Rate constant for reaction of hydroxyl radicals with bicarbonate ions

Buxton, George V.; Elliot, A. John

doi:10.1016/1359-0197(86)90059-7

Cited by 90 publications

(93 citation statements)

References 11 publications

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“…Accordingly, the pH dependence for radical production under our conditions did not correlate with superoxide radical anion production (Fig. 4) or with the reactivity of the hydroxyl radical toward the bicarbonate/carbonate anion (Reactions 7 and 8) (17,18), but rather, it correlated with the equilibrating concentration of carbon dioxide (Reactions 5 and 6). This result, a faster electron than proton transfer during XO turnover (8), and the recent NMR characterization of the peroxymonocarbonate anion in aqueous mixtures of bicarbonate/hydrogen peroxide (K ϭ 0.33) (28,29) argue for the mechanism shown in Fig.…”

Section: Production Of Carbonate Radical Anion Monitored By Spin Trapmentioning

confidence: 92%

“…This behavior further excludes the possibility that DHR oxidation is being mediated by carbonate radical anions produced through Fenton chemistry in the bulky solution. In this case, a higher oxidation rate would be expected at alkaline pH, because the hydroxyl radical reacts much faster with the carbonate (Reaction 8) than with bicarbonate anion (Reaction 7) (17,18).…”

Section: Production Of Radicals Monitored By Dhr Oxidation-dhrmentioning

confidence: 99%

“…Formation of this radical through Fenton chemistry was proposed to explain the low level chemiluminescence detected in incubations of acetaldehyde, XO, and bicarbonate at pH 10.2 (Reactions 1-9) (17,18 There has been a renewed interest in the pathophysiological roles of the carbonate radical anion since its direct EPR detection from flow mixtures of peroxynitrite with the bicarbonatecarbon dioxide pair in aqueous solutions at physiological pH (19). In addition to being considered an important mediator of peroxynitrite effects in vivo (reviewed in Refs.…”

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confidence: 99%

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Production of the Carbonate Radical Anion during Xanthine Oxidase Turnover in the Presence of Bicarbonate

Bonini¹,

Miyamoto²,

Mascio

et al. 2004

Journal of Biological Chemistry

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Xanthine oxidase is generally recognized as a key enzyme in purine catabolism, but its structural complexity, low substrate specificity, and specialized tissue distribution suggest other functions that remain to be fully identified. The potential of xanthine oxidase to generate superoxide radical anion, hydrogen peroxide, and peroxynitrite has been extensively explored in pathophysiological contexts. Here we demonstrate that xanthine oxidase turnover at physiological pH produces a strong one-electron oxidant, the carbonate radical anion. The radical was shown to be produced from acetaldehyde oxidation by xanthine oxidase in the presence of catalase and bicarbonate on the basis of several lines of evidence such as oxidation of both dihydrorhodamine 123 and 5,5-dimethyl-1-pyrroline-N-oxide and chemiluminescence and isotope labeling/mass spectrometry studies. In the case of xanthine oxidase acting upon xanthine and hypoxanthine as substrates, carbonate radical anion production was also evidenced by the oxidation of 5,5-dimethyl-1-pyrroline-N-oxide and of dihydrorhodamine 123 in the presence of uricase. The results indicated that Fenton chemistry occurring in the bulk solution is not necessary for carbonate radical anion production. Under the conditions employed, the radical was likely to be produced at the enzyme active site by reduction of a peroxymonocarbonate intermediate whose formation and reduction is facilitated by the many xanthine oxidase redox centers. In addition to indicating that the carbonate radical anion may be an important mediator of the pathophysiological effects of xanthine oxidase, the results emphasize the potential of the bicarbonate-carbon dioxide pair as a source of biological oxidants.

