Investigation of DNA/BSA binding of three Ru(II) complexes by various spectroscopic methods, molecular docking and their antimicrobial activity

<p>An intercalative ligand, ppip (ppip = {2-(4-(piperidin-1-yl)phenyl)-1<i>H</i>-imidazo[4,5-f][1,10]phenanthroline}), and its mononuclear Ru(II) polypyridyl complexes, [Ru(phen)₂(ppip)]²⁺ (<b>1</b>) (phen=1,10-phenanthrolene), [Ru(bpy)₂(ppip)]²⁺ (<b>2</b>) (bpy=2,2′-bipyridine) and [Ru(dmb)₂(ppip)]²⁺ (<b>3</b>) (dmb=4,4′-dimethyl-2,2′-bipyridine), have been synthesized and characterized by elemental analysis and spectroscopic techniques such as UV–vis, IR, ¹H, as well as ¹³C NMR and ESI-MS. The interaction of these complexes with DNA/BSA (bovine serum albumin) was investigated using absorption, emission spectroscopy, viscosity measurements and molecular docking studies. The docking study infers that the binding strength (<i>K</i>_b) of these complexes was in agreement with results from absorption and emission techniques. These studies reveal that these three Ru(II) polypyridyl complexes bind to DNA/BSA. The binding ability of these complexes in the presence of different ions and solvents were also reported. All complexes were effectively cleaving pBR322 DNA in different forms and follows order which is similar to absorption and emission studies. These complexes were effective exhibiting the antimicrobial activity against different microbes <i>Bacillus subtilis</i>, <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>.</p

Antiangiogenic Activity of Mononuclear Copper(II) Polypyridyl Complexes for the Treatment of Cancers

A series of four new mononuclear copper­(II) polypyridyl complexes (<b>1</b>–<b>4</b>) have been designed, developed, and thoroughly characterized by several physicochemical techniques. The CT-DNA binding properties of <b>1</b>–<b>4</b> have been investigated by absorption, emission spectroscopy, and viscosity measurements. All the complexes especially <b>1</b> and <b>4</b> exhibit cytotoxicity toward several cancer cell lines, suggesting their anticancer properties as observed by several in vitro assays. Additionally, the complexes show inhibition of endothelial cell (HUVECs) proliferation, indicating their antiangiogenic nature. In vivo chick embryo angiogenesis assay again confirms the antiangiogenic properties of <b>1</b> and <b>4</b>. The formation of excessive intracellular ROS (H₂O₂ and O₂^•–) and upregulation of BAX induced by copper­(II) complexes may be the plausible mechanisms behind their anticancer activities. The present study may offer a basis for the development of new transition metal complexes through suitable choice of ligands for cancer therapeutics by controlling tumor angiogenesis