Coordination properties of 1,3-benzothiazoles. Formation of a polymeric complex with square-planar coordination around the copper(II) ion in the reaction of CuCl2·6H2O with 1,2-bis[2-(1,3-benzo-thiazol-2-yl)phenylthio]ethane

It is shown that a coordination polymer is formed by the reaction of 1,2-bis[2-(1,3-benzothiazol-2-yl)-phenylthio]ethane with copper(II) chloride in a mixture of ethanol and chloroform at room temperature. The structure of the polymer has been determined by X-ray crystallography. The copper atom in the coordination polymer has a square-planar ligand environment and is coordinated to the nitrogen atoms of the benzothiazole rings of two different molecules of ligand and two chloride anions. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1576-1580, October, 2008.     

New organic picolylamine-type ligands and electrochemical study of their complexation with Cu(MeCN)<Subscript>4</Subscript>ClO<Subscript>4</Subscript>

A series of novel organic ligands with dipicolylamine and disulfide groups connected by polymethylene, alkylaryl, alkoxyaryl, or alkoxycarbonyl linker was synthesized. The electrochemical study by cyclic voltammetry was carried out for two synthesized ligands, and the formation of the complexes with Cu(MeCN)ClO₄ in the solution or on the gold electrode surface was established. The complex of Cu^I with 1,24-bis[N,N-bis(2-pyridylmethyl)-glycinoyloxy]-12,13-dithiatetracosane chemisorbed on the Au electrode is capable of binding molecular oxygen from solution.     

Novel aurophilic organic ligands based on 1,3-dibromo-propan-2-ol and 2-aminothiophenol

The nucleophilic substitution reactions in 1,3-dibromo-propan-2-ol and the products of its acylation under the action of 2-aminothiophenol were investigated. It was shown that the resulting derivatives containing nitrogen and sulfur donor atoms form coordination compounds in the reactions with copper(II) salts. The possibility of chemosorption of the obtained ligands and complexes containing additional disulfide fragments on the gold electrode surface with the formation of an Au-S bond was demonstrated.     

Synthesis of dispirooxindoles containing N-unsubstituted heterocyclic moieties and study of their anticancer activity

A convenient method is proposed for the synthesis of N-unsubstituted spiroxindoles with different heterocyclic moieties (2-thiohydantoin, hydantoin, and thiazolidine) by the regio-selective 1,3-dipolar cycloaddition of azomethine ylides, generated from isatins and sarcosine, to arylidene derivatives of corresponding heterocycles. The cytotoxicity of compounds was tested by the MTT method against MCF7, A549, HEK, and VA13 cell lines and compared with the anticancer drug Nutlin-3a. The best bioactivity was observed for hydantoin-based dispiroindolinones, the most cytotoxic compound demonstrated selectivity against A549 lung cancer cells with an IC₅₀ value of 6.6±1.6 μmol L^?1.

     

Synthesis of ethynyl-3-hydroxyquinoline-4-carboxylic acids

Russian Chemical Bulletin - 3-Hydroxyquinoline-4-carboxylic acids containing ethynyl moiety in the 6th and 8th positions were obtained for the fi rst time. A synthetic approach to aforementioned...     

Synthesis and Biological Evaluation of S-, O- and Se-Containing Dispirooxindoles

A series of novel S-, O- and Se-containing dispirooxindole derivatives has been synthesized using 1,3-dipolar cycloaddition reaction of azomethine ylide generated from isatines and sarcosine at the double C=C bond of 5-indolidene-2-chalcogen-imidazolones (chalcogen was oxygen, sulfur or selenium). The cytotoxicity of these dispiro derivatives was evaluated in vitro using different tumor cell lines. Several molecules have demonstrated a considerable cytotoxicity against the panel and showed good selectivity towards colorectal carcinoma HCT116 p53^+/+ over HCT116 p53^−/− cells. In particular, good results have been obtained for LNCaP prostate cell line. The performed in silico study has revealed MDM2/p53 interaction as one of the possible targets for the synthesized molecules. However, in contrast to selectivity revealed during the cell-based evaluation and the results obtained in computational study, no significant p53 activation using a reporter construction in p53wt A549 cell line was observed in a relevant concentration range.     

Use of gold nanoparticles for immobilization of <Emphasis Type="Italic">L</Emphasis>-cysteine on TLC plates

A new method of immobilization of the chiral selector on the surface of TLC plates by means of stepwise impregnation by gold nanoparticles and L-cysteine is described. The novel silica- and alumina-based stationary phases for TLC demonstrate enantioselectivity toward tetrahydrozoline, hydroxyzine, ketoprofen, fenoprofen, pindolol, and fluoxetine. The influence of the composition of the mobile phase on the R _f values and enantioselectivity is also discussed.     

A convenient synthesis of copper(II) bis[5-(pyridin-2-yl-methylidene)-2-thiohydantoin] complexes

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Erratum to: Conformations,vibrational spectra and force field of 1-methyl-2-(2′-pyridyl)benzimidazole: experimental data and density functional theory investigation in comparison with 2-(2′-pyridyl)benzimidazole

Structural Chemistry -     

Novel 2-aminoimidazole-4-one complexes of copper(II) and cobalt(II): Synthesis,structural characterization and cytotoxicity

A series of 2-aminosubstituted (5Z)-3-phenyl-5-(pyridine-2-ylmethylene)-3,5-dihydro-4H-imidazole-4-ones (L) was prepared by the reaction of the corresponding 2-alkylthio-3,5-dihydro-4H-imidazole-4-ones with morpholine or piperidine in the presence of ytterbium(III) triflate. The resulting ligands were subsequently reacted with CuCl₂·2H₂O and CoCl₂·6H₂O to give the corresponding copper(II) and cobalt(II) complexes, respectively. Analysis revealed that the complexes were formed with an LMCl₂ (M = Cu, Co)-type composition in all cases. The structures of the three cobalt complexes prepared in this way were determined by X-ray crystallography. The results revealed that the cobalt ions in these complexes were tetrahedrally coordinated to two chloride anions and two nitrogen atoms from the pyridine and imidazole moieties of the ligand. The electrochemical properties of the ligands and their complexes were evaluated by cyclic voltammetry, and the results revealed that the first stage in the reduction of the Co(II) and Cu(II) complexes involved the reversible formation of the corresponding Co(I) and Cu(I) complexes, respectively. The cytotoxicity activities of the organic ligands and their complexes were evaluated against several cancer cell lines, including MCF-7, A549 and HEK293 cells. The copper complexes of the organic ligands bearing a phenyl or allyl moiety at their N(3) position together with a piperidine substituent at the 2-position of their imidazolone ring exhibited the greatest cytotoxicity of all of the compounds tested in the current study.