Spin Trapping: ESR parameters of spin adducts 1474 1528V

Buettner, Garry R.

doi:10.1016/s0891-5849(87)80033-3

Cited by 1,672 publications

(1,049 citation statements)

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“…The predominant spin adduct formed ( fig.2B) consists of a triplet of doublets and can be computer-simulated using hyperfine coupling constants, ON = 1.58 mT, a& = 2.28 mT ( fig.ZC). These spectral parameters are consistent with those previously reported for DMPO-hydroxyethyl radical formed following the reaction of 'OH with ethanol [23]. Although at the concentration of ethanol used all 'OH formed should react with this reagent, the additional ESR lines observed in fig.2B show that a small fraction of DMPO-OH is also formed.…”

Section: Resultssupporting

confidence: 91%

“…Reducing the instrument scan range from 2000 G to 100 G and the modulation amplitude from 10 G to 0.5 G, these additional 4 lines become well resolved into the 1:2:2:1 pattern shown in fig.lB. This ESR spectrum with hyperfine coupling constants, ON = a& = 1.49 mT, corresponds to the DMPO-OH spin adduct [23]. Since DMPO-OH may be formed by pathways other than the direct addition of 'OH to DMPO, an experiment was done reacting vanadyl sulfate (1 x 10m3 M) with Hz02 (1 x 10m3 M) in the presence of D,L-histidine (1 x 10-2 M) and the spin trap MNP (1 x 10e2 M) in order to verify the generation of 'OH.…”

Section: Resultsmentioning

confidence: 89%

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Vanadyl‐induced Fenton‐like reaction in RNA

Carmichael¹

1990

FEBS Letters

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Vanadyl (VO*+) complexed to RNA reacts with hydrogen peroxide in a Fenton-like manner producing hydroxyl radicals ('OH). The hydroxyl radicals can be spin trapped with $5dimethyl-1-pyrroline-l-oxide (DMPO) forming the DMPO-OH spin adduct. In addition, in the presence of ethanol the formation of the hydroxyethyl radical adduct of DMPO (DMPO-ETOH) confirms the production of hydroxyl radicals by the RNA/ VO*' complex. When the reaction between the RNA/VO*+ complex and H202 is carried out in the presence of the spin trap 2-methyL2nitrosopro-pane (MNP), radicals produced in the reaction of 'OH with RNA are trapped. Base hydrolysis of the MNP-RNA adducts (pH 12) followed by a reduction in the pH to pH 7 after hydrolysis is complete, yields an MNP adduct with a well-resolved ESR spectrum identical to the ESR spectrum obtained from analogous experiments with poly U. The ESR spectrum consists of a triplet of sextets (uN = 1.48 mT, a,8=0.25 mT and &=0.14 mT), indicating that the unpaired nitroxide electron interacts with the nuclei of a b-nitrogen and b-hydrogen. The results suggest that the 'OH generated in the RNA/V02+ reaction with H,Oz add to the C(5) carbon of uracil forming a C(6) carbon centered radical. This radical is subsequently spin trapped by MNP.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 89%

Vanadyl‐induced Fenton‐like reaction in RNA

Carmichael¹

1990

FEBS Letters

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“…2d). Even though these constants could be assigned to lipid radicals, spin trapping studies cannot readily distinguish between peroxyl (ROOÁ), alkoxyl (ROÁ) and alkyl (RÁ) adducts, owing to the similarity of the corresponding coupling constants (Buettner 1987).…”

Section: Lipid Radical Generation Of Isolated Liver ''Microsomes''mentioning

confidence: 99%

Effects of seasonal and latitudinal cold on oxidative stress parameters and activation of hypoxia inducible factor (HIF-1) in zoarcid fish

