Synthesis, Crystal Structure and In Vitro Cytotoxicity of Novel Cu(II) Complexes Derived from Isatin Hydrazide-Hydrazone Ligands

Abstract

In this study, two innovative hydrazine-hydrazone ligands were synthesized through the chemical reaction involving the isatin moiety with 4-hydroxybenzohydrazide and salicyloylhydrazine. Subsequent to the synthesis of these ligands, Cu(II) complexes were meticulously prepared, and their molecular structures were comprehensively analyzed utilizing an array of spectroscopic techniques. Furthermore, the crystallographic investigation was employed to elucidate the precise crystal structure of the Cu(L2)2 complex, incorporating the salicyloylhydrazine moiety. The research focuses on investigating the cytotoxic effects of Cu(II) complexes bearing isatine groups on cancer cells. These complexes were tested against lung carcinoma (A549) and breast carcinoma (MCF-7) cell lines using the MTT assay, with cisplatin as a positive control. Additionally, their effects on human normal cell line 3T3 were assessed. The Cu(L1)2 complex exhibited significant inhibitory effects on tumor cells in a dose-dependent manner, although not as potent as cisplatin. The cytotoxic selectivity indices (SI) indicated acceptable selectivity levels for both cancer cell lines, indicating potential for selective lethality. The crystal structure of one compound was confirmed, revealing van der Waals interactions and hydrogen bonding in the packing.