Contributions of electron spin resonance spectroscopy to the study of vitamins C, E and K

Craw, M. T.; Depew, M. C.

doi:10.1007/bf03155990

Cited by 20 publications

(7 citation statements)

References 152 publications

(149 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…That radical is well characte¡ in liquid solution [10,11] and has a large hyperfine splitting of about 0.8 mT from the methyl protons. If present, such a large splitting would certainly be resolved in either the X-band or the 2 mm-band EPR spectra [34].…”

Section: Cation Radicalsmentioning

confidence: 99%

Characterization of free radicals from vitamin K1 and menadione by 2 mm-band EPR, ENDOR and ESEEM

et al. 1992

View full text Add to dashboard Cite

The anion and cation radicals of vitamin K 1 and its analog menadione were characterized using the magnetic resonance techniques of Electron Nuclear Double Resonance (ENDOR), Electron Spin Echo Envelope Modulation (ESEEM), and Electron Paramagnetic Resonance (EPR) at X-band and 2 mm-band. The g-factor anisotropy of the radicals at 2 mmband allow them to be distinguished from each other in the solid state. The g-factor matrix of the radical anion of vitamin K~ is virtually identicat with that reported for the reduced A~ acceptor in green plant photosystem I thus demonstrating that reduced A~ is the anion radical of vitamin K 1.

show abstract

Section: Cation Radicalsmentioning

confidence: 99%

Characterization of free radicals from vitamin K1 and menadione by 2 mm-band EPR, ENDOR and ESEEM

et al. 1992

View full text Add to dashboard Cite

show abstract

“…The oxidation of ascorbic acid has been and continues to be chemically and biologically significant because its electron redox property is a factor in its biological function [65,66]. The reduction of aminoxyl radicals by ascorbic acid has been studied by many investigators from a variety of viewpoints.…”

Section: Reaction With Ascorbic Acidmentioning

confidence: 99%

Electron transfer reactions of piperidine aminoxyl radicals

Zhang

Liu

2010

Chin. Sci. Bull.

View full text Add to dashboard Cite

This review article summarizes the electron transfer reactions of piperidine aminoxyl radicals. Electrochemical studies revealed the single electron transfer nature of piperidine aminoxyl radicals. In solution, piperidine aminoxyl radicals serve as single electron transfer oxidation reagent to react with various biologically interesting molecules such as glutathione, cysteine, ascorbic acid, and amines. The reaction product distribution, reaction kinetics, intermediates, and the reaction features in biological mimic environments including micelles and cyclodextrins were investigated. Oxoammonium salts, the one-electron transfer oxidation products of piperidine aminoxyl radicals, are agents of organic synthesis to selectively generate ketones or di-ketones from alcohols or ketones bearing α-methylene group under mild conditions. The new reactions of oxoammonium salts with aromatic amines, phenols, heterocycles including phenothiazines, papaverine, and bilirubin are also illustrated. aminoxyl radical, nitroxide, nitroxyl radical, iminoxyl radicals, oxoammonium salt, electron transfer, reduction and oxidation Citation:Zhang F, Liu Y C. Electron transfer reactions of piperidine aminoxyl radicals.

show abstract

“…Controversial results are also documented in literature concerning the kinetics and mechanism of the autoxidation of ascorbic acid [3,4,[41][42][43]. A most recent report [44] shows that the oxidation of ascorbate is solvent dependent.…”

Section: Ha-+a~2amentioning

confidence: 99%

“…0.07 gauss) was also observed. They suggest the structure 17 with the unpaired electron spreading over an extended conjugated tricarbonyl system, which has generally been accepted [3,4,30,31]. However, Sapper et al [32] argued that the assignment based on the splitting of 0.17 gauss for the triplet seems too large for the C-6 protons which are in the ~/-position of the radical center.…”

mentioning

confidence: 97%