The Journal of V.N.Karazin Kharkiv National University. Series «Biology»

A system for identification of structural markers of Ames mutagenicity based on similarity of xenobiotic structure fingerprints

S.V. Kislyak — 2025-07-24

The article focuses on the assessment of the genotoxic potential of chemical compounds that may be released into the environment. The necessity of changing the basic vector of development of modern toxicology in view of the achievements in the field of computer science and information technology is proved. In the framework of the study, attention was focused on the in silico approach, which allows to draw conclusions about the genotoxicity of a chemical compound in accordance with the identified functional groups that may underlie the manifestations of mutagenicity. The Ames system for determining structural markers of mutagenicity was implemented in accordance with publicly available databases of chemical compounds (EFSA, Kazius/Bursi and Hansen). The initial number of the merged dataset was increased by mycotoxins, and duplicates were removed. For each xenobiotic presented in the dataset, the mutagenic potential was determined using the in vitro Ames test. In order to effectively identify functional groups that may be signals of mutagenicity, it was decided to divide the xenobiotics of the combined data set into five structural classes. Such an approach to the formation of homogeneous groups of xenobiotics that may exhibit potential genotoxic properties allows us to identify structural markers of Ames mutagenicity within each class of mutagens. To obtain reliable information on the presence of a certain functional group - mutagenicity signal, taking into account the studied structural class of xenobiotics, it was proposed to use distance matrices calculated for each mutagen/non-mutagen pair of the combined data set. The similarity between the compounds was evaluated using classical similarity evaluation metrics (Tanimoto and Heming) according to the calculated three types of molecular fingerprints for each xenobiotic. The last stage of the implementation of the Ames system for detecting structural markers of mutagenicity was associated with the search for and application of an effective algorithm for visualizing multidimensional data. The literature analysis allowed us to choose the optimal algorithm for solving this problem. The chosen algorithm (t-SNE) allows multidimensional data (distance matrices for all mutagens and non-mutagens) to be represented in two-dimensional space. This visualization allows us to find all pairs (mutagen/non-mutagen) that have a sufficiently high similarity index and draw conclusions about the presence of certain functional groups that may underlie the manifestations of mutagenicity for each of the five structural classes of potential mutagens. It is quite interesting from the scientific point of view to analyze the effectiveness of using different types of structure fingerprints to identify structural warnings of Ames mutagenicity, which was carried out in the framework of this study. The result of the work is the developed software that allows determining structural markers of Ames mutagenicity based on the similarity of the structure fingerprints of chemical compounds represented in the combined data set. The possibility of using the proposed approach to solve the problem of finding cause-and-effect relationships between mutagenicity and the presence of certain functional groups in the structure of the studied xenobiotics is demonstrated.

In silico analysis of free heme action on the dimerization and activity of the human redox sensor PARK7

T. Barannik — 2025-07-24

Protein PARK7 (Parkinson disease protein 7) has several enzymatic activities and also functions as a redox sensor,copper chaperone andtranscription regulator. Under oxidative stress PARK7promotes cell survival by activating the ERK1/2 and the PIK3 signaling. PARK7 inactivation causes the reactive oxygen species accumulation and oxidative stress progression. PARK7 disorders has been revealed under neurodegenerative diseases, diabetes and other pathologies. PARK7 functioning is based on the redox changes of conserved Cys106 in the active center. In some neurodegenerative diseases, such as Parkinson's disease, the superoxidation of redox-activeCys106is the basis of the disorder. The removal of 15 amino acid residues from C-end is an obligatory step for the proteolytic active center formation. Modifications observed under oxidative stress affect dimerization of PARK7 necessary for protein maximum activation.

Erythrocyte lysis is known to result in a significant heme accumulation but heme effect on the activity of PARK7 has not yet been investigated. Therefore, the potential heme-binding sites in PARK7 and heme binding effect on the amino acid residues were analyzed.

