Electron paramagnetic resonance spin trapping

Connor, H.D., Gao, W., Nukina, S., Lemasters, J.J., Mason, R.P. and Thurman, KG. (1992). Evidence that free radicals are involved in graft failure following orthotopic liver transplantation in the rat an electron paramagnetic resonance spin trapping study. Transplantation 54, 199-204. 

Buettner, G. R., KeUey, E. E., and Bums, C. P., 1993, Membrane hpid free radicals produced from LI 210 murine leukemia ceUs by photofrin photosensitization an electron paramagnetic resonance spin trapping study. Cancer Res. S3 3670-3673. 

Under this approaeh, one of the biggest question is if the reaction (19) is not to slow to compete with the reaetion (18). On the other hand, Fe appears to be a weaker oxidant than OH radieal Koppenol and Liebman 1984 Rahhal and Richter 1988). Experimental evidences (using the electron paramagnetic resonance spin-trapping method) have shown the existence of several intermediated oxidant in the Fenton proeess, like OH bound OH and high-valence iron speeies Yamazaki and Piette 1991 De Laat and Gallard 1999 Gallard and De Laat 2001). 

Pietraforte et al. (1994) have recently examined the effect of gpl20 envelope protein from HIV-1 on NO induction in human M, using electron paramagnetic resonance spin trapping and NOl production. They detected a two- to threefold increase in NOi over control values within 15 hr. Dexamethasone sensitivity suggested that this was iNOS mediated. Interestingly, it was not CD4 mediated, suggesting an interaction of virus with immune cells unique from that described for infection (Pietraforte et al., 1994). 

Karlsson, J., Emgard, M., Brandin, P., and Burkitt, M.J., tra 5-Resveratrol protects embryonic mesencephalic cells from tert-butyl hydroperoxide electron paramagnetic resonance spin trapping evidence for a radical scavenging mechanism, J. Neurochem., 75 (1), 141-150,2000. 

Singlet oxygen adds to the double bonds of unsaturated fatty acids producing lipid hydroperoxides. Schafer and Buettner (2000) used electron paramagnetic resonance spin trapping with a-(4-pyridyl-1-oxide) AT-terf-butylnitrone to detect lipid-derived radical formation from HL-60 human leukaemia cells. Free radical formation increased with increasing iron concentration in the absence of ex-... 

Yang 1981). Support for the theory of alkyl radical transfer was provided by Ortiz de Monellano et al. (1983) who used the electronic paramagnetic resonance spin-trapping technique to detect the 2-phenylethyl radical formed during microsomal biotransformation of phenelzine. Production of the a-(4-pyridyl 1 -oxide)-N-ferf-butylnitrone/2-phenyl-ethyl radical adduct was dependent on the presence of active microsomes, phenelzine, NADPH (or NADH), and spin trap a-(4-pyridyl l-oxide)-N-ferf-butylnitrone (Ortiz de Monellano et al. 1983). The addition of catalase and superoxide dismutase resulted in a 28.5 and 24 % decrease in radical production, respectively (Rumyantseva et al. 1991). The concentration of the a-(4-pyridyl l-oxide)-N-ferf-butylnitrone/2-phenylethyl radical adduct decreased significantly in the presence of metal chelators, i.e. EDTA, diethylenetriaminepentaacetic acid (DTPA), or deferoxamine mesylate. 

Kolberg M, Bleifuss G, Sjdberg B-M, Graslund A, Lubitz W, Lendzian F, Lassmann G. 2002. Generation and electron paramagnetic resonance spin trapping detection of thiyl radicals in model proteins and in the R1 subunit of Escherichia coli ribonucleotide reductase. Arch Biochem Biophys 397 57-68. 

Registration of ROS was carried out by electron paramagnetic resonance (EPR) technique using spin trap l-hydroxy-2,2,6,6-tetramethyl-piperidine-4-OH (2 x 10 3 M). EPR spectra in the samples were registered at room temperature in quartz cuvette with the volume of 200 pi (Burlaka et al., 1994). 

