title: Binding and photocleavage of DNA by mixed ligand Co(III) and Ni(II) complexes of thiophene[2, 3-b] quinoline and phenanthrolie/bipyridine.
abstract: In order to systematically perform an experimental and theoretical study on DNA binding and photocleavage properties of transition metal complexes of the type [M(L)2(L1)](PF6)n x xH2O (where M = Co(III) or Ni(II), L = 1,10-phenanthroline or 2.2' bipryidine, L1 = Thiophene [2,3-b] quinoline (qt), n = 3 or 2 and x = 5 or 2) have been synthesized and characterized by elemental analysis, IR, 1H NMR, UV and magnetic susceptibility data. The DNA-binding properties of these complexes have been investigated with UV-Vis, viscosity measurements, thermal denaturation and cyclic voltametric studies. It is experimentally found that all the complexes are bound to DNA via intercalation in the order [Co(bpy)2(qt)](PF6)3 > [Co(phen)2(qt)](PF6)3 > [Ni(phen)2(qt)](PF6)2 > [Ni(bpy)2(qt)](PF6)2. The photocleavage studies with pUC19 DNA shows that all these complexes promoted the conversion of SC form to NC form in absence of 'inhibitors'.
authors.affiliation: Department of P.G. Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta-577451, Shimoga, Karnataka, India.
authors.forename: Mustur C
authors.initials: MC
authors.lastname: Prabahkara
authors.forename: Halehatty S
authors.initials: HS
authors.lastname: Bhojya Naik
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D053837:DNA Cleavage; D004278:DNA, Superhelical / Q000737:chemistry* / Q000528:radiation effects; D006358:Hot Temperature; D008024:Ligands; D009532:Nickel / Q000737:chemistry; D009691:Nucleic Acid Denaturation; D010618:Phenanthrolines / Q000737:chemistry*; D010777:Photochemistry; D011804:Quinolines / Q000737:chemistry*; D013057:Spectrum Analysis; D013876:Thiophenes / Q000737:chemistry*; D014783:Viscosity
chemical_list: D004278:DNA, Superhelical; D008024:Ligands; D010618:Phenanthrolines; D011804:Quinolines; D013876:Thiophenes; D003035:Cobalt; D015082:2,2'-Dipyridyl; D009532:Nickel