DNA Binding Properties of Water-Soluble Mixed Ligand Nickel(II) Complex with Calf-thymus DNA Using Different Instrumental Methods

Bioactive Heterometallic CuII-ZnII Complexes with Potential Biomedical Applications

A series of multinuclear heterometallic Cu-Zn complexes of molecular formula [(CuL)₂Zn(dca)₂] (1), [(CuL)₂Zn(NO₃)₂] (2), [(CuL)₂Zn₂(Cl)₄] (3), and [(CuL)₂Zn₂(NO₂)₄] (4) have been synthesized by reacting [CuL] as a "metalloligand (ML)" (where HL = N,N'-bis(5-chloro-2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine) and by varying the anions or coligands using the same molar ratios of the reactants. All of the four products including the ML have been characterized by infrared and UV-vis spectroscopies and elemental and single-crystal X-ray diffraction analyses. By varying the anions, different structures and topologies are obtained which we have tried to rationalize by means of thorough density functional theory calculations. All of the complexes (1-4) have now been applied for several biological investigations to verify their therapeutic worth. First, their cytotoxicity properties were assessed against HeLa human cervical carcinoma along with the determination of IC₅₀ values. The study was extended with extensive DNA and protein binding experiments followed by detailed fluorescence quenching study with suitable reagents to comprehend the mechanistic pathway. From all of these biological studies, it has been found that all of these heterometallic complexes show more than a few fold improvement of their therapeutic values as compared to the similar homometallic ones probably because of the simultaneous synergic effect of copper and zinc. Among all of the four heterometallic complexes, complex 3 exhibits highest binding constants and IC₅₀ values suggest for their better interaction toward the biological targets and hence have better clinical importance.

Synthesis and characterization of new unsymmetrical Schiff base Zn (II) and Co (II) complexes and study of their interactions with bovin serum albumin and DNA by spectroscopic techniques

Two novel tetra-coordinated Cobalt(II) and Zinc (II) chelate series with the general formula of [Co (L)·2H₂O] (1) and [Zn (L)] (2) [L=N-2-hydroxyacetophenon-N'-2-hydroxynaphthaldehyde-1,2 phenylenediimine)] with biologically active Schiff base ligands were synthesized and recognized by elemental analysis and multi-nuclear spectroscopy (IR and ¹H and ¹³C NMR); then, their biological activities including DNA and protein interactions were studied. The interaction of the synthesized compounds with bovine serum albumin (BSA) was investigated via fluorescence spectroscopy, showing the affinity of the complexes for these proteins with relatively high binding constant values and the changed secondary BSA structure in the presence of the complexes. The interaction of these compounds with CT-DNA was considered by UV-Vis technique, emission titration, viscosity measurements, helix melting methods, and circular dichroism (CD) spectroscopy, confirming that the complexes were bound to CT-DNA by the intercalation binding mode. Furthermore, the complexes had the capability to displace the DNA-bound MB, as shown by the competitive studies of these complexes with methylene blue (MB), thereby suggesting the intercalation mode for the competition. Finally, the theoretical studies carried out by the docking method were performed to calculate the binding constants and recognize the binding site of the BSA and DNA by the complexes. In addition, in vitro and in silico studies showed that the compounds were degradable by bacterial and fungal biodegradation activities.

A saccharinate-bridged palladacyclic dimer with a Pd–Pd bond: experimental and molecular docking studies of the interaction with DNA and BSA and in vitro cytotoxicity against human cancer cell lines

The synthesis, characterization and biological activities of a saccharinate-bridged palladacyclic dimer are reported in this work.

Study on the interaction of berberine with nucleic acids in the presence of silver nanoparticles, and the fluorometric determination of nucleic acids

The partial intercalation binding between BER and ctDNA, and the anti-photobleaching ability of BER were both strengthened by AgNPs. A metal enhanced fluorescence-based sensitive method for the determination of nucleic acids was obtained.