DNA Binding and Anti-Cancer Activity of Redox-Active Heteroleptic Piano-Stool Ru(II), Rh(III), and Ir(III) Complexes Containing 4-(2-Methoxypyridyl)phenyldipyrromethene

Abstract

The synthesis of four novel heteroleptic dipyrrinato complexes [(η(6)-arene)RuCl(2-pcdpm)] (η(6)-arene = C6H6, 1; C10H14, 2) and [(η(5)-C5Me5)MCl(2-pcdpm)] (M = Rh, 3; Ir, 4) containing a new chelating ligand 4-(2-methoxypyridyl)-phenyldipyrromethene (2-pcdpm) have been described. The complexes 1-4 have been fully characterized by various physicochemical techniques, namely, elemental analyses, spectral (ESI-MS, IR, (1)H, (13)C NMR, UV/vis) and electrochemical studies (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)). Structures of 3 and 4 have been determined crystallographically. In vitro antiproliferative and cytotoxic activity of these complexes has been evaluated by trypan blue exclusion assay, cell morphology, apoptosis, acridine orange/ethidium bromide (AO/EtBr) fluorescence staining, and DNA fragmentation assay in Dalton lymphoma (DL) cell lines. Interaction of 1-4 with calf thymus DNA (CT DNA) has also been supported by absorption titration and electrochemical studies. Our results suggest that in vitro antitumor activity of 1-4 lies in the order 2 > 1 > 4 > 3.

Study of single and double chain surfactant–cobalt(iii) complexes and their hydrophobicity, micelle formation, interaction with serum albumins and antibacterial activities

“…42 Complexes 1-4 were dissolved in a mixture of water and n-octanol followed by shaking for 1 hour. The mixture was allowed to settle over a period of 30 minutes and the resulting two phases were collected separately without cross contamination of one solvent layer into another.…”

Synthesis, Characterization, In Vitro Cytotoxicity, and Apoptosis-Inducing Properties of Ruthenium(II) Complexes

“…Transition metal complexes have potential advantages, such as variable coordination numbers and geometries, accessible redox states, rich physicochemical properties, and extensive structural diversity, over common organic-based drugs. Therefore, the metal-based cancer drug is a focus of research in bioinorganic chemistry [1]–[6]. Cisplatin is widely used as an anticancer drug to treat many cancers, but severe side effects and acquired resistance caused by prolonged treatment have resulted in the search for alternatives to circumvent drug resistance [7].…”

Synthesis, structure elucidation and DFT studies of a new coumarin-derived Zn(ii) complex: in vitro DNA/HSA binding profile and pBR322 cleavage pathway

“…5). 23 The results reveal that the complex interacts with DNA either by external contact (electrostatic interaction) with the phosphate backbone of the DNA double helix or by the formation of H-bonds between the carbonyl and carboxylate groups of 1 with suitable donors such as N 3 of the adjacent thymine base of DNA, supported by the favorable hydrophobic interaction of the coumarin ring with the surface of DNA, all of these interactions contribute to the overall hyperchromism. The intrinsic binding constant K b for 1 is calculated from the plot of [DNA]/(3 a À 3 f ) versus [DNA], and is found to be 5.12 Â 10 4 M À1 .…”