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The data on complex metabolite profiling of Dracocephalum nutans L. of Lamiaceae family obtained using the analytical platform of gas chromatography with mass-selective detection are presented. The products of basic metabolism, phenol compounds, as well as mono-, sesqui-, and triterpenes were detected in the composition of metabolic pool. The main components of Dracocephalum nutans essential oil are germacrene D and B, (E)-caryophyllene, α-humulene, β-elemene, hexahydroxyfarnesylacetone and bicyclogermacrene. Oleanolic, ursolic, corosolic and maslinic acids, as well as rosmarinic acid, salvianic acid A (danshensu) and a number of other biologically active compounds were found in the methanol extracts. To describe the results of such non-targeted profiling, the term “molecular resource” is proposed.

The North Crimean Canal (NCC) is an irrigation and water supply canal built in 1961-1971 to provide water to low-water and arid areas of Crimea. The canal waters are used for economic purposes, so investigation of the processes that were formed after the destruction of the Kakhovka Reservoir in 2023 and currently occur in the watercourse is urgent. In this work, we determined the concentrations of hydrocarbons (with safety assessment), features of the distribution of n-alkanes, potential sources of their income in the water and bottom sediments of the canal and adjacent water areas. The total concentrations of hydrocarbons and separately n-alkanes were determined by gas chromatography. Exceedance of the maximum permissible concentrations of hydrocarbons in water (0.05 mg/L) was detected in 50 % of samples in 2024, independently of sampling territory and time. The hygienic standard of hydrocarbon content (0.1 mg/L) was not exceeded in any sample, which makes the water suitable for drinking water supply. In all the bottom sediment samples collected in the canal in 2024, the standard level of HC content (50 mg/kg) was exceeded. Conditionally clean bottom sediments were detected only in the Biyuk-Karasu River bed. The genesis of hydrocarbons in 2024 in the waters of the canal and adjacent areas was mixed, mainly biogenic. The molecular composition of n-alkanes in the bottom sediments of the canal corresponded to the mixed origin of hydrocarbons with the predominance of allochthonous components.

In the studies of various kinds of biological activity of sulphur-containing monoterpenoids, we previously revealed a practically promising leading compound, the product of the reaction of limonene-(+)-1,2-oxide with methylmercaptoacetate. In the present work, investigation of the antioxidant and membrane-protecting activity of this leading compound is presented in comparison with the starting structures for its synthesis: limonene and limonene-1,2-oxide. For the studies of antioxidant activity, erythrocytes from the blood of laboratory animals were used as a cell test system, and a heterogeneous substrate based on the brain homogenate of laboratory animals was the non-cellular test system. Membrane-protective activity was studied under the conditions of Н₂О₂-induced hemolysis and with oxidative stress induction by 2,2'-azobis-(2-amidinopropane)dihydrochloride. It is shown that all the three compounds exhibit statistically significant antioxidant and membrane-protective activity in both test systems. The most active compound is the leading one, thioterpenoid with the methylmercaptoacetate fragment. In order to expand the synthesis possibilities of monoterpenes of menthane series in thiating reactions, and develop the approach to the synthesis of new potentially bioactive thioterpenoids, the pharmacophoric methylmercaptoacetate fragment was introduced into the structure of limonene dioxide and carvone. The reaction of limonene with methylmercaptoacetate in a basic medium resulted in obtaining a bicyclic product of intramolecular cyclisation participated by the OH group at isopropenyl fragment. The reaction of carvone with methylmercaptoacetate under acid catalysis occurred regioselectively, with the formation of terpene sulphide at the endo-cyclic double bond. The crystal structures of the two latter terpene sulphides were studied by X-ray diffraction. Both thioterpenoids in the crystals under investigation are represented by only one enantiomer.

The chemical composition of volatile organic compounds emitted by tropical and subtropical plants representing four families Begoniaceae, Liliaceae, Myrtаceae, Moraceae used in indoor landscaping are investigated. Seven species and one interspecific hybrid are studied. The sampling procedure has been developed to provide concentrating the organic substances from air onto a specially treated sorbent placed in sampling tubes. The composition of volatile organic compounds was determined by high performance liquid chromatography. The compounds were identified using the spectrophotometric mode and witness method. The compounds detected in the volatile emissions of plants included carbonyls (aldehydes and ketones), carboxylic acids, as well as normal and branched hydrocarbons. The composition of emitted compounds and their ratios were determined to depend on the phases of plant development. The data on the composition of volatile organics were compared with the data on the seasonal variations of antibacterial and antifungal activity of these plants against test microorganisms Escherichia coli, Staphylococcus epidermidis and Candida albicans. Among exometabolites, the compounds that can enhance the phytoncide action have been detected. Thus, an increase in the activity of gaseous emissions of plants against E. coli was determined to be accompanied by the appearance or a sharp increase in the concentration of furfural derivatives, in particular 5-methylfurfural, 5-hydroxymethylfurfural, while an increase in the activity against C. albicans coincided with the appearance of o-methoxybenzaldehyde in volatile exometabolites. The possibility to use the studied species of decorative plants to improve the indoor air quality was assessed.

