Insights into the strong in-vitro anticancer effects for bis(triphenylphosphane)iminium compounds having perchlorate, tetrafluoridoborate and bis(chlorido)argentate anions

Three new compounds containing the bis(triphenylphosphane)iminium cation (PPN(+)) with ClO4(-), BF4(-) and [AgCl2](-) as counter anions have been synthesized and structurally characterized. The two derivatives with ClO4(-) and BF4(-) were found to be isostructural by single crystal X-ray diffraction. Interestingly, the three compounds show extremely potent antiproliferative effects against the human cancer cell line SKOV3. To gain insights into the possible mechanisms of biological action, several intracellular targets have been considered. Thus, DNA binding has been evaluated, as well as the effects of the compounds on the mitochondrial function. Furthermore, the compounds have been tested as possible inhibitors of the seleno-enzyme thioredoxin reductase.

Synthesis of a DNA-targeting nickel (II) complex with testosterone thiosemicarbazone which exhibits selective cytotoxicity towards human prostate cancer cells (LNCaP)

Testosterone thiosemicarbazone, L and its nickel (II) complex 1 were synthesized and characterized by using FTIR, CHN, (1)H NMR, and X-ray crystallography. X-ray diffraction study confirmed the formation of L from condensation of testosterone and thiosemicarbazide. Mononuclear complex 1 is coordinated to two Schiff base ligands via two imine nitrogens and two tautomeric thiol sulfurs. The cytotoxicity of both compounds was investigated via MTT assay with cisplatin as positive reference standard. L is more potent towards androgen-dependent LNCaP (prostate) and HCT 116 (colon). On the other hand, complex 1, which is in a distorted square planar environment with L acting as a bidentate NS-donor ligand, is capable of inhibiting the growth of all the cancer cell lines tested, including PC-3 (prostate). It is noteworthy that both compounds are less toxic towards human colon cell CCD-18Co. The intrinsic DNA binding constant (Kb) of both compounds were evaluated via UV-Vis spectrophotometry. Both compounds showed Kb values which are comparable to the reported Kb value of typical classical intercalator such as ethidium bromide. The binding constant of the complex is almost double compared with ligand L. Both compounds were unable to inhibit the action topoisomerase I, which is the common target in cancer treatment (especially colon cancer). This suggest a topoisomerase I independent-cell death mechanism.

A one-dimensional coordination polymer based on Cu3-oximato metallacrowns bridged by benzene-1,4-dicarboxylato ligands: structure and magnetic properties

A one-dimensional linear coordination polymer {[Cu₃(μ₃-OH)(2-pyao)₃(bdc)]·6(H₂O)}_n (1) composed of trinuclear metallacrown cores has been obtained.

New palladium(ii) and platinum(ii) 5,5-diethylbarbiturate complexes with 2-phenylpyridine, 2,2′-bipyridine and 2,2′-dipyridylamine: synthesis, structures, DNA binding, molecular docking, cellular uptake, antioxidant activity and cytotoxicity

DNA interaction, antioxidant and cytotoxic activities of Pd(ii)/Pt(ii) 5,5-diethylbarbiturate complexes were evaluated.

Cytotoxicity, genotoxicity and oxidative stress of malachite green on the kidney and gill cell lines of freshwater air breathing fish Channa striata

The cytotoxicity, genotoxicity and oxidative stress of malachite green (MG) was investigated using the fish Channa striata kidney (CSK) and Channa striata gill (CSG) cell lines. Five concentrations ranging from 0.001 to 10 μg mL(-1) were tested in three independent experiments. Cytotoxicity was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Rhodamine 123 and Alamar Blue. The mitochondrial changes and apoptosis of MG-exposed cells were observed by Rhodamine 123 and acridine orange/ethidium bromide (AO/EB) staining, respectively. In vitro potential DNA damaging effect of MG was tested using comet assay. Mitochondrial damage, apoptosis and DNA fragmentation increased in a concentration-dependent manner. Additionally, DNA electrophoretic mobility experiments were carried out to study the binding effect of MG to double-stranded DNA (dsDNA) of cells. DNA shift mobility experiments showed that MG is capable of strongly binding to linear dsDNA causing its degradation. Biochemical parameters such as lipid peroxidation (MDA), catalase (CAT) activity and reduced glutathione (GSH) levels were evaluated after exposure to MG. In CSK and CSG cell lines exposed to MG for 48 h, a significant increase in lipid peroxidation, which might be associated with decreased levels of reduced glutathione and catalase activity in these cell lines (p < 0.001), was observed.

