A. R. Gataulina

Impedimetric Aptasensor for Ochratoxin A Determination Based on Au Nanoparticles Stabilized with Hyper-Branched Polymer

An impedimetric aptasensor for ochratoxin A (OTA) detection has been developed on the base of a gold electrode covered with a new modifier consisting of electropolymerized Neutral Red and a mixture of Au nanoparticles suspended in the dendrimeric polymer Botlorn H30®. Thiolated aptamer specific to OTA was covalently attached to Au nanoparticles via Au-S bonding. The interaction of the aptamer with OTA induced the conformational switch of the aptamer from linear to guanine quadruplex form followed by consolidation of the surface layer and an increase of the charge transfer resistance. The aptasensor makes it possible to detect from 0.1 to 100 nM of OTA (limit of detection: 0.02 nM) in the presence of at least 50 fold excess of ochratoxin B. The applicability of the aptasensor for real sample assay was confirmed by testing spiked beer samples. The recovery of 2 nM OTA was found to be 70% for light beer and 78% for dark beer.

Synthesis of Hyperbranched Polyester Polymaleic Acids Third Generation

The third generation hyperbranched polyesterpolyol has been modified with maleic anhydride at various ratios of the polyol to the modifying agent, from 1: 6 to 1: 18. The prepared modified polyols are capable of the complex formation with copper(II), cobalt(II), and nickel(II) ions.

Synthesis and properties of hyperbranched polyester polyacrylic acids and their metal complexes

New polydentate ligands based on the hyperbranched third generation polyesters containing terminal acrylic acid fragments were synthesized. The ionization and complexation parameters of new compounds in solution were estimated by spectrophotometry and pH-metric titration followed by experimental data processing using mathematical simulation by the CPESSP program. The procedure for the synthesis was proposed. The polynuclear cobalt(II), nickel(II), and copper(II) complexes with polyester polycarboxylates were synthesized.

Synthesis and spectral characteristics of a hyperbranched polyester poly(phenylcarbamate)

Synthesis of new hyperbranched polymers attracts both theoretical and practical interest due to broad spectrum of their applications [1, 2]. Hyperbranched aliphatic polyesters polyols (HBPO) are widely used in the materials chemistry, in particular for the preparation of polymers for biomedical purposes and polymers with improved mechanical performance, as well as for modification of membrane properties and drug delivery control [3–5]. Modification of hyperbranched aliphatic polyesters polyols with certain organic fragments could extend the scope of their application. The nature of the terminal group modifier determines the set of useful properties, while functionalization procedure is an independent problem in the field of organic synthesis. Taking into account the above stated, we have synthesized a hyperbranched polyester polycarbamate and studied its physicochemical properties with a view to subsequent use as hybrid complexing agent. Carbamates are known as good chelators for metal ion extraction–sorption systems [6]. A combination of the hyperbranched polyester polyol scaffold with terminal carbamate fragments could give rise to a new hybrid modifier for the development of sorption systems. In this communication we describe a procedure for the synthesis of a hyperbranched polyester polycarbamate via electrophilic addition [7, 8] of phenyl isocyanate to HBPO H20 (1) containing 16 terminal hydroxy groups. The resulting hyperbranched polymer 2 contained phenylcarbamate fragments at the terminal positions. Polymer 2 was isolated as a light brown amorphous substance which was insoluble in water and diethyl ether and soluble in acetone, dioxane, tetrahydrofuran, DMSO, and DMF. The IR spectrum of 2 displayed a medium-intensity absorption band at 3319 cm due to NH stretching vibrations, amide II band (δ NH) at 1534 cm, and amide III bands (νC–N) at 1315 and 1082 cm. Stretching vibrations of aromatic and aliISSN 1070-4280, Russian Journal of Organic Chemistry, 2015, Vol. 51, No. 10, pp. 1499–1501.

Synthesis and spectral characteristics of 2,2-bis(hydroxymethyl)propionic acid derivatives as model compounds for the estimation of properties of modified hyperbranched polyesters polyols

New amino and carboxy derivatives of methyl 2,2-bis(hydroxymethyl)propionate have been synthesized as models of terminal fragments of hyperbranched polyester polyamines and polyesters polycarboxylic acids, and their spectral characteristics have been studied.

Hyperbranched polyester poly(3-diethylamino)propionates and their copper(ii) complexes

Novel polydentate ligands were obtained from second and third generation hyperbranched polyesters containing terminal (3-diethylamino)propionate groups. Polynuclear CuII complexes with these ligands were synthesized. The degree of diethylamination of the polyesters increases when moving from the second to the third generation (from 56 to 81%). In polynuclear complexes, the ratios of Cu to hyperbranched ligand are 6 : 1 and 13 : 1 for second and third generation polyester polyamines, respectively. It was demonstrated using IR and ESR spectroscopy that each coordination polyhedron in the complexes is an isolated paramagnetic center of the formula CuN2O2Solv2 (Solv = H2O, DMSO).

Synthesis of hyperbranched polyesterpolytrimethylsiloxanes

The number of reports on the synthesis of siliconcontaining dendrimers with a variety of organic components is steadily increasing. Carboxysilane, siloxane, silane, and so-called “hybrid” dendrimers have been obtained [1], and dendrimers have been also synthesized with inorganic polycyclosiloxane inner sphere and the organic layer on the periphery [2]. At the same time, the silyl derivatives of hyperbranched polyesterpolyols were not described.

Hyperbranched Functionalized Polyesters for the Creation of Promising Chemically Modified Sorbents

This work presents the procedure for the preparation and the physicochemical characteristics of a new chemically modified sorbent on the basis of a NaX zeolite and hyperbranched polyester polyurethane. The procedure for the preliminary activation of the surface of the zeolite by a solution of NaOH allows optimizing the process of immobilization of hyperbranched polyester polyurethane on the surface of the zeolite. The increase in the sorption capacity of the new chemically modified sorbent with respect to Cu(II) ions in model solutions is proven. The obtained data will allow developing a technology for the sorption extraction of rare earth metal ions from objects of environmental control.

Hyperbranched polyester poly[3-(morpholin-4-yl)propionates] and their copper(II) complexes

Novel polydentate ligands on the basis of second- and third-generation hyperbranched polyesters containing terminal poly[3-(morpholin-4-yl)propionate] groups and their 6 : 1 and 13 : 1 polynuclear copper(II) complexes were synthesized. The degree of functionalization of the polyesters with morpholine increases in going from the second (56%) to third generation (68%). According to IR and electronic spectroscopy data, each coordination entity in the complexes is an isolated paramagnetic center of the formula CuN2O2Solv2 (Solv = H2O, DMSO).

Phosphorylation and Thiophosphorylation of Oligomeric Polyesterpolyols of Boltorn H20, H30, and H40

Abstract Dialkyl phosphate derivatives of Boltorn H20, H30, and H40 were prepared by the use of ultrasound irradiation in the substitution reactions of the polyesterpolyols with dialkyl chlorophosphates. Unsaturated polyacrylates were obtained by the reactions of Boltorn H20, H30, and H40 with acryloyl and methacryloyl chlorides. The reactions of these polyacrylate esters with O,O-dialkyl dithiophosphoric acids in the presence of Lewis acid catalysts have brought about the formation of the corresponding dithiophosphates.