physicochemical methods
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2022 ◽  
Vol 19 ◽  
Author(s):  
Gulu Abbasova ◽  
Ajdar Medjidov

Abstract: A one-pot conversion of 2-hydroxy-1-naphthoic aldehyde to hydroxamic acid was described. An efficient photoorganocatalytic method of synthesis was developed. The obtained hydroxamic acid was identified by various physicochemical methods such as IR, UV- and NMR-spectroscopy. Solid colored complexes of copper (II) and iron (II), respectively, green and brown colours with the obtained hydroxamic acid were synthesized in ethanol medium for the first time. The molar ratio of ligand and metal in the complex was 2:1. Their structures were established using IR, UV- spectroscopy and thermogravimetric analysis.


Author(s):  
Lyudmila A. Kayukova ◽  
Elmira M. Yergaliyeva ◽  
Anna V. Vologzhanina

The reaction of β-(thiomorpholin-1-yl)propioamidoxime with tosyl chloride in CHCl3 in the presence of DIPEA when heated at 343 K for 8 h afforded the title hydrated salt, C7H14N3S+·Cl−·H2O, in 84% yield. This course of the tosylation reaction differs from the result of tosylation obtained for this substrate at room temperature, when only 2-amino-8-thia-1,5-diazaspiro[4.5]dec-1-ene-5-ammonium tosylate was isolated in 56% yield. The structure of the reaction product was established by physicochemical methods, spectroscopy, and X-ray diffraction. The single-crystal data demonstrated that the previously reported crystal structure of this compound [Kayukova et al. (2021). Chem. J. Kaz, 74, 21–31] had been refined in a wrong space group. In the extended structure, the chloride anions, water molecules and amine groups of the cations form two-periodic hydrogen-bonded networks with the fes topology.


Author(s):  
Zoulikha Abdelsadek ◽  
Sergio Gonzalez-Cortes ◽  
Feroudja Bali ◽  
OuizaCherifi ◽  
Djamila Halliche ◽  
...  

AbstractHydrotalcite catalysts derived from NiAl and NiAlMg mixed oxides were successfully prepared by coprecipitation at a constant pH of 11. Physicochemical methods were investigated to determine their structural and textural properties. Using isopropanol as a probe molecule, the acid–base properties of the catalysts were investigated, and the evaluation of reactivity, selectivity and lifetime was established.


Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 266
Author(s):  
Valentina S. Borovkova ◽  
Yuriy N. Malyar ◽  
Irina G. Sudakova ◽  
Anna I. Chudina ◽  
Andrey M. Skripnikov ◽  
...  

Spruce (Piceaabies) wood hemicelluloses have been obtained by the noncatalytic and catalytic oxidative delignification in the acetic acid-water-hydrogen peroxide medium in a processing time of 3–4 h and temperatures of 90–100 °C. In the catalytic process, the H2SO4, MnSO4, TiO2, and (NH4)6Mo7O24 catalysts have been used. A polysaccharide yield of up to 11.7 wt% has been found. The hemicellulose composition and structure have been studied by a complex of physicochemical methods, including gas and gel permeation chromatography, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The galactose:mannose:glucose:arabinose:xylose monomeric units in a ratio of 5:3:2:1:1 have been identified in the hemicelluloses by gas chromatography. Using gel permeation chromatography, the weight average molar mass Mw of hemicelluloses has been found to attain 47,654 g/mol in noncatalytic delignification and up to 42,793 g/mol in catalytic delignification. Based on the same technique, a method for determining the α and k parameters of the Mark–Kuhn–Houwink equation for hemicelluloses has been developed; it has been established that these parameters change between 0.33–1.01 and 1.57–472.17, respectively, depending on the catalyst concentration and process temperature and time. Moreover, the FTIR spectra of the hemicellulose samples contain all the bands characteristic of heteropolysaccharides, specifically, 1069 cm−1 (C–O–C and C–O–H), 1738 cm−1 (ester C=O), 1375 cm−1 (–C–CH3), 1243 cm−1 (–C–O–), etc. It has been determined by the thermogravimetric analysis that the hemicelluloses isolated from spruce wood are resistant to heating to temperatures of up to ~100 °C and, upon further heating, start destructing at an increasing rate. The antioxidant activity of the hemicelluloses has been examined using the compounds simulating the 2,2-diphenyl-2-picrylhydrazyl free radicals.


2022 ◽  
Vol 42 ◽  
pp. 01028
Author(s):  
E. B. Farzaliyev ◽  
V.N. Golubev ◽  
G.K. Hafizov

The use of sea buckthorn fruits in medicine, cosmetology and as a source of ingredients that improve the quality of food has already been studied and continues to be studied. One of these ingredients can serve as pectin substances of sea buckthorn, isolated from it in its pure form. Considering the relevance of this direction, the main task of this work was the study and identification of pectin substances isolated from the fruits of wild sea buckthorn growing in Azerbaijan. Using cavitation-membrane technology, samples of pectin substances from sea buckthorn pomace were obtained under optimal technological conditions, after which the physicochemical characteristics were studied and their identification was carried out using physicochemical methods - elementary analysis, IR and NMR spectroscopy. Data have been obtained indicating that sea buckthorn pectin is a low-esterified pectin, which consists of a mixture of linear and highly branched polymers of α-D-galacturonane and other polysaccharides, whose macromolecules include galacturonic acid residues and neutral sugars. The high complexing ability of the obtained pectin in relation to lead ions has been established, which makes it possible to recommend it as an active ingredient for therapeutic and prophylactic products. The data obtained allow us to get a more complete picture of the biotechnological potential of local sea buckthorn as a source of pectin substances.


Author(s):  
Екатерина Анатольевна Богданова ◽  
Владимир Михайлович Скачков ◽  
Игорь Маратович Гиниятуллин ◽  
Данил Ильич Переверзев ◽  
Ксения Валерьевна Нефедова

В статье обсуждается возможность получения упрочненного композиционного материала с пористой структурой на основе наноструктурированного гидроксиапатита, синтезированного методом осаждения из раствора. Новый материал получен путем механохимичекого синтеза гидроксиапатита с армирующими добавками диоксида циркония и кремниевой кислоты. Синтезированные образцы аттестованы с использованием современных физико-химических методов анализа. Показано влияние качественного и количественного состава композита на протекание процессов спекания, пористость, прочностные характеристики, степень дисперсности и морфологию исследуемых образцов. Экспериментально установлено, что максимальными прочностными характеристиками и постоянным составом обладает образец Ca(PO)(OH) -15%SiO⋅nHO-5%ZrO. Композиционный материал обладает плотной равномерной структурой с высокой степенью кристалличности, с развитой пористостью, является перспективным материалом для дальнейших исследований с целью внедрения его в медицинскую практику. На разработанный композиционный материал подана заявка на патент. The article discusses the possibility of obtaining a hardened composite material with a porous structure based on nanostructured hydroxyapatite (HAP) synthesized by precipitation from a solution. The new material was obtained by the mechanochemical synthesis of HAP with reinforcing additives of zirconium dioxide and silicic acid. The synthesized samples are certified using modern physicochemical methods of analysis. The influence of the qualitative and quantitative composition of the composite on the sintering processes, porosity, strength characteristics, the degree of dispersion and morphology of the studied samples is shown. It has been experimentally established that the sample has the maximum strength characteristics and a constant composition of Ca(PO)(OH) -15%SiO⋅nHO-5%ZrO. The composite material has a dense uniform structure with a high degree of crystallinity, with a developed porosity, is a promising material for further research in order to introduce it into medical practice. A patent application has been filed for the developed composite material.


2021 ◽  
pp. 14-21

The aim of this work is to study the effect of the nature of electron-donor and electron-withdrawing substituents in the molecules of heterocyclic ligands, the nature of acidoligands and transition metal ions on the properties of the synthesized coordination compounds. A method for the synthesis of new complex compounds of Mn (II), Cо (II), Cu (II) and Zn with 5-amino-2-mercaptobenzimidazole has been developed and the composition and structure of the synthesized complex compounds have been studied using modern physicochemical methods, such as elemental, thermogravimetric, X-ray phase analysis and IR spectroscopy. Coordination competing donor centers, electronic and geometric structures of the ligand molecule were studied using quantum-chemical calculations in the Gaussian09 LanL2DZ software package. It was shown that during the formation of a metal complex, the ligand 5-amino-2-mercaptobenzimidazole is coordinated through the localized nitrogen atom of the imidazole ring.


Author(s):  
Д.С. Ильясов ◽  
С.Г. Ильясов

Исследовано взаимодействие комплексной соли хлорида никеля (II) с диаминомочевиной в присутствии глиоксаля. Получены различные комплексные соли катионного типа на основе никеля (II) с диаминомочевиной и на их основе были синтезированы соответствующие макроциклические соединения. Полученные комплексы и макроциклы исследованы физико-химическими методами анализа. The interaction of a complex salt of nickel (II) chloride with diamino urea in the presence of glyoxal was studied. Various complex salts of the cationic type based on nickel (II) with diamino urea were obtained and the corresponding macrocyclic compounds were synthesized on their basis. The resulting complexes and macrocycles were studied by physicochemical methods of analysis.


2021 ◽  
Vol 22 (24) ◽  
pp. 13563
Author(s):  
Sergey Tikhonov ◽  
Petr Ostroverkhov ◽  
Nikita Suvorov ◽  
Andrey Mironov ◽  
Yulia Efimova ◽  
...  

Photodynamic therapy (PDT) is currently one of the most promising methods of cancer treatment. However, this method has some limitations, including a small depth of penetration into biological tissues, the low selectivity of accumulation, and hypoxia of the tumor tissues. These disadvantages can be overcome by combining PDT with other methods of treatment, such as radiation therapy, neutron capture therapy, chemotherapy, etc. In this work, potential drugs were obtained for the first time, the molecules of which contain both photodynamic and chemotherapeutic pharmacophores. A derivative of natural bacteriochlorophyll a with a tin IV complex, which has chemotherapeutic activity, acts as an agent for PDT. This work presents an original method for obtaining agents of combined action, the structure of which is confirmed by various physicochemical methods of analysis. The method of molecular modeling was used to investigate the binding of the proposed drugs to DNA. In vitro biological tests were carried out on several lines of tumor cells: Hela, A549, S37, MCF7, and PC-3. It was shown that the proposed conjugates of binary action for some cell lines had a dark cytotoxicity that was significantly higher (8–10 times) than the corresponding metal complexes of amino acids, which was explained by the targeted chemotherapeutic action of the tin (IV) complex due to chlorin. The greatest increase in efficiency relative to the initial dipropoxy-BPI was found for the conjugate with lysine as a chelator of the tin cation relative to cell lines, with the following results: S-37 increased 3-fold, MCF-7 3-fold, and Hela 2.4-fold. The intracellular distribution of the obtained agents was also studied by confocal microscopy and showed a diffuse granular distribution with predominant accumulation in the near nuclear region.


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