Home – Home – Jornals – Chemistry for Sustainable Development 2021 number 4

The oils of the Central part of the Siberian platform are very diverse in their physicochemical properties. The studied oils were divided into four groups relying on the data on the group composition of hydrocarbons and the content of resin-asphaltene substances. Physicochemical properties of oils were determined in each group. The features of the individual composition of saturated hydrocarbons ( n -alkanes, isoprenoids, 12- and 13-monomethylalkanes, cyclopentanes, cyclohexanes, terpanes, and steranes) and aromatic hydrocarbons (alkylbenzenes, naphthalenes, fluorenes, biphenyls, phenanthrenes) were determined by means of gas-liquid chromatography and gas chromatography/mass spectrometry. The regularities of changes in the composition and physicochemical properties during the transition from group I oils characterized by rather low content of resinous and asphaltene components to the high-resinous oils of the IV group were determined. These changes are mainly related to the differences in the conditions under which the oil source rocks were accumulated and to the extent of their thermal maturity.

A review of scientific publications and the results of experiments in the area of synthesis and investigation of the biological activity of functionally substituted norbornene derivatives is presented. The high antibacterial, antifungal and antiseptic activity of different derivatives of bicyclo[2.2.1]-heptene was demonstrated, which is explained by the presence of a pharmacophore conformational rigid framework of the norbornene fragment, as well as its saturated analogue. The synthesis of norbornene-containing Mannich bases was carried out through a one-pot three-component aminomethylation participated by norbornenylmethanol, formaldehyde and secondary amines. It is stressed that norbornenylmethanol, synthesized previously on the basis of a diene synthesis reaction between cyclopentadiene and allyl alcohol, was first used as an alcohol component in the Mannich reaction. The synthesized norbornene-containing Mannich bases were tested for antimicrobial and antifungal activity against various microorganisms. It was established that the synthesized compounds exhibit high antimicrobial activity against gram-positive ( Staphylococcus aureus ), gram-negative ( Escherichia coli , Pseudomonas aeruginosa ) bacteria, and antifungal activity against the fungi of Candida genus. The minimum inhibitory and minimum bactericidal concentrations of these compounds against some of the above-listed microorganisms were determined. Comparative characteristics of the antimicrobial and antifungal properties of the synthesized norbornene-containing Mannich bases with respect to well-known reference drugs widely used in medical practice (carbolic acid, rivanol, furacilin, chloramine) were determined. It was shown that the synthesized compounds possess higher biological activity than the reference preparations.

The results of the studies into the synthesis of ether derivatives of nornornene series, their properties and application areas are analyzed. The main directions of the use of ether derivatives of norbornene, as well as the ways and prospects of their further application, are shown. A broad application of norbornene ethers as additives to synthetic oil and fuel compositions, plasticizers, modifying agents and hardeners, as components in the perfumery industry, antimicrobial and antifungal preparations, catalysts and cocatalysts are highlighted. It is demonstrated that adding these esters to diesel fuel leads to a significant improvement in its thermal oxidation stability, a decrease in its pour point and an increase in the flash point. The ethers of norbornene series are considered as new functionally substituted monomers for the synthesis of modified norbornene-containing polymers and co-polymers. It has been established that fluorine-substituted norbornene-containing ethers are applied as a matrix material for photoresists used in microlithography.

This work deals with the problem of utilization of iron-containing waste and its processing into a pigment with improved colouring properties. Steel scrap has been used as an alternative raw material for the electrochemical synthesis of pigments based on iron oxide for use in the production of construction materials. Investigation of the samples by means of X-ray diffraction analysis and scanning electron microscopy showed that the conditions of electrochemical synthesis have no effect on the phase composition and morphology of the samples. It was established that iron oxide powders after thermal treatment at 750 ^oC are composed of hematite α-Fe₂O₃, are characterized by pure and bright colour, and by the absence of impurities. To determine the colouring properties of the pigment, the resulting iron oxide was mixed with clay rock in various proportions and heated to high temperatures.

A brief review of the results of studies in the area of obtaining linear and polycyclic derivatives of dicarboxylic acids is presented. Attention to the indicated compounds is due to the broad and diverse areas of their application in technology, in agrochemical and pharmaceutical industries, as biologically active agents, fragrances, additives to lubricating oils, plasticizers, stabilizing and modifying agents for polymer materials, etc. Biologically active compounds - the derivatives of bisamides of dicarboxylic acids possessing antibacterial, antiviral, anticonvulsant, antitumour, analgesic, fungicide properties are used for prophylactics and treatment of cardiovascular, viral and oncological diseases. The high thermal and thermal-oxidative stability of the adamantine derivatives based on dicarboxylic acids is also of great interest. These compounds, due to their properties caused by the presence of the framework fragment, are used for the synthesis of high-molecular compounds, in the production of fuel and lubricants or as additives to them. The rational use of more available, cheap raw material and the possibilities to use it for obtaining the derivatives of dicarboxylic acids in higher yields define the relevance of the studies aimed at the search for new promising methods to synthesize these compounds.

The reaction of 6'-aminodubamine (2-(4',5'-methylendioxy-2';-aminophenyl)-quinoline) with various aliphatic acids was studied. Amides were obtained in the yields of 23.0-64.9 %. The structure of amides was established on the basis of the analysis of spectral data and X-ray diffraction analysis. The antimicrobial activity of the obtained amides was studied.

The early data on the distribution and the forms of uranium and thorium migration in different geochemical types of natural waters of the Baydar Valley (the Crimean Peninsula) are obtained. Fresh and ultrafresh waters, mainly with hydrocarbonate calcium composition with total dissolved solids from 208 to 1269 mg/dm³, widely occur in the region. Fracture-karst waters, which are best protected from the continental salination, relate to weakly alkaline (pH 7.7), fresh with total dissolved solids 444 mg/dm³, and not very high Si concentrations (2.23 mg/dm³), hydrocarbonate calcium by composition. The waters of the zone of regional fracturing and fissure-vein waters are prone to the influence of continental salination processes and anthropogenic load. They are characterized by pH from neutral to alkaline (7.1-8.6); they are mainly fresh (269-1269 mg/dm³), with average Si content of 4.61-4.70 mg/dm³, their composition is hydrocarbonate calcium with increased concentrations of SO₄^2-, Mg²⁺ and Na⁺. The surface waters are prone to continental salination; they are weakly alkaline (рН 8.3), moderately fresh (207-364 mg/dm³), with the average Si concentration of 1.18 mg/dm³, hydrocarbonate calcium composition and increased concentrations of Cl^-, Mg²⁺ and Na⁺. The determined concentrations of uranium (²³⁸U) vary within the range from 2.64 • 10^-5 to 2.25 • 10^-3 mg/dm³, thorium (²³²Th) - from 2.04 • 10^-7 to 2.50 • 10^-5 mg/dm³. The nature of radioactivity of the studied objects is due to ²³⁸U, because the waters are characterized by the oxidative parameters of the geochemical environment with pH 7.1-8.9, Eh 67.2-209.3 mV and the concentration of dissolved oxygen 3.19-12.25 mg/dm³. The ratio ²³²Th/²³⁸U is (1.09 • 10^-3)-0.71. Waters enriched with ²³⁸U to the highest extent are the waters of regional fracturing zone, mainly related to sodium aluminosilicates, subjected to continental salination under the conditions of anthropogenic impact, and waters enriched with ²³²Th are those of the regional fracturing zone, mainly related to sodium silicates (long-term interaction in the water - rock system) subjected to continental salination. ²³⁸U migrates in the form of anion complexes UO₂(CO₃)₃^4- and UO₂(CO₃)₂^2-, to a lower extent (<1 % of the total content) in the form of Ca₂UO₂(CO₃)₃(aq) and CaUO₂(CO₃)₃^2-. Results of calculations over ²³²Th revealed its presence only in the form of complex Th(OH)₃CO₃^-.

This review combines and clarifies data from studies which have examined the chemical composition and pharmacological properties of Polygala sibirica L. Detailed information on molecular diversity is presented, including selected structural formulas. These include: xanthones, triterpene saponins, new flavonol glycoside compounds, acetophenones, phenolcarboxylic acid derivatives, and other secondary metabolite groups. Data from studies examining the antioxidant, antibacterial, and other types of biological activity of extracts, their fractions, or individual components are also presented. The overall data confirm the possibility of using P. sibirica as an additional source of medicinal raw materials.

The component composition of the chloroform fraction of the ethanol extract of Dictamnus angustifolius plant of the Rutaceae family , collected in the Tashkent Region of the Republic of Uzbekistan, is investigated. Alkaloids skimmianine, γ-fagarine, haplamine, and the new base angucine were isolated using column chromatography as a separation method. The obtained compounds were identified by means of ¹Н, ¹³С NMR, IR Fourier spectroscopy, and X-ray diffraction analysis.

The content of reserve and biologically active substances in the leaves and rhizomes of the Regal Air variety of Hemerocallis hybrida species cultivated in the Central Siberian Botanical Garden, in the forest-steppe zone of Western Siberia, was determined. Comparative data on the specific features of the accumulation of reserve substances (sugar, starch), phenolic compounds (catechins, flavonols), pectin substances (pectins, protopectins), saponins, and ascorbic acid in the vegetative organs of this variety during the years 2013-2015 are presented. An increase in the content of ascorbic acid in the leaves by the fruiting period by a factor of 1.2-2.5 was determined, depending on the growing season. The highest content of ascorbic acid in the leaves was determined in 2014, varying from 81.30 • 10^-3 to 202.91 • 10^-3 %. A stable concentration of flavonols in the leaves (0.75 - 0.83 %) was detected during the growing season of 2015. The highest amount of saponins in the rhizomes was detected during the spring growing season and fruiting, which was 2 times more than in the leaves. The high content of catechins (0.89-1.00 %) was detected in the leaves of the Regal Air variety during the early summer growing period. The amount of starch in the rhizomes in different phenophases and years of development varied from 24.12 to 43.54 %. It was determined that the content of ascorbic acid, sugars, flavonols is higher in the leaves than in the rhizomes, while the rhizomes contain higher amounts of starch, pectins, protopectins, saponins. The content of reserve and biologically active substances in the leaves and rhizomes of H. hybrida , Regal Air variety, adapted to the conditions of the forest-steppe zone of the Novosibirsk Region, depends on the features of development and the year of vegetation of the plants.

A brief review of low molecular weight compounds used to impart antibacterial properties to polymeric materials is presented. The main methods of introducing these compounds into the structure of polymers are considered. The prospects for the use of various antibacterial agents are analyzed from the point of view of creating materials capable of acting on antibiotic-resistant strains of microorganisms.

For geochemical typification of oils and condensates from the fields of the Tambey group (the Yamal Peninsula) and determination of their assumed sources, the data on the organic geochemistry of the major oil-gas-source rock masses were generalized and compared with the results of geochemical interpretation of the analytical data on the composition of the studied naphtides. In accordance with the genetic hydrocarbon indicators (concentration ratios based on the composition of n -alkanes, acyclic isoprenanes, steranes, terpanes) and with the isotopic composition of carbon, three genetic types of naphthides are distinguished in the considered collection. The mixed genotype predominates, one sample corresponds to the aquagene genotype, and several samples correspond mainly to the terragenic genotype. Maturity indices with respect to the composition of steranes, terpanes and arenes provide evidence of the formation of the analyzed samples under the conditions of the main oil generation zone. Relying on gas-liquid chromatographic data (the naphthenic hump, the absence of n -alkanes or their lower content compared to acyclic isoprenanes), condensates from the Albian-Cenomanian and, partially, from the Aptian deposits underwent microbial oxidation of the moderate and initial stages, respectively. The features of the physicochemical properties indicate the condensation type of most of the studied samples. This is consistent with the localization of the deposits in the zone of predominant gas-condensate accumulation.

Procedures for the control of iron content at all stages of the mechanochemical synthesis of lithium aluminates were developed. The procedures were proposed to determine iron content using two independent methods: molecular and atomic spectroscopy. Atomic absorption spectrometry should be used for iron content lower than 10^-3 mass %, as well as for aluminium-containing samples. It was found that lithium content in the sample up to 1 g/L does not affect the analytical signal of iron in the sample with iron concentration 2-5 µg/mL of iron when analyzing lithium carbonate by means of atomic absorption.