Ternary Co(II), Ni(II) and Cu(II) Complexes Containing Dipyridophenazine and Saccharin: Structures, Reactivity, Binding Interactions with Biomolecules and DNA Damage Activity

Publication date: Available online 17 February 2020Source: Inorganica Chimica ActaAuthor(s): Priyaranjan Kumar, Ray J. Butcher, Ashis K. PatraAbstractHerein, we report physiochemical aspects, crystal structures, biological reactivity and interaction, DNA damage activity and preliminary antimicrobial properties of three metal complexes, [Co/Ni(dppz)2(sac)(H2O)]ClO4 [Co(II), 1; Ni(II), 2] and [Cu(dppz)2(sac)]ClO4 (3), where dppz is dipyrido[3,2-a:2′,3′-c]phenazine as potential photosensitizer and DNA intercalator and sac is artificial sweetener saccharin (o-sulfobenzimide). The solid-state structural analysis revealed that the bivalent metal centre is in distorted octahedral [MN5(OH2); M = Co(II) (1), M = Ni(II) (2)] and square pyramidal [MN5; M = Cu(II) (3)] geometries arising from N,N donor-dppz and saccharinate (sac) ligands. The complexes showed redox responses with characteristic metal and ligand (dppz) redox couples. The reactivity and speciation of complexes were studied with glutathione (GSH) and sodium L(+) ascorbate (asc) from UV-vis, fluorescence and ESI-MS analyses. The complexes exhibit high binding affinity (K ∼ 105–107 M-1) to human serum albumin (HSA) with a preferential binding affinity towards tryptophan (Trp-214) residue. The fluorescence resonance energy transfer (FRET) analysis showed an efficient energy transfer to the complexes. The monocationic complexes strongly bind CT-DNA (Kb ∼ 105–106 M-1) by intercalation from planar dppz and stabilized ...
Source: Inorganica Chimica Acta - Category: Chemistry Source Type: research