Spin trapping using 2,2-dimethyl-2H-imidazole-1-oxides.
The ability of novel cyclic nitrones, 4-substituted 2,2-dimethyl-2H-imidazole-1-oxides (IMO's) to trap a variety of short-lived free radicals has been investigated using ESR spectroscopy. IMO's scavenge oxygen-, carbon- and sulfur-derived free radicals to give persistent nitroxides. Compared to the spin trap 5,5-dimethyl-pyrroline-1-oxide, a higher lifetime of hydroxyl radical adducts and a higher selectivity related to the trapping of carbon-centered radicals was found. A reaction between IMO's and superoxide was not observed. ESR parameters of 4-carboxyl-2,2-dimethyl-2H-imidazole-1-oxide (CIMO) spin adducts are highly sensitive to the structure of the trapped radical, e.g., different spectra were detected with radicals derived from Na2SO3 and NaHSO3. From the data obtained, a successful application of these new spin traps in biological systems can be expected.
Research Institute of Molecular Pharmacology, Berlin, Germany.
E
E
Klauschenz
R F
RF
Haseloff
L B
LB
Volodarskii
I E
IE
Blasig
D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005609:Free Radicals; D006735:Horseradish Peroxidase / Q000378:metabolism; D017665:Hydroxyl Radical; D007093:Imidazoles; D015394:Molecular Structure; D013113:Spin Labels / Q000138:chemical synthesis; D013329:Structure-Activity Relationship; D013481:Superoxides
D003497:Cyclic N-Oxides; D005609:Free Radicals; D007093:Imidazoles; D013113:Spin Labels; D013481:Superoxides; D017665:Hydroxyl Radical; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D006735:Horseradish Peroxidase