Antioxidant activity evaluation of some novel 2-hydroxy-benzamides derivatives

Salicylamides, as well as O-substituted salicylamide, are classes of compounds with a broad spectrum of biological activity. The goal of this research was to evaluate the antioxidant capacity of some new 2-hydroxy-benzamide derivatives, esters, hydrazides and hydrazones using chemical and electrochemical methods. So, antioxidant activities of the synthesized compounds were studied by in vitro 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging method, 2,2´-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging capacity assay, ferric reducing antioxidant potential (FRAP) assay and cyclic voltammetry and were expressed as Trolox equivalents for a good correlation between electrochemical results and antioxidant activities determined by chemical methods. Meanwhile 1,1-diphenyl-2-picrylhydrazyl (DPPH) method does not seem to be suitable for the antioxidant activity evaluation in case of this class of compounds due to too slow kinetics of the reaction between 1,1-diphenyl-2-picrylhydrazyl (DPPH) and tested compounds, the other chemical methods and cyclic voltammetry proved to be simple and fast techniques for the antioxidant properties evaluation of the organic compounds.