Thiosemicarbazone Schiff base ligands and their complexes with nickel, palladium and platinum show anticancer and antibacterial activities

Abstract

The thiosemicarbazone containing polydentate Schiff base ligand is attracting interest in the field of coordination and biological application. The metal complexes exhibited stronger activity than free ligands against both cancer and bacteria due to the greater lipophilicity of complexes. These ligands possess hard and soft base S-N-O coordinating sites, which participate in chelation simultaneously with metal ions. These ligands could coordinate to transition metals through various modes. The paper focuses on the coordination of the thiosemicarbazone Schiff base ligands with nickel, palladium, and platinum metal ions to generate biologically active complexes. Both the ligands and the metals have strong biological properties. So, the most important biological activities, particularly anticancer and antibacterial are considered in the study. There is a lot of scientific data available regarding Schiff base ligands and their transition metal complexes. Still, our study collects more informative data, from the past to date, of Schiff base thiosemicarbazone ligands and their complexes. The nickel complex showed higher activity than cisplatin against Hela cancer cell, HCT 116 with IC₅₀ of 7.9 ± 0.2 µM and 10.1 ± 0.09 µM respectively. These types of compounds could be used as potential medicinal agents in the near future against various lethal diseases.