The Molecular Structure and Chromatographic Parameters of Calix[4]аrеnehydroxymethylphosphonic Acids

The basic chromatographic characteristics (retention time, tR, capacity factors, k’, and coeffi cients of asymmetry peaks, KS) of the number of biologically signifi cant calix[4]аrenehydroxymethylphosphonic acids and their sodium salts have been obtained in a reversed-phase high-performance liquid chromatography (RP HPLC) on Zorbax CN. The structure of calix[4]аrenehydroxymethylphosphonic acids have been studied by the molecular modeling method (TURBOMOLE program). The relationship between the structure and chromatographic characteristics of the calix[4]аrenes, as well as their sorption mechanism on the column surface have been discussed.Основні хроматографічні характеристики (часи утримання tR коефіцієнти ємкості к', коефіцієнти асиметрії піків КS) низки біологічно значимих калікс[4]аренгідроксиметилфосфонових кислот та їх натрієвих солей були визначені методом обернено-фазної високоефективної рідинної хроматографії (ОФ ВЕРХ) при застосуванні хроматографічної насадки Zorbax CN. Будову калікс[4]аренгідроксиметилфосфонових кислот було досліджено методом молекулярного моделювання (програмний пакет TURBOMOLE). Обговорено взаємозв'язок між будовою, хроматографічною поведінкою та механізмом сорбції каліксаренів поверхнею хроматографічної насадки.Основные хроматографические характеристики (времена удерживания коэффициенты емкости к', коэффициенты асимметрии пиков КS) серии биологически значимых каликс[4]аренгидроксиметилфосфоновых кислот и их натриевых солей определены методом обращенно-фазной высокоэффективной жидкостной хроматографии (ОФ ВЭЖХ) при использовании хроматографической насадки Zorbax CN. Строение каликс[4]аренгидроксиметилфосфоновых кислот исследовано методом молекулярного моделирования (программный пакет TURBOMOLE). Обсуждена взаимосвязь между строением и хроматографическим поведением и механизмом сорбции каликсаренов поверхностью хроматографической насадки

Multi-element gas sensor based on surface plasmon resonance: recognition of alcohols by using calixarene films

This work is devoted to development of a multi-element gas sensor based on surface plasmon resonance (SPR) to recognize some alcohols. As sensitive layers capable to change their optical properties when interacting with volatile alcohol molecules, we investigated bulk-porous sorbents – calixarenes (tret-butyl-calix[4,6,8]arenes (С[4]А, С[6]А, С[8]А), tetra-amyl-calix[4] resorchinolaren (C[4]Re). Each calixarene was studied to obtain its kinetic concentration SPR characteristics for interaction with ethanol, isopropanol and penthanol vapors. To realize SPR measurements, the sensitive calixarene films (d ∼ 100 nm) were deposited on a gold film (d ∼ 45 nm) by using the method of thermal evaporation in vacuum. Experimental multi-element SPR device was designed as based on the analysis of TV image obtained for the studied array of calixarene films and tested using saturated ethanol vapors

New facile method for preparing acylisocyanates by thermal decomposition of triacylisocyanurates

Acylisocyanates are prepared by thermal decomposition of triacylisocyanurates. method provide an easy access to various acylisocyanates in hight yield and purity.Ацилюванням трис(триметилсиліл)ціануратів отримано триацетилізо-ціанурати. Термічне розкладення останніх — простий та зручний шлях до синтезу ацилізоціанатів з високими виходами та чистотою.При ацилировании трис(триметилсилил)цианурата получены триацетил-изоцианураты, термическое разложение которых является простым путем синтеза ацетилизоцианатов с высокими выходами и чистотой

Calixarenes and related macrocycles as gene delivery vehicles

International audienc

The role of shear modulus and viscosity of thin organic films on the adsorption response of QCM sensor

This work reports on the results of numerical calculations of quartz microbalance (QCM) sensors response under adsorption of analyte molecules. The influence of share modulus and viscosity has been studied. It was shown that even in the case of sufficiently thin films (hundreds of nanometers), the viscosity effects can significantly affect the sensor response during adsorption. In the case of sufficiently thick layers, the viscosity effects can turn out to radically change the response of QCM to the adsorption of volatile molecules. Thus, utilizing QCM-based sensors in viscous medium it is necessary to take into account not only mass loaded (adsorbed) onto quartz surface but also effect of viscosity on sensor response

Calix[4]arene methylenebisphosphonic acids as inhibitors of fibrin polymerization.

