Síntese, análise estrutural e avaliação da atividade catalítica mimética da superóxido dismutase e peroxidases de complexos derivados do piridoxal e cobre

Abstract

This work presents the synthesis and characterization of copper complexes that mimic the activity of the superoxide dismutase enzyme, which operates in the elimination of reactive oxygen species or in the activation of hydrogen peroxide. In the synthesis, the ligands used were obtained from the condensation of pyridoxal hydrochloride with substituted anilines possessing different halogens. Subsequently, a method was employed which enabled the quantification of antioxidant/pro-oxidant activity in order to find a correlation between the influence of the coordination geometry and the halogen position on the catalytic activity. In this study, the following thirteen compounds were synthesized: [Cu(Pyridoxal-H-aniline)2]Cl2·2H2O (C1), [Cu(Pyridoxal-2-F-aniline)2] (C2), [Cu(Pyridoxal-2-Cl-aniline)2] (C3), [Cu(Pyridoxal-2- Br-aniline)2] (C4), [Cu(Pyridoxal-2-I-aniline)2] (C5), [Cu(Pyridoxal-3-F-aniline)2] (C6), [Cu(Pyridoxal-3-Cl-aniline)2] (C7), [Cu(Pyridoxal-3-Br-aniline)2] (C8), [Cu(Pyridoxal-3- l-aniline)2] (C9), [2Cu(Pyridoxal-4-F-aniline)2] (C10), [2(Cu(Pyridoxal-4-Cl-aniline)2)] (C11), [2(Cu(Pyridoxal-4-Br-aniline)2)] (C12), and [2(Cu(Pyridoxal-4-I-aniline)2)] (C13). The methodology used to quantify the mimetic activity of the superoxide dismutase antioxidant was the photoreduction of NBT, and in the case of quantification of the peroxidase, a phenol oxidation method, using 4- aminoantipyrineas the indicator, was analyzed. The results showed that the mimetic compounds exhibit high activity levels of the superoxide dismutase and peroxidase enzymes.