.; Edimecheva, Irina; Moroz, A.G.; Sosnovskaya, A. A.; Yurkova, Irina; Полозов, Г. И.

doi:10.1080/1071576021000005294

Cited by 57 publications

(22 citation statements)

References 24 publications

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“…Electrochemical behavior of semi-or dihydroquinones (quinoles) can be different (6,38). Reduced quinones can autoxidize, inducing ROS generation, or can transfer electrons to Complexes II, III, or IV, shunting ETC functions, changing redox balance in mitochondria, and working as potent antioxidants (13,23,37,46,47,49,55).…”

Section: Discussionmentioning

confidence: 99%

“…It is known that exogenous quinones can both be oxidized and reduced by ETC complexes (11,13,23,28,37,46,47,49,55). However, because they are not a primary substrate of these enzymes, the efficiency of oxidation/reduction has to be strongly dependent on the availability of primary substrates and "saturation" of electrons in the ETC (reduction states of components of ETC), just as the electron leak from ETC and superoxide production depend on the reduction states of ETC components and the proton gradient (25).…”

Section: Discussionmentioning

confidence: 99%

“…Quinones are capable of regulating cell functions, inducing reactive oxygen species (ROS) generation or, vice versa, manifesting antioxidant properties (in a reduced form). Another mechanism for quinone regulation of cellular properties is arylation of SH and NH 2 groups of some functionally significant proteins (6,39,49,50,55). The rate and direction of oxidation-reduction reactions are determined by quinone reduction potentials.…”

Section: Introductionmentioning

confidence: 99%

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Redox regulation of mitochondrial functional activity by quinones

et al. 2016

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Quinones are among the rare compounds successfully used as therapeutic agents to correct mitochondrial diseases and as specific regulators of mitochondrial function within cells. The aim of the present study was to elucidate the redox-dependent effects of quinones on mitochondrial function. The functional parameters [respiratory activity, membrane potential, and reactive oxygen species (ROS) generation] of isolated rat liver mitochondria and mitochondria in intact cells were measured in the presence of eight exogenously applied quinones that differ in lipophilicity and one-electron reduction potential. The quinones affected the respiratory parameters of mitochondria, and dissipated the mitochondrial membrane potential as well as influenced (either decreased or enhanced) ROS generation, and restored the electron flow during electron transport chain inhibition. The stimulation of ROS production by juglone and 2,5-di-tert-butyl-1,4-benzoquinone was accompanied by a decrease in the acceptor control and respiration control ratios, dissipation of the mitochondrial membrane potential and induction of the reverse electron flow under succinate oxidation in isolated mitochondria. Menadione and 2,3,5-trimethyl-1,4-benzoquinone, which decreased the mitochondrial ROS generation, did not affect the mitochondrial potential and, vice versa, were capable of restoring electron transport during Complex I inhibition. In intact C6 cells, all the quinones, except for coenzyme Q 10 , decreased the mitochondrial membrane potential. Juglone, 1,4-benzoquinone, and menadione showed the most pronounced effects. These findings indicate that quinones with the reduction potential values E 1/2 in the range from −99 to −260 mV were effective redox regulators of mitochondrial electron transport.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Redox regulation of mitochondrial functional activity by quinones

et al. 2016

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“…The smaller A value for Cu(L III ) 2 has been attributed to the high covalency of the Cu-S bonding [54]. 2 and Cu(L IV ) 2 by the presence of a narrow singlet with g near 2 ( Table 2). On the basis of g values (respectively 2.0043 and 2.0045), it may be suggested that they belong to phenoxyl radicals.…”

Section: Esr Spectramentioning

confidence: 99%

“…[2][3][4]. Moreover, a sulfur-containing SHD derivative exhibits a high antiviral, neurotropic and nootropic activity [5][6][7], and many phenolic compounds have antibacterial activities [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Copper (II) complexes of sterically hindered o-diphenol derivatives: synthesis, characterization and microbiological studies

