MESO-TETRA-p-TOLYLPORPHYRIN: SYNTHESIS, CHARACTERISATION, ANTIOXIDANT ACTIVITY AND DETERMINATION OF BINDING PARAMETERS OF WITH SUPEROXIDE ANION RADICAL

Abstract

In this paper we present the synthesis and the evaluation of the antioxidant activity of meso-tetra-p-tolylporphyrin (TPPH2(p-methyl)) using superoxide anion radical . 2 (O )  in DMF as a solvant. The binding parameters of the interaction between the synthesised compound and the radical . 2 O were also measured using cyclic voltammetry techniques. TPPH2(p-methyl) shows lower antioxidant activity (30.7 ± 0.08 mg/mL) than that of α-tocopherol standard (3.04 ± 0.03 mg/mL). The value of the binding Gibbs energy of -8.15 KJ.mol-1 calculated for TPPH2(p-methyl) suggests an electrostatic interaction of . 2 O with TPPH2(p-methyl) which has been found to be the dominant interaction mode. The kinetics of the interaction reaction was also mesured having second-order rate constant values equal to 0.2 M-1 s-1.