Chromium (III) Complexes of 4,5-diazafluoren-9-one Ligand as Potential Anti-proliferative Agents: Synthesis, Characterization, DNA Binding, Molecular Docking and In-vitro Cytotoxicity Evaluation

Three novel Cr(III) complexes, [Cr(dafone)2(H2O)2](NO3)3 (1), [Cr(opd) (dafone)2](NO3)3 (2) and [Cr (phen-dione) (dafone) (H2O)2].(NO3)3 (3) were synthesized and characterized by different techniques. Fluorescence spectroscopy, gel electrophoresis, viscosity measurement, and circular dichroism (CD) were applied to explore the interaction of Cr complexes with FS-DNA. The binding constant (Kb) was obtained from UV–Vis measurements. The obtained results exhibited the effective binding of target complexes to DNA double-strand. The fluorescence data appraised both binding and thermodynamic constants of complexes-DNA interactions. The measured thermodynamic factors (∆S˚, ∆H˚, ∆G˚) revealed that hydrogen bonding and van der Waals forces for DNA- Cr(III) complexes bear the most important roles. As well, the Stern–Volmer quenching constants (Ksv) and the binding constants (Kb) of synthesized compounds and DNA were calculated. The results of thermodynamic parameters showed that the binding of synthesized Cr(III) compounds to DNA was driven mainly through hydrogen bonds and van der Waals interactions. Viscosity measurement results showed that increasing the concentration of synthesized compounds, did not make any major changes in specific viscosity of FS-DNA. The data of viscosity and circular dichroism (CD) support the groove binding mode.