Theoretical study on the DNA interaction properties of copper(II) complexes

Binding profile of a mixed-ligand silver(I) complex with DNA and Topoisomerase I

A new mixed-ligand Ag(I) complex, [Ag(daf)(phen)]NO₃ (daf = 4,5-diazafluoren-9-one and dian = N-(4,5-diazafluoren-9-ylidene)aniline), was synthesized. The elemental analysis, FTIR, ¹HNMR, UV-Vis spectroscopy, cyclic voltammetry, and DFT (Density Functional Theory) geometry optimization method were applied in order to predict the Ag(I) complex structure which concluded to a distorted tetrahedral N4 coordination around the Ag(I) center. A detailed in silico analysis of the bioaffinity of the complex to DNA and human DNA-Topoisomerase I was conducted using molecular docking simulations and ONIOM (Our own N-layered Integrated molecular Orbital and molecular Mechanics) techniques. In this overall scenario, the results suggest the dominance of π-π stacking interactions of the heteroaromatic ligands in the intercalating pocket of DNA and the active site of the enzyme and the rational correlation between being a good intercalator and a potent Topoisomerase I inhibitor. In vitro DNA-binding experiments by spectrophotometric, spectrofluorometric, Voltammetric, and viscometric techniques at physiological pH also confirmed the computational results. The complex inhibited MCF-7 cell growth in a dose-dependent manner while being nontoxic on HUVEC normal cells.

Theoretical investigation on hydrolysis mechanism of cis-platin analogous Pt(II)/Pd(II) complex by DFT calculation and molecular docking approach for their interaction with DNA & HSA

The properties to be an active drug candidate of the complex Pt(TEEDA)Cl₂, C1; Pd(TEEDA)Cl₂, C2 and their hydrolysed product [Pt(TEEDA)(OH₂)₂]²⁺, C1' and [Pd(TEEDA)(OH₂)₂]²⁺, C2' were predicted by Lipinski's rule of 5 and PASS (prediction of activity spectra for substances) web tool. Their structural profile, HOMO-LUMO energy and electronic potential surface ware analysed by DFT calculation. Their TD-DFT spectra were compared with experimental UV-Vis spectra. The hydrolysis mechanisms of C1 & C2 to the diaqua form C1' and C2' were extensively investigated by DFT method in different levels of theory and using CPCM/water model and compared with recognised Pt based anticancer drugs. All the stationary states, including the transition state for the reactions were identified by the DFT calculation. The IRC calculation confirmed that the transition states are well connected and corelate with reactants and products. Interaction of the complexes with DNA & HSA was also investigated by molecular docking study.