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 nisoldipine by N-acetylcysteine assessed by cyclic volatammetry (CV) and EPR spectroscopic techniques. Studies by CV on the reactivity of the radical 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 on the second order decay rate constant of the radical (ki=4.857[Msec]-1. EPR spectra recorded in situ using DMF/0.1 N NaOH (pH 13) of the nitro radical anion from nisoldipine electrochemically generated was completely inhibited for a 20 mM concentration of N-acetylcystein