A Theoretical Study of Spin Trapping by Nitrone: Trapping of Hydrogen, Methyl, Hydroxyl, and Peroxyl Radicals

1994 ◽  
Vol 98 (45) ◽  
pp. 11705-11713 ◽  
Author(s):  
Susan L. Boyd ◽  
Russell J. Boyd
Keyword(s):  
Theoretical Study ◽  
Spin Trapping ◽  
Peroxyl Radicals

Theoretical study on the oxidative damage to cholesterol induced by peroxyl radicals

2015 ◽  
Vol 28 (7) ◽  
pp. 504-508 ◽  
Author(s):  
Manuel E. Medina ◽  
Annia Galano ◽  
Ángel Trigos
Keyword(s):  
Oxidative Damage ◽  
Theoretical Study ◽  
Peroxyl Radicals

Lyoluminescence and spin trapping

1982 ◽  
Vol 60 (12) ◽  
pp. 1549-1559 ◽  
Author(s):  
Kamil V Ettinger ◽  
Alexander R Forrester ◽  
Charles H Hunter
Keyword(s):  
Spin Trap ◽  
Light Yield ◽  
Spin Trapping ◽  
Water Soluble ◽  
Peroxyl Radicals ◽  
Nitroso Compounds ◽  
Γ Irradiation ◽  
Alkyl Radicals ◽  
Emitting Species ◽  
Aromatic Nitroso Compounds

The chemical origin of lyoluminescence has been probed using spin trapping techniques. Radicals derived from amino acids and saccharides by γ-irradiation in the solid state have been identified after trapping with aliphatic and aromatic nitroso compounds. Most of the radicals trapped were secondary alkyl radicals. Reaction of peroxyl radicals derived therefrom are thought to produce the emitting species (excited carbonyl compound and/or singlet oxygen). The effect which thermal annealing of the solids after γ-irradiation has on (a) the concentration of radicals in the solid, (b) the concentration of trapped radicals, and (c) the light yield has been investigated. One new water-soluble spin trap has been prepared.

The β-carotene dilemma: ESR study with coordinated peroxyl radicals

2006 ◽  
Vol 60 (3) ◽  
Author(s):  
A. Tkáč ◽  
G. Scott
Keyword(s):  
Vitamin E ◽  
Peroxyl Radical ◽  
Cell Damage ◽  
Transition Metal Ions ◽  
Spin Trapping ◽  
Peroxyl Radicals ◽  
Polar Solvents ◽  
Primary Attack ◽  
Peroxy Group ◽  
Β Carotene

AbstractThe apparently unpredictable behaviour of β-carotene in the supplementation of the diet of smokers is discussed in the light of the reactions of peroxyl radicals with β-carotene in the absence of oxygen. The decay of tert-butylperoxyl radicals in the presence of β-carotene was studied at ambient temperature in non-polar solvents by ESR spectroscopy. The primary reaction in the absence of oxygen is interpreted as a spin-trapping effect of a peroxyl radical by β-carotene producing an intermediate labile free radical, which disappears after recombination with a second tert-butylperoxyl radical. The result is the transformation of β-carotene to a diamagnetic compound with two peroxy bonds. In the presence of chelating transition metals with unpaired d-electrons as electron donors the peroxy group of the oxidized β-carotene can be split to alkoxyl free radicals. The primary attack of tert-butylperoxyl radicals is completely inhibited in the presence of vitamin E followed by production of free aryloxy radicals and the presence of oxygen has no significant effect on this reaction. Spin-trapping of peroxyl radicals by the double bond of vitamin A leads to its oxidation in the absence of vitamin E.Transition metal ions such as Co, Cr, Fe, and Mn, known to be present in the aerosol of cigarette smoke, homolyse the peroxyl bonds of peroxidised β-carotene, which results in cell damage.

scholarly journals Studies on the photolytic breakdown of hydroperoxides and peroxidized fatty acids by using electron spin resonance spectroscopy. Spin trapping of alkoxyl and peroxyl radicals in organic solvents

1986 ◽  
Vol 240 (3) ◽  
pp. 789-795 ◽  
Author(s):  
M J Davies ◽  
T F Slater
Keyword(s):  
Fatty Acids ◽  
Spin Trap ◽  
Hydrogen Abstraction ◽  
Spin Trapping ◽  
Ring Closure ◽  
Peroxyl Radicals ◽  
Resonance Spectroscopy ◽  
Oxygen Oxygen ◽  
Low Levels ◽  
Trap Radical

Spin trapping using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) has been used to detect and distinguish between the carbon-centred, alkoxyl, and peroxyl radicals produced during the photolytic decomposition of hydroperoxides. Photolysis of tert-butyl and cumene hydroperoxides, and peroxidized fatty acids, in toluene, with low levels of u.v. light, is shown to lead to the initial production of alkoxyl radicals by homolysis of the oxygen-oxygen bond. Subsequent reaction of these radicals with excess hydroperoxide leads, by hydrogen abstraction, to the production of peroxyl radicals that can be detected as their corresponding adducts with the spin trap. Subsequent breakdown of these adducts produces alkoxyl radicals and a further species that is believed to be the oxidized spin-trap radical 5,5-dimethyl-1-pyrrolidone-2-oxyl. No evidence was obtained at low hydroperoxide concentrations, with either the cumene or lipid alkoxyl radicals, for the occurrence of beta-scission reactions; the production of low levels of carbon-centred radicals is believed to be due to the alternative reactions of hydrogen abstraction, ring closure, and/or 1,2 hydrogen shifts. Analogous experiments with 3,3,5,5-tetramethyl-1-pyrroline N-oxide (TMPO) led only to the trapping of alkoxyl radicals with no evidence for peroxyl radical adducts, this is presumably due to a decreased rate of radical addition because of increased steric hindrance.

Spin Trapping Studies of Peroxyl Radicals. Detection of the Reactive Intermediates for Oxidation Generated from O2−•and Sulfonyl, Sulfinyl, and Phosphoryl Chlorides

1989 ◽  
Vol 18 (1) ◽  
pp. 167-170 ◽  
Author(s):  
Yong Hae Kim ◽  
Sang Chul Lim ◽  
Mikio Hoshino ◽  
Yasuo Ohtsuka ◽  
Takeshi Ohishi
Keyword(s):  
Reactive Intermediates ◽  
Spin Trapping ◽  
Peroxyl Radicals
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