Cytotoxicity and Antibacterial Potentials of Mixed Ligand Cu(II) and Zn(II) Complexes: A Combined Experimental and Computational Study

Abstract

3 (2) have been synthesized and characterized by ultraviolet−visible (UV−vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, mass spectrometry, thermogravimetric analysis/differential thermal analysis (TGA/ DTA), X-ray diffraction (XRD), scanning electron microscopy− energy-dispersive X-ray spectroscopy (SEM-EDX), and molar conductance, and supported by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. Square pyramidal and tetrahedral geometries are proposed for Cu(II) and Zn(II) complexes, respectively, and the XRD patterns showed the polycrystalline nature of the complexes. Furthermore, in vitro cytotoxic activity of the complexes was evaluated against the human breast cancer cell line (MCF-7). A Cu(II) centered complex with an IC 50 value of 4.09 μM was more effective than the Zn(II) centered complex and positive control, cisplatin, which displayed IC 50 values of 75.78 and 18.62 μM, respectively. In addition, the newly synthesized complexes experienced the innate antioxidant nature of the metal centers for scavenging the DPPH free radical (up to 81% at 400 ppm). The biological significance of the metal complexes was inferred from the highest occupied molecular orbital−lowest unoccupied molecular orbital (HOMO−LUMO) energy band gap, which was found to be 2.784 and 3.333 eV, respectively for 1 and 2, compared to the ligands, 1,10-phenathroline (4.755 eV) and chrysin (4.403 eV). Moreover, the molecular docking simulations against estrogen receptor alpha (ERα; PDB: 5GS4) were strongly associated with the in vitro biological activity results (E B and K i are −8.35 kcal/mol and 0.76 μM for 1, −7.52 kcal/mol and 3.07 μM for 2, and −6.32 kcal/mol and 23.42 μM for cisplatin). However, more research on in vivo cytotoxicity is suggested to confirm the promising cytotoxicity results.

Unusual Ni⋯Ni interaction in Ni(ii) complexes as potential inhibitors for the development of new anti-SARS-CoV-2 Omicron drugs

“…The antibacterial results are consistent with the other transition metal complexes, which were tested in vitro for their antibacterial activities against G(−) and G(+) bacteria using disc diffusion method or minimum inhibitory concentration (MIC) method. 80,81 The antibacterial activities of the synthesized Ni( ii ) complexes [Ni(L)] 2 ( 1 ) and [Ni(L)] n ( 2 ) are comparable to those of the reported Schiff base nickel( ii ) complexes. 82,83…”

Cytotoxic Cu(II) Complexes with a Novel Quinoline Derivative Ligand: Synthesis, Molecular Docking, and Biological Activity Analysis

“…aureus ATCC 25926 compared to the Gram-negative bacterial pathogens tested in this study. Related literature reports on copper complexes also showed stronger MIC against Gram-positive bacteria as compared to Gram-negative bacteria …”

“…Related literature reports on copper complexes also showed stronger MIC against Gram-positive bacteria as compared to Gram-negative bacteria. 67 …”

Multi-Faceted Antimicrobial Efficacy of a Quinoline-Derived Bidentate Copper(II) Ligand Complex and Its Hydrogel Encapsulated Formulation in Methicillin-Resistant Staphylococcus aureus Inhibition and Wound Management

“…It has been suggested in previously published literature that a percent cellular viability of >70% can be considered safe, and lower viabilities are generally considered cytotoxic. 34,35 The % cellular viabilities of >70% at even the MBC of 50 μM for all three tested cell lines provided assurance that SG-Cu can be used therapeutically and is a good candidate for immediate preclinical investigations.…”