Synthesis, DNA-binding and photocleavage studies of cobalt(III) complexes [Co(bpy)2(dpta)]3+ and [Co(bpy)2(amtp)]3+

Abstract

Two novel cobalt(III) mixed-polypyridyl complexes ½CoðbpyÞ 2 ðdptaÞ 3þ and ½CoðbpyÞ 2 ðamtpÞ 3þ (bpy = 2,2¢-bipyridine, dpta = dipyrido-[3,2-a;2¢,3¢-c]-thien-[3,4-c]azine, amtp = 3-amino-1,2,4-triazino[5,6-f]-1,10-phenanthroline) have been synthesized and characterized. The interaction of Co III complexes with calf thymus DNA was investigated by spectroscopic and viscosity measurements. Results suggest that the two complexes bind to DNA via an intercalative mode. Moreover, Co III complexes have been found to promote the photocleavage of plasmid DNA pBR322 under irradiation at 365 nm. The mechanism studies reveal that hydroxyl radical (OH • ) is likely to be the reactive species responsible for the cleavage of plasmid DNA by ½CoðbpyÞ 2 ðdptaÞ 3þ and superoxide anion radical (O 2 •) ) acts as the key role in the cleavage reaction of plasmid DNA by ½CoðbpyÞ 2 ðamtpÞ 3þ .

Thieno[3,4‐b]pyrazines and Its Extended Analogs: Important Buildings Blocks for Conjugated Materials

“…It should be pointed out that while the condensation to produce simple dialkyl‐TPs can readily occur at room temperatures, the production of such extended analogs all require heating at elevated temperatures to achieve effective yields. As might be expected, 28 is an effective chelating ligand, and Ji and coworkers ] have reported its transition metal complexes.…”

Binding and photocleavage of DNA by mixed ligand Co(III) and Ni(II) complexes of thiophene[2, 3-b] quinoline and phenanthrolie/bipyridine

“…In these mixed ligand complexes, the ligands or metal ion may be varied in an easily controlled way to facilitate the individual application (Hiort et al 1993). The transition metal complexes containing planar or fused ring systems can bind to DNA by non-covalent interactions such as electrostatic, intercalative and groove binding (Hartshorn et al 1992;Pebg et al 2007). All the studies reveal that modification of the metal or ligands would lead to subtle or substantial changes in the DNA binding modes, location and affinity.…”

Inorganic pharmaceuticals

“…Two novel cobalt(III) mixed-polypyridyl complexes [Co(2,2 0 -bipy) 2 (dpta)] 3+ and [Co(2,2 0 -bipy) 2 (amtp)] 3+ have been synthesised and characterised. 61 The interaction of these Co III complexes with calf thymus DNA has been investigated by spectroscopic and viscosity measurements, which suggest that the two complexes bind to DNA via an intercalative mode. 61 The Co III complexes were found to promote the photocleavage of pBR322 DNA plasmid on irradiation at 365 nm.…”

“…61 The interaction of these Co III complexes with calf thymus DNA has been investigated by spectroscopic and viscosity measurements, which suggest that the two complexes bind to DNA via an intercalative mode. 61 The Co III complexes were found to promote the photocleavage of pBR322 DNA plasmid on irradiation at 365 nm. 61 The mechanistic studies revealed that the hydroxyl radical (OH d ) was likely to be the reactive species responsible for the cleavage of plasmid DNA by [Co(bpy) 2 (dpta)] 3+ and that the superoxide anion radical (O 2…”