NEW METAL COMPLEXES WITH ARIL-ACETIC STRUCTURE: PREPARATION, CHARACTERIZATION, AND IN VITRO ANTIINFLAMMATORY EFFECTS

New tridentate ONO hydrazone Schiff base ligands were synthesised by the condensation reaction of some hydroxybenzaldehydes with diclofenac-hydrazide. Afterward, by complexing the ligands with copper (II), zinc (II), and nickel (II), new dimeric complexes were obtained. The structure of ligands (1a-d) and of corresponding metal complexes (2a-d, 3a -d, 4a-d) was established through spectroscopic data (FT-IR, UV-Vis). The thermal behaviour of metal complexes was studied using thermogravimetric analysis (TGA) and derivative thermogravimetry (DTA) in an inert atmosphere. Upon heating, all compounds decompose progressively into metal oxides, which are the final products of pyrolysis. The ligands and their metal complexes were subjected to in vitro anti-inflammatory evaluation using a serum albumin denaturation assay and an erythrocyte membrane stabilisation assay. The obtained results support the improved anti-inflammatory effect of diclofenac through complexation with different bivalent metals via hydrazone Schiff base ligands. Moreover, it was noted that the anti-inflammatory effect of the metal complexes increases with concentration. The most active were nickel (II) complexes, which showed appreciable anti-inflammatory effects compared to both ligands and diclofenac, used as a reference drug.