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)<sub>2</sub>(ppip)]<sup>2+</sup> (<b>1</b>) (phen=1,10-phenanthrolene), [Ru(bpy)<sub>2</sub>(ppip)]<sup>2+</sup> (<b>2</b>) (bpy=2,2′-bipyridine) and [Ru(dmb)<sub>2</sub>(ppip)]<sup>2+</sup> (<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, <sup>1</sup>H, as well as <sup>13</sup>C 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><sub>b</sub>) 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>