Physico-chemical characterization and anti- microbial activity of copper(II) complexes with 2-amino and 2-methylbenzimidazole derivatives

Copper(II) chloride, in warm ethanolic solution, reacted with 2-amino and 2-methylbenzimidazole derivatives to give complexes of the formula CuL2Cl2·nH2O, where L=1-benzyl-2-aminobenzimidazole 1-(4-methylbenzyl)-2-aminobenzimidazole, 1-benzyl-2-methylbenzimidazole and 1-(4-methylbenzyl)-2-methylbenzimidazole( n=1 or 2). The complexes were characterized by elemental analysis of the metal, molar conductivity magnetic susceptibility measurements and IR spectra. The molar conductivities of copper(II)complexes in dimethyl formamide (DMF) corresponding to a 1:1 type of electrolyte indicate that in all the complexes one of the coordinated chloride ions has been replaced by DMF molecule. The room temperature effective magnetic moments and IR data of the complexes suggest that all Cu(II) complexes have a tetrahedral configuration, which is realized by participation of the pyridine nitrogen of two organic ligand molecules and two chloride anions. The antimicrobial activity of the ligands and their complexes against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus, Sarcina lutea and Saccharomyces cerevisiae was investigated. The effect of copper complexation on the ligand antimicrobial activity is discussed

Synthesis, physico-chemical characterization and biological activity of 2-aminobenzimidazole complexes with different metal ions

Complexes of 2-aminobenzimidazole (L) with nitrates of cobalt(II) nickel(II), copper (II), zinc(II) and silver(I) were synthesized. The molar ratio metal:ligand in the reaction of the complex formation was 1:2. It should be noticed, that the reaction of all the metal salts yielded bis(ligand) complexes of the general formula M(L)2(NO3)2 × nH2O (M=Co, Ni Cu, Zn or Ag; n=0, 1, 2 or 6). The complexes were characterized by elemental analysis of the metal, molar conductivity, magnetic susceptibility measurements and IR spectra. Co(II), Ni(II) and Cu(II) complexes behave as non-electrolytes, whilst Zn(II) and Ag(I) are 1:1 electrolytes. Cu(II) complex has a square-planar stereochemistry, Ag(I) complex is linear, whilst the Co(II), Ni(II) and Zn(II) complexes have a tetrahedral configuration. In all the complexes ligand is coordinated by participation of the pyridine nitrogen of the benzimidazole ring. The antimicrobial activity of the ligand and its complexes against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus and Saccharomyces cerevisiae was investigated. The effect of metal on the ligand antimicrobial activity is discussed

Transition metal complexes with Girard reagents and their hydrazones

This is the first review dealing with the coordination chemistry of metal complexes with Girard's reagents and their hydrazones. The short introduction points out to chemical properties and significance of these organic compounds. The next section briefly describes synthetic methods for preparing complexes with Girard's reagents, as well as modes of coordination of these ligands. The last two extensive sections review the preparation, stereochemistry and structural characteristics of metal complexes with Girard's hydrazones, including some newer non-hydrazonic derivatives of Girard's reagents, also.[Acknowledgments. Projekat Ministarstva nauke Republike Srbije, br. 172014

Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II) bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC). Crystal structure of [Cu(PLITSC−H)H2O]Br•H2O

The synthesis and structural characterization of a square-planar copper(II) complex with pyridoxal S-methylisothiosemicarbazone (PLITSC) of the formula [Cu(PLITSC−H)H2O]Br•H2O (1) as the first Cu(II) complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSC)Br2] (2) and [Cu(PLITSC)Br(MeOH)]Br (3) were characterized by elemental analysis, IR and electronic spectra and also by the methods of thermal analysis, conductometry and magnetochemistry. [Projekat Pokrajisnkog sekretarijata za nauku i tehnoloski razvoj Vojvodine i Ministarstva nauke Republike Srbije, br. 172014

Bis{N,N,N-trimethyl-2-oxo-2-[2-(2,3,4- trihydroxy­benzyl­idene)hydrazin­yl]ethanaminium} tetra­chlorido­zincate(II) methanol solvate1

The asymmetric unit of the title compound, (C12H18N3O4)2[ZnCl4]·CH3OH, consists of two Girard reagent-based cations, a tetra­chlorido­zincate anion and a mol­ecule of methanol as solvate. These components are inter­connected in the crystal structure by an extensive network of O—H⋯O, N—H⋯O, C—H⋯O, O—H⋯N, O—H⋯Cl, N—H⋯Cl and C—H⋯Cl hydrogen bonds. The shortest inter­molecular inter­action is realized between the cation and anion [H⋯Cl = 2.29 (5) Å; O—H⋯Cl = 167 (3)°]. C—H⋯O inter­actions also play a important role in the inter­connection of the cations

Syntheses and characterization of 2-acetylpyridine-aminoguanidine and its copper(II) complexes: Crystallographic and antimicrobial study

The syntheses, physico-chemical and microbiological properties of the ligand, 2-acetylpyridine-aminoguanidine dihydrogensulfate monohydrate and its five complexes with Cu(II) are described. The compounds were characterized by single crystal X-ray crystallography. Common fragments encountered in some of the structures were compared by r.m.s. overlay calculations as well as half-normal probability plots. In these complexes the chelate ligand is coordinated in its neutral form in a tridentate N-3-coordination mode, via pyridine, azomethine and imino nitrogen atoms of the aminoguanidine fragment. In these complexes the Cu(II) ion is situated in moderately or severely distorted square-pyramidal surroundings. The antimicrobial activity of the ligand and the complexes were examined against 6 selected bacterial and 3 fungal strains.This is peer-reviewed version of the following article: Vojinović-Ješić, L. S.; Radanović, M. M.; Rodić, M. V.; Živković-Radovanović, V.; Jovanović, L. S.; Leovac, V. M. Syntheses and Characterization of 2-Acetylpyridine-Aminoguanidine and Its Copper(II) Complexes: Crystallographic and Antimicrobial Study. Polyhedron 2016, 117, 526–534. [https://doi.org/10.1016/j.poly.2016.06.032]Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3583

