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Interaction of Maleic Anhydride with 1,2-phenylenediamine under Different Conditions

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

The reaction of maleic anhydride with 1,2-phenylenediamine when heated in an aprotic solvent, regardless of temperature, proceeds with the initial formation of the primary addition product, namely, 4-[(2-aminophenyl)amino)-4-oxobut-2-enoic acid, which further undergoes heterocyclization within two ways, due to the presence of several electrophilic centers in the molecule, depending on the reaction conditions.

Transport Properties of Membranes on the Basis of Tetradecylammonium Associates with Complex Compounds Silver(I)-сefotaxime

Authors: Kulapina E. G., Tyutlikova M. S., Mursalov R. K.

Transport properties of the plasticized polyvinylchloride membranes on the basis of tetradecylammonium associates with complex connections silver (I) – cefotaxime in the conditions of a diffusive mass transfer and a direct current are investigated. With variation of concentration of electrode active substances (0.5; 1; 2; 3%), the external solutions contacting with membranes (10-2–10-7 M). It is established that resistance of membranes depends on the content of electrode active substances (EAS) and concentration of perimembrane solutions of a cefotaxime.

Test-Determination of Amoxicillin in Medications

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

Amoxicillin is a semi-synthetic aminopenicillin β-lactam series with a wide spectrum of antibacterial activity against many gram-positive and gram-negative microorganisms. It is included in the list of essential drugs. Test systems for the detection and identification of amoxicillin are missing. We have obtained indicator papers with immobilized ninhydrin and p-dimethylaminobenzaldehyde for the test determination of amoxicillin. The reaction conditions were selected, depending on the temperature and time. Color scales for visual colorimetric and colorimetric determination were constructed.

Influence of Ascorbic Acid Isoforms on the Hydrodynamic Behavior of Chitosan Ascorbate Macromolecules in Aqueous Solution

Authors: Malinkina О. N., Gegel N. O., Shipovskaya A. B.

The hydrodynamic behavior of chitosan macromolecules in aqueous solutions of ascorbic acid (AscA) diastereomers was studied by means of capillary viscometry. A comparison of these systems with chitosan solutions in such traditional solvent media as hydrochloric and acetic acids, Na-acetate buffer was made. Concentration dependencies of the specific viscosity were plotted, and the intrinsic viscosity and the Huggins constant were evaluated.

Catalytic Conversion of Ethyl Alcohol on Zeolite Catalysts

Authors: Kuzmina R. I., Khoroshilov I. I., Chebotarev S. A.

This article describes the possibility of using bioethanol as a substitute for conventional fuel from petroleum feedstocks. Bioethanol obtained by fermentation from biomass is considered not only as an analogue of gasoline or a fuel additive, but also as a source of raw materials for the production of olefins, aromatic hydrocarbons and gasoline range hydrocarbons by means of catalytic conversion. At present, it is believed that the conversion of ethanol on zeolites proceeds in several stages.

Trifluoroacylation of Benzopirrolimidazolons under Various Conditions

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

The introduction of the (trifluoro)acetyl moiety into different heterocycles allows one to vary their physicochemical properties, change the nature and magnitude of biological activity, and also to carry out further chemical transformations. At the same time, modern methods of organic chemistry are aimed, inter alia, at increasing the efficiency of known and widely used chemical reactions and the possibility of directing along other paths when conducting syntheses under conditions, which are different from the classical ones.

Determination of Synthetic Food Dyes E110 and E124 in the Joint Presence by Vierordt’s Method and Derivative Spectrophotometry

Authors: Silaev D. V., Shestopalova N. B., Fomina Y. A., Rusanova T. Y.

The application of the Vierordt’s and the first derivative at the “zero crossing” methods was evaluated for the simultaneous determination of synthetic food dyes Yellow “sunset” (E110) and Ponso 4R (E124) in model solutions. The concentrations interval of components is established at which the principle of optical densities additivity is observed. For the implementation of the Vierordt’s method, wavelengths with the maximum difference in the absorption coefficients of the individual components (470.2 and 536.7 nm) were chosen.

On the Interaction of the Phosphoric Molybdenum Acid with the α-Amino Acids and Possible Applications of the Reaction Products in Ionometry

Authors: Chernova R. K., Varygina O. V., Zakharevich A. M.

The conditions of synthesis of ion associates of phosphorus-molybdenum ions with protonated form of lysine hydrochloride have been considered. It has been shown that the phosphoric molybdenum acid undergoes hydrolysis with the formation of the following products: НРО42– + Мо12О42– + 11Н2О. At pH 2 in aqueous solutions, the PhMA is stable, exists as anion [РМо12О42]3– and interacts with protonated form of lysine with the formation of associates 3[НLys]+[FMC]3–.

Data Approximation for Plotting the Binodal Curve on the Phase Diagrams of Some Ternary Salt – Water – Isopropyl (n-Propyl) Alcohol Systems

Authors: Cherkasov D. G., Il’in K. K.

A brief review of computational methods for the liquid-liquid equilibrium has been carried out, and their capabilities and limitations have been shown. Complications of such computational models for the liquid–liquid–solid equilibrium lead to a decreased accuracy of calculations. In this case, it is advisable for researchers to make use of the approximation of experimental data on the liquid – liquid and liquid – liquid – solid equilibria.

2-amino-3-formilchromen-4-one as “Connection-platform” in the Synthesis of Hybrid Systems under the Action of N-Nucleophiles

Authors: Ivanova A. L., Kanevskaya I. V., Ibragimova D. K., Fedotova О. V.