Panchenko, A., Dilger, H., Kerres, J., Hein, M., Ullrich, A., Kaz, T. and Roduner, E. 2004. In situ spin trap electron paramagnetic resonance study of fuel ceU processes. Physical Chemistry Chemical Physics 6 2891-2894. 

Cheletrophic spin trapping of nitric oxide. Ultraviolet light converts the phenolic compound to a biradical, which rapidly reacts with nitric oxide to form a stable nitroxyl radical that is readily observable by electron paramagnetic resonance. 

Kochany and Bolton (1992) studied the primary rate constants of the reactions of hydroxyl radicals, benzene, and some of its halo derivatives based on spin trapping using detection by electron paramagnetic resonance (EPR) spectroscopy. The competitive kinetic scheme and the relative initial slopes or signal amplitudes were used to deduce the kinetic model. Based on a previously published rate constant (4.3 x 109 M 1 s ) in the pH range of 6.5 to 10.0 for the reaction of hydroxyl radicals with the spin trap compound 5,5 -d i methy I pyrro I i ne N-oxide (DMPO), rate constants for the reaction of hydroxyl radicals with benzene and its halo derivatives were determined. 

Jin F, Leitich J, von Sonntag C (1993) The superoxide radical reacts with tyrosine-derived phenoxyl radicals by addition rather than by electron transfer. J Chem Soc Perkin Trans 2 1583-1588 Jones CM, Lawrence A, Wardman P, Burkitt MJ (2002) Electron paramagnetic resonance with spin trapping investigation into the kinetics of glutathione oxidation by the superoxide radical re-evaluation of the rate constant. Free Rad Biol Med 32 982-900 Jones CM, Lawrence A, Wardman P, Burkitt MJ (2003) Kinetics of superoxide scavenging by glutathione an evaluation of its role in the removal of mitochondrial superoxide. Biochem Soc Trans 31 1337-1339... 

Hildenbrand K (1995) Spin-trapping studies of the reaction of the sulfate radical ion with N1-substituted pyrimidine bases. Comparison with continuous-flow electron paramagnetic resonance experiments.) Chem Soc Perkin Trans 2 2153-2162 Hildenbrand K, Schulte-Frohlinde D (1997) Time-resolved EPR studies on the reaction rates of per-oxyl radicals of polyfacrylic acid) and of calf thymus DNA with glutathione. Re-examination of a rate constant for DNA. Int J Radiat Biol 71 377-385 Hildenbrand K, Behrens G, Schulte-Frohlinde D, Herak JN (1989) Comparison of the reaction OH and S04- radicals with pyrimidine nucleosides. An electron spin resonance study in aqueous solution. J Chem Soc Perkin Trans 2 283-289... 

The electron paramagnetic resonance (EPR) spin-trapping technique was used to study the photochemical-, thermal-, and electrochemical-initiated decomposition of hydrogenated 1,2-diazocines 16 <1998MRC13>. 

The existence of free hydroxyl radicals in photo-initiated AOPs can be proven by applying a well-established method, the so-called spin trapping technique. The diamagnetic spin trap 5,5 -dimethyl-1-pyrroline N-oxide (DMPO) forms a stable paramagnetic spin-adduct with OH radicals. Its formation can be detected by electron paramagnetic resonance (EPR) spectroscopy. The underlying chemistry of... 

The presence of hydroxylated compounds as reaction intermediates and the detection of hydroxyl radicals through electron spin resonance (ESR) technique lead to the conclusion that in many cases the oxidations are via HO jg-attack (Turchi and Ollis, 1989 1990). Other studies also report the detection of hydroxyl radicals with various techniques such as spin trapping with electron paramagnetic resonance (EPR) (Riegel and Bolton,... 

UV-induced skin carcinogenesis by azthioprine (216), photochemical interaction between triamterene and hydrochlorthiazide (217) photochemistry of diclofenac (218), kinetic treatment of photochemical reactions (219) and a direct electron paramagnetic resonance (EPR) and spin-trapping study of light-induced free radicals from 6-mercaptopurine and its oxidation products (220). 

The elegant work of Riesz and coUaborators used electron paramagnetic resonance with chemical spin-traps to demonstrate... 

---