Synthesis and structural characterization of Cd(II) complexes with 2-acetylpyridine-aminoguanidine - a novel coordination mode

The structures of the first two complexes with bidentate coordination of aminoguanidine Schiff base, i.e., 2-acetylpyridine-aminoguanidine (L), are reported. The complex of the formula [Cd2Cl6(HL)2] (1) was obtained in the reaction of warm aqueous solutions of chloride salts of Cd(II), Zn(II) and the ligand, while the reaction of cadmium bromide and the ligand in the presence of deprotonating agent as well as ammonium thiocyanate resulted in the formation of the complex in which Schiff base has both the role of the ligand and the counterion, viz., [HL][Cd(HL)(NCS)2XY]·H2O (2), where X is Cl- or Br-, and Y Br- or SCN-. The complexes were characterized by IR spectroscopy, elemental analysis, conductometric measurements and single crystal X-ray diffraction. The unusual bidentate coordination of the Schiff base lead to significant changes in the geometry of this molecule (from almost planar in free form and as a tridentate ligand to twisted as a bidentate ligand). Besides, in complex 1 relatively rare bridging coordination of Cl- in octahedral Cd(II) is found, while the crystal structure of complex 2 exhibits substitutional disorder, and contains four different anions: [Cd(HL)(NCS)2Br(SCN)]- (ca. 61 %), [Cd(HL)(NCS)2Cl(SCN)]- (ca. 35 %), [Cd(HL)(NCS)2Br2]- (ca. 3 %) and [Cd(HL)(NCS)2ClBr]- (ca. 1 %)

Insight in miRNome of severe multiple sclerosis: Pilot study of distinctive relapse-onset MS phenotypes

Molecular background and biomarkers of highly heterogenous and hardly predictable disease progression among relapse-onset MS patients are of high research interest. In the current pilot study, we aimed to employ next-generation sequencing to investigate the expression of whole small non-coding microRNAs (miRNome) in two groups of MS patients with highly distinctive progression phenotype: one with fast progressing, severely disabling course vs. mild course of MS, longitudinally followed 10 years. Peripheral blood mononuclear cells (PBMC) miRNome data was obtained from mild phenotype MS (n=4 patients) and progressive phenotype MS (n=5 patients), using TakaraBio SMARTer smRNA-Seq Kit on iSeq100 (Illumina). Pre-processing of raw sequencing data, quality control and miRNA differential expression analysis was performed using sRNAtoolbox pipeline. Functional interpretation of differentially expressed miRNA target genes was done in DIANA-miRPathv3.0. Tarbase v8.0 served as a resource of miRNA:gene interactions. Achieved read depth was approximately 1 million raw reads/sample, allowing detection of up to 92 mature miRNAs after genome alignment and miRbase v22 annotation. Differential expression analysis identified the significant upregulation of hsa-miR-23c (log2FC=4.29, Padj= 0.03) in progressive phenotype. Top significantly enriched KEGG pathways in hsa-miR-23c targets suggested regulation of molecular pathways involved in autoimmunity (antigen presentation, Epstein-Barr virus infection) and cancer. In conclusion, this pilot study indicates phenotype-related differences in expression of miRNAs, molecules with high regulatory and biomarker properties. Although detected in PBMC, has-miR-23c is highly expressed in the brain and target MS relevant genes such as, HLA (A, B, C), transferrin receptor, Nrf2, recently proposed to play important role in neurodegeneration

First cobalt complexes with methyl pyruvate semi/thiosemicarbazone - synthesis, physico-chemical and structural characterization

In the reaction of acetone solutions of CoX2∙nH2O (X = Cl, Br) with methyl pyruvate semi/thiosemicarbazone (Hmps, Hmpt) the first Co(II) complexes with these ligands, i.e., [Co(Hmps)(H2O)X2] (X = Cl (1), Br (2)), [Co(Hmpt)2][CoCl4]∙2H2О (3) and [Co(Hmpt)2]Br2∙Me2CO (4) were obtained. Complexes 1 and 2 represent the first examples of metal complexes of Hmps. All the obtained compounds were characterized by elemental analysis, conductometry, magnetic measurements, and IR spectra, and for complexes 2–4, single crystal X-ray diffraction analysis was also performed. The effective magnetic moments were close to the upper limit (5 μB) for complexes 1 and 2, and close to the lower limit (4.4 μB) for complexes 3 and 4, and as such are characteristic for high-spin Co(II) complexes. Structural analysis showed that both ligands coordinate in a neutral form in a tridentate manner, via the ester oxygen, imine nitrogen and the oxygen atom of the ureido (Hmps), or the sulfur atom of the thioureido group (Hmpt). The central metal atoms are situated in a deformed octahedral coordination environment. Complex 2 has cis-Br configuration, while complexes 3 and 4 have mer-configuration

Amino­(5-{2-[amino­(iminio)meth­yl]hydrazin-1-yl}-3,5-dimethyl-4,5-dihydro-1H-pyrazol-1-yl)methaniminium dinitrate

The reaction of aqueous solutions of amino­guanidine hydrogennitrate and acetyl­acetone produces the title pyrazole salt, C7H18N8 2+·2NO3 −. The crystal structure is stabilized by a complex N—H⋯O hydrogen-bonding network. The difference in the engagement of the two nitrate anions in hydrogen bonding is reflected in the variation of the corresponding N—O bond lengths