Organoruthenium(II) compounds with pyridyl benzoxazole/benzthiazole moiety: studies on DNA/protein binding and enzyme mimetic activities.

We report herein synthesis and characterization of four new organoruthenium(II) complexes of the type [RuH(CO)(PPh3)2(L1,2)]Cl (1,3) and [Ru(CO)(Cl)2(AsPh3)(L1,2)] (2,4) derived from the reaction of [RuHCl(CO)(EPh3)3] (E = P or As) with 2-(pyridine-2yl)benzoxazole (L1) and 2-(pyridine-2yl)benzthiazole (L2). Single-crystal X-ray diffraction data of2proved octahedral geometry of the complexes with a 1 : 1 ratio between the metal and the coordinated ligands. The binding affinities of1–4toward calf-thymus DNA (CT-DNA) and BSA were thoroughly studied by various spectroscopic techniques. Furthermore, the coordination compounds exhibit catecholase-like activities in the aerial oxidation of 3,5-di-tert-butylcatechol to the correspondingo-quinone and phosphatase-like activities in the hydrolysis of 4-nitrophenyl phosphate to 4-nitrophenolate ion. The kinetic parameters have been determined using Michaelis–Menten approach. The highestkcatvalues suggested that coordination compounds exhibit higher rates of catalytic efficacy. [ABSTRACT FROM PUBLISHER]