Investigation of spin-trapping artifacts formed by the Forrester-Hepburn mechanism

Leinisch, Fabian; Jiang, Jiansheng; DeRose, Eugene F.; Khramtsov, Valery V.; Mason, Ronald P.

doi:10.1016/j.freeradbiomed.2013.07.006

Cited by 26 publications

(13 citation statements)

References 38 publications

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“…Moreover, the intensity of DMPO–OH signal did not weaken at all in the presence of excessive TBA as the scavenger for • OH (Figure b), while that in the Fenton process was remarkably suppressed under comparable conditions but with much lower concentration of TBA (Figure S17). These results collectively suggested that the observed DMPO–OH signal should not be arbitrarily attributed to • OH but to an artifact spin trap that has been widely recognized. , …”

Section: Resultsmentioning

confidence: 65%

Unraveling the Overlooked Involvement of High-Valent Cobalt-Oxo Species Generated from the Cobalt(II)-Activated Peroxymonosulfate Process

Zong

Guan

et al. 2020

Environ. Sci. Technol.

417

191

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Sulfate radical (SO 4•− ) is widely recognized as the predominant species generated from the cobalt(II)-activated peroxymonosulfate (PMS) process. However, in this study, it was surprisingly found that methyl phenyl sulfoxide (PMSO) was readily oxidized to the corresponding sulfone (PMSO 2 ) with a transformation ratio of ∼100% under acidic conditions, which strongly implied the generation of highvalent cobalt-oxo species [Co(IV)] instead of SO 4•− in the Co(II)/PMS process. Scavenging experiments using methanol (MeOH), tert-butyl alcohol, and dimethyl sulfoxide further suggested the negligible role of SO 4•− and hydroxyl radical ( • OH) but favored the generation of Co(IV). By employing 18 O isotope-labeling technique, the formation of Co(IV) was conclusively verified and the oxygen atom exchange reaction between Co(IV) and H 2 O was revealed. Density functional theory calculation determined that the formation of Co(IV) was thermodynamically favorable than that of SO 4•− and • OH in the Co(II)/PMS process. The generated Co(IV) species was indicated to be highly reactive due to the existence of oxo-wall and capable of oxidizing the organic pollutant that is rather recalcitrant to SO 4•− attack, for example, nitrobenzene. Additionally, the degradation intermediates of sulfamethoxazole (SMX) in the Co(II)/PMS process under acidic conditions were identified to further understand the interaction between Co(IV) and the representative contaminant. The developed kinetic model successfully simulated PMSO loss, PMSO 2 production, SMX degradation, and/or PMS decomposition under varying conditions, which further supported the proposed mechanism. This study might shed new light on the Co(II)/PMS process.• OH-mediated pathways (eqs e and f). 15−17

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Section: Resultsmentioning

confidence: 65%

Unraveling the Overlooked Involvement of High-Valent Cobalt-Oxo Species Generated from the Cobalt(II)-Activated Peroxymonosulfate Process

Zong

Guan

et al. 2020

Environ. Sci. Technol.

417

191

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“…5.2 ). Since its first application to biological systems in 1979, important contributions have been made to improve spin trap structures based on mechanistic analysis of the spin trapping reaction and of the spin adduct decomposition pathways [362] , [363] , but also to improve the methodology by characterizing its limitations, artefacts, and sources of misinterpretations [364] , [365] , [366] , [367] , [368] . Intracellular detection and quantification are not straightforward, and in vivo detection of O 2 •- is impossible with spin traps coupled to EPR.…”

Section: Optimizing Ros Detection Using Epr or Fluorescence: In Vivo mentioning

confidence: 99%

European contribution to the study of ROS: A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)

et al. 2017

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The European Cooperation in Science and Technology (COST) provides an ideal framework to establish multi-disciplinary research networks. COST Action BM1203 (EU-ROS) represents a consortium of researchers from different disciplines who are dedicated to providing new insights and tools for better understanding redox biology and medicine and, in the long run, to finding new therapeutic strategies to target dysregulated redox processes in various diseases. This report highlights the major achievements of EU-ROS as well as research updates and new perspectives arising from its members. The EU-ROS consortium comprised more than 140 active members who worked together for four years on the topics briefly described below. The formation of reactive oxygen and nitrogen species (RONS) is an established hallmark of our aerobic environment and metabolism but RONS also act as messengers via redox regulation of essential cellular processes. The fact that many diseases have been found to be associated with oxidative stress established the theory of oxidative stress as a trigger of diseases that can be corrected by antioxidant therapy. However, while experimental studies support this thesis, clinical studies still generate controversial results, due to complex pathophysiology of oxidative stress in humans. For future improvement of antioxidant therapy and better understanding of redox-associated disease progression detailed knowledge on the sources and targets of RONS formation and discrimination of their detrimental or beneficial roles is required. In order to advance this important area of biology and medicine, highly synergistic approaches combining a variety of diverse and contrasting disciplines are needed.

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“…It is essential that spin trap solutions are free of contamination by hydroxylamine and nitroxide impurities that can impair O2 •-detection and give artifacts. Contaminating hydroxylamines can be tested by treatment with ferricyanide which converts them to EPR-visible nitroxides [62]. Most commercially available DMPO contains paramagnetic impurities.…”

Section: Spin Trap Stock Solutionsmentioning

confidence: 99%

“…Timmins et al proposed a technique involving pre-incubation with isotopically labeled spin traps to identify such artifacts [106]. This was further refined by Leinisch et al [62,107] and completed by auxiliary experiments by Ranguelova et al [98].…”

Section: False Positivesmentioning

confidence: 99%

Use of spin traps to detect superoxide production in living cells by electron paramagnetic resonance (EPR) spectroscopy

Abbas

Babić

Peyrot

2016

Methods

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Detection of superoxide produced by living cells has been an on-going challenge in biology for over forty years. Various methods have been proposed to address this issue, among which spin trapping with cyclic nitrones coupled to EPR spectroscopy, the gold standard for detection of radicals. This technique is based on the nucleophilic addition of superoxide to a diamagnetic cyclic nitrone, referred to as the spin trap, and the formation of a spin adduct, i.e. a persistent radical with a characteristic EPR spectrum. The first application of spin trapping to living cells dates back 1979. Since then, considerable improvements of the method have been achieved both in the structures of the spin traps, the EPR methodology, and the design of the experiments including appropriate controls. Here, we will concentrate on technical aspects of the spin trapping/EPR technique, delineating recent breakthroughs, inherent limitations, and potential artifacts.

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Investigation of spin-trapping artifacts formed by the Forrester-Hepburn mechanism

Cited by 26 publications

References 38 publications

Unraveling the Overlooked Involvement of High-Valent Cobalt-Oxo Species Generated from the Cobalt(II)-Activated Peroxymonosulfate Process

Unraveling the Overlooked Involvement of High-Valent Cobalt-Oxo Species Generated from the Cobalt(II)-Activated Peroxymonosulfate Process

European contribution to the study of ROS: A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)

Use of spin traps to detect superoxide production in living cells by electron paramagnetic resonance (EPR) spectroscopy

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