The possibility of using the carboxyl ion exchanger TOKEM-200 as a carrier of biogenic ions necessary for plant growth has demonstrated. The main objective of the study was to determine the ionic ratio of the content of K⁺, Mg²⁺, and Ca²⁺ in it, the pH of the substrate solution and the total electrolytes concentration. Physiologically acceptable values of these parameters were determined. The corresponding substrates were obtained under laboratory conditions, and their suitability for growing the test plant – lettuce (Lactuca sativa L.) – was tested. The test plants, grown on new 100% ion-exchange substrates BIONA, containing TOKEM-200 cation exchange resin, developed normally over three consecutive growing seasons. The yield of aboveground biomass of the plants was almost independent of the type of anionic component optimized for ionic composition. The plants contained nitrate ions in concentrations no higher than 680 mg/kg of green biomass.

Studies of the surface tension at the interface between aqueous and saline solution of hydrochloric acid Armoflote 619–air have shown that the salt of alkylmorpholine is not prone to precipitation even in saturated solutions. The study of the foaming ability of the hydrochloric acid salt of Armoflote 619 in both aqueous and saline solutions, up to saturated ones, showed the high resistance of the salt of Armoflote 619 to the precipitating effect of inorganic electrolytes. For the enrichment of polymineral ore the optimal composition and density of the flotation solution were selected. It is a water magnesium chloride solution with a density of 1 295 kg/m³, presaturated with ore to a density of 1 305 kg/m³. It has been established that the use of acidified flotation solution with pH 3–4 leads to an increase in the extraction of halite into the foam product. The recovery of NaCl is 95–96 %. The acidic environment of the flotation solution leads to a decrease in KCl losses by 1.3 times and MgSO₄ by 2.8 times. The accumulation of alkylmorpholine in flotation solution helps to reduce the collector consumption during flotation in circulating brines: if in the primary brine 89,55 % of sodium chloride can be extracted from the ore at the consumption of alkylmorpholine of 460 g/t, then during flotation in the brine of the 8th recirculating cycle at the consumption of 160 g/t of ore, 94,57 % of it is extracted.

Extraction of para-hydroxybenzoic acid and nine parabens (methylparaben, ethylparaben, propylparaben, iso-propylparaben, butylparaben, iso-butylparaben, pentylparaben, benzylparaben, phenylparaben) from their water solutions by organic solvents (n-hexane, chloroform, isoamyl alcohol) was studied. Analytes were quantified by high-performance liquid chromatography with diode-array detection. The distribution constants were calculated. The influence of the nature of extractants and the structure of the studied substances on the obtained values of the constants was analyzed. It was found that the values of the decimal logarithms of the distribution constants for para-hydroxybenzoic acid and parabens increase in the series n-hexane < chloroform < isoamyl alcohol, which corresponds to an increase in the extractive capacity of organic solvents.

The article presents the results of kaempferol and its glycosides identification in plant extracts using the method of high-performance chromatography-mass spectrometry (HPLC-MS). The study is focused on the selection and optimization of chromatographic conditions for efficient separation and identification of these flavonoids with high biological activity, as well as at searching for new types of plant raw materials for the pharmaceutical industry of the Republic of Belarus. The use of the mass-spectrometric and spectrophotometric detection ensured high sensitivity and selectivity in the identification of kaempferol and its glycosides. Astragalin in an amount of more than 2.20 mg/g of absolutely dry raw material is contained in the extracts of Asclepias incarnate L., Geranium pratense L. and Glycyrrhiza uralensis Fisch. ex DC. Three glycosides of kaempferol were also identified in Glycyrrhiza uralensis Fisch. and Glycyrrhiza glabra L. extracts, and two glycosides – in the extracts of Borago officinalis L. The conducted study demonstrates the efficiency of the HPLC-MS method for analyzing flavonoids in multicomponent plant matrices and can be used for the quality control of plant raw materials and in pharmacognosy.

In the present work, at first, density functional theory calculations were performed to investigate the molecular structure anabasine, cytisine, quinine alkaloids acyl derivatives by CAM-B3LYP/MidiX level of theory. A detail of quantum molecular descriptors of the title compounds such as Ionization Potential (IP) and Electron Affinities (EA), Hardness (η), Softness (S), Electronegativity (μ), Electrophilic Index (ω), Electron Donating Power (ω^–), Electron Accepting Power (ω⁺) and Energy Gap (E_g) have been calculated. Pharmacokinetic properties of the title compounds and their bioactivity were investigated. In the following, a molecular docking study was carried out to screen for effective available compound which may work as a strong inhibitor for the SARS-CoV-2 main protease M^pro. The binding energy between SARS-CoV-2 main protease M^pro and derivatives of natural alkaloids showed a good binding affinity. Therefore, studied derivatives of natural alkaloids can be used for potential application against the SARS-CoV-2 main protease M^pro.

The proteins VEGF165 and ANGPT1 are key regulators of angiogenesis, which underpins therapeutic approaches for chronic lower-extremity ischemia. Designing a fusion protein based on these molecules has the potential to significantly enhance the therapeutic effect. To determine the optimal arrangement of functional domains of the fusion protein (VEGF165_ANGPT1 or ANGPT1_VEGF165) and establish the ideal length and sequence of the peptide linker between the two proteins, we performed an analysis of molecular dynamics trajectories and spatial structures of 134 fusion proteins. The optimal linkers that contribute to the increased stability of the fusion proteins were identified as follows: for ANGPT1_VEGF165, the optimal linkers are GGGSGGGGSGGGSGGGS, GGGGSGGGGSGGGGS, GGGSGGGGS, and PAPAPAP; for VEGF165_ ANGPT1, the optimal linkers are GGGGSGGGGGS, GGGSGGGGSGGGGSGGGS, and GGGGSGGGGSGGGGSGGGGS.

Based on the results, we selected the variant of the ANGPT1_VEGF165 protein with the GGGSGGGGSGGGSGGGS linker to analyze its functional activity.

The main component of the printing ink binder is pine resin rosin. This work examines the composition and properties of metallized paint based on rosin derived from cherry tree resin in order to reduce the percentage of imported components and expand the range of metallized paints. The composition of metallized paint based on rosin from cherry tree resin was studied by IR spectroscopy. A comparative analysis of the infrared spectra of paints based on rosin from cherry tree resin and those made in China, taken for comparison, showed their chemical identity. The stability of the paint was determined using stand-ard methods and was characterized by its drying time on a non-absorbent surface. It was revealed that paint made from al-ternative raw materials has a shorter drying time, which is one of the necessary conditions for the offset printing process. The potential of IR spectroscopy as a method in printing ink production is demonstrated by its efficiency and ability to accurately determine the chemical composition and degree of similarity to reference samples. Using a paint with an identical composition based on cherry tree resin rosin can help address raw material shortages and expand the range of printing inks.

The twisting power and compatibility of several oxygenand nitrogen-containing derivatives of terpenoid acids (maleopimaric, citraconopimaric and fumaropimaric) in liquid crystal (LC) compositions with positive anisotropy of permittivity (LC-1285, Merck LC-6809-000, LC-6810-000, BN-104) were studied. Chiral nematic LC compositions were prepared based on the synthesized optically active terpenoid products. The twisting power of the chiral additive (dopant) and the helix pitch of the resulting LC compositions were determined using the Cano-Grandjean wedge method. The effect of the structure (presence and type of substituents, length of alkyl, alkoxy and mesogenic groups) of the terpenoid dopant on the twisting power and compatibility with LC materials is analyzed. The thermal stability of a number of maleopimaric acid derivatives (amides, imidoamides) is studied by derivatography and its dependence on the compound structure is analyzed. Data on the values of specific rotation of the plane of polarized light ([α]_D) are presented for a number of the compounds obtained. Electro-optical characteristics of some obtained chiral LC compositions with additives of maleopimaric amides and imidoamide were determined. It was shown that the developed dopants enable the synthesis of LC materials with controlled selective light transmission, promising for use in energy-efficient “smart windows” and smart glasses for privacy control systems.