Synthesis, characterization and scavenger effects of OH• and O−•2 radicals of lanthanide(III) complexes with pyruvic acid semicarbazone

Crystal structure of (Z)-N'-[1-(3-methyl-5-oxo-1-phenyl-1,5-di-hydro-4H-pyrazol-4-yl-idene)prop-yl]benzene-sulfono-hydrazide

The title compound crystallizes in the keto form and the carbonyl O atom forms an intra­molecular N—H⋯O hydrogen bond with the neighbouring NH group. In the crystal, mol­ecules are linked by pairs of N—H⋯O hydrogen bonds to form inversion dimers, which are linked via pairs of C—H⋯O hydrogen bonds, forming chains propagating along [100].

The title compound, C₁₉H₂₀N₄O₃S, was synthesized by refluxing equimolar amounts of 1-phenyl-3-methyl-4-propionylpyrazol-5-one and benzene­sulfonyl hydrazide in ethanol. The compound crystallizes in the keto form and the carbonyl O atom forms an intra­molecular N—H⋯O hydrogen bond with the neighbouring NH group. There is also C—H⋯O short contact involving the neighbouring phenyl ring. Probably as a result of this, the phenyl ring is inclined to the pyrazolone ring by only 7.58 (12)°. The dihedral angle between the phenyl ring and the benzene­sulfonyl ring is 22.78 (11)°. In the crystal, mol­ecules are linked by pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R²₂(14) ring motif. The dimers are linked via pairs of C—H⋯O hydrogen bonds, forming chains propagating along [100].

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.

Evaluation of DNA-binding, DNA cleavage, antioxidant and cytotoxic activity of mononuclear ruthenium(II) carbonyl complexes of benzaldehyde 4-phenyl-3-thiosemicarbazones

Two 4-phenyl-3-thiosemicarbazone ligands, (E)-2-(2-chlorobenzylidene)-N-phenylhydrazinecarbothioamide (HL(1)) and (E)-2-(2-nitrobenzylidene)-N-phenylhydrazinecarbothioamide (HL(2)), and its ruthenium(II) complexes were synthesized and characterized by physico-chemical and spectroscopic methods. The Schiff bases act as bidentate, monobasic chelating ligands with S and N as the donor sites and are preferably found in the thiol form in all the complexes studied. The molecular structure of HL(1) and HL(2) were determined by single crystal X-ray diffraction method. DNA binding of the compounds was investigated by absorption spectroscopy which indicated that the compounds bind to DNA via intercalation. The oxidative cleavage of the complexes with CT-DNA inferred that the effects of cleavage are dose dependent. Antioxidant study of the ligands and complexes showed significant antioxidant activity against DPPH radical. In addition, the in vitro cytotoxicity of the ligands and complexes assayed against HeLa and MCF-7 cell lines showed higher cytotoxic activity with the lower IC50 values indicating their efficiency in killing the cancer cells even at low concentrations.

Synthesis, antimicrobial, DNA-binding and photonuclease studies of cobalt(III) and nickel(II) Schiff base complexes

New metal complexes of the type [M(nih)(L)](PF(6))(n)·xH(2)O and [M(nih)(2)](PF(6))·xH(2)O (where M=Co(III) or Ni(II), L=1,10-phenanthroline (phen)/or 2,2' bipyridine (bpy), nih=2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone, n=2 or 1 and x=3 or 2) have been synthesized and characterized by elemental analysis, magnetic, IR and (1)H NMR spectral data. The electronic and magnetic moment 2.97-3.07 B.M. data infers octahedral geometry for all the complexes. The IR data reveals that Schiff base (nih) form coordination bond with the metal ion through azomethine-nitrogen, phenolic-oxygen and carbonyl-oxygen in a tridentate fashion. In addition, DNA-binding properties of these six metal complexes were investigated using absorption spectroscopy, viscosity measurements and thermal denaturation methods. The results indicated that the nickel(II) complex strongly bind with calf-thymus DNA with intrinsic DNA binding constant K(b) value of 4.9×10(4) M(-1) for (3), 4.2×10(4) M(-1) for (4), presumably via an intercalation mechanism compared to cobalt(III) complex with K(b) value of 4.6×10(4) M(-1) (1) and 4.1×10(4) M(-1) (2). The DNA Photoclevage experiment shows that, the complexes act as effective DNA cleavage agent.

Synthesis, molecular modeling and spectroscopic characterization of nickel(II), copper(II), complexes of new 16-membered mixed-donor macrocyclic schiff base ligand incorporating a pendant alcohol function

Complexes of Cu(II) and Ni(II) of the composition [M(L)X] [where M=Ni(II), Cu(II) and X=Cl-, NO3-, CH3COO-] were synthesized with 1,5-dioxo-9,10-diaza-3,ol-tribenzo-(7,6,10,11,14,15) peptadecane, a N2O2 macrocyclic ligand. The complexes were characterized by elemental analysis, molar conductance measurements, UV-vis, IR, 1H NMR, 13C NMR, EPR and molecular modeling studies. All the complexes are non-electrolyte in nature. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes and a tetragonal geometry for Cu(II) complexes.

