Mononuclear Co(III) and Ni(II) Complexes with Polypyridyl Ligands, [Co(phen)2(taptp)]3+ and [Ni(phen)2(taptp)]2+: Synthesis, Photocleavage and DNA-binding

Abstract

Two novel, mixed ligand complexes of cobalt(III) and nickel(II), [Co(phen) 2 (taptp)] 3+ (1) and [Ni(phen) 2 (taptp)] 2+ (2) (phen 0 1,10-phenanthroline and taptp 0 4,5,9,18-tetraazaphenanthreno [9,10-b]triphenylene), were synthesized and characterized by elemental analyses, UVvisible and NMR spectroscopies. The binding interactions of the two complexes with DNA have been investigated using absorption and emission spectroscopy methods and electrophoresis measurement mode. The intrinsic binding constants for these complexes to DNA are in the order of 10 5 . In Tris buffer, the Co(III) complex shows a moderate luminescence which was enhanced after binding to DNA. However for complex Ni(II), no emission was observed in Tris buffer. The [Co(phen) 2 (taptp)] 3+ and [Ni(phen) 2 (taptp)] 2+ can cause the photocleavage of DNA supercoiled pBR322 upon irradiation by 360 nm light. Based on the data, an intercalative mode of DNA binding is suggested for the two complexes. Keyword Photocleavage . Intercalative mode . Polypyridyl ligands . Co (III) and Ni(II) complexes . Mixed-ligand . DNA binding

A water-soluble Pd(ii) complex with a terpyridine ligand: experimental and molecular modeling studies of the interaction with DNA and BSA; and in vitro cytotoxicity investigations against five human cancer cell lines

“…2,13 Coordination of the biologically active organic molecules as ligands to the transition metal ions shows promise in this field because of their unique ability to bind different biological targets. 1,14 Some studies have recently found that polypyridyl complexes can function efficiently as electrochemical probes for nucleic acid sensing, particularly for CT-DNA, [15][16][17] as fluorescent probes for nuclear and protein components, 18 as DNA photocleavage agents, 19,20 or as catalytic inhibitors (or poisons) of human topoisomerase IIa. 19 They also display good binding propensity to transporting proteins, 21 and cytotoxicity against cancer cell lines.…”

“…1,14 Some studies have recently found that polypyridyl complexes can function efficiently as electrochemical probes for nucleic acid sensing, particularly for CT-DNA, [15][16][17] as fluorescent probes for nuclear and protein components, 18 as DNA photocleavage agents, 19,20 or as catalytic inhibitors (or poisons) of human topoisomerase IIa. 19 They also display good binding propensity to transporting proteins, 21 and cytotoxicity against cancer cell lines. 22 Terpyridine (tpy) and its derivatives are attracting considerable interest due to their ability to act as ligands in a wide range of transition metal complexes and DNA-binding agents.…”

Two polypyridyl copper(ii) complexes: synthesis, crystal structure and interaction with DNA and serum protein in vitro

“…11 In general, polypyridyl metal complexes displayed the intercalative binding modes to DNA for their large planar ligands and p-p overlapping interaction. 12,13 Over the past few decades, it has been considered that the polypyridyl metal complexes can probe nonradioactive nucleic acid and effectively cleave DNA. 14 In general, the DNA cleavage mode mainly contained oxidative cleavage, photocleavage and hydrolytic cleavage.…”