Synthesis and crystal structure determination of copper(II)-complex: In vitro DNA and HSA binding, pBR322 plasmid cleavage, cell imaging and cytotoxic studies

New Cu(II) complex 1 of indole-3-propionic acid and 1,10-phenanthroline was synthesized and characterized by analytical, spectroscopic and single crystal X-ray diffraction. In vitro DNA binding studies of 1 was performed by employing UV-vis and fluorescence spectroscopic techniques. The binding affinity towards human serum albumin (HSA) was also investigated to understand the carrier role in body system, as the time dependent HPLC experiment of 1 revealed that bonded drug with protein releases slowly in presence of DNA. Complex 1 exhibited good anti-tumor activity (GI50 values <10 μg/ml), and to elucidate the mechanism of tumor inhibition, topoisomerase I enzymatic activity was carried out and further validated by cell imaging studies which clearly showed its nuclear localization.

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.

Four new trinuclear {Cu3(μ3-OH)(oximate)3}2+ clusters: crystal structure and magnetic behaviour

Four new triangular copper(ii) complexes with the fragment {Cu₃(μ₃-OH)(oximate)₃}²⁺ are reported. They exhibit strong antiferromagnetic coupling and antisymmetric exchange interaction.

De novo design, synthesis and spectroscopic characterization of chiral benzimidazole-derived amino acid Zn(II) complexes: Development of tryptophan-derived specific hydrolytic DNA artificial nuclease agent

Novel ternary dizinc(II) complexes 1-3, derived from 1,2-bis(1H-benzimidazol-2-yl)ethane-1,2-diol and l-form of amino acids (viz., tryptophan, leucine and valine) were synthesized and characterized by spectroscopic (IR, (1)H NMR, UV-vis, ESI-MS) and other analytical methods. To evaluate the biological preference of chiral drugs for inherently chiral target DNA, interaction of 1-3 with calf thymus DNA in Tris-HCl buffer was studied by various biophysical techniques which reveal that all these complexes bind to CT DNA non-covalently via electrostatic interaction. The higher K(b) value of L-tryptophan complex 1 suggested greater DNA binding propensity. Further, to evaluate the mode of action at the molecular level, interaction studies of complexes 1 and 2 with nucleotides (5'-GMP and 5'-TMP) were carried out by UV-vis titrations, (1)H and (31)P NMR which implicates the preferential selectivity of these complexes to N3 of thymine rather than N7 of guanine. Furthermore, complex 1 exhibits efficient DNA cleavage with supercoiled pBR322. The complex 1 cleaves DNA efficiently involving hydrolytic cleavage pathway. Such chiral synthetic hydrolytic nucleases with asymmetric centers are gaining considerable attention owing to their importance in biotechnology and drug design, in particular to cleave DNA with sequence selectivity different from that of the natural enzymes.

Biological evaluation of cobalt(II) complexes with non-steroidal anti-inflammatory drug naproxen

Cobalt(II) complexes with the non-steroidal anti-inflammatory drug naproxen in the presence or absence of nitrogen-donor heterocyclic ligands (pyridine, 2,2'-bipyridine or 1,10-phenanthroline) have been synthesized and characterized with physicochemical and spectroscopic techniques. The deprotonated naproxen acts as monodentate ligand coordinated to Co(II) ion through a carboxylato oxygen. The crystal structure of [bis(aqua)bis(naproxenato)bis(pyridine)cobalt(II)], 2 has been determined by X-ray crystallography. The EPR spectrum of complex 2 in frozen solution reveals that it retains its structure. UV study of the interaction of the complexes with calf-thymus DNA (CT DNA) has shown that the complexes can bind to CT DNA and [(2,2'-bipyridine)bis(methanol)bis(naproxenato)cobalt(II)] exhibits the highest binding constant to CT DNA. The cyclic voltammograms of the complexes recorded in DMSO solution and in the presence of CT DNA in 1/2 DMSO/buffer (containing 150 mM NaCl and 15 mM trisodium citrate at pH 7.0) solution have shown that they can bind to CT DNA by the intercalative binding mode which has also been verified by DNA solution viscosity measurements. Competitive study with ethidium bromide (EB) has shown that the complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB. Naproxen and its cobalt(II) complexes exhibit good binding propensity to human or bovine serum albumin proteins having relatively high binding constant values. The antioxidant activity of the compounds has been evaluated indicating their high scavenging activity against hydroxyl free radicals and superoxide radicals.

