Homoleptic bisterpyridyl complexes: Synthesis, characterization, DNA binding, DNA cleavage and topoisomerase II inhibition activity

Abstract

Abstractt Octahedral complexes of type [Co(L)2]·2NO3 1, [Co(L)2]·3NO3 2 and [Zn(L)2]·2NO3 3 (L = 4′-phenyl-2,2′:6′,2″ terpyridine) are synthesized and characterized using elemental analysis, NMR, IR, UV–Vis and fluorescence spectra and further supported by their X- ray diffraction studies. The binding properties of the complexes with DNA are carried out using UV–Vis, fluorescence titrations. Viscosity measurement supported partial intercalation of the complexes with DNA. Gel electrophoretic mobility assay of the complexes with Plasmid DNA (pBR322) shows that complex 1 binds with the major groove of double helical DNA. The molecular docking showed that complex 1 binds to DNA via groove binding in GC-rich sequence. It also inhibits topoisomerase II activity with IC50 value as 30. Other complexes do not bind DNA significantly.