Chemistry

Phase Equilibria and Salting Out of Butyric Acid in the Sodium Chloride – Water – Butyric Acid Ternary System

Authors: Cherkasov D. G., Hrykina A. V., Umetchikov V. A., Smotrov M. P.

Phase equilibria in the water–butyric acid binary system in the range of −10÷0° C and in the sodium chloride–water–butyric acid ternary system in the range of 10.0÷60.0° C were studied using the visual polythermal method. The phase diagram of the water–butyric acid binary system at −9.5° C is characterized by eutectic equilibrium, the solid phases of which being ice and butyric acid crystals. The metastable delamination range was found on the ice crystallization field, bounded by a binodal curve with an upper critical solution temperature of −3.7° C.

Assessment of Growth-Regulating Activity and Ecotoxicity of Diarylidene-Substituted Cyclohexanones

Authors: Rogachaeva S. M., Zhutov A. S., Shilova N. A., Klochkova I. N., Borisova S. V.

The search of new biologically active substances to be used as herbicides and plant growth regulators is carried out. The two compounds were used – 2-benzylidene-6-(m-nitrobenzylidene) cyclohexanone (1) and 2-benzylidene-6-(p-fluorobenzylidene) cyclohexanone (2). They are similar in structure, but containing different functional groups in one of the benzene rings: -NO2, and -F. Their dose-dependent effect on the germination and growth of Triticum aestivum and Barbarea vulgaris was investigated.

Improved Synthesis of 2,3,4,6-tetra-О-acetyl-α-D-glucopyranosylhalogenes and 2,3,4,6-tetra-О-acetyl-α,β-D-glucopyranose – Glycosylating Agents of Biologically Active Compounds

Authors: Spiridonova A. V., Krasnikova N. V., Krasnikov S. V.

O,N-Glycosylation reactions are used for the synthesis of prodrugs based on various pharmaceutical substances. This, in turn, can significantly improve their pharmacokinetic and pharmacodynamic parameters, as well as reduce toxic effects. In current study, the objective was to propose new variants of the synthesis of active glycosylating agents, superior to the previously known ones in terms of the use of highly toxic substances, the anomeric composition of the products and the reaction time.

Синтез и конформационные особенности пергидропирролодиазациклоалканонов

Authors: Grinev V. S., Linkova E. I., Yegorova A. Y.

The reactions of 4-phenyl and 4-(p-tolyl)-4-oxobutanoic acids with 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane by heating in an aprotic non-polar solvent initially proceed through a nucleophilic attack of the amino group on the carbon atom of the oxoacid carbonyl group to form the corresponding amide.

Quasi-binary Section Ag2SnS3-Sb2S3

Authors: Mamedov S. H.

Silver thiostannates and chalcostannates are widely used as promising functional materials which have semiconductor, thermoelectric, and photoelectric properties. The goal of this research is to study the Ag2SnS3-Sb2S3 phase diagram and determine the boundaries of solid solutions based on both components. Alloys were investigated using methods of physicochemical analysis. Based on the results of the study, a condition diagram of the Ag2SnS3-Sb2S3 system was constructed.

Synthesis and Physicochemical Properties of Grafted Copolymers of Chitosan and Acrylic Monomers

Authors: Bayburdov T. А., Shmakov S. L.

The search and analysis of English-language 2004–2019 scientific literature devoted to the graft polymerization of acrylic monomers (acrylic acid and acrylamide being examples) onto chitosan to obtain novel materials with valuable properties was made. It was revealed that radical copolymerization, with potassium or ammonium persulfate, cerium-ammonium nitrate being initiators was used for grafting. Microwave, UV radiation and gamma rays were also used. To obtain gel, a cross-linking agent (N,N’- methylenebisacrylamide) was introduced. Glutaraldehyde was also used for cross-linking.

Total Charge of Chitosan and Chitosan Succinyl Macromolecules Effect on the Stability of Particles of Silver Iodide Sols in Polymer-Colloidal Based Dispersions

Authors: Bazunova M. V., Bazunova A. A., Khlobystova E. S., Kulish E. I.

Obtaining stable polymer-colloidal dispersions based on watersoluble polymers and inorganic colloidal particles, such as silver iodide sol, followed by removal of the dispersion medium is one of the ways to create hybrid biomedical materials (e.g. films, threedimensional matrices). The current work is devoted to studying the possibility of increasing the stability of polymer-colloidal systems based on silver iodide sols, succinyl chitosan and chitosan polysaccharides by reducing the total charge of macromolecules.

Alkaline Hydrolysis Kinetics and Physico-Chemical Properties of Acrylic Copolymers Based on Acrylic Acid, Its Esters and Vinyl Acetate

Authors: Bayburdov T. А., Obshitser А. S., Romanova Y. O.

Kinetic regularities of the alkaline hydrolysis of copolymers of methyl acrylate, butyl acrylate, vinyl acetate and acrylic acid of several chemical compositions under various conditions were studied by IR spectrometry. The initial rate of alkaline hydrolysis and the limiting conversion degree were shown to increase with increasing concentrations of the components of the reaction mass and temperature.

Visual Colorimetric and Colorimetric Determination of Cefuroxime

Authors: Marakaeva A. V., Kosyreva I. V.

Cefuroxime is a cephalosporin antibiotic with a wide spectrum of antibacterial activity for gram-positive and gram-negative microorganisms. It is in the list of vital and essential drugs for medical use. Currently, spectroscopic, chromatographic, electrochemical methods are used to determine cefuroxime. In current study we developed test agents in the form of indicator papers and powders with an immobilized Fehling reagent for the rapid determination of cefuroxime. Cellulose paper and silica gel were used as a solid matrix to create testing means.

The Research of the Behavior of Cefixime in Aquatic and Biological Media by Spectrophotometric Method

Authors: Kulapina E. G., Kulapina O. I., Anikina V. D.

The research of behavior of cefixime in biological media was conducted by spectrophotometric method. It was shown that the maximum of light absorption of cefixime against the background of oral fluid is observed at λ = 292 nm and for blood serum at λ = 289 nm. The interval of linear dependence optical density – concentration of cefixime is 3–50 mkg/ml. The optimal conditions of precipitation of proteins in the studied biological media were revealed.

Pages