et al. 2006

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Abstract:Cu (II) complexes with the sterically hindered diphenol derivatives 3,5-di(tertbutyl)-1,2-benzenediol (I), 4,6-di(tert-butyl)-1,2,3-benzenetriol (II) and the sulfur-containing 4,6-di(tert-butyl)-3-(2-hydroxyethylsulfanyl)-1,2-benzenediol (III) and 2-[4,6-di(tert-butyl)-2,3-dihydroxyphenylsulfanyl]acetic acid (IV) have been synthesized and characterized by elemental analysis, TG/DTA, FT-IR, ESR, XPS, XPD and conductivity measurements. Compounds I-III can coordinate in their singly deprotonated forms and act as bidentate ligands. These compounds yield Cu (II) complexes of the stoichiometry Cu(L) 2 , which have square planar geometry (g > g ⊥ >g e ). Unlike them, compound IV behaves as a terdentate ligand, and its complex Cu(L IV ) 2 has distorted octahedral geometry. According to ESR data, only the Cu(L II ) 2 complex contains a very small amount of phenoxyl radicals. Antimicrobial activities of these ligands and their respective Cu (II) complexes have been determined with respect to Gram-positive and Gram-negative bacteria, as well as on yeasts. Their phytotoxic properties against Chlorella vulgaris 157 were also examined.

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Effect of flavonols on radiation-induced reactions with the participation of α-hydroxyl-containing organic radicals

Grintsevich

Шадыро

2005

High Energy Chem

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1 Flavonols, which are plant polyphenols, are widely used for the regulation of free-radical oxidation processes in biological systems [1][2][3][4]. The antioxidant activity of flavonols, as well as a number of other flavonoids, is responsible for their useful therapeutic properties. Because of this, it is of considerable interest to study the properties of this class of compounds.Previously [5][6][7][8], it was found that biologically important molecules exposed to γ -radiation and other initiators of free-radical processes can be damaged not only by oxidation but also as a result of fragmentation. In the latter process, the step of degradation of α -hydroxyl-containing radicals plays a key role. It was also found [9, 10] that carbonyl-containing compounds and quinones affect free-radical processes that involve α -hydroxyl-containing carbon-centered organic radicals. As regards flavonoids, only a few publications [11][12][13][14] have been devoted to their reactivity toward carbon-centered radicals.In this paper, we report data that allow us to judge the probabilities and reaction pathways of flavonols and structurally related model compounds with organic radicals formed in the radiolysis of ethanol and aqueous ethylene glycol and 2-methoxyethanol solutions. EXPERIMENTALThe figure summarizes the structural formulas of compounds used in this study. Commercial quercetin (more than 95% purity), rutin (more than 95% purity), morin (more than 95% purity), maltol (more than 98% purity), and kojic acid (more than 98% purity) from Aldrich were used without additional purification. Ethanol (96 vol %) was purified using Wolfen Zeosorb LA zeolite and distilled using a 3-m rectification column. 1 Ethylene glycol and 2-methoxyethanol were purified by double distillation. The purity of the substances was monitored by chromatography.Before dissolving samples, ethanol was sparged with high-purity argon (99.9%) for 50 min. All of the subsequent procedures up to sealing ampules with solutions were performed in an argon atmosphere.Ethylene glycol and 2-methoxyethanol solutions at a concentration of 3 mol/l were prepared with twicedistilled water, fresh solutions being used for each particular set of experiments. Required concentrations of additives in the resulting solutions were obtained by introducing weighed portions of test substances into the solutions. Oxygen was removed by five freezingpumping-thawing cycles. Next, the ampules were sealed under vacuum.The γ -radiation of 137 Cs was used as an initiator of free-radical processes in model systems. Irradiation was performed in sealed ampules (inner diameter, 6 mm; height, 40 mm; sample volume, 0.7 ml). The dose rate was 0.31 ± 0.01 Gy/s; the absorbed dose range 0.2-3.5 kGy was used.All of the data given were obtained by averaging the results of no less than three sets of experiments. The radiation-chemical yields of formation of substances were determined from the dose dependence of the buildup of these substances.The concentrations of acetaldehyde, 2,3-butanediol, and methano...

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Quinones as Free-radical Fragmentation Inhibitors in Biologically Important Molecules

Cited by 57 publications

References 24 publications

Redox regulation of mitochondrial functional activity by quinones

Redox regulation of mitochondrial functional activity by quinones

Copper (II) complexes of sterically hindered o-diphenol derivatives: synthesis, characterization and microbiological studies

Effect of flavonols on radiation-induced reactions with the participation of α-hydroxyl-containing organic radicals

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