Biological evaluation of non-steroidal anti-inflammatory drugs-cobalt(II) complexes

Cobalt(II) complexes with the non-steroidal anti-inflammatory drug mefenamic acid in the presence or absence of nitrogen donor heterocyclic ligands (2,2'-bipyridine, 1,10-phenanthroline or pyridine) have been synthesized and characterized with physicochemical and spectroscopic techniques. The experimental data suggest that mefenamic acid acts as deprotonated monodentate ligand coordinated to Co(II) ion through a carboxylato oxygen. The crystal structures of tetrakis(methanol)bis-(mefenamato)cobalt(II), 1 and (2,2'-bipyridine)bis(methanol)bis(mefenamato)cobalt(II), 2 have been determined by X-ray crystallography. The EPR spectra of complexes 1 and 2 in frozen solution reveal that they retain their structures. UV study of the interaction of the complexes with calf-thymus DNA (CT DNA) has shown that the complexes can bind to CT DNA and bis(methanol)bis(pyridine)bis-(mefenamato)cobalt(II) exhibits the highest binding constant. Competitive study with ethidium bromide (EB) has shown that the complexes can displace the DNA-bound EB indicating that they bind to DNA in strong competition with EB. The cyclic voltammograms of the complexes recorded in dmso solution and in the presence of CT DNA in 1 : 2 dmso : buffer (containing 150 mM NaCl and 15 mM trisodium citrate at pH 7.0) solution have shown that they can bind to CT DNA by the intercalative binding mode. Mefenamic acid and its cobalt(II) complexes exhibit good binding propensity to human or bovine serum albumin protein having relatively high binding constant values. The antioxidant activity of the compounds has been evaluated indicating their high scavenging activity against hydroxyl free radicals and superoxide radicals.

Non-steroidal antiinflammatory drug-copper(II) complexes: structure and biological perspectives

Copper(II) complexes with the non-steroidal antiinflammatory drug mefenamic acid in the presence of aqua or nitrogen donor heterocyclic ligands (2,2'-bipyridine, 1,10-phenanthroline, 2,2'-bipyridylamine or pyridine) have been synthesized and characterized. The crystal structures of [(2,2'-bipyridine)bis(mefenamato)copper(II)], 2, [(2,2'-bipyridylamine)bis(mefenamato)copper(II)], 4, and [bis(pyridine)bis(methanol)bis(mefenamato)copper(II)], 5, have been determined by X-ray crystallography. UV study of the interaction of the complexes with calf-thymus DNA (CT DNA) has shown that the complexes can bind to CT DNA and [bis(aqua)tetrakis(mefenamato)dicopper(II)] exhibits the highest binding constant to CT DNA. The cyclic voltammograms of the complexes in the presence of CT DNA solution have shown that the complexes can bind to CT DNA by the intercalative binding mode verified also by DNA solution viscosity measurements. Competitive studies with ethidium bromide (EB) indicate that the complexes can displace the DNA-bound EB suggesting strong competition with EB. Mefenamic acid and its complexes exhibit good binding propensity to human or bovine serum albumin protein having relatively high binding constant values. All the compounds have been tested for their antioxidant and free radical scavenging activity as well as for their in vitro inhibitory activity against soybean lipoxygenase showing significant activity.

Cytogenetic evaluation and DNA interaction studies of the food colorants amaranth, erythrosine and tartrazine

Food coloring agents, amaranth, erythrosine and tartrazine have been tested at 0.02-8mM in human peripheral blood cells in vitro, in order to investigate their genotoxic, cytotoxic and cytostatic potential. Amaranth at the highest concentration (8mM) demonstrates high genotoxicity, cytostaticity and cytotoxicity. The frequency of SCEs/cell was increased 1.7 times over the control level. Additionally, erythrosine at 8, 4 and 2mM shows a high cytotoxicity and cytostaticity. Finally, tartrazine seems to be toxic at 8 and 4mM. No signs of genotoxicity were observed. Reversely, tartrazine showed cytotoxicity at 1 and 2mM. Furthermore, spectroscopic titration studies for the interaction of these food additives with DNA showed that these dyes bind to calf thymus DNA and distinct isosbestic points are observed clearly suggesting binding of the dyes to DNA. Additionally DNA electrophoretic mobility experiments showed that these colorants are obviously capable for strong binding to linear dsDNA causing its degradation. PCR amplification of all DNA fragments (which previously were pre-treated with three different concentrations of the colorants, extracted from agarose gel after separation and then purified), seems to be attenuated with a manner dye concentration-dependent reflecting in a delayed electrophoretic mobility due to the possible binding of some molecules of the dyes. Evaluation of the data and curves were obtained after quantitative and qualitative analysis of the lanes of the gel by an analyzer computer program. Our results indicate that these food colorants had a toxic potential to human lymphocytes in vitro and it seems that they bind directly to DNA.