Heise

Estevez²,

Puntarulo³

et al. 2007

J Comp Physiol B

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Acute, short term cooling of North Sea eelpout Zoarces viviparus is associated with a reduction of tissue redox state and activation of hypoxia inducible factor (HIF-1) in the liver. The present study explores the response of HIF-1 to seasonal cold in Zoarces viviparus, and to latitudinal cold by comparing the eurythermal North Sea fish to stenothermal Antarctic eelpout (Pachycara brachycephalum). Hypoxic signalling (HIF-1 DNA binding activity) was studied in liver of summer and winter North Sea eelpout as well as of Antarctic eelpout at habitat temperature of 0°C and after long-term warming to 5°C. Biochemical parameters like tissue iron content, glutathione redox ratio, and oxidative stress indicators were analyzed to see whether the cellular redox state or reactive oxygen species formation and HIF activation in the fish correlate. HIF-1 DNA binding activity was significantly higher at cold temperature, both in the interspecific comparison, polar vs. temperate species, and when comparing winter and summer North Sea eelpout. Compared at the low acclimation temperatures (0°C for the polar and 6°C for the temperate eelpout) the polar fish showed lower levels of lipid peroxidation although the liver microsomal fraction turned out to be more susceptible to lipid radical formation. The level of radical scavenger, glutathione, was twofold higher in polar than in North Sea eelpout and also oxidised to over 50%. Under both conditions of cold exposure, latitudinal cold in the Antarctic and seasonal cold in the North Sea eelpout, the glutathione redox ratio was more oxidised when compared to the warmer condition. However, oxidative damage parameters (protein carbonyls and thiobarbituric acid reactive substances (TBARS) were elevated only during seasonal cold exposure in Z. viviparus. Obviously, Antarctic eelpout are keeping oxidative defence mechanisms high enough to avoid accumulation of oxidative damage products at low habitat temperature. The paper discusses how HIF could be instrumental in cold adaptation in fish.

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“…A major limitation of this technique is the inability to directly detect some highly reactive radical species with very short life (e.g. superoxide, hydroxyl radicals, sulfur centered radicals and alkoxyl radicals) [10]. Fortunately, this can be overcome through the use of spin traps, which are diamagnetic compounds (often nitrones or nitroso compounds) capable of yielding long-lived radical products upon reaction with free radicals [10].…”

Section: Introductionmentioning

confidence: 99%

“…superoxide, hydroxyl radicals, sulfur centered radicals and alkoxyl radicals) [10]. Fortunately, this can be overcome through the use of spin traps, which are diamagnetic compounds (often nitrones or nitroso compounds) capable of yielding long-lived radical products upon reaction with free radicals [10]. EPR spin trapping has been successfully used to elucidate many mechanistic questions [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Free radical generation induced by ultrasound in red wine and model wine: An EPR spin-trapping study

Zhang

Shen

Fan

et al. 2015

Ultrasonics Sonochemistry

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Direct evidence for the formation of 1-hydroxylethyl radicals by ultrasound in red wine and air-saturated model wine is presented in this paper. Free radicals are thought to be the key intermediates in the ultrasound processing of wine, but their nature has not been established yet. Electron paramagnetic resonance (EPR) spin trapping with 5,5-dimethyl-l-pyrrolin N-oxide (DMPO) was used for the detection of hydroxyl free radicals and 1-hydroxylethyl free radicals. Spin adducts of Hydroxyl free radicals were detected in DMPO aqueous solution after sonication while 1-hydroxylethyl free radical adducts were observed in ultrasound-processed red wine and model wine. The latter radical arose from ethanol oxidation via the hydroxyl radical generated by ultrasound in water, thus providing the first direct evidence of the formation of 1-hydroxylethyl free radical in red wine exposed to ultrasound. Finally, the effects of *Corresponding author. Tel.: +86 29 85310517; fax: + 86 29 85310517. E-mail address: qinganzhang@snnu.edu.cn (Q.A. Zhang). ultrasound frequency, ultrasound power, temperature and ultrasound exposure time were assessed on the intensity of 1-hydroxylethyl radical spin adducts in model wine.

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Spin Trapping: ESR parameters of spin adducts 1474 1528V

Cited by 1,672 publications

References 405 publications

Vanadyl‐induced Fenton‐like reaction in RNA

Vanadyl‐induced Fenton‐like reaction in RNA

Effects of seasonal and latitudinal cold on oxidative stress parameters and activation of hypoxia inducible factor (HIF-1) in zoarcid fish

Free radical generation induced by ultrasound in red wine and model wine: An EPR spin-trapping study

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