Показано, что 4H-хроменоны, функционализированные альдегидной группой в положении С3, способны образовывать гибридные системы, имеющие в своей структуре помимо хроменонового пиридиновый, пиримидиновый циклы. Кислая среда способствует раскрытию γ-лактонного фрагмента. Показана возможность дезактивации альдегидной группы с последующим деформилированием. 

The Effect of Surfactant Micelles on the Fluorescent Properties of a Complex of Yttrium with Levofloxacin

Authors: Danilina T. G., Smirnova T. D., Bryshkina A. D., Levina N. A., Nevryueva N. V.

The effect of complexation with yttrium ions and micellar media of surfactants on the fluorescent properties of levofloxacin was studied. The luminescence of levofloxacin depends on the acidity of the medium Т. Г. Данилина и др. Влияние мицелл поверхностно-активных веществ 378 Научный отдел Изв. Сарат. ун-та. Нов. сер. Сер. Химия. Биология. Экология. 2019. Т. 19, вып. 4 and is maximum in an acidic medium. It was shown that complexation with yttrium ions promotes the growth of the intrinsic fluorescence of levofloxacin by a factor of 2.

Extraction-Photometric Determination of Cobalt (II) with Hydroxytiophenols and Hydrophobic Amines

Authors: Zalov A. Z., Ibragimova S. A.

The possibility of using hydroxythiophenols (HTP) for the photometric determination of cobalt (II) has been studied. Aminophenols (AP) were used as hydrophobic amine: 2- (N,N-methylamino methyl)-phenol (AP1) and 2- (N, N-methylaminomethyl) -4-methylphenol (AP2). Dichloroethane, chloroform and carbon tetrachloride turned out to be the best extractants. With a single extraction with chloroform, 97.5–99.5% of cobalt is recovered as a complex. The cobalt (II) complex is extracted into chloroform in the pH range of 3.6–6.3.

Chemometric Algorithms for the Monitoring of Milk Quality by Potentiometric Titration

Authors: Monakhova Y. B., Kuznetsova I. V.

The acute problem in the analysis of dairy products is the potentiometric determination of the active and total titrated acidity of pasteurized milk from different manufacturers and their comparison with those for raw cow milk. In addition, for various expert purposes, fast definition of the manufacturer of this product is necessary. The conditions of potentiometric titration of pasteurized milk are specified. It is shown that the total acidity of pasteurized milk produced by different manufacturers differs insignificantly.

Comparison of Cytotoxic Activity of Compounds from the Benzimidazolequinazoline and Pyridopyrimidine Series

Authors: Ivonin M. A., Fomin A. S., Burygin G. L., Sorokin V. V.

Colorimetrically using the MTT assay the cytotoxic activity of 5-aryl-1,2,3,4,5,6-hexahydrobenz[4,5]imidazolo[1,2-a]quinazolines and a tautomeric mixture of 4-amino-2-phenyl-6H-pyrido[1,2-a] pyrimidin-3-carbonitrile with 2-(phenyl(pyridin-2-ylamino)methyl)- malononitrile was screened. These compounds were obtained by the three-component condensation of aromatic aldehydes (benzaldehyde, 3-bromobenzaldehyde, 4-methoxybenzaldehyde), heterocyclic amines (2-aminobenzimidazole or 2-aminopyridine) and cyclohexanone or malonic acid dinitrile in comparison with the starting amines.

Extractive Crystallization of Salt and Phase Equilibria in the Ternary System Sodium Nitrate – Water – Dipropylamine

Authors: Mezhueva M. A., Danilina V. V., Kurskii V. F., Cherkasov D. G.

Phase equilibria in the ternary system sodium nitrate – water – dipropylamine where the constituent binary liquid system is characterized by a trend to form a lower critical solution temperature (LCST) were studied using the visual-polythermal method in the range −10.0–90.0° C. It was found that the introduction of sodium nitrate into the water – dipropylamine system led to a significant decrease in the mutual solubility of the components.

Researching the Oxidation Process of Sulfur-Alkalaine Sewage Components Using Ni2+ Catalyst – Containing Galvanic Wastewater

Authors: Savelyeva A. V., Savelyev S. N., Levin A. S., Fridland S. V.

The effect of different concentrations of nickel (II) ions on the oxidation rate of mixed wastewater pollutants with ozone-air mixture for 30 minutes with an ozone concentration of 3 mg/l was studied. It was shown that adding nickel (II) ions at a concentration of 300 mg/l reaches the maximum degree purification of wastewater as a result of oxidative processes on the COD value, equal to 40.4%, which is 10.1% more compared to the catalytic oxidation of the investigated wastewater pollutants with the air oxygen participation.

The Synthesis of New Organoselenium Heterocyclic Compounds: 2,4-Diaryl-5,6,7,8-Tetrahydroselenochromilium’s Salts

Authors: Direnko D. Y., Drevko Y. B., Drevko B. I.

The synthesis of novel organoselenium heterocyclic compounds is of great theoretical and practical interest because of high biological activity. The known methods of synthesis of hexatomic selenium containing heterocyclic compounds allow us to obtain only monoaryl-substituted tetrahydroselenochromilium salts. In this study, the reactions of 2-(3-oxo-1-aryl-3-phenylpropyl) cyclohexanones were carried out with hydrogen selenide in situ under conditions of acid catalysis in diethyl ether.

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.

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.

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.

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