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Section: Production Of Carbonate Radical Anion Monitored By Spin Trapmentioning

confidence: 92%

Section: Production Of Radicals Monitored By Dhr Oxidation-dhrmentioning

confidence: 99%

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confidence: 99%

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Production of the Carbonate Radical Anion during Xanthine Oxidase Turnover in the Presence of Bicarbonate

Bonini¹,

Miyamoto²,

Mascio

et al. 2004

Journal of Biological Chemistry

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“…In case of hard water, OH radicals could react with bicarbonate ions to produce carbonate radicals, through the following reaction [23,24]: Being a highly oxidizing species, is known to be active in the oxidation of some organic compounds by direct electron transfer to produce the corresponding cation radical and carbonate anion [24]:…”

Section: Effect Of Reactive Speciesmentioning

confidence: 99%

Mechanism of Calcium Ion Precipitation from Hard Water Using Pulsed Spark Discharges

Yang

Kim

Starikovskiy

et al. 2010

Plasma Chem Plasma Process

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Direct pulsed spark discharge treatment was found to be able to induce the precipitation of calcium ions in supersaturated hard water (Yang et al. in Water Res 44:3659, 2010). The present study investigated possible pathways for the plasma-induced precipitation. Both UV and reactive species were found not the major factors that stimulate the precipitation in present setup. A transient hot-wire method was used to investigate the effect of plasma-induced local micro-heating. Approximately 15% drop in the calcium-ion concentration was observed, indicating that the local micro-heating effect could be the major contributing factor. Additionally, a nanosecond pulsed corona discharge was used to investigate the non-thermal effect of plasma, and a maximum 7% drop in the calcium hardness was observed. Calcite with rhombohedron morphology was observed in both cases, similar to the structure observed in the spark discharge treatment case, indicating that calcium-ion precipitation process could be attributed to both the thermal and nonthermal effects produced by the plasma.

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“…The CO 3 ÀÁ radical can be generated by oxidation of HCO 3 À with sulfate radical anion (SO 4 ÀÁ ) which can be obtained by photodissociation of persulphate anions [39] and through a number of other mechanisms including one-electron oxidation of HCO 3 À at the active site of Cu-Zn superoxide dismutase [40,41]. The rate constants of oxidation of CO 2À 3 and HCO 3 À by OHÁ are appreciably lower than those of the reactions of OHÁ with most biomolecules [42]. It has been observed that CO 3…”

Section: Introductionmentioning

confidence: 96%

Quantum theoretical study of mechanism of the reaction between guanine radical cation and carbonate radical anion: Formation of 8‐oxoguanine

Yadav¹,

Mishra²

2011

Int J of Quantum Chemistry

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ABSTRACT:The reaction between guanine radical cation (G þÁ ) and carbonate radical anion (CO 3 ÀÁ ) producing the mutagenic product 8-oxoguanine that has been observed experimentally was investigated using density functional and second-order Møller-Plesset perturbation (MP2) theories. The structures of reactant, intermediate, and product complexes as well as those of the transition states were fully optimized at the B3LYP/6-31G**, B3LYP/AUG-cc-pVDZ, and BHandHLYP/AUG-cc-pVDZ levels of density functional theory in gas phase. Single point energy calculations were performed at the MP2/AUG-cc-pVDZ level using the BHandHLYP/AUG-cc-pVDZ level gas-phase optimized geometries. To obtain the equivalent solvent that would approximately represent the complex medium used in the experimental study, bulk solvent effect on the stability of the reactant complex was studied by single point energy calculations in various solvent media (toluene, chlorobenzene, dichloroethane, acetone dimethylsulfoxide, and water) using the polarizable continuum model. Thus, chlorobenzene was found to represent the experimental medium fairly closely. The calculated Gibbs free barrier and released energies show that the reaction under consideration would occur efficiently. V

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Rate constant for reaction of hydroxyl radicals with bicarbonate ions

Cited by 90 publications

References 11 publications

Production of the Carbonate Radical Anion during Xanthine Oxidase Turnover in the Presence of Bicarbonate

Production of the Carbonate Radical Anion during Xanthine Oxidase Turnover in the Presence of Bicarbonate

Mechanism of Calcium Ion Precipitation from Hard Water Using Pulsed Spark Discharges

Quantum theoretical study of mechanism of the reaction between guanine radical cation and carbonate radical anion: Formation of 8‐oxoguanine

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