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The novel ligand (L) 1‐(furanyl)‐3‐(pyrrolyl)propenone had been synthesized, and its novel chelates of some 3d series of transition metal ions had been prepared and characterized. The structural properties of the titled compounds were explored using elemental analyses, spectroscopic techniques (UV–visible, MS, and FT‐IR), molar conductivity, and magnetic susceptibility measurements. The scanning electron microscope (SEM) showed that the ligand and its metal chelates exist in stick crystallized structures and sizes of their molecules can exist in nanoform. Thermal analyses techniques (TG and DTA) measured the investigated chelates during their thermal degradation to elucidate their structures. It was proved that ligand (L) acts as bibasic bidentate ligand coordinating to metal cations via its two oxygen atoms of carbonyl and epoxy groups. The optimization of the structural formula for the examined ligand had been performed by using Gaussian 09 program. The energy gaps were calculated using the DFT/B3LYP method. The ligand and its chelates had been fixed to have consistent bond lengths and bond angles that proved via quantum chemical factors. The ligand (L) and its transition metal chelates had been tested for their antibacterial activities. In vitro biological properties for ligand (L) and its transition metal complexes were carried out against Gram‐positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli and Pseudomonas aeruginosa) by agar diffusion technique. The results showed that title compounds are biologically active than the parent ligand in their sticks crystalline and possible nanostructures and consequently large surface interactions. Molecular docking showed favorable interaction between ligand and crystal structures of 3t88 E. coli, 3ty7 S. aureus, 5h67 B. subtilis, and 5i39 P. aeruginosa. This docking study proved that nanosize of ligand helps it to interact efficiently with proteins of bacteria. [ABSTRACT FROM AUTHOR]

Coordination compounds of Cr(III), Ru(III), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) ions were synthesized from the furan ligand [5-hydroxymethylfuran-2-yl-methyleneaminoquinolin-2-one] (H-MFMAQ) derived from the condensation of 5-hydroxymethylfuran-2-carbaldehyde and 1-aminoquinolin-2(1H)-one. Elemental analytical data, IR, NMR (1H, 13C, and 15N), EPR, XRD, SEM, TEM, EDX, TGA, mass, molar conductance, magnetic moment, and UV-Visible spectra techniques were used to confirm the structure of the synthesized chelates. According to the data obtained, the composition of the 1 : 1 metal ions : furan Schiff base ligand was found to be [M(MFMAQ)Cl2] (M = Cr(III) and Ru(III)) and [M(MFMAQ)Cl(H2O)]·nH2O in which (M = Mn(II); n=1, Co(II); n=0, Ni(II); n=2, Cu(II); n=0 and Zn(II); n=2.5). The measurements of magnetic susceptibility, ligand field parameter, and reflectance spectra suggested an octahedral geometry for the complexes. Central metals ions and furan Schiff base coordinated via O3 and N donor sites which was observed from IR spectra. The cytotoxic activities of all inspected compounds were evaluated towards human breast (MCF-7) and lung cancer (A549) cell lines. [ABSTRACT FROM AUTHOR]

A new series of complexes of 4-(4-hydroxy)-3-(2-pyrazine-2-carbonyl)hydrazonomethylphenyl-diazen-yl-benzenesulfonamide (HL) with Mn(II), Co(II), Ni(II), Zn(II) and Cd(II) have been prepared and characterized by different physical techniques. The IR spectra of the prepared complexes were suggested that the ligand behaves as a tri-dentate ligand through the carbonyl oxygen, azomethine nitrogen and phenolic oxygen atoms (ONO). Electronic spectra and magnetic susceptibility measurements reveal octahedral geometry for all complexes. The elemental analyses and mass spectral data have justified the ML 2 composition of complexes. The EPR spectra of Mn(II), Co(II) and Ni(II) complexes support the mononuclear structure. The crystal field splitting, Racah repulsion and nephelauxetic parameters and determined from the electronic spectra of the complexes. Thermal properties and decomposition kinetics of all complexes are investigated. The geometry of the metal complexes has been optimized with the help of molecular modeling. The biological activity of these compounds against various fungi has been investigated. [ABSTRACT FROM AUTHOR]

New Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Cd(II) complexes derived from bidentate Schiff base ligand, 5-chloro-2-[4-phenylthiazol-2-yl-iminomethyl]phenol (HL) have been synthesized. The molar ratio for all synthesized complexes is M: L = 1:2 which was established from the results of chemical analysis. The complexes have been characterized by elemental analysis, spectral (IR, UV–Vis, ( 1 H and 13 C) NMR, mass, ESR, XRD, CV, fluorescence, and magnetic as well as thermal analysis measurements. The IR spectra of the prepared complexes were suggested that the Schiff base ligand behaves as a bi-dentate ligand through the azomethine nitrogen atom and phenolic oxygen atom. The crystal field splitting, Racah repulsion and nepheloauxetic parameters and determined from the electronic spectra of the complexes. The presence of co-ordinated water molecules were confirmed by thermal studies. The spectroscopic studies suggest the octahedral geometry. From the modeling studies, the bond length, bond angle, core–core interaction, heat of formation, electronic energy, binding energy, HOMO, LUMO and dipole moment had been calculated to confirm the geometry of the ligand and their investigated complexes. Also, the thermal behavior and the kinetic parameters of degradation were determined using Coats–Redfern, Horowitz–Metzger and Piloyan–Novikova methods. Moreover, the in vitro antibacterial studies of all compounds screened against pathogenic bacteria (two Gram +ve and three Gram −ve) and three antifungal to assess their inhibiting potential. The assay indicated that the inhibition potential is metal ion dependent. The interaction of the complexes with calf thymus DNA (CT-DNA) has been investigated by UV absorption method, and the mode of CT-DNA binding to the complexes has been explored. Furthermore, the DNA cleavage activity by the complexes was performed. [ABSTRACT FROM AUTHOR]

The Schiff base ligand 1,2‐bis(2‐vinylphenoxy)ethane‐4,6‐diaminopyrimidine‐2‐thiol derived from the condensation of 4,6‐diaminopyrimidine‐2‐thiol with bisaldehyde was synthesized and characterized. Coordination compounds of this Schiff base with transition metal cations Cd(II), Zn(II), Ni(II), Co(II), Mn(II), Cu(II) and Fe(III) were synthesized and characterized. Microanalytical data, magnetic moments, mass, 1H NMR and infrared spectra, molar conductance measurements and thermal analyses were used to confirm the structures of the obtained Schiff base ligand and its chelates. According to the data obtained, the 1:1 general stoichiometric formulae of chelates are given by [M(HL)(H2O)2]Cl2 (M = Cd(II), Zn(II), Ni(II), Co(II), Mn(II), Cu(II)) and [Fe(HL)(H2O)2]Cl3. The diffuse reflectance spectra and magnetic moment measurements suggest an octahedral geometry for the complexes. The bis‐Schiff base ligand and metal ions are coordinated in a tetradentate manner via OO and NN donor sites as confirmed by infrared spectra. These complexes were then subjected to antibacterial studies using Gram‐positive (Streptococcus pyogenes and Bacillus subtilis) and Gram‐negative (Proteus vulgaris and Escherichia coli) organisms. The ligand and metal complexes exhibited pronounced antimicrobial activity against both types of bacteria. A docking study was conducted to evaluate the nature of the binding of the ligand and the most biologically active complexes to protein active sites of these bacteria. A novel bis‐Schiff base ligand, 1,2‐bis(2‐vinylphenoxy)ethane‐4,6‐diaminopyrimidine‐2‐thiol, was prepared. Coordination compounds of this Schiff base with transition metal cations Cd(II), Zn(II), Ni(II), Co(II), Mn(II), Cu(II) and Fe(III) were synthesized and characterized. Their biological activities were experimentally determined and confirmed using theoretical molecular docking. [ABSTRACT FROM AUTHOR]

