Zn(II)–carbamazepine complex: synthesis, characterization, and evaluation of biological and anticancer activity

This research centers upon the synthesis of a new Zn(II) complex. It is characterized by using various analytical and spectroscopic tools, including FTIR, mass, PXRD, molar conductivity, elemental and thermal analyses. From the results obtained, Zn(II) metal reacts with carbamazepine (CBZ) ligand in the ratio of 1:2 [M2+:CBZ] with formula [Zn(CBZ)2(H2O)Cl]Cl · H2O. The spectroscopic and analytical data demonstrated that CBZ acts as a bidentate ligand through the nitrogen of the N-H bond and the oxygen of the amide group, forming a distorted octahedral geometry complex. The synthesized complex has been investigated against different pathogenic microorganisms, such as fungi, two Gram-negative bacteria, and two Gram-positive bacteria, as well as the cytotoxicity activity of CBZ and its Zn(II) complex has been tested against two human cancer cell lines, indicating the Zn(II) complex shows higher efficiency than CBZ, with values of 0.019 µM for HepG-2 and 0.031 µM for MCF-7. Density functional theory calculations demonstrated that CBZ forms a stable Zn(II) complex via bidentate coordination, thereby reducing the HOMO–LUMO gap and increasing thermodynamic stability. Both the CBZ and Zn(CBZ)2 complexes can interact with the active site of the MCF-7 breast cancer receptor via hydrogen bonding and hydrophobic interactions, according to molecular docking experiments.