Solvent effects on the nitrogen and β-hydrogen hyperfine splitting constants of aminoxyl radicals obtained in spin trapping experiments

1982 ◽  
Vol 60 (21) ◽  
pp. 2725-2733 ◽  
Author(s):  
Edward G. Janzen ◽  
Gregory A. Coulter ◽  
Uwe M. Oehler ◽  
John P. Bergsma
Keyword(s):  
Linear Relationship ◽  
Solvent Effects ◽  
Hyperfine Splitting ◽  
Spin Trapping ◽  
Tert Butyl ◽  
Aminoxyl Radicals ◽  
Structural Significance

The nitrogen and β-hydrogen hyperfine splitting constants (hfsc) for phenyl, 4-nitrophenyl, 4-pyridyl, benzoyl, and trichloromethyl spin adducts of α-phenyl tert-butyl nitrone (PBN) as well as for the tert-butoxyl adduct of 5,5-dimethylpyrroline-N-oxide (DMPO) have been obtained as a function of solvent (30 solvents). A useful linear relationship between the β-H hfsc and the N-hfsc of each aminoxyl is found except for the benzoyl adduct of PBN. Some speculations regarding the structural significance of these correlations is presented.

First Synthesis of C-Phenyl N-tert-Butyl [15N]nitrone (PBN-15N) for the EPR Spin Trapping Methodology

1996 ◽  
Vol 51 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Yong-Kang Zhang
Keyword(s):  
Hyperfine Splitting ◽  
Spin Trap ◽  
Spin Trapping ◽  
Paramagnetic Resonance ◽  
Tert Butyl ◽  
Hyperfine Splitting Constant ◽  
Percent Increase ◽  
Splitting Constant ◽  
Epr Spin Trapping ◽  
Electron Paramagnetic

As compared to normal PBN, about fifty percent increase of electron paramagnetic resonance (EPR) spin trapping sensitivity has been gained by using a new 100% 15N-enriched spin trap, C-phenyl N-tert-butyl[15N]nitrone (PBN-15N). PBN-15N has been prepared by a convenient four-step route using ammonium-15N chloride as the starting material. This synthetic method produces 2-methyl-2-[15N]nitropropane which is useful for the synthesis of many other PBN-15N type spin traps for the purpose of increasing spin trapping sensitivity. EPR spin trapping with PBN-15N in benzene and in phosphate buffer has been investigated. The 15N hyperfine splitting constant (15N-hfsc) is larger than 14N-hfsc by 40%. The larger 15N-hfsc gives more opportunity to identify different radical addends within the same system.

A comparative spin trapping study of the interaction of hypobromous and hypochlorous acids with tert-butyl hydroperoxide

BIOPHYSICS ◽  
2007 ◽  
Vol 52 (1) ◽  
pp. 1-7 ◽  
Author(s):  
A. V. Chekanov ◽  
A. N. Osipov ◽  
Yu. A. Vladimirov ◽  
V. I. Sergienko ◽  
O. M. Panasenko
Keyword(s):  
Spin Trapping ◽  
Butyl Hydroperoxide ◽  
Tert Butyl ◽  
Tert Butyl Hydroperoxide

Paraquat-induced lung injury: prevention by N-tert-butyl-alpha-phenylnitrone, a free-radical spin-trapping agent

1992 ◽  
Vol 262 (2) ◽  
pp. L147-L152
Author(s):  
T. Sata ◽  
E. Kubota ◽  
H. P. Misra ◽  
M. Mojarad ◽  
H. Pakbaz ◽  
...  
Keyword(s):  
Free Radical ◽  
Lung Injury ◽  
Guinea Pig ◽  
Weight Ratio ◽  
Spin Trapping ◽  
Lung Weight ◽  
Paramagnetic Resonance ◽  
Arterial Perfusion ◽  
Tert Butyl ◽  
Trapping Agent

