Synthesis, characterization, and antioxidant evaluation of solid-state mefenamates of some bivalent metals

Solid-state M-mef compounds, where M stands for bivalent Mn, Fe, Co, Ni, Cu, or Zn and mef is mefenamate, have been synthesized and characterized by thermoanalytical and spectroscopic techniques, molecular modeling, and antioxidant capacity evaluations. The TG-DTA and DSC curves show that the cobalt, nickel, and zinc compounds were hydrated while the manganese, iron, and copper compounds were anhydrous. The results provided information on the composition, dehydration, thermal stability, ligand denticity, crystallinity, thermal decomposition, as well as the gaseous products that evolved during the thermal decomposition of these compounds. The thermal stability of the anhydrous compounds depended on the nature of the metal ion, and followed the order: Ni > Mn > Zn > Co > Cu-Fe. The antioxidant activity of M-mef was higher than that of mefenamic acid, indicating that they are good models in treating a variety of inflammatory diseases and may lead to the development of new drugs.