Nitric oxide release from the unimolecular decomposition of the superoxide radical anion adduct of cyclic nitrones in aqueous medium

2005 ◽  
Vol 3 (17) ◽  
pp. 3220 ◽  
Author(s):  
Edward J. Locigno ◽  
Jay L. Zweier ◽  
Frederick A. Villamena
Keyword(s):  
Nitric Oxide ◽  
Aqueous Medium ◽  
Radical Anion ◽  
Superoxide Radical ◽  
Unimolecular Decomposition ◽  
Superoxide Radical Anion ◽  
Nitric Oxide Release ◽  
Cyclic Nitrones

scholarly journals Reactivity of Superoxide Radical Anion with Cyclic Nitrones:  Role of Intramolecular H-Bond and Electrostatic Effects

2007 ◽  
Vol 129 (26) ◽  
pp. 8177-8191 ◽  
Author(s):  
Frederick A. Villamena ◽  
Shijing Xia ◽  
John K. Merle ◽  
Robert Lauricella ◽  
Beatrice Tuccio ◽  
...  
Keyword(s):  
Radical Anion ◽  
Superoxide Radical ◽  
Electrostatic Effects ◽  
Superoxide Radical Anion ◽  
Cyclic Nitrones

scholarly journals Oxidative denitrification of Nω-hydroxy-l-arginine by the superoxide radical anion

1996 ◽  
Vol 317 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Steven A. EVERETT ◽  
Madeleine F. DENNIS ◽  
Kantilal B. PATEL ◽  
Michael R. L. STRATFORD ◽  
Peter WARDMAN
Keyword(s):  
Nitric Oxide ◽  
Superoxide Dismutase ◽  
Catalytic Activity ◽  
Radical Anion ◽  
Superoxide Radical ◽  
Superoxide Radical Anion ◽  
Prototropic Equilibrium ◽  
Ph Dependent ◽  
Oxide Synthase ◽  
Cytochrome P 450

The superoxide radical anion (O2-•) produced during the catalytic activity of nitric oxide synthase (NOS) and cytochrome P-450 has been implicated in the oxidative denitrification of hydroxyguanidines (> C = NOH). The reactivity of the radiolytically generated O2-• radical with Nω-hydroxy-l-arginine (NHA) is pH dependent and appears to parallel the prototropic equilibrium of the hydroxyguanidino group (> C = NOH ⇌ > C = NO- + H+; pK = 8). The Nω-hydroxyguanidino group is more reactive towards O2-• when deprotonated but exhibits negligible reactivity when protonated. Based on a model, the rate constant for the reaction of the O2-• with NHA was estimated as k (O2-•+ > C = NO-) ≈ 200–500 M-1·s-1, which is probably too low to compete with O2-• reactions with NO• or superoxide dismutase, which occur many orders of magnitude faster. The oxidative elimination of NO from NHA by O2-• was not accompanied by the formation of l-citrulline. Since only 21% of NHA will exist in the deprotonated > C = NO- form at physiological pH, it is unlikely that oxidative denitrification of NHA by cytochrome P-450 or NOS-derived O2-• radicals will prove a major free-radical pathway to NO• and l-citrulline.

N,N.N′,N′-tetramethylhydroethidine (TMHE) - in search for better probes for the detection of superoxide radical anion

2017 ◽  
Vol 108 ◽  
pp. S38
Author(s):  
Adam Sikora ◽  
Radosław Michalski ◽  
Micael Hardy ◽  
Olivier Ouari ◽  
Jan Adamus ◽  
...  
Keyword(s):  
Radical Anion ◽  
Superoxide Radical ◽  
Superoxide Radical Anion
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