Kinetic and mechanistic study on the reactions of ruthenium(ii) chlorophenyl terpyridine complexes with nucleobases, oligonucleotides and DNA.

摘要: In this study, we investigated the ability of Ru(II) polypyridyl complexes to act as DNA binders. The substitution reactions three chlorophenyl terpyridine complexes, i.e. [Ru(Cl-Ph-tpy)(en)Cl]Cl (1), [Ru(Cl-Ph-tpy)(dach)Cl]Cl (2) and [Ru(Cl-Ph-tpy)(bpy)Cl]Cl (3) (Cl-Ph-tpy = 4′-(4-chlorophenyl)-2,2′:6′,2′′-terpyridine, en 1,2-diaminoethane, dach 1,2-diaminocyclohexane, bpy 2,2′-bipyridine), with a mononucleotide guanosine-5′-monophosphate (5′-GMP) oligonucleotides such fully complementary 15-mer 22-mer duplexes centrally located GG-binding site for DNA, 13-mer RNA were studied quantitatively by UV-Vis spectroscopy. Duplex reacts faster 1–3 than duplex while shorter (15mer GG) compared 22mer GG DNA. measured enthalpies entropies activation (ΔH≠ > 0, ΔS≠ < 0) support an associative mechanism process. 1H NMR spectroscopy studies performed on complex 3 demonstrated that after hydrolysis Cl ligand, it is capable interact guanine derivatives (i.e., 9-methylguanine (9MeG) 5′-GMP) through N7, forming monofunctional adducts. molecular structure cationic compound was determined in solid state X-ray crystallography. interactions calf thymus (CT) herring testes (HT) examined stopped-flow spectroscopy, which HT sensibly more reactive CT reactivity towards formation Ru–DNA adducts also revealed gel mobility shift assay, showing 1 2 have stronger unwinding 3. Overall, bidentate aliphatic diamines proved be superior those terms capability bind here biomolecules.