Vol 24, No 2 (2024)
Chemistry
Thionation of 4-((4-oxo-4H-chromen-3-yl)methylene)-2-phenyloxazol-5(4H)-one using the LAWESSON’S reagent
Abstract
Analysis of periodicals has showed that there is no information on the behavior of hybrid heterocyclic systems containing several
pharmacophore fragments based on oxazol-5(4H)-ones and chromen-4(4H)-ones in reactions with thionizing reagents under various
conditions. The interaction of 4-((4-oxo-4H-chromen-3-yl)methylene)-2-phenyloxazol-5(4H)-one with Lawesson’s reagent (LR) (2,4-bis-[pmethoxyphenyl])
has been studied for the fi rst time – 1,3- dithiaphosphetane-2,4-disulfi de) under conditions of thermal activation of the
reaction mixture and the use of a closed reactor in the environment of non-polar solvents. Lawesson’s reagent is used as a mild thioniation
agent. The scheme of the interaction has been discussed. Initially, it is assumed that the Lawesson reagent (LR) molecule dissociates into the
particles of ylide structure, then the interaction with the carbonyl group of the chromen-4-one fragment of the initial substrate takes place,
resulting in the formation of a spirocyclic intermediate, the subsequent decomposition of which produces the fi nal product. It has been
established that the use of a closed reactor makes it possible to reduce the transformation time and achieve an increase in the yield of the
target product compared to the conventional type of activation of the reaction mixture. It has been shown that under the chosen conditions
the transformation proceeds with the preservation of the oxazol-5(4H)-one ring. The composition and structure of the resulting compound
have been established on the basis of complex data from elemental analysis, IR and NMR spectroscopy.
Keywords: oxazol-5(4H)-ones, chromen-4(4H)-ones, chromenyloxazolone thio derivatives, physicochemical methods, pressurized vessel reactor,
hybrid structures, spectroscopy, Lawesson’s reagent (LR)
Acknowledgements. This work received fi nancial support
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):
Synthesis of 2-alkyl-5-phenyl-4,5,6,7-tetrahydro-[1,2,4]triazolo[1,5-a]pyrimidin-7-ol derivatives
Abstract
The problem of acid corrosion of steel is of signifi cant importance, particularly in the context of the oil extraction industry, where acid treatment of wells and surrounding spaces is widely employed. This research article focuses on the synthesis and investigation of previously unstudied derivatives of the class of 2-alkyl-5-phenyl-4,5,6,7-tetrahydro-[1,2,4]triazolo[1,5-a]pyrimidin-7-ols – organic compounds potentially highly eff ective as inhibitors of acid corrosion of steel. The method for synthesizing the proposed compounds involves the condensation of 3-alkyl5-amino-1H-1,2,4-triazoles with cinnamaldehyde. The structure of the synthesized compounds has been confi rmed using 1H NMR and LCMS methods. The study has revealed that the developed synthesis conditions yield the target tetrahydrotriazolopyrimidinols with alkyl substituents containing up to three carbon atoms. However, an increase in the length of alkyl substituents intensifi es side reactions, making the isolation of the target compounds challenging. The obtained research results are signifi cant for the development of eff ective organic inhibitors of acid corrosion of steel of a new class. These fi ndings can serve as a basis for further research in this area, contributing to the development of new methods for corrosion prevention and improving the resistance of materials used in the oil industry. Thus, this study not only describes a new synthetic approach to obtaining inhibitors of corrosion in the tetrahydrotriazolopyrimidinol class but also holds prospective practical value in the fi eld of industrial technologies and materials science.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):129-134
129-134
Non-destructive testing of non-steroidal anti-inflammatory drugs using near-field infrared spectroscopy method
Abstract
The use of near-infrared spectroscopy for quality control of nonsteroidal anti-infl ammatory drugs (NSAIDs) in blister packs is demonstrated. NSAIDs with the active ingredients ibuprofen, diclofenac, naproxen, etoricoxib, acetylsalicylic acid and meloxicam have been studied. IR spectra have been recorded using a Frontier FTIR spectrometer with a NIRA attachment, used to collect diff use refl ectance spectra of solids. Processing and visualization of the study results has been carried out using chemometric algorithms – principal component analysis (PCA), hierarchical cluster analysis (HCA) and partial least squares regression (PLS). It is shown that using these algorithms it is possible to identify drugs by their manufacturer and determine the concentration of active substances. In the PCA method, the points corresponding to the samples of the analyzed tablets are located in separate quadrants depending on their manufacturer. The use of hierarchical cluster analysis (HCA) made it possible not only to diff erentiate the analyzed tablets by manufacturer, but also to determine the content of the active substance in them. “Measured-predicted” calibration models have been constructed, the values of the root mean square residual of calibration (RMSEC) did not exceed 6.28 mg. The relative discrepancies between the values obtained during the analysis and those assigned correspond to the permissible deviations established by order of the Ministry of Health of the Russian Federation dated October 26, 2015 no. 751n. The duration of the analysis was 7–10 min.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):135-143
135-143
Description and investigation of chemical interaction in the Li+,Na+||F- ,Cl- ,Вг- system
Abstract
The use of melts in various fi elds of industry and scientifi c research is based on the study of the properties of melts and the chemical processes occurring in them. In modern engineering and technology, a signifi cant number of processes are associated with the use of mixtures of lithium and sodium halides as mixtures that accumulate heat, as electrolytes for medium-temperature chemical current sources. Therefore, the interest in the study of systems involving such systems is continuously increasing. The paper calculates the thermal eff ects of exchange reactions and Gibbs energy in ternary reciprocal systems of a quaternary reciprocal system Li+,Na+||F- ,Cl- ,Br- , as well as for a mixture corresponding to the central point of the conversion line. The conversion line is obtained as a result of the intersection of unstable and stable triangles. In accordance with the calculation data, it is shown that the conversion lines in the skeleton of the compositions intersect at the conversion point K3 with the maximum thermal eff ect of the reaction equal to the sum of the thermal eff ects of the reactions (as well as the Gibbs energies) for mixtures corresponding to the conversion points K1 and K2.To confi rm the stability of the LiF-NaCl-NaBr triangle linking the stable tetrahedron LiF-NaCl-NaBr-NaF and the stable pentatope LiF-LiCl-LiBr-NaCl-NaBr, the interaction of the initial powder mixture of 50 mol % NaF+25 mol.% LiCl+25 mol.% LiBr has been studied by thermogravimetry. The phase transition temperatures are assigned to the heating curve of the mixture. When heated at a rate of 20 K/min, the exothermic eff ect begins at 463 oC and ends at 504 оC. For a stable triangle, a melt crystallization scheme of the composition of the central point of the conversion line is shown. Stable crystallizing phases have been confi rmed by X-ray phase analysis.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):144-152
144-152
Grafting of acrylic monomers onto polyethylene surface (review)
Abstract
A search and review of English-language scientifi c literature about the graft copolymerization of acrylic monomers onto a solid-phase polymeric surface has been carried out. Grafting onto plates and fi lms of high- and low-density polyethylene is considered. The monomers used were acrylic and methacrylic acids, glycidyl acrylate and glycidyl methacrylate, etc., and the main method was UV photopolymerization with an initiator – benzophenone, etc. Problems of graft polymerization in terms of surface modifi cation of polymeric materials are touched upon, and possible areas of their application are outlined.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):153-162
153-162
Biology
Evaluation of polymeric submicron microcapsule accumulation in cellular and intercellular space of 3D spheroids
Abstract
Multicellular spheroids are three-dimensional in vitro models of organs and tissues. Multicellular spheroids have gained great interest in the fi eld of biotechnology as they are reproducible and mimic real organs and tissues so can be used as test systems for new forms of drugs, allowing minimizing the use of in vivo animal models. Flow cytometry was used to describe the accumulation of submicron polymeric microcapsules in cellular spheroids, which allowed us to identify the main aspects of drug carrier-cell interactions within the spheroid. Spheroids were generated using 4T1 mouse breast cancer cells and healthy L929 mouse fi broblast cells. The arrangement of microcapsules with 300, 500, 1000 nm diameter with biocompatible shells in cell spheroids was evaluated in their intercellular and intracellular spaces.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):163-171
163-171
On the distribution of Allium caeruleum and A. regelianum (Alliaceae Borkh.) in the territory of the Saratov region
Abstract
Concerning the distribution of Allium caeruleum Pall. and A. regelianum A. K. Becker, recent literary sources provide confl icting information. Based on the data from the doctoral dissertation of A. O. Tarasov, the results of expeditionary research and our own herbarium collections, it is stated that Allium caeruleum is distributed in the Ozinsky (at least in the vicinity of the village of Nepryakin) and in the Aleksandrovo-Gaisky (at least in the vicinity of the village of Kamyshki) districts of the Saratov region. The presence of A. regelianum in the Saratov region is, however, unlikely. The published key for identifying species of the genus Allium (Bulany et al., 2023) is incorrect, since it does not take into account the presence of bulblets in the infl orescence of A. caeruleum. It is proposed to make changes to the key for identifying onions, taking into account the presence of onions in the infl orescence of A. caeruleum.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):172-176
172-176
Combination ability of new dihaploid corn lines in the conditions of the Right Bank of the Saratov region
Abstract
Dihaploid lines, or lines obtained on the basis of doubled haploids, are a valuable material for the creation of high-heterosis corn hybrids. The most eff ective method of evaluating the starting material when selecting parental couples for obtaining hybrids is diallell analysis. The article presents the results of the analysis of indicators of 6 dihaploid corn lines and 30 simple corn hybrids of the dialle scheme. The combinative ability of lines along the stem length, the cob attachment height, and the panicle length was studied. The eff ects of the GCA and SCA dispersion, as well as the components of genetic dispersion for the above characteristics were revealed. Lines with high GCA and SCA rates were identifi ed. The variation of the indicators of combinative ability during the years of the study indicates that the degree of strength of the eff ects of GCA and the dispersion of SCA morphometric parameters in certain lines varies to some extent under the infl uence of growing conditions. The analysis of the components of genetic dispersion showed that, depending on the growing conditions, the formation of stem length was infl uenced by 1 to 3, cob height by 1 to 3, and panicle length by 1 to 2 genes or groups of genes. A pattern has been revealed: in more favorable conditions in 2021 and 2023, the number of genes that control the manifestation of the stem length and the panicle length traits increases. A signifi cant impact of dominance components (H1 , H2 ) has been established. Dominance in stem length, ear height and panicle length is directed towards the parental forms with greater expression of the trait.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):177-183
177-183
Formation of Langmuir monolayers from native phospholipids of bacteria of various systematic groups
Abstract
Phospholipids are the most important structural elements of the bacterial cell wall, participate in the adaptation of microorganisms to the environment and can act as biomarkers for environmental changes and one of the components of environmental monitoring. Native phospholipids are used to form models of cell membranes, the biophysical properties of which can be studied by the Langmuir-Blodgett method. The aim of this work was to isolate and characterize the phospholipids of the cell membranes of the bacteria Staphylococcus aureus and Bacillus cereus and the formation of Langmuir monolayers based on them. The composition and ratio of fatty acids were determined by gas-liquid chromatography of fatty acid methyl esters. Fatty acids, found in the extract of the bacteria S. aureus 209-P and B. cereus 8035, are: hexadecanoic, trans-9-octadecenoic, octadecanoic, tetradecanoic, 13-methyltetradecanoic, 14-methylpentadecanoic, 15-methylhexadecanoic, cis-9-octadecanoic. To form a monolayer, a working solution of native phospholipids in chloroform with a concentration of C = 10-3 М was used. The monolayer formed when a 50 μl solution of a phospholipid mixture is applied to the surface has a more perfect structure, which is manifested in the constancy of its mechanical properties. The analysis of the obtained data has not yet revealed a clear dependence of the monolayer parameters on temperature. The changes in the compression modulus and compressibility were very minor. With an increase in the salt concentration, both an increase and a decrease in the compression modulus, and, consequently, the rigidity of the monolayer, is observed.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):184-195
184-195
Dynamics of formation of tolerance to blue (405 nm) led radiation in Staphylococcus aureus upon repeated exposure
Abstract
In this work, we studied the development of tolerance to low-intensity violet (405 nm, 80 mW/cm2 , 72 J/cm2 ) LED radiation in a standard antibiotic-resistant strain of Staphylococcus aureus 2a. The change in numbers during 20 cycles of irradiation was studied, the reaction of bacterial cells to oxidative stress was studied – sensitivity to the presence of hydrogen peroxide in the environment and catalase activity. It was shown hat from cycles 1 to 5 there was a signifi cantly insignifi cant reduction in survival rate – from 85% to 82%, from cycles 5 to 10 of irradiation the decrease in the number of cells became more pronounced – from 82 to 63%, then, from cycles 10 to 15, recovery was noted, showing numbers to higher values (65–76%), from cycle 15 to 20, the survival value after irradiation remained at the same level (80%). It has been established that, starting from the 15th irradiation cycle, the culture becomes 2 times more resistant to the action of oxidative factors. The results obtained showed that the use of the photodynamic therapy method in practice must be approached with caution, since the formation of tolerance to the eff ects in the tagret microorganism occurs by the 15th irradiation cycle and can signifi cantly worsen the treatment results.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):196-201
196-201
Optimization of phage display technology for obtaining antibodies specific to tetracycline
Abstract
Large-scale production and use of antimicrobials in human, veterinary and agricultural applications has led to antibiotic contamination of water resources. Therefore, it is relevant to develop methods for monitoring the content of antibiotics, especially in water resources. Biosensor methods are successful for the analysis of antibiotics. One of the main elements of a biosensor system is the selection of a recognition element. An alternative tool for selecting a sensitive element (recognition element) is phage display of antibodies, which makes it possible to obtain antibodies to low molecular weight antigens. The purpose of the work was to conduct research to develop and optimize the methodology for obtaining antibodies specifi c to tetracycline by using phage display technology, and to evaluate the possibility of their use for the indication of tetracycline. The work included studies of optimization of conditions for the production of phage antibodies specifi c to tetracycline, as well as the preservation of their activity during storage. The promise of using phage display technology for the production of anti-tetracycline antibodies has been shown. Using the dot immunoassay method, the possibility of using the obtained phage antibodies for tetracycline detection was shown.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):202-207
202-207
Ecology
A new host plant for Cameraria ohridella Deschka and Dimic, 1986 (Lepidoptera: Gracillariidae) in Volga region
Abstract
Six years have passed since, in 2018, an invasive species from Europe – the Ohrid miner Cameraria ohridella (Lepidoptera: Gracillariidae) penetrated into the Lower and Middle Volga region and began to actively populate urban landscapes planted with horse chestnut. Using the example of the regional center of Saratov, the temporary aspects of settlement and damage to horse chestnut trees over the specifi ed period are considered. As a result of the settlement of the species and the annual increase in its population density, the degree of damage to the leaves of horse chestnut in parks and alleys of the regional center – showed a massive drying and leaf fall in Aesculus hippocastanum in early August 2023. The total output of the imago of the 3rd generation of the occupier completed the process of withering and shrinking of the trees by switching to another type of urban tree – walnut. This is the fi rst case of such a choice of a new host object for this type of invader in the Volga region.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):208-213
208-213
Assessment of ecosystem services of green spaces in Yoshkar-Ola
Abstract
In many parts of the world, urban green spaces are being explored as a source of ecosystem services. Their role in the provision of regulation of and, support of ecosystem services and even in the provision of cultural services is considered. At the same time, species assessment of the composition and vital condition of trees that provide ecosystem benefits in an urbanized environment is becoming increasingly relevant. The purpose of this study was to assess the contribution of the most common species of woody plants in urban greening to the provision of ecosystem services. The research was carried out in Yoshkar-Ola, in different functional areas of the city: residential, recreational and industrial, where the assortment of trees was studied and their vital condition was assessed. For the most common tree species, the potential supply of providing ecosystem services was determined on a ten-point scale, taking into account adverse effects (so-called «ecosystem disservices»). It was established that Betula pendula, Tilia cordata, Sorbus aucuparia were the predominant species in the landscaping of the city, their share in the studied plantings reached 36–64%. Of the introduced species, Acer negundo, Picea pungens, and Thuja occidentalis are the most common in the landscaping of the city. Most of the trees of different functional zones belonged to the 1st and 2nd categories of life condition (healthy and with signs of slight oppression). Strongly weakened trees accounted for no more than 12% of the total number, and dying plants were rare. Betula pendula makes a significant contribution to the provision of ecosystem services in Yoshkar-Ola. Tilia cordata, Picea pungens and Sorbus aucuparia – do so mainly due to their high carbon storage capacity, phytoncide and aesthetic value. Acer negundo is considered to be a dangerous urban explerent and, despite its regulating and maintaining ecosystem services, its distribution in the urban environment should be limited.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):214-224
214-224
Dynamics of the populations of stink bugs of the genera Aelia and Neottiglossa (Heteroptera, Pentatomidae) in overgrown with vegetation burnt areas of the Usman Forest (Voronezh region)
Abstract
Based on quantitative counts of the abundance of four species of the genera Aelia and Neottiglossa (Heteroptera, Pentatomidae), the process of formation of their populations in the overgrown burnt areas of the Usman Forest (Voronezh region) after a fi re in 2010 was modeled. It has been established that mesoxerophilic species Ae. acuminata and N. leporina appeared in the formerly burnt areas 5–6 years after the fi re. The mesophilic species N. pusilla is a permanent inhabitant of ecotone biotopes and has not shown a tendency to colonize the formerly burnt areas. Xerophilic Ae. rostrata colonized the overgrown burnt area ten years after the fi re, refl ecting the process of xerophylization of the post-pyrogenic ecosystem in forest-steppe conditions.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):225-230
225-230
The structure of the existing system and the problems of functioning of the future specially protected natural territories of the Voronezh region
Abstract
The Biological Diversity Convention and the National Strategy for the Conservation of Biodiversity in Russia have laid the basis for the implementation of large-scale scientifi c and practical research aimed at fi nding eff ective solutions to this issue. The creation of the SPNA network which includes federal, regional and local signifi cance is one of the promising directions for the conservation, maintenance and reproduction of biodiversity at all levels. The Voronezh Region situated at the junction of forest-steppe and steppe zones, features complex fl oral, faunal complexes and a unique soil cover dominated by chernozems. The long-term agricultural use of the region’s soils has led to a reduction in areas with natural ecosystems. This has created the prerequisites for establishing a complex, extensive SPNA network in the Voronezh region. The establishment SPNA network is based on a comprehensive regulatory framework, which includes federal laws of the Russian Federation, resolutions of the Voronezh Region Government, the law of the Voronezh Region, orders of the Ministry of Natural Resources and Ecology of the Voronezh Region, etc. To date, the SPNA network comprises 256 protected areas, of which 4 are of federal signifi cance, 211 are of regional signifi cance, and 41 are of local signifi cance. This structure of protected areas has positioned the Voronezh Region as one of the leaders in these indicators among the Central Chernozem Regions (ССR). The largest number was created in the Belgorod region – 332 objects, objects, accounting for 11.2% of its territory, the Voronezh region ranks second in terms of the number of objects and the third in terms of the share of protected areas relative to the total area. The functioning of existing and the creation of the new ones face several challenges, among which an important place is occupied by insuffi cient public awareness of the need to create protected areas as a tool for the conservation of nature and its biological diversity holds a signifi cant place.
Izvestiya of Saratov University. New series. Series: Chemistry. Biology. Ecology. 2024;24(2):231-236
231-236