Heteroleptic N, N donor carbonitrile based Au(III) complexes: DNA/BSA interaction studies, Molecular Docking, and cytotoxicity studies

Abstract

A series of square planar substituted carbonitrile based Au(III) complexes (2a-2e) with the type of [(N^N)Au(Cl₂)]⁺Cl^- [Where, N^N = 5- Amino-3-phenyl-1-(pyridin-2-yl)-1H-pyrazole-4-carbonitrile (1a), 5-amino-3-(4-chlorophenyl)-1-(pyridin-2-yl)-1H-pyrazole-4-carbonitrile (1b), 5-amino-3-(4-bromophenyl)-1-(pyridin-2-yl)-1H-pyrazole-4-carbonitrile (1c), 5-amino-3-(4-flourophenyl)-1-(pyridin-2-yl)-1H-pyrazole-4-carbonitrile (1d), 5-amino-3-(4-methoxyphenyl)-1-(pyridin-2-yl)-1H-pyrazole-4-carbonitrile (1e) were synthesized and characterized by analytical techniques. UV-Vis spectroscopy, fluorescence spectroscopy, Viscosity measurements, and molecular docking studies were used to identify the binding mechanism between complexes and HS-DNA (Herring sperm-DNA), results suggest an intercalation mode of DNA binding. Protein binding studies of the complexes were evaluated using UV–visible and fluorescence spectroscopy. The antibacterial activity of the metal chelates were performed against three Gram (-ve) and two Gram (+ve) bacteria, and the results indicate that all of the complexes perform better than their ligands against microorganisms. The in vitro cytotoxicity against BSLB (Brine shrimp lethality bioassay) of ligands and metal chelates were also carried out. The LC₅₀ values of the ligands and complexes were found in the range of 10.45–13.28 µg/mL and 6.30–6.99 µg/mL, respectively. All compounds were tested for anti-cancer activity against the human adenocarcinoma (MCF-7) cancer cell line. The results show that effective toxicity against the tested cell line of all metal chelates. The SwissADME webserver analysis confirmed that most of the synthetic compounds comply with drug-likeness principles. Additionally, they demonstrated promising biological activities, indicating their potential for further drug development.