The structure of prepared triazole ligand 4‐amino‐5‐(heptadec‐8‐en‐1‐yl)‐4H‐1,2,4‐triazole‐3‐thiol and its coordination behaviour towards transition metal ions Ni (II), Co (II), Fe (III), Cd (II) and Cu (II) have been studied using magnetic measurements, elemental analyses and electronic, Fourier transform infrared and 1H NMR spectroscopies. The thermal behaviours of the triazole ligand and its chelates were investigated and their thermal decomposition possibilities are proposed. The stages of all thermal decompositions are discussed. The Gaussian09 program was used to optimize the structural formula for the triazole ligand. Applying the DFT/B3LYP/6–311 basis set method, important theoretical parameters were calculated. The target triazole and its metal chelates were investigated in vitro against Escherichia coli, Staphylococcus aurous, Aspergillus flavus and Candida albicans, and were found to exhibit good antimicrobial activity. These results were confirmed using theoretical molecular docking. Biological activity of ligand and its metal chelates. [ABSTRACT FROM AUTHOR]

New ligand (HMPBT) ligand is prepared via condensation of 2-mercaptoaniline and 2-mercaptobenzoic acid in 1:1 ratio. Metal complexes are prepared and characterized by different physical techniques (IR, UV/Vis., 1 H NMR, 13 CNMR, TGA, DTA, DSC, XRD, magnetic moment and electrical conductance measurements). From the elemental analyses data, the complexes were proposed to have the general formulae [M(MPBT) 2 ] (where M = Co(II), Ni(II), Cu(II) and Zn(II) and MPBT = Ligand. The molar conductance data reveal that all the metal chelates were non-electrolytes. Infrared spectra of the complexes indicate deprotonation and coordination of the thiol SH. It also confirms that nitrogen atom of the benzothiazole group contribute to the complexation. Electronic spectra and magnetic susceptibility measurements as well as quantum chemical calculations reveal square planar geometry for Cu(II) and Ni(II) complexes and tetrahedral geometry for Co(II) and Zn(II) complexes. The activation of thermodynamic parameters are calculated using Coast-Redfern (CR), Horowitz–Metzger (HM), and Piloyan–Novikova (PN). The geometries of the complexes are confirmed using DFT method from DMOL 3 calculations and ligand field parameters. The investigated ligand and metal complexes were screened for their in-vitro antimicrobial activities against different types of fungal and bacterial strains. The resulting data assert on the inspected compounds as a highly promising bactericides and fungicides. The binding activities of zinc (II) complex with CT-DNA was investigated using absorption titration, fluorescence spectroscopy and cyclic voltammetry measurements in a Tris-HCl buffer system at pH 7.0. In addition to these methods, gel electrophoresis and viscosity measurements were also carried out to determine DNA-binding activities with zinc (II) complex in a buffer solution. The results indicated that zinc (II) complex interacts strongly with CT-DNA through the intercalative binding mode. [ABSTRACT FROM AUTHOR]

Drugs of cancer based upon ionizing radiation or chemotherapeutic treatment may affect breaking of DNA double strand in cell. DNA-PK enzyme has emerged as an attractive target for drug discovery efforts toward DNA repair pathways. Hence, the search for potent and selective DNA-PK inhibitors has particularly considered state-of-the art and several series of inhibitors have been designed. In this article, a novel benchmark DNA-PK database of 43 compounds was built and described. Ligand-based approaches including pharmacophore and QSAR modeling were applied and novel models were introduced and analyzed for predicting activity test for DNA-PK drug candidates. Based upon the modeling results, we gave a report of synthesis of fifteen novel 2-((8-methyl-2-morpholino-4-oxo-4 H -benzo[ e ][1,3]oxazin-7-yl)oxy)acetamide derivatives and in vitro evaluation for DNA-PK inhibitory and antiproliferative activities. These fifteen compounds overall are satisfied with Lipinski's rule of five. The biological testing of target compounds showed five promising active compounds 7c , 7d , 7f , 9e and 9f with micromolar DNA-PK activity range from 0.25 to 5 µM. In addition, SAR of the compounds activity was investigated and confirmed that the terminal aryl moiety was found to be quite crucial for DNA-PK activity. Moreover flexible docking simulation was done for the potent compounds into the putative binding site of the 3D homology model of DNA-PK enzyme and the probable interaction model between DNA-PK and the ligands was investigated and interpreted. [ABSTRACT FROM AUTHOR]