Synthesis, Characterization, Antimicrobial, DNA cleavage, and Cytotoxicity Studies of Some Metal (II) Complexes of Tridentate Schiff Base Ligand: 2-hydroxy-3-((4-(4-phenylthiazol-2-yl) semicarbazide) methyl) Benzoic Acid

Objective: The main aim of the present work was to synthesize a novel Schiff base ligand 2-hydroxy-3-((4-(4-phenylthiazol-2-yl) semicarbazide) methyl) benzoic acid is obtained by the condensation of N-(4-phenylthiazole-2-yl) hydrazine carboxamide with 3-Aldehydosalicylic acid and its Cu(II), Co(II), Ni(II), and Zn(II) complexes and study of their biological activity. Methods: The compounds are characterized by elemental analysis and various physicochemical techniques like IR, 1H NMR, ESI-mass, and molar conductance data. All the compounds were screened for their antibacterial and antifungal activity by MIC method. Further, to study the in vitro cytotoxicity properties of all the compounds against Artemia salina and DNA cleavage activity by Agarose Gel Electrophoresis (AGE) method. Results: Spectral investigations suggested square pyramidal coordination geometrical arrangement for all the metal (II) complexes, having 1: 1 stoichiometric ratio of the type [ML (Cl) 2]. The antimicrobial activity results revealed that the metal complexes were found to be more active than the free ligand. Furthermore, the DNA cleavage activity of the compounds on plasmid DNA pBR322 molecule showed moderate activity. Conclusion: The newly synthesized ligand acts as OON donor tridentate chelate and coordinated through an oxygen of azomethine nitrogen, Phenolic OH and Carboxylic acid (COOH) of 3-Aldehydosalicylic acid to the Cu, Co, Ni and Zn metal ions and form square pyramidal geometrical arrangement. All the complexes are found to be non-electrolytic in nature. Further, all the newly prepared compounds showed moderate biological activity.