REACTIVITY OF THE NITRO RADICAL-ANION FROM NISOLDIPINE WITH N-ACETYLCYSTEINE - EPR SPECTROSCOPIC AND ELECTROCHEMICAL EVIDENCE

This paper reports the scavenging of the nitro radical anion of nisold ipine by N-acetylcysteine assessed by cyclic voltammetry (CV) and EPR spectroscopic techniques. Studies by CV on the reactivity of the radic al were conducted on the mercury electrode in mixed media at pH 9.0 (0 .012 M aqueous citrate buffer/DMF 40/60, 0.1 M TBAI). Interaction rate constant was significantly higher than that of the second order decay rate constant of the radical (k(i) = 4.857 [Msec](-1) vs k(2) = 283 [ Msec](-1). EPR spectra recorded in situ using DMF/0.1 N NaOH (pH 13) o f the nitro radical anion from nisoldipine electrochemically generated was completely inhibited for a 20 mM concentration of N-acetylcystein e.