Investigations on the antioxidant activity of fruit and vegetable aqueous extracts on superoxide radical anion using chemiluminescence techniques

2005 ◽  
Vol 536 (1-2) ◽  
pp. 101-105 ◽  
Author(s):  
T. Triantis ◽  
A. Stelakis ◽  
D. Dimotikali ◽  
K. Papadopoulos
Keyword(s):  
Antioxidant Activity ◽  
Radical Anion ◽  
Superoxide Radical ◽  
Aqueous Extracts ◽  
Fruit And Vegetable ◽  
Superoxide Radical Anion

scholarly journals Theoretical Study of the Iron Complexes with Aminoguanidine: Investigating Secondary Antioxidant Activity

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 756
Author(s):  
Guillermo García-Díez ◽  
Nelaine Mora-Diez
Keyword(s):  
Antioxidant Activity ◽  
Rate Constant ◽  
Thermodynamic Stability ◽  
Radical Anion ◽  
Superoxide Radical ◽  
Theoretical Study ◽  
Initial Step ◽  
Stable Complex ◽  
Oh Radicals ◽  
Superoxide Radical Anion

A thorough analysis of the thermodynamic stability of various complexes of aminoguanidine (AG) with Fe(III) at a physiological pH is presented. Moreover, the secondary antioxidant activity of AG is studied with respect to its kinetic role in the Fe(III) reduction to Fe(II) when reacting with the superoxide radical anion or ascorbate. Calculations are performed at the M05(SMD)/6-311+G(d,p) level of theory. Solvent effects (water) are taken into account in both geometry optimizations and frequency calculations employing the SMD solvation method. Even though the results of this study show that AG can form an extensive number of stable complexes with Fe(III), none of these can reduce the rate constant of the initial step of the Haber–Weiss cycle when the reducing agent is O2•−. However, when the reductant is the ascorbate anion, AG is capable of reducing the rate constant of this reaction significantly, to the point of inhibiting the production of •OH radicals. In fact, the most stable complex of Fe(III) with AG, having a ∆Gf° of −37.9 kcal/mol, can reduce the rate constant of this reaction by 7.9 × 105 times. Thus, AG possesses secondary antioxidant activity relative to the Fe(III)/Fe(II) reduction with ascorbate, but not with O2•−. Similar results have also been found for AG relative to the Cu(II)/Cu(I) reduction, in agreement with experimental results.

scholarly journals The redox properties and antiradical activity of terpenophenols

2019 ◽  
Vol 484 (5) ◽  
pp. 568-571
Author(s):  
M. A. Polovinkina ◽  
M. N. Kolyada ◽  
V. P. Osipova ◽  
N. T. Berberova ◽  
I. Yu. Chukicheva ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Radical Anion ◽  
Superoxide Radical ◽  
Antiradical Activity ◽  
Model System ◽  
Redox Properties ◽  
Superoxide Radical Anion ◽  
Transfer Processes ◽  
Electron Transfer Processes

The redox properties and antiradical activity of terpenophenols (2,6-diisobornyl-4-methylphenol and 3-isocamphyl-2-naphthol) in comparison with BHT (butylhydroxytoluol, 2,6-di-tret-butyl-4-methylphenol) have been studied. The terpenophenols have been shown to react more readily in electron transfer processes as compared with BHT, and they have been found to react with electrochemically generated superoxide radical anion (О2•–). The effect of the compounds on the rate of generation upon adrenaline oxidation in an alkaline medium and the ability of biopreparations based on Russian sturgeon liver and gonad homogenates to deactivate have been studied. Adrenaline oxidation inhibition and the increase in superoxide dismutation activity of the biopreparations in the presence of terpenophenols have been shown, and this fact can indicate the ability of these compounds to decrease the probability of oxidative stress enlargement. A correlation has been established between the redox properties and antioxidant activity of terpenophenols in the model system of adrenaline oxidation in the presence of the biopreparations.

N,N.N′,N′-tetramethylhydroethidine (TMHE) - in search for better probes for the detection of superoxide radical anion

2017 ◽  
Vol 108 ◽  
pp. S38
Author(s):  
Adam Sikora ◽  
Radosław Michalski ◽  
Micael Hardy ◽  
Olivier Ouari ◽  
Jan Adamus ◽  
...  
Keyword(s):  
Radical Anion ◽  
Superoxide Radical ◽  
Superoxide Radical Anion

scholarly journals Reactivity of Superoxide Radical Anion with Cyclic Nitrones:  Role of Intramolecular H-Bond and Electrostatic Effects

2007 ◽  
Vol 129 (26) ◽  
pp. 8177-8191 ◽  
Author(s):  
Frederick A. Villamena ◽  
Shijing Xia ◽  
John K. Merle ◽  
Robert Lauricella ◽  
Beatrice Tuccio ◽  
...  
Keyword(s):  
Radical Anion ◽  
Superoxide Radical ◽  
Electrostatic Effects ◽  
Superoxide Radical Anion ◽  
Cyclic Nitrones

Concerted double proton-transfer electron-transfer between catechol and superoxide radical anion

2017 ◽  
Vol 19 (38) ◽  
pp. 26179-26190 ◽  
Author(s):  
Jorge Quintero-Saumeth ◽  
David A. Rincón ◽  
Markus Doerr ◽  
Martha C. Daza
Keyword(s):  
Electron Transfer ◽  
Proton Transfer ◽  
Superoxide Anion ◽  
Radical Anion ◽  
Reaction Rate ◽  
Superoxide Radical ◽  
Superoxide Radical Anion ◽  
Double Proton Transfer

Catechol reacts with a superoxide anion via concerted double proton-transfer electron-transfer with a reaction rate that is dominated by tunneling.

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