Copper(ii) hydrazone complexes with different nuclearities and geometries: synthetic methods and ligand substituent effects

The effect of synthetic methods on the nuclearity and geometry of copper(ii) complexes with aroylhydrazones was investigated. Thermally induced structural transformations of dinuclear complexes under solvent-free conditions are also described.

DMSO containing ruthenium(ii) hydrazone complexes: in vitro evaluation of biomolecular interaction and anticancer activity

Synthesis, spectral, electrochemical and single crystal X-ray diffraction data of a new series of DMSO containing bivalent ruthenium hydrazone complexes are presented. XRD data of two of the new complexes revealed an octahedral coordination around the ruthenium ion satisfied by NOS2Cl2 atoms. Electrochemical studies showed the metal centred, quasi-reversible, one-electron redox behaviour of the new complexes. The binding of these complexes with biomolecules such as calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) protein investigated by different spectrophotometric methods revealed an intercalative mode of interaction. The in vitro cytotoxicity of these complexes evaluated by the MTT assay on a panel of cancer and normal cell lines indicated that the above complexes are more toxic to cancer cells with a few micromolar concentrations as the IC50 value, but are significantly less toxic to normal cell lines. The observed variations in the binding interactions and cytotoxicity of the complexes were attributed to the nature of the hydrazide moiety of the hydrazones that influences their biological activities.

Synthesis and spectroscopic characterization of diorganotin(iv) complexes of N′-(4-hydroxypent-3-en-2-ylidene)isonicotinohydrazide: chemotherapeutic potential validation by in vitro interaction studies with DNA/HSA, DFT, molecular docking and cytotoxic activity

A diorganotin(iv) hydrazide complex as a potential cancer chemotherapeutic agent targeting DNA using the carrier protein HSA.

Molecular oxygen reduction catalyzed by a highly oxidative resistant complex of cobalt–hydrazone at the liquid/liquid interface

Syntheses, structure and spectroscopic studies of a new cobalt complex with a hydrazine ligand. The first report on a highly oxidative resistant complex in the ORR electrocatalysis at the liquid–liquid interface.

A family of mixed-ligand oxidovanadium(v) complexes with aroylhydrazone ligands: a combined experimental and computational study on the electronic effects of para substituents of hydrazone ligands on the electronic properties, DNA binding and nuclease activities

Substituents at 5-position in the acetophenone ring of the hydrazone ligands in a family of mixed-ligand oxidovanadium(v) complexes show marked influence on the electronic properties, DNA binding ability and nuclease activity.

Significant differences in the biological activity of mononuclear Cu(ii) and Ni(ii) complexes with the polyquinolinyl ligand

The difference in the redox activity of metal ions Cu(ii) and Ni(ii) results in some discrepancy in the biological activity of their complexes.

Evaluation of the cell cytotoxicity and DNA/BSA binding and cleavage activity of some dioxidovanadium(V) complexes containing aroylhydrazones

Three dioxidovanadium(V) complexes [VO2L(1-3)] (1-3) [HL(1)=1-napthoyl hydrazone of 2-acetyl pyridine, HL(2)=2-furoyl hydrazone of 2-acetyl pyridine and H2L(3)=isonicotinoyl hydrazone of 2-hydroxy benzaldehyde] have been reported. All the complexes were characterized by various spectroscopy (IR, UV-visible and NMR) and the molecular structures of 1 and 2 were characterized by single crystal X-ray diffraction technique. Structural report established five-coordinate geometries, distorted toward square pyramidal for each of 1 and 2, based on a tridentate -O,N,N coordinating anion and two oxido-O atoms. The experimental results show that the complexes interact with calf-thymus DNA (CT-DNA) possibly by a groove binding mode, with binding constants of ~10(5)M(-1). All complexes show good photo-induced cleavage of pUC19 supercoiled plasmid DNA with complex 1 showing the highest photo-induced DNA cleavage activity of ~68%. 1-3 also exhibit moderate binding affinity in the range of 10(3)-10(4)M(-1) towards bovine serum albumin (BSA), while all the complexes show good photo-induced BSA cleavage activity. Moreover the antiproliferative activity of all these complexes was studied, which reveal all compounds are significantly cytotoxic towards the HeLa cell line.