Synthesis, spectroscopic studies and structures of square-planar nickel(II) and copper(II) complexes derived from 2-{(Z)-[furan-2-ylmethyl]imino]methyl}-6-methoxyphenol

Two new nickel(II) [Ni(L)(2)] and copper(II) [Cu(L)(2)] complexes have been synthesized with bidentate NO donor Schiff base ligand (2-{(Z)-[furan-2-ylmethyl]imino]methyl}-6-methoxyphenol) (HL) and both complexes Ni(L)(2) and Cu(L)(2) have been characterized by elemental analyses, IR, UV-vis, (1)H, (13)C NMR, mass spectroscopy and room temperature magnetic susceptibility measurement. The tautomeric equilibria (phenol-imine, O-H...N and keto-amine, O...H-N forms) have been systemetically studied by using UV-vis absorption spectra for the ligand HL. The UV-vis spectra of this ligand HL were recorded and commented in polar, non-polar, acidic and basic media. The crystal structures of these complexes have also been determined by using X-ray crystallographic techniques. The complexes Ni(L)(2) and Cu(L)(2) crystallize in the monoclinic space group P2(1)/n and P2(1)/c with unit cell parameters: a=10.4552(3)A and 12.1667(4)A, b=8.0121(3)A and 10.4792(3)A, c=13.9625(4)A and 129.6616(3)A, V=1155.22(6)A(3) and 1155.22(6)A(3), D(x)=1.493 and 1.476 g cm(-3) and Z=2 and 2, respectively. The crystal structures were solved by direct methods and refined by full-matrix least squares to a find R=0.0377 and 0.0336 of for 2340 and 2402 observed reflections, respectively.

Bis{4-[(Z)-(4-fluoro-benzyl-amino)(phenyl)-methyl-ene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-onato-κN,O}nickel(II)

The mol­ecule of the title compound, [Ni(C₂₄H₁₉FN₃O)₂], has twofold rotation symmetry. The Ni^II ion is in a square-planar coordination geometry which is distorted towards tetra­hedral and is coordinated by two N atoms of imine and two O atoms of pyrazolone from two Schiff base 4-[(Z)-(4-fluoro­benzyl­amino)phenyl­methyl­ene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-onate ligands.

Infrared and DNA-binding on ultraviolet and fluorescence spectra of new copper and zinc complexes with a naringenin Schiff-base ligand

A naringenin Schiff-base ligand (H(3)L) and its copper(II) and zinc(II) complexes have been synthesized and characterized by elemental analyses, molar conductivities, (1)H NMR, IR spectra, UV spectra and thermal analyses. The DNA-binding properties of the Cu(II) and Zn(II) complexes have been investigated by fluorescence spectroscopy, ultraviolet spectroscopy and by viscosity measurements. The results indicate that complexes and ligand may bind to DNA by intercalation modes, but the binding affinity of the complexes is much higher than that of the ligand.

Synthesis, characterization and DNA-binding studies of 2-carboxybenzaldehydeisonicotinoylhydrazone and its La(III), Sm(III) and Eu(III) complexes

2-Carboxybenzaldehydeisonicotinoylhydrazone (HL), and its three lanthanide complexes, LnL(3).4H2O [Ln=La(1), Sm(2), Eu(3)], have been synthesized and characterized on the basis of elemental analyses, molar conductivities, IR spectra and thermal analyses. In addition, the DNA-binding properties of the ligand and its complexes have been investigated by absorption, fluorescence and viscosity measurements. The experimental results indicated that the complexes (2) and (3) can bind to DNA, but the ligand and the complex (1) cannot; the binding affinity of the complex (3) is higher than that of the complex (2) and the intrinsic binding constant Kb of the complex (3) is 7.86x10(4) M-1.

Synthesis, characterization, cytotoxic activities, and DNA-binding properties of the La(III) complex with Naringenin Schiff-base

A new Naringenin Schiff-base ligand (H3L) and its complex, [La(H2L)2(NO3).3H2O], have been synthesized and characterized on the basis of elemental analyses, molar conductivities, mass spectra, 1H NMR, thermogravimetry/differential thermal analysis (TG-DTA), UV spectra, and IR spectra. Spectrometric titrations, ethidium bromide displacement experiments, and viscosity measurements indicate that the two compounds, especially the La(III) complex, strongly bind with calf-thymus DNA, presumably via an intercalation mechanism. The intrinsic binding constants of the La(III) complex and ligand with DNA were 1.83 x 10(7) and 9.46 x 10(5) M(-1), respectively. Comparative cytotoxic activities of the La(III) complex and ligand were also determined by MTT [3-(4,5-dimethyl-2-thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide] and SRB (sulforhodamine B) methods. The results showed that the La(III) complex had significant cytotoxic activity against the tested cells.