Item does not contain fulltextCalix[4]arenes bearing two or four methylenebisphosphonic acid groups at the macrocyclic upper rim have been studied with respect to their effects on fibrin polymerization. The most potent inhibitor proved to be calix[4]arene tetrakis-methylene-bis-phosphonic acid (C-192), in which case the maximum rate of fibrin polymerization in the fibrinogen + thrombin reaction decreased by 50% at concentrations of 0.52 x 10(-6) M (IC(50)). At this concentration, the molar ratio of the compound to fibrinogen was 1.7 : 1. For the case of desAABB fibrin polymerization, the IC(50) was 1.26 x 10(-6) M at a molar ratio of C-192 to fibrin monomer of 4 : 1. Dipropoxycalix[4]arene bis-methylene-bis-phosphonic acid (C-98) inhibited fibrin desAABB polymerization with an IC(50) = 1.31 x 10(-4) M. We hypothesized that C-192 blocks fibrin formation by combining with polymerization site 'A' (Aalpha17-19), which ordinarily initiates protofibril formation in a 'knob-hole' manner. This suggestion was confirmed by an HPLC assay, which showed a host-guest inclusion complex of C-192 with the synthetic peptide Gly-Pro-Arg-Pro, an analogue of site 'A'. Further confirmation that the inhibitor was acting at the initial step of the reaction was obtained by electron microscopy, with no evidence of protofibril formation being evident. Calixarene C-192 also doubled both the prothrombin time and the activated partial thromboplastin time in normal human blood plasma at concentrations of 7.13 x 10(-5) M and 1.10 x 10(-5) M, respectively. These experiments demonstrate that C-192 is a specific inhibitor of fibrin polymerization and blood coagulation and can be used for the design of a new class of antithrombotic agents.1 april 201

Cationic amphiphilic calixarenes to compact DNA into small nanoparticles for gene delivery

International audienc

Dipole properties of the upper rim phosphorylated calix[4]arenes in the Langmuir-Blodgett films

π-A - diagrams, ellipsometry and contact potential difference measurements were used to study the preparation and surface potential of calixarenes LBFs modified with phosphorylated groups at upper molecular rim (see text). The Langmuir nature of the obtained films on the silicon substrates has been proved. The surface potentials and molecular concentrations have been measured for all the compounds under investigation. Normal components of the dipole moments were analyzed for observed calixarenes. In monolayered structures they appeared to be positive for the molecules as a whole as well as for their parts

Merrifield resin modified with thiacalixarene-tetraphosphonates: synthesis, characterization and europium sorption

Tetrahydroxythiacalixarene tetraphosponates were synthesized and chemically linked to chloromethylated polystyrene (Merrifield resin) surface via the Williamson reaction. In order to evaluate the effect of thiacalixarene platform structure on the properties of sorbents, phosphorylated resins with P=O groups attached to the polymer surface via methylene spacers were synthesized by the Arbuzov reaction of the iodomethylpolysterene with trialkylphosphites. Composition and structure of the obtained materials was established by elemental analysis and IR spectroscopy. The sorbents obtained remove up to 99 % of Eu(III) ions from aqueous solutions of average mineralization level at pH of 5.5-6. The optimum contact time was established to be 2 h. Due to cooperative (macrocyclic) effect of P=O binding groups pre-organized at the upper rim of the thiacalixarene platform the resins exhibit better uptake parameters than the resins modified with para-unsubstituded, para-tert-butylsubstituted thiacalixarenes or the resins bearing the phosphonate groups directly bound to the Merrifield resin surface. Europium distribution coefficient for the best sorbents obtained was equal to 11.3