An investigation on new ruthenium(II) hydrazone complexes as anticancer agents and their interaction with biomolecules

A new set of ruthenium(II) hydrazone complexes [Ru(H)(CO)(PPh3)2(L)] (1) and [RuCl2(DMSO)2(HL)] (2), with triphenyl phosphine or DMSO as co-ligands was synthesized by reacting benzoyl pyridine furoic acid hydrazone (HL) with [Ru(H)(Cl)(CO)(PPh3)3] and [RuCl2(DMSO)4]. The single crystal X-ray data of complexes 1 and 2 revealed an octahedral geometry around the ruthenium ion in which the hydrazone is coordinated through ON and NN atoms in complexes 1 and 2 respectively. The interaction of the compounds with calf thymus DNA (CT-DNA) has been estimated by absorption and emission titration methods which indicated that the ligand and the complexes interacted with CT-DNA through intercalation. In addition, the DNA cleavage ability of these newly synthesized ruthenium complexes assessed by an agarose gel electrophoresis method demonstrated that complex 2 has a higher DNA cleavage activity than that of complex 1. The binding properties of the free ligand and its complexes with bovine serum albumin (BSA) protein have been investigated using UV-visible, fluorescence and synchronous fluorescence spectroscopic methods which indicated the stronger binding nature of the ruthenium complexes to BSA than the free hydrazone ligand. Furthermore, the cytotoxicity of the compounds examined in vitro on a human cervical cancer cell line (HeLa) and a normal mouse embryonic fibroblasts cell line (NIH 3T3) revealed that complex 2 exhibited a superior cytotoxicity than complex 1 to the cancer cells but was less toxic to the normal mouse embryonic fibroblasts under identical conditions.

Binuclear copper complexes: synthesis, X-ray structure and interaction study with nucleotide/protein by in vitro biochemical and electrochemical analysis

Two new, binuclear copper(II) hydrazone complexes have been synthesized and characterized by various physico-chemical techniques including single crystal X-ray diffraction. Interaction of these complexes with nucleotide and protein were analyzed by in vitro biochemical and electrochemical analysis. Both the complexes exhibited intercalative mode of binding with DNA. Further, gel electrophoresis assay demonstrated the ability of the complexes to cleave the supercoiled pBR322 plasmid DNA to nicked circular DNA form. Cytotoxicity of the complexes performed against a panel of cancer cell lines and a normal cell line proved that these complexes are potentially cytotoxic against the cancerous cell lines, particularly with IC50 as low as 0.7 μM against HeLa cell line.

Synthesis, characterization, and binding properties towards CT-DNA and lipoxygenase of mixed-ligand silver(I) complexes with 2-mercaptothiazole and its derivatives and triphenylphosphine

Mixed-ligand silver(I) complexes of formulae [AgCl(TPP)2(MTZD)] (1), {[AgCl(TPP)2(MBZT)]·(MBZT)·2(toluene)} (2), and [AgCl(TPP)2(CMBZT)] (3) were obtained by refluxing toluene solutions of silver(I) chloride with triphenylphosphine (TPP) and the appropriate heterocyclic thioamides 2-mercaptothiazolidine (MTZD), 2-mercaptobenzothiazole (MBZT), and 5-chloro-2-mercaptobenzothiazole (CMBZT). The complexes were characterized by the melting point, vibrational spectroscopy (Fourier transform mid-IR), (1)H-NMR spectroscopy, UV-vis spectroscopy, and X-ray crystallography. DNA binding tests indicate the ability of complexes 1-3 to modify the activity of cells. The binding constants of 1-3 towards calf-thymus DNA (CT-DNA) [(3.5 ± 8.5) × 10(4) M(-1) for 1, (10.0 ± 0.0) × 10(4) M(-1) for 2, and (46.4 ± 7.0) × 10(4) M(-1) for 3] indicate strong interaction of 3. Changes in the fluorescence of ethidium bromide in the presence of DNA suggest intercalation into or electrostatic interactions with DNA. The corresponding apparent binding constants (K app) towards CT-DNA calculated through fluorescence spectra are (3.5 ± 0.7) × 10(4) M(-1) for 1, (10.0 ± 0.0) × 10(4) M(-1) for 2, and (46.4 ± 7.0) × 10(4) M(-1) for 3. Docking studies on DNA complexes confirm the binding of 1 and 2 in the major groove of CT-DNA and of 3 in the minor groove. Moreover, the influence of 1-3 on the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase was studied kinetically and theoretically. The antibacterial effect of 1-3 against the bacterial species Pseudomonas aeruginosa and Escherichia coli was evaluated. Complex 1 exhibits the strongest activity.