Structural alignment of PARK7 mutant forms with Cys53 and Cys106 substitutions and wild type has not revealed significant differences (RMSD<0.2Å). Two areas have been found as probable targets for heme binding in PARK7: near the C-terminal region (175-189) that is cleaved for protein activation and in the redox-center with Cys106 and His126. Heme binding to the PARK7 protein could potentially affect its activity by several mechanisms. C-end heme binding can prevent peptide removal necessary for catalytic activity. Cys106 oxidative modification to sulfinic acid could occur under low free heme level and activate PARK7 as a cytoprotector. Significant heme accumulation can result in cysteine superoxidation to sulfonic acid and disrupt PARK7 functionality. Free iron ions as products of heme degradation can compete with copper ions for Cys106 and Glu18 residues therefore inhibit PARK7 activity as SOD1 chaperon. Heme attachment to the sites of oxidation (Cys46, 53 and 106) or sumoylation (Lys130) could disrupt the regulation of PARK7 under stress. Some of the potential heme binding sites of PARK7 protein are involved in protein dimerization, so hemecan block the formation of functional PARK7 dimers.

Therefore free heme accumulation could have multiple negative effect on PARK7 functioning and be one of the mechanisms of PARK7-dependent neurological disorders.

Evolution of metallo-beta-lactamases in focus of the antibiotic resistance problem

V.B. Moskalov — 2025-07-24

The article considers the place of metallo-beta-lactamases among the mechanisms of antibiotic resistance. These enzymes have important differences from serine beta-lactamases, which affect the mechanism of their catalytic activity, inhibition, rate of spread and evolution. The history of the study and the social significance of antibiotic resistance in general and beta-lactamases in particular are described. The classifications of enzymes that hydrolyze the beta-lactam ring are presented, the structure of the reaction center of metallo-beta-lactamases and a hypothetical model of its functioning are described. Two fundamentally different mechanisms of inhibition of metallo-beta-lactamases (zinc-dependent and zinc-independent) and their consequences for the development of therapeutic strategies are also considered. Metallo-beta-lactamases were distributed among non-pathogenic natural populations of bacteria, and then began to spread to pathogenic ones (initially gram-negative), which determines the importance of their study from the point of view of public health. The high rate of spread of these enzymes is due to their localization in structures such as integrons, insertion sequences and conjugation plasmids and can be illustrated by the example of the NDM enzyme, first isolated in New Delhi in 2009, which spread throughout the world in ten years and formed three dozen mutant variants. The fact that metallo-beta-lactamases arose in evolution twice is almost proven. Today, the phylogenetic relationships between different representatives of this enzyme family have been more precisely clarified and the presence of ten monophyletic groups has been established. The data presented in the article can serve as a starting point for planning comprehensive work on predicting the evolution of metallo-beta-lactamases, which carry serious risks for the treatment of infectious diseases.

The influence of the inducer of the transcription factor Nrf2 on metabolic parameters in rat tissues upon injection of hemin

S.M. Okhrimenko — 2025-07-24

Heme is an essential cofactor involved in many biological processes: oxygen transport and storage, electron transfer, drug and steroid metabolism, signal transduction, etc. However, excess free heme is highly toxic due to its ability to stimulate oxidative stress. One of the main responses of the body to oxidative stress is the formation of the transcription factor Nrf2, which enters the nucleus and stimulates the induction of genes encoding key proteins of the antioxidant defense system. Nrf2 is a redox-sensitive transcription factor that regulates the expression of genes containing the responsive element ARE in their promoters. Nrf2 is currently considered the main regulator of redox homeostasis, controlling the expression of over 100 genes involved in protection against reactive oxygen species and electrophiles. One of the inducers of the Nrf2 transcription factor is dimethyl fumarate (DMF), which induces endogenous antioxidant defense via the Nrf2 pathway. The effect of Nrf2 on nitrogen metabolism and the thiol system under oxidative stress remains insufficiently studied. In this regard, the aim of this study was to investigate nitrogen metabolism parameters and the content of non-protein thiols under conditions of hemin administration, the introduction of the Nrf2 transcription factor inducer dimethyl fumarate, as well as their combined administration. The study subjects were outbred white male rats weighing 180–260 g, which received intraperitoneal injections of hemin solution at a dose of 50 μg per kg of body weight and oral administration of dimethyl fumarate. After 24 hours, the animals were used in the experiment in accordance with the Convention on the Treatment of Animals. Blood plasma was obtained from collected blood samples. The liver was perfused with cooled physiological saline. Homogenates were prepared from the liver, kidneys, and heart, which were used to determine catalase, aminotransferase, and arginase activity, as well as the content of TBARS (thiobarbituric acid-reactive substances) and reduced SH-groups. Urea levels were determined in blood plasma. The study results indicate the following: hemin administration caused an increase in TBARS content in the heart, a decrease in reduced thiol levels in the rat organs, and catalase activation in the kidneys; dimethyl fumarate administration led to a decrease in TBARS levels in the heart, an increase in total thiol groups in the kidneys, and an increase in arginase activity in the liver; combined administration of hemin and DMF after 24 hours resulted in an increase in TBARS content in the kidneys and heart, non-protein SH-groups in the liver, plasma urea levels, as well as an increase in aminotransferase and arginase activity in the studied organs. These observed changes may reflect the activation of Nrf2 in the presence of a pro-oxidant factor and its effect on the expression of a number of genes whose products participate in adaptive processes under oxidative stress.

Population changes dynamics of rare ephemeroid species in the Gorgany nature reserve

R.I. Kuznetsov — 2025-07-24

The objects of study were the populations of three species: Crocus heuffelianus Herb., Galanthus nivalis L., Leucojum vernum L. – the early flowering plants of the Gorgany Nature Reserve. The study involved analyzing the results of long-term monitoring of populations of these species, identifying the dynamics peculiarities of the age structure and changes in the numbers of individuals under the abiotic and biotic factors. The study was carried out at the botanical permanent monitoring plots No. 4–6 on the territory of the Gorgany Environmental Scientific Research Department for 20 years from 2004. To determine the density of populations, we used the methodology of T.O. Rabotnov with additions and A.A. Uranov, tested by numerous researchers. L. vernum age groups were distinguished according to the classification given by N.V. Shumska, C. heuffelianus – according to the classification of V.I. Melnyk and G. nivalis - according to the classification of G.B. Budnikov. The results of the study showed that abiotic factors have a significant impact on populations of ephemeroids . Abiotic factors that led to changes in the number of individuals within different age groups of the C. heuffelianus include significant height of the snow cover and its abrupt melting, low average daily temperatures, heavy rains and flooding of plants with water in the lowlands of the botanical monitoring plot. Among the biotic factors, a very high population density should be noted. The generative development of L. vernum is significantly affected by low average daily temperatures. At the beginning of the growing season, the number and abundance of G. nivalis plants is affected by significant snow cover, repeated snowfall and low average daily temperatures. We discovered that the spring temperature drop and repeated snowfall after the beginning of the growing season significantly affect the duration of phenological phases of the ephemeroids. The beginning of phenophases has shifted to later dates. On the contrary, positive values of air and soil temperatures lead to an early start of the growing season, as well as earlier onset of subsequent phenophases.

Egg size Variation in the Collared Flycatcher (Ficedula albicollis Temminck, 1815)

T. Atemasova — 2025-07-24

This work aims to examine the factors influencing variation of the Collared Flycatcher’s egg size at the southern borders of the distribution of deciduous forests (Homil’shanski Lisy National Park, Ukraine). In total, data on 298 clutches and 1971 eggs of the Collared Flycatcher in artificial nest-boxes for 2006‒2011 and 2013‒2021 were used for analyses. As the meteorological indicators we used the temperature, a number of days with rainfall during the 1st decade of May; and humidity indices. All statistical analyses were performed with R statistical software version 4.4.2, A Shapiro–Wilk test for normality revealed that data were not normally distributed. Therefore, for further analysis, we used the Kruskal – Wallis test and Dunn test as well as Permutational Analysis of Variance (PERMANOVA) of the distance matrix. The vegan package was used for analysis. We analyzed the effects of meteorological indicators on egg size using generalized additive models. Statistical analyses were performed using mgcv packages.

In the studied subpopulation, the average egg length tends to decrease in the period from 2006 to 2021 and is slightly dependent on clutch size and the decade of first-egg laying. The seasons with the smallest egg sizes in the studied subpopulation spanned 2014 - 2018; later on, there was an increase in egg diameter towards the usual size for this subpopulation. The consistently small diameter of the eggs can be assumed to indicate that during this period, young females predominated in the studied subpopulation.

In general, the size of the eggs in the last season was similar and even somewhat larger (especially in length) to those obtained in the Sumy region of Ukraine, and in certain years exceeded the indicators of the eggs of flycatchers from the Bialowieza Forest. It can be assumed that larger eggs are laid by females under optimal conditions within the species’ range; as they move towards the borders of the range to the north and east, the morphometric parameters may decrease due to the decline in the quality (abundance of food) of the environment.

The analysis of the repeatability of egg sizes in the same female should answer the question of whether the size of the egg is an individual’s characteristics of females. However, we did not receive a definitive answer.

The humidity of the pre-laying decade has a significant negative impact on the morphological parameters. The humidity during the egg-laying decade has a positive influence, while to a lesser extent, the temperature of the decade prior to egg-laying also positively affects the length of the eggs. The temperature of the previous decade and the number of rainy days play a minor role. At the same time, there is an optimum for these indicators, beyond which the effect of their influence on the size of the eggs changes to the opposite. In the studied area, the length and diameter of eggs from early and late did not differ significantly. Only in certain years, the differences in length, diameter, and volume are significant.

The variation of the morphological parameters are an integrated response to the instability of environmental parameters. One of the reasons for high variability in egg sizes may be humidity. The size of the eggs itself cannot be explained by the climatic conditions of the current year. They are an integrated indicator of the female's maturity and the nutritional conditions of the season.

The wood mouse Sylvaemus tauricus (Mammalia) in the south of Ukraine: limits and features of distribution in a historical biogeographical context

I. Zagorodniuk — 2025-07-24

The article analyses the specifics of distribution of the species Sylvaemus tauricus in the south of Ukraine, particularly in the coastal regions, where it reaches the northern limits of the steppe natural zone. The number of records describing the southern limit of distribution in the continental part of the range (i.e., outside the Crimea) is generally not large (about 30), but all of them eloquently testify to some common features. The first is that the species penetrates deep into the steppe zone, essentially to the border between the northern (gully) and southern (driest) steppe. Secondly, the species demonstrates the possibility and high speed of forming new populations, including banded populations, in areas of expansion, both along natural eco-corridors (primarily along rivers) and using artificial eco-networks (forest belts, roadside or canal-side tree and shrub strips). Thirdly, there is a unified front of habitats, which indicates that the range corresponds to the natural zonation. Comparison of the obtained distribution scheme with the forestry zonation of Ukraine shows that the species is completely absent in the zone of dry (treeless) steppes, which belong to the Black Sea–Pryazovia South Steppe District. However, the boundary is even more northern: it runs along the middle of the Northern Steppe District (bayrak steppe zone), in some places with the species crossing the southern border of this district. Available data indicate the species' expansion to the south, which may be due to the spread of artificial stands, both of stripe-type (forest belts and stands along water canals, railways, and highways) and focal-type (forest park areas around settlements, artificial forests, etc.). One of the signs of expansion is the increasing share of the species in captures in different types of stands: in Luhansk Oblast, the share of this species in places of its occurrence has gradually increased from 0.64% in 1957–1965 to 13.8% in 2002–2014. The southward expansion of this wood mouse species is in contrast with the trend of the natural zones shifting northward, which demonstrates the importance of non-natural habitats in species dispersals. The hypotheses of the connection between the mainland range of the species and the Crimean isolate are discussed. It is assumed that the species' range in the coastal regions has undergone repeated pulsations with the formation of a continuous distribution of the species. Nevertheless, it is possible that the species could have entered the Crimea from the Western Caucasus during the period of sea level regression and the formation of the Kerch–Taman land bridge.

Typology of Great Cormorant (Phalacrocorax carbo) Nesting Colonies in the Azov-Black Sea Region of Ukraine

A.I. Sydorenko — 2025-07-24

This study presents an analysis of the nesting settlement typology of the Great Cormorant (Phalacrocorax carbo) in the Azov-Black Sea region of Ukraine. It was established that cormorants actively utilize a wide range of habitats for colony establishment, with a preference for natural islands of marine, riverine, and lagoon origin, where optimal conditions for successful nesting are formed. The choice of nesting sites is influenced by the availability of building materials, elevation above water level, distance from the mainland, and the presence of protection from predators. Cormorants build their nests on sandy-shell, clay, and rocky islands, as well as within vegetation cover, selecting trees, shrubs, and reeds.

A particularly interesting aspect is the cormorants' ability to adapt to nesting on man-made structures such as gas platforms, power line pylons, and sunken ships. This phenomenon is becoming increasingly widespread due to the limited availability of natural nesting sites, which is a consequence of anthropogenic impact, and reflects the species’ adaptation to environmental changes. An analysis of 72 colonies revealed that the number of birds significantly increases on artificial structures despite the annual removal of nests during maintenance operations. Cormorants demonstrate high resilience to such interventions, rebuilding their colonies even after destruction.

The study also examined the influence of various factors on nest site selection, including island area, availability of building materials, elevation above water level, and distance from the mainland and human settlements. A direct correlation was found between the number of nests and the size of the nesting territory. Additionally, it was noted that colonies located on islands closer to the mainland face higher risks due to increased accessibility for predators and humans.

This research provides new insights into the nesting ecology of the Great Cormorant in Ukraine and highlights the importance of further studies on the impact of artificial structures on the species’ nesting behavior.

Biological peculiarities of ptinid beetles (Coleoptera, Ptinidae) – xylobionts of deciduous trees in the forest-steppe of Left-Bank Ukraine

V.V. Terekhova — 2025-07-24

In the forest-steppe zone of Left-Bank Ukraine, 30 xylobiont species of the Ptinidae family developing on deciduous trees were registered. Own collections during 2005-2021 and collection materials of the Museum of Nature of V. N. Karazin Kharkiv National University and I. I. Schmalhausen Institute of Zoology confirmed the presence of 28 species in the studied area. The trophic specialization of the Ptinidae xylobiont species was analyzed, 4 trophic groups were identified. 19 species (63%) were classified as xylophages, 5 species (17%) as saprophages, 4 species (13%) as mycetophages, and 2 species (7%) as xylomycetophages. The method of incubation in the laboratory using photoeсlectors revealed host plants for 21 species. Most Ptinidae species develop on pedunculate oak Quercus robur – 11 species, followed by linden Tilia сordata, which is a host plant for 8 Ptinidae species. The remaining woody plant species are hosts for a smaller number of ptinid species: Acer sp. (2 species) Alnus glutinosa (4 species), Betula pendula (5 species), Corylus avellana (2 species), Fraxinus excelsior (4 species), Populus tremula (2 species), Salix alba (3 species), Ulmus sp. (2 species). Nocturnal activity and flight into the light have been recorded for 12 species: Ptinus rufipes A. G. Olivier, 1790, P. subpillosus Sturm, 1837, Cacotemnus rufipes (Fabricius, 1792), Hemicoelus canaliculatus (C. G. Thomson, 1863), Gