Ruthenium(II) complexes of 2-(2′-pyridyl)naphthoimidazole: synthesis, characterization and DNA-binding studies

Abstract

The perchlorate salts of two new ruthenium(II) complexes incorporating 2-(2 0 -pyridyl)-naphthoimidazole are synthesized in good yield. Complexes [Ru(phen) 2 (PYNI)] 2þ (phen ¼ 1,10-phenanthroline) 1 and [Ru(dmp) 2 (PYNI)] 2þ (dmp ¼ 2,9-dimethyl-1,10-phenanthroline, PYNI ¼ 2-(2 0 -pyridyl)naphthoimidazole) 2 are fully characterized by elemental analysis, FAB-MS, ES-MS, 1 H NMR and cyclic voltammetric methods. The DNA-binding behavior of the complexes have been studied by spectroscopic titration, viscosity measurements and thermal denaturation. Absorption titration and thermal denaturation studies reveal that these complexes are moderately strong binders of calf-thymus DNA (CT-DNA), with their binding constants spanning the range (2.73-5.35) Â 10 4 M À1 . The experimental results show that 1 interacts with calf thymus DNA (CT-DNA) by intercalative mode, while 2 binds to CT-DNA by partial intercalation.

Some new Ag(I), VO(II) and Pd(II) chelates incorporating tridentate imine ligand: Design, synthesis, structure elucidation, density functional theory calculations for DNA interaction, antimicrobial and anticancer activities and molecular docking studies

“…The variation was clarified in that the bands of the metal imine chelates contrasted with that of the control DNA. This indicates that the control DNA alone did not show any visible cleavage whereas the metal chelates did show cleavage . However, the nature of reactive intermediates involved in the DNA binding by the metal chelates was not clear .…”

“…Otherwise, when drug molecules attach exclusively to the DNA grooves, it results in less pronounced increase in the viscosity of DNA solution . Partial intercalation of the compounds may occur with the DNA helix, resulting in the reduction of its effective length and, consequently, its viscosity . Figure shows that the relative viscosity of DNA solution increases significantly as the amount of the metal imine chelate increases.…”

Novel azomethine Pd (II)‐ and VO (II)‐based metallo‐pharmaceuticals as anticancer, antimicrobial, and antioxidant agents: Design, structural inspection, DFT investigation, and DNA interaction

“…The overall findings of this section indicate that an improvement in the anticancer potency occurred upon coordination of the NBA ligand with the designated metal ions. The increased cytotoxicity observed for the metal complexes is most likely due to the positive charge of the metal ions, which increased the acidity of the coordinated NBA ligand that bears protons, thereby giving rise to more potent hydrogen bonds with a negative charge in the DNA of the cancer cells . The results obtained for the in vitro cytotoxic activities of the as‐prepared complexes are in agreement with their DNA and protein binding capacities.…”

A Promising Dna Groove Binder and Photocleaver Based on a Dinuclear Ruthenium(ii) Complex

“…[41][42][43][44] In order to identify this transition process, the melting temperature T m , which is defined as the temperature where half of the total base pairs are unpaired, is usually introduced. The melting curves of DNA in the absence and presence of the complex [Ru 2 (bpy) 4 (bip-phenol)] 4+ are presented in compared to that of pure DNA sample, which is much larger than ΔT m < 2 °C for the DNA in the presence of electrostatic DNA binder of [Ru(bpy) 3 ] 2+ [45] and ΔT m = 7.7 °C and 9 °C for DNA partial intercalators of [Ru(phen) 2 (pyni)] 2+ {pyni = 2-(2′-pyridyl)naphthoimidazole)} [46] and [Ru(dipn)(pat)] 2+ {dipn = N-(3-aminopropyl)propane-1,3-diamine, pat = 9-(1,10-phenanthrolin-2-yl) acenaphtho[1,2-e][1,2,4]triazine)}, [47] but comparable to ΔT m > 15 °C that previously reported for DNA threading intercalators of [Ru 2 (bpy) 4 L] 4+ [11] and DNA groove binder of azo based complex [{(bpy) 2 Ru} 2 (4-azo)] 4+ . [21] Therefore, the electrostatic binding mode can be eliminated for the complex; the relatively high ΔT m value is most likely indicative of a groove binding mode or an intercalation binding mode.…”