The herbicide paraquat causes lung injury that is believed to be oxygen-radical mediated. To further characterize this injury and explore new methods of preventing it, we used the spin-trapping agent N-tert-butyl-alpha-phenylnitrone (PBN) to identify the paraquat radical in lung tissue and to reduce the injury resulting from the subsequent generation of reactive oxygen species. The formation of a paraquat free radical by guinea pig lung was detected under anaerobic conditions by electron paramagnetic resonance spectrometry. Infused (25, 50, or 100 mg/kg) into guinea pig lungs (perfused at constant flow with Krebs solution containing 4% bovine serum albumin and ventilated with 95% O2-5% CO2), paraquat produced dose-dependent increases in peak airway pressure (Paw), mean pulmonary arterial perfusion pressure (Ppa), and wet-to-dry (W/D) lung weight ratio. At 100 mg/kg, paraquat increased Paw by 589.6 +/- 59.8% (mean +/- SE, n = 8) and W/D ratio from 5.33 +/- 0.07 to 6.29 +/- 0.11 (P less than 0.001). Pulmonary vascular leak index increased from 0.40 +/- 0.09 to 1.96 +/- 0.45 (P less than 0.02), without changes in pulmonary microvascular pressure. Perfusate concentrations of thromboxane B2 and 6-ketoprostaglandin F1 alpha increased, but indomethacin did not reduce the injury. PBN (2.3 mM) markedly attenuated all evidence of lung injury, which was also reduced by catalase, mannitol, ethanol, and vitamin E.(ABSTRACT TRUNCATED AT 250 WORDS)

Nitrone spin trapping compound N-tert-butyl-α-phenylnitrone prevents seizures induced by anticholinesterases

1999 ◽  
Vol 850 (1-2) ◽  
pp. 63-72 ◽  
Author(s):  
Marko Zivin ◽  
Dejan Milatovic ◽  
Wolf-D Dettbarn
Keyword(s):  
Spin Trapping ◽  
Tert Butyl

Spin trapping of peroxy radicals by phenyl N-(tert-butyl) nitrone and methyl N-duryl nitrone

1983 ◽  
Vol 105 (6) ◽  
pp. 1498-1503 ◽  
Author(s):  
Etsuo Niki ◽  
Seiichi Yokoi ◽  
Jyunichi Tsuchiya ◽  
Yoshio Kamiya
Keyword(s):  
Spin Trapping ◽  
Peroxy Radicals ◽  
Tert Butyl

Quantitative Electron Paramagnetic Resonance: The Importance of Matching the Q-Factor of Standards and Samples

2001 ◽  
Vol 55 (10) ◽  
pp. 1375-1381 ◽  
Author(s):  
Richard L. Blakley ◽  
Dwight D. Henry ◽  
Walter T. Morgan ◽  
William L. Clapp ◽  
Carr J. Smith ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Free Radicals ◽  
Free Radical ◽  
Spin Trapping ◽  
Microwave Energy ◽  
Q Factor ◽  
Paramagnetic Resonance ◽  
Tert Butyl ◽  
Electron Paramagnetic ◽  
Stable Free Radicals

Electron paramagnetic resonance (EPR) quantification of free radicals from different samples facilitates comparison of free radical concentrations. Stable free radicals, such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), in a suitable solvent (e.g., benzene) can be used as a quantification standard. Free radicals found in samples can be shorter lived than radicals in prepared standards and require stabilizing spin-trapping agents such as N-tert-butyl-α-phenylnitrone (PBN) in an appropriate solvent (e.g., benzene). Analysis in our laboratory showed that free radicals from spin-trapped samples quantified against a standard of TEMPO in benzene displayed large differences among identical samples measured on either a Micro-Now 8300, Micro-Now 8400, or Bruker EMX EPR instrument. The Bruker instrument reported that the typical TEMPO in benzene standard had a Q-factor of ∼4400 while the Q-factor of our PBN-containing samples was ∼2500. (The Q-factor is inversely proportional to the amount of dissipated microwave energy in an EPR cavity.) By placing the TEMPO standard in a PBN/benzene solvent matrix we were able to match the Q-factor of our standards and samples, resulting in each of the three EPR instruments giving the same quantified free radical yields for the samples. This result points out the importance of matching the Q-factor between samples and standards for any quantitative EPR measurement.

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