Electrochemical study of methyl 2-[p-nitrophenyl(hydroxy)methyl]acrylate -

Electrochemical experiments with methyl 2-[p-nitrophenyl(hydroxy)methyl]acrylate (1) were performed in protic (EtOH+phosphate buffer 1:9, 0.1 mol L-1, pH 6.9; EtOH+phosphate buffer+NaOH 1:9, 0.1 mol L-1 or 0.2 mol L-1, pH 9.4 and EtOH+NaHCO3+NaOH 2:8, 0.18 mol L-1, pH 9.6) and aprotic [dimethylformamide (DMF)+tetrabutylammonium perchlorate (TBAP), 0.1 mol L-1] media. The primary reduction behavior in aprotic medium was typical of nitroaromatics along with an additional wave related to the reduction of the acrylate function. Kinetic analysis carried out in aprotic and aqueous basic media pointed out to the high stability of the electrogenerated nitro radical anion, especially in DMF+TBAP. Reduced (GSH) and oxidized (GSSG) gluthatione in phosphate buffer influenced the reduction behavior of 1, due mainly to protonation effects. Direct reduction of 1, in the presence of GSH, led to a transient nitroso-GS adduct. In the presence of GSSG, hydrogen-bonding-associated GSSG-hydroxylamine was the main product. Electrochemical studies of 1, in the presence of oxygen, showed no chemical reactivity between O-2 and 1(-center dot). These electrochemical results help in the understanding of the anticancer activity of 1 that can be considered a bioreductive agent with a glutathione depleting function. (c) 2007 The Electrochemical Society.