An Experimental and Molecular modelling Study of Ruthenium(II) Polypyridyl Complexes with a Thiazole-Imidazo-Phenanthroline Ligand and their DNA Affinity
摘要
Mononuclear Ru(II)Polypyridyl complexes of type [Ru(A)2MTZIP] (ClO4)2.2H2O, where MTZIP = (2-(4-methyl thiazol-5-yl)-1 H-imidazole [4,5-f] [
The intrinsic binding constant (kobs) data show 1 > 2>3 > 4, indicating the phen complex (1.0 × 106) has a higher binding capacity than the bpy, dmp, and dmb (4.5 × 105,3.5 × 105, 2.0 × 105), demonstrating the auxiliary ligand effect on the specificity of DNA binding. The HOMO-LUMO gap (Eg) values for the complexes 1–4 are in the range of 5.6375–5.7398 eV, ligand MTZIP (7.3026 eV), indicative of a more reactivity for complexes. The 3D contour maps show that in complexes LUMO is primarily concentrated on or near the Ru (II) metal ion and auxiliary ligands; on the contrary, the HOMO has constraints to the intercalating ligand’s nitrogen. The phen complex has greater chemical reactivity than the bpy, dmp and dmb complexes, so complex 1 is more vulnerable to nucleophilic attack. All four complexes were active against Gram-positive bacterial pathogens (Staphylococcus and Bacillus strains) as well as Gram-negative bacterial species (E. Coli and Klebsiella) and antifungal activity (candida, aspergillus). All the complexes showed good anticancer activity, but the phen complex with IC50 = 22.89 ± 0.814 against the MCF-7 cell line.