The content of total ash, ascorbic acid, tannins was determined in the leaves and flowers of Hemerocallis species: H. citrina, H. fulva, H. lilio-asphodelus, H. middendorffii, H. minor, cultivated under the conditions of the forest-steppe zone of the Novosibirsk Region. Biochemical parameters were determined during the flowering period in 2022. It has been found that the concentration of tannins, ascorbic acid, total ash in the leaves is 1.3-1.5 times higher than in the flowers. The leaves are distinguished by the highest content of ascorbic acid (11.43-16.35 mg/100 g). The specificity of the content of these substances in plants depending on the species, vegetative and generative organs during the flowering period is noted.

The paper presents the results of creating a new oil-displacing composition based on the ternary system of deep eutectic solvents (DES) “pentaerythritol - urea - choline chloride” with surfactants, and the results of laboratory tests of its effect on the filtration characteristics of the heterogeneous formation of the Usinskoye field with heavy and high-viscosity oil. As a result of studying the physicochemical characteristics and phase equilibrium of the ternary DES system, a new oil-displacing composition of prolonged action was created, based on the ternary DES system “pentaerythritol - urea - choline chloride” and surfactant, applicable for various geological and physical conditions of fields, in particular in the Arctic zone of the Russian Federation. The effectiveness of the composition was assessed for sections of the field at the early and late stages of development. It has been established that the use of the composition based on DES and surfactants leads to the equalisation of filtration flows with an increase in formation coverage, restoration of the initial permeability and, as a consequence, to a significant increase in the oil displacement coefficient at both low and high temperatures.

Maintaining a stable content of phenylpropanoids (rosavins: rosavin, rosarin, rosin, and cinnamic alcohol) and phenylethanoids (salidroside and tyrosol) in line with pharmacopoeial standards remains a critical challenge for scaling up the cultivation of Rhodiola rosea L. to meet global demand. One possible cause of low compound levels is the inadequacy of current standardisation methods for raw materials and preparations of Rhodiola rosea. This study aimed to identify the optimal drying temperature for raw materials from even-aged clonal plants of Rhodiola rosea cv. ‘Mattmark’. Results showed that higher drying temperatures reduced phenylethanoid levels, with room-temperature drying is optimal. In contrast, the maximal concentrations of rosavins, mainly rosavin, were detected at increased temperature (80 °C). Analysis of the relative distribution of phenylpropanoids revealed that higher drying temperature causes an increase in the proportion of rosavin and a decrease in cinnamic alcohol content, while rosarin and rosin levels remained stable. It has been shown that rosavin is the dominant phenylpropanoid independently of temperature. Thus, drying rhizomes at 80 °C enhanced rosavin content by 20 % but significantly (by a factor of 1.5-2) reduced total phenylethanoids. Therefore, drying at room temperature is recommended to maximise the total phenylethanoid and phenylpropanoid content in the raw material.

The elements of D. I. Mendeleev’s Periodic System (Mendeleev’s Table) have the relative atomic weight calculated as the average value of the atomic weights of several isotopes. The number of these isotopes is quite large; however, there is a lack of convenient and accessible systematisation for practical work. This article proposes a method and a device for such systematisation.

Antimicrobial resistance (AMR) constitutes one of the foremost threats to global public health in the XXI century: according to the data of the World Health Organization for 2025, one of the six laboratory-confirmed bacterial infections exhibits resistance to standard antibiotic therapy, with annual resistance rates increasing by 5-15 % across more than 40 % of pathogen-antibiotic combinations. Amid the declining efficacy of single-target antibiotics, the development of multitarget hybrid antibacterial agents - single molecules incorporating two or more pharmacophoric moieties capable of simultaneously engaging distinct bacterial targets - has gained critical relevance. This review systematically outlines the principal strategies for designing such hybrids: linked, fused, and merged pharmacophores. It also addresses key pharmacokinetic and toxicological considerations, limitations inherent to conventional combination therapy, and the advantages conferred by hybrid molecules, including a unified pharmacokinetic profile, elimination of chemical incompatibilities between components, and simplified dosing regimens. Particular emphasis is placed on the mechanisms of action of hybrid compounds. Several reviewed hybrids demonstrate low minimum inhibitory concentrations, reduced frequencies of spontaneous resistance emergence, and favourable fractional inhibitory concentration indices (FIC ≤ 0.5), underscoring the therapeutic potential of this approach. Some examples of compounds are highlighted for their potent activity against diverse resistant bacterial strains and biofilms. A number of hybrid compounds have successfully advanced through clinical trials (TNP-2092, TNP-2198, cefilavancin, DNV-3837).

The structure and morphology of pellets from nanoscale hydroxyapatite after CO₂ laser beam treatment are studied. It is shown that the use of a compacted layer of the material under treatment allows a significant reduction of the diameter of the laser spot. The effects of scanning speed and density of a hydroxyapatite pellet on the structure and morphology of the treated surface are investigated. It is shown that the congruent melting of the material is observed in the case of the high speed of laser beam movement. A decrease in the speed leads to the transition to sintering mode. The optimal values of the density and thickness of the sintered material are determined, which are to be kept during 3D printing of products from hydroxyapatite by means of selective laser melting.