Synthesis, X-ray crystal structure, DNA/BSA binding, DNA cleavage and cytotoxicity studies of phenanthroline based copper(II)/zinc(II) complexes

Abstract

Research on copper 1,10-phenanththroline (phen) derivatives continues to attract interest in the context of structure and biological properties. In this paper, two metal complexes [Cu(phen)(μ-Cl)]Cl (1), [Zn(phen)(HO)Cl]Cl·4HO (2) were synthesized and characterized. The crystal structures of 1 and 2 were determined by X-ray diffraction. In order to investigate the biological properties of the prepared complexes, spectroscopic and biological studies were performed. Results of X-ray diffraction showed that 1 and 2 form two types of crystal structures in a given system: dinuclear and mono-nuclear complex. The preliminary study on the DNA cleavage activity has shown that 1 under study behaved as the chemical nucleases. The DNA binding interaction of 1 & 2 with CT-DNA has been investigated by UV-Visible and fluorescence emission spectrometry and the apparent binding constant (K ) values are 5.1 × 10 and 1.2 × 10 M, respectively. In addition, fluorescence spectrometry of bovine serum albumin (BSA) with 1 & 2 showed that the quenching mechanism might be a static quenching procedure with one binding sites for BSA. In addition, the cytotoxicity of 1 in vitro on tumor cells lines (MCF-7, HepG2 and HT29) was examined by MTT and showed better antitumor effect on the tested cells.

Recent Development of Copper (II) Complexes of Polypyridyl Ligands in Chemotherapy and Photodynamic Therapy

“…The group prepared phenanthroline based binuclear Cu(II) complex [Cu 2 (phen) 2 (μ-Cl) 2 ]Cl 2 , 42 and mononuclear Zn based complex [Zn-(phen) 2 (H 2 O)Cl]Cl • 4H 2 O, 43. [102] Both the complexes have similar type of moderate binding capability determined from UV-Vis spectral titration of metal complex solution (10 μM) with gradual addition of CT-DNA (0-50 μM) and fluorescence displacement assay using gradual addition of metal complex solution 0-25 μM) to Ethidium bromide-DNA conjugates. The intrinsic and apparent binding constant of the complexes towards DNA are calculated by UV-VIS titration and ethidium bromide displacement assay were of the order of 10 4 M À 1 .…”

“…They reported that binuclear copper complex has DNA cleavage activity following chemical nuclease pathway and significantly higher cytotoxic activity towards tumor cell lines (MCF-7, HepG2 and HT29). [102] Patricia A. M. Williams et al has reported a ternary complex of Cu(II) metal ion [Cu(5HTP)(phen)(H 2 O)](NO 3 ) • 2H 2 O (44) with phenanthroline and antioxidant agent 5-hydroxytryptophan (5-HTP) (Figure 4). [103] It has been seen that the complex Cu-5HTPphen, 44 capable of inhibiting the growth of A549 cell line at 24 h in dose-dependent manner with a IC 50 value of 3.6 μM.…”

“…The intrinsic and apparent binding constant of the complexes towards DNA are calculated by UV‐VIS titration and ethidium bromide displacement assay were of the order of 10 4 M −1 . They reported that binuclear copper complex has DNA cleavage activity following chemical nuclease pathway and significantly higher cytotoxic activity towards tumor cell lines (MCF‐7, HepG2 and HT29) [102] …”

The BIOLOGICAL EFFICACY OF MIXED LIGAND COPPER(II) COMPLEXES OF N(4)-SUBSTITUTED THIOSEMICARBAZONE AND DIIMINE CO-LIGANDS AS CHELATING N, N’- DONOR LIGAND

“…Moreover, the majority of the mixed ligand complexes exhibit efficient oxidative cleavage higher than copper(II) bis complexes. In addition, complexes with diimine co-ligands act as a DNA recognition element and engage strong DNA interaction with an extended aromatic ring of bpy and phen [27]. It was apparently due to the partial intercalation and deeper insertion of the diimine coligands would predominately increase the DNA cleavage activity [28].…”

Synthesis, Characterization of Zinc Complexes with Neutral ?-Diimine Ligands and Application in Ring-opening Polymerization of ?-Caprolactone

“…zinc, magnesium, calcium, and iron complexes) [2,[8][9][10] to catalyze the ring-opening polymerization (ROP) of ε-CL or the polymerization of lactide. Zinc catalysts with a phenylic amino, [11] or a β-imino group, [12] or with a Schiff base moiety [13] were proven to have high activity and excellent capability of dimensional control. However, these catalysts are unstable, sensitive to the impact of air and moisture, and difficult to store.…”