The stability in water and at pH = 7.2, substitution reactions with Tu, 5’-GMP, GSH and l-Met, DNA/BSA interactions, cytotoxicity, DFT and molecular docking of gold(iii) complexes with phenanthroline derivatives as inert ligands were studied.
In this work we synthesized new monofunctional gold(III) complex [Au(Cl‐Ph‐tpy)Cl]Cl2 (Cl‐Ph‐tpy = 4′‐[4‐chlorophenyl]‐2,2′:6′, 2″‐terpyridine). This complex was characterized by UV–Vis, NMR, IR, and ESI‐MS spectrometry. The kinetic study of the substitution reactions of the Au‐Cl‐Ph‐tpy complex with biomolecules showed that the rate constants depend on the nature of the entering nucleophile. Based on the calculated values of entropy (∆H≠ > 0) and enthalpy (∆S≠ < 0) the proposed substitution mechanism is associative. Additionally, the relative stability and thermodynamic properties of Au‐Cl‐Ph‐tpy complex were compared with the analogue Au‐tpy complex by the B3LYP/def2‐svp method. DNA/BSA binding studies showed that Au‐Cl‐Ph‐tpy complex interacts with CT DNA through the intercalation and moderately quenches the fluorescence of tryptophan residues in serum albumin (BSA). Molecular docking confirmed results obtained by spectroscopic experiments and suggested site I (subdomain IIA) for binding of Au complex to BSA. We demonstrated that the Au chlorophenyl terpyridine complex possessed significant in vitro cytotoxic activity against human oral squamous carcinoma cells (CAL‐27), induced apoptosis, inhibited proliferation of CAL‐27 cells, and induced cell cycle disturbance. Treatment of CAL‐27 cells with the Au complex enhanced expression of cyclin‐dependent kinase inhibitors p21 and p27, resulting in cell cycle arrest in the G1 phase, reduced the percentage of CAL‐27 cells in S phase and decreased expression of Ki‐67. Additionally, Au complex reduced expression of phosphorylated STAT3 and downstream regulated molecules associated with cancer stemness, NANOG, and Sox2 protein.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.