On spin trapping hydroxyl and hydroperoxyl radicals

Abstract

. Can. J. Chem. 56,2237Chem. 56, (1978.The assignments of the hydroxyl, hydroperoxyl, and alkylperoxyl radical spin adducts of a-phenyl N-tert-butyl nitrone (PBN) are discussed. Results of new experiments designed to test the assignments of the first two are described. It is concluded that the hydroxy adduct assignment is correct. The relationship between upH and a N is This equation gives a good fit for the seven pairs of constants reported for the hydroxy adduct.

Characterization of Free Radical Spin Adducts of 5-Diisopropyloxy-Phosphoryl-5-Methyl-1-Pyrroline-N-Oxide Using Mass Spectrometry and 31P Nuclear Magnetic Resonance

“…the mass spectra were assigned, on the basis of their m/z value, to the nitrone and the hydroxylamine, respectively, formed by oxidation, reduction and/or dismutation from the initial nitroxide spin adduct. therefore, the mass spectrum reported in figure 5 2 . other peaks at m/z 105 and m/z 77 could be assigned as fragments containing the aromatic ring.…”

“…[1][2][3][4] During this technique, a highly reactive free radical typically reacts with a double bond of a diamagnetic compound (the spin trap) to form a more stable radical (the spin adduct) which can be detected by EPr spectrometry. [5][6][7][8][9] Nitrones are the most frequently used compounds as spin trapping agents, and the spin adducts being, in this case, a nitroxide.…”

Oxygen-radical-mediated effects of the toxic phytoplankter Heterosigma carterae on juvenile rainbow trout Oncorhynchus mykiss

“…The generation of hydroxyl radicals in Heterosigma carterae suspension was measured by electron spin resonance (ESR) trapping. Janzen et al (1978) reported that hydroxyl radical reacts with a spin trap, 5,5-dimethyl-l-pyrroline-N-oxide (DMPO, Sigma), to yield a DMPO-OH signal (aN = aH = 1.48 mT). A mixture of algal suspension (4.3 x 104 cells ml-l) and diethylenetriaminepen- Bioassay for protection of yearling rainbow trout from toxic Heterosigma carterae cells b y catalase or catalase plus SOD.…”

Solid-state Spin Trapping of the Hydroxyl Radical Formed by Gamma-irradiation in Ice and the Scavenging Effect of Sodiuml-Ascorbate

“…The spectra were measured at room temperature as a function of the time after melting. In the spectrum at 5 min, the strong four-line absorption pattern wit.h ~n intensity ratio of 1 : 2: 2: I and a 1.48 mT hyperfine splIttIng constant is definitely assignable to DMPO-OH 10) showing that DMPO-OH was formed and lived long eno~gh for ESR measurements. This result, therefore, means that trapping the OH radical with DMPO was possible even in the frozen state.…”