Effects of resveratrol and its analogs on scavenging hydroxyl radicals: Evaluation by EPR spin trapping method

2002 ◽  
Vol 22 (4) ◽  
pp. 475-481 ◽  
Author(s):  
M. Lu ◽  
J. -G. Fang ◽  
Z. -L. Liu ◽  
L. -M. Wu
Keyword(s):  
Hydroxyl Radicals ◽  
Spin Trapping ◽  
Trapping Method ◽  
Epr Spin Trapping

Kinetic model for formation of DMPO-OH in water under ultrasonic irradiation using EPR spin trapping method

2012 ◽  
Vol 38 (9) ◽  
pp. 2191-2204 ◽  
Author(s):  
Masaki Kubo ◽  
Kazuhiro Sekiguchi ◽  
Naomi Shibasaki-Kitakawa ◽  
Toshikuni Yonemoto
Keyword(s):  
Kinetic Model ◽  
Ultrasonic Irradiation ◽  
Spin Trapping ◽  
Trapping Method ◽  
Epr Spin Trapping

The photodegradation of model quinolone carboxylates in aqueous media

2014 ◽  
Vol 7 (1) ◽  
pp. 1-8
Author(s):  
Miroslava Bobeničová ◽  
Andrea Čaklóšová ◽  
Dana Dvoranová
Keyword(s):  
Titanium Dioxide ◽  
Hydroxyl Radicals ◽  
Aqueous Media ◽  
Spin Trapping ◽  
Alkaline Media ◽  
Uva Irradiation ◽  
Epr Spin Trapping ◽  
Photoinduced Processes

Abstract This work was focused on the study of photoinduced processes of quinolone carboxylates in the presence of titanium dioxide in an alkaline media. UVA irradiation without/with titanium dioxide caused the decomposition of molecules, with higher efficiency of degradation in the presence of titanium dioxide. EPR spin trapping experiments proved that investigated quinolone carboxylates behave as the efficient scavengers of hydroxyl radicals produced upon irradiation of aerated alkaline titanium dioxide systems.

scholarly journals EPR study of the production of oh radicals in aqueous solutions of uranium irradiated by ultraviolet light

2009 ◽  
Vol 74 (6) ◽  
pp. 651-661 ◽  
Author(s):  
Marko Dakovic ◽  
Milos Mojovic ◽  
Goran Bacic
Keyword(s):  
Aqueous Solutions ◽  
Hydroxyl Radicals ◽  
Fluorescence Decay ◽  
Uranyl Acetate ◽  
Oh Radicals ◽  
Solution Ph ◽  
Trapping Method ◽  
Wide Ph Range ◽  
Ph Range ◽  
Epr Spin Trapping

The aim of the study was to establish whether hydroxyl radicals (?OH) were produced in UV-irradiated aqueous solutions of uranyl salts. The production of ?OH was studied in uranyl acetate and nitrate solutions by an EPR spin trap method over a wide pH range, with variation of the uranium concentrations. The production of ?OH in uranyl solutions irradiated with UV was unequivocally demonstrated for the first time using the EPR spin-trapping method. The production of ?OH can be connected to speciation of uranium species in aqueous solutions, showing a complex dependence on the solution pH. When compared with the results of radiative de-excitation of excited uranyl (+22*UO ) by the quenching of its fluorescence, the present results indicate that the generation of hydroxyl radicals plays a major role in the fluorescence decay of + 22 *UO . The role of the presence of carbonates and counter ions pertinent to environmental conditions in biological systems on the production of hydroxyl radicals was also assessed in an attempt to reveal the mechanism of +22*UO de-excitation. Various mechanisms, including ?OH production, are inferred but the main point is that the generation of ?OH in uranium containing solutions must be considered when assessing uranium toxicity.

Investigating the DMPO-formate spin trapping method for the study of paper iron gall ink corrosion

2016 ◽  
Vol 40 (11) ◽  
pp. 9098-9110 ◽  
Author(s):  
Alice Gimat ◽  
Valeryia Kasneryk ◽  
Anne-Laurence Dupont ◽  
Sabrina Paris ◽  
Frédéric Averseng ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydroxyl Radicals ◽  
Reactive Oxygen ◽  
Spin Trapping ◽  
Oxygen Species ◽  
Paper Degradation ◽  
Trapping Method ◽  
Iron Gall

Reactive oxygen species evidenced in acidic iron gall inks are not hydroxyl radicals and are not linked to paper degradation.

scholarly journals Hydroxyl Radical Generation by the H2O2/CuII/Phenanthroline System under Both Neutral and Alkaline Conditions: An EPR/Spin-Trapping Investigation

2021 ◽  
Vol 11 (2) ◽  
pp. 687
Author(s):  
Elsa Walger ◽  
Nathalie Marlin ◽  
Gérard Mortha ◽  
Florian Molton ◽  
Carole Duboc
Keyword(s):  
Spin Trapping ◽  
Fenton Reagent ◽  
Pulp Bleaching ◽  
H2o2 Decomposition ◽  
Cellulosic Fibers ◽  
Neutral Ph ◽  
Trapping Method ◽  
Alkaline Conditions ◽  
Phenanthroline Complex ◽  
Epr Spin Trapping

The copper–phenanthroline complex CuI(Phen)2 was the first artificial nuclease studied in biology. The mechanism responsible for this activity involves CuII(Phen)2 and H2O2. Even if H2O2/Cu systems have been extensively studied in biology and oxidative chemistry, most of these studies were carried out at physiological pH only, and little information is available on the generation of radicals by the H2O2/CuII-Phen system. In the context of paper pulp bleaching to improve the bleaching ability of H2O2, this system has been investigated, mostly at alkaline pH, and more recently at near-neutral pH in the case of dyed cellulosic fibers. Hence, this paper aims at studying the production of radicals with the H2O2/CuII-Phen system at near-neutral and alkaline pHs. Using the EPR/spin-trapping method, HO• formation was monitored to understand the mechanisms involved. DMPO was used as a spin-trap to form DMPO–OH in the presence of HO•, and two HO• scavengers were compared to identify the origin of the observed DMPO–OH adduct, as nucleophilic addition of water onto DMPO leads to the same adduct. H2O2 decomposition was enhanced by the addition of CuII–Phen (and only slightly by addition of CuSO4), reaching a level similar to the Fenton reagent at near-neutral pH. This evidences the role of Phen, which improves the effect of CuII by tuning the electronic structure and structural properties of the corresponding CuII complexes.

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