Physicochemical Studies of Benzocaine Bearing Heterocycles as Potential Antioxidant Agents

Abstract

Series of new thirteen annulated heterocyclic were prepared and screened for their antioxidant activities. The ethyl-4(2-cyanoacetamido)benzoate as a multifunctional component which possess both electrophilic and nucleophilic centers that were utilized in organic synthesis of different candidates. These new compounds studied as antioxidants at different concentrations based on DPPH and ABTS assays using ascorbic acid as a standard antioxidant. The most potent compound was 5 that recorded as the best antioxidant compound with IC50 equal 0.006 mg/ml for DPPH results. While for ABTS study, compound 4 anticipated the best result with IC50 equal 27.46 µM. Different reactive and thermodynamic descriptors were calculated as a preliminary step for a comparative thermodynamic study for antioxidant property. The results clarified that the potent compounds showed dependence on SET–PT mechanism than HAT or SPLET mechanism. These mechanisms depended on different parameters as proton affinity and electron transfer energy that were studied. SET–PT mechanism was dependent on two descriptors: IP and BDE which were studied and observed that were less-valued in site A for two potent compounds 4 and 5.