Tetracarboxylic acids on a thiacalixarene scaffold: Synthesis and binding of dopamine hydrochloride

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018. For the first time thiacalix[4]arene derivatives in 1,3-alternate conformation simultaneously containing amide, carboxyl and hydroxyl groups capable of forming 1:1 stoichiometry complexes with dopamine hydrochloride were obtained. The efficiency of dopamine hydrochloride binding was evaluated by a number of spectral methods. Using the methods of fluorescent, UV-Vis and NMR spectroscopy, the mechanism of interaction of the synthesized macrocycles with dopamine has been studied. It was shown that quenching of dopamine fluorescence by the studied macrocycles is carried out through a static mechanism

Suppression of activity of Candida Albicans proteinases by cobalt chloride

Influence of cobalt (II) chloride on the system of Candida albicans proteinase (SAP C. alb.) (both in solution and immobilized on a surface of nitrocellulose membranes) has been investigated. In solution cobalt chloride inactivated inducible but not constitute enzyme. In the heterogenous sytem proteolitical effect of the cobalt ion on inductible proteinase was also observed

Supramolecular motifs for the self-assembly of monosubstituted pillar[5]arenes with an amide fragment: from nanoparticles to supramolecular polymers

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. Monosubstituted pillar[5]arenes with an N-alkylcarbamoyloxymethyl fragment were successfully prepared by aminolysis with good yields. One- and two-dimensional NMR spectroscopy clearly indicated that the inclusion of the alkyl substituent in the macrocyclic cavity is typical of the synthesized compounds. According to 1H and 1H-1H NOESY NMR data, only four carbon atoms of the alkyl fragment (-NHCH2CH2CH2CH2-group) are included in the macrocyclic cavity regardless of the alkyl chain length. The formation of an intramolecular hydrogen bond between the NH proton and the oxygen atom of the oxymethylene fragment was confirmed by IR spectroscopy. On the basis of nanoparticle trajectory analysis and transmission electron microscopy data, the aggregation of the new synthesized derivatives of pillar[5]arene varied from supramolecular polymers in chloroform to spherical nanosized aggregates in DMSO. The length of the substituent had no effect on the size of the aggregates formed in DMSO, whereas a direct correlation was established between the substituent length and the size of the supramolecular polymer formed in chloroform

A new surfactant-copper(ii) complex based on 1,4-diazabicyclo[2.2.2]octane amphiphile. Crystal structure determination, self-assembly and functional activity

© the Owner Societies 2018. A new surfactant-copper(ii) complex [Cu(L)Br3] (where LBr is 1-cetyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide) containing a transition metal in the head group has been synthesized and characterized. Physicochemical properties, thermal stability and 3D structure were determined using X-ray diffractometry, UV-vis spectroscopy, simultaneous thermogravimetry and differential scanning calorimetry combined with mass-spectrometry of evolved vapors. The study of the self-assembly and morphological features of associated structures was performed by potentiometry using a bromide ion selective electrode and fluorescence of pyrene and 1,6-diphenyl-1,3,5-hexatriene. The influence of the metal ion embedded into the surfactant structure on critical micelle concentration, degree of counterion binding, aggregation numbers and morphology of the associates was elucidated. High solubilizing capacity and complexation ability of the metal containing micelles with respect to Orange-OT hydrophobic dye and oligonucleotide were determined. Importantly, the functional properties of this metallosurfactant complex are much better compared to those of classical cationic surfactants bearing cyclic and acyclic head groups, LBr and the LBr-CuBr2 mixture. The new cationic metallosurfactant could be recommended for investigation in gene therapy

Quantitative Evaluation of the Effect of Alkaline-Earth Metal Ions in Immobilized Choline Esterase

A possibility is considered of the quantitative evaluation of activation processes basing on voltammetric measurements with an example of the effect of Ca2+ and Ba2+ ions on immobilized choline esterase incorporated into a biochemical sensor. The activation constants indicate the greater activating effect of Ca2+ ions

Complexation of 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide with nickel nitrate in acetone

© 2016, Pleiades Publishing, Ltd.The complexation of 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide with Ni(II) nitrate in acetone is studied by means of spectrophotometry (the Job–Ostromisslensky technique and molar ratios). The formation of 3: 1 and 1: 1 ligand: metal complexes is established and confirmed by mathematical modeling. The stability constants of the complexes and the change in the Gibbs free energy are determined

Influence of ZN(II) and MN(II) on catalytic activity of aspartic proteinases of Candida albicans

The interaction of secreted aspartic proteinases Candida albicans (SAP C. albicans) with ZnCl2 and MnCl2 was studied. Logarithms of stability constant from the data of electronic spectroscopy were calculated: lgβ = 4,73±0,20 for the complex [SAP C, albicans - Zn(II)] and lgβ = 7,02±0,20 for the complex [SAP C. albicans - Mn(II)]. The composition and maximum accumulation of complexes in solution were calculated. The optimal conditions of hydrolysis of the substrate, HAS (human serum albumin) in the presence of proteinases were determined: [HSA]=0.004 g/ml, [SAP]=2.33 μM, pH=4.5, the time of incubation of 25 min. The activity SAP C. albicans in the presence of ZnCl2 and MnCl2 in different concentrations in optimal conditions of enzymic hydrolysis was estimated. For the first time the activating action of ZnCl2 on catalytic activity of proteinase in concentration 5×10-7 mol/1 was discovered. The maximal rate of enzymic reaction (Vm), the Michaelis constant (Km) and constants of effects in presence and absence as the effector of ZnCl2 were calculated. The estimation of albuminatic activity of C. albicans infections family in different diseases localization in the presence and the absence as the effector of ZnCl2 was evaluated

Data of one-and two-dimensional NMR spectroscopy in the study of structure and nature of associations of hyperbranched polyester polyol BOLTORN H20-OH

Structure of the hyperbranched polyester of the polyol BOLTORN H20-OH was studied by oneand two-dimensional 1H and 13C NMR spectroscopy in combination with the IR spectroscopy and semiempirical quantum-chemical calculations (method AM1). The polyol structure was shown not to be stereoregular. Three basic types of H-bonding interactions of intra-or intermolecular nature were revealed: C=O...HO, OH...OH, and C=O...HO...HO. © Pleiades Publishing, Ltd., 2010

Synthesis and Complexing Ability of Hyperbranched Polyester Polyols Containing Carboxylic Acid Fragments

© 2018, Pleiades Publishing, Ltd. New hyperbranched polyester polycarboxylic acids containing terminal propanoic and acrylic acid fragments have been synthesized. According to the IR spectral data, the complexation of polydentate hyperbranched polyester polycarboxylic acids with Co(II), Ni(II), and Cu(II) ions involves chelation and bidentate bridging coordination by the terminal carboxy groups. All Co(II), Ni(II), and Cu(II) complexes with the obtained polyester polypropanoic acids are characterized by octahedral geometry of the coordination entity (MO6). The Co(II), Ni(II), and Cu(II) complexes with polyester polyacrylic acids have tetrahedral configuration of the coordination entity (MO4)

Determination of a Candida albicans antigen using an amperometric immunoenzyme sensor | Opredelenie antigena Candida albicans s pomoshch'iu amperometricheskogoimmunofermentnogo sensora.

Determination new variant enzyme immunoassay with amperometric enzyme immunosensor, including the immobilizing enzyme-choline esterase and antibodies against Candida albicans (CA) in biosensitivity part of sensor, for diagnose disease of CA. The method for determination of CA based on combination immunochemical reactions and voltammetric indication of analytical signal was developed. Amperometric enzyme immunosensor developed has been used as detector. Differences dilutions of antibody (Ab) against antigen (Ag) of CA immobilizing in common with choline esterase (CE). The method of immobilization developed allows to receive the sensor with including the immobilized CE and Ab in common. The method of determination of CA based on combination the reaction of forming immune complex tAb-AgI with enzyme immunosensor for its detection. The dynamic range of concentrations determined of Ag depends on degree of dilution of Ab used for manufactory biosensitivity part of sensor. The data indicate that the [Ab-Ag] immune complexes are stable. This is also confirmed by the values of [Ab-Ag] binding constants, obtained in Scatchard coordinates. This method of determination doesn't require special preparation of a sample. Selectivity, sensitivity, simplicity and quickness are characterize of this method which could be used for manufacturing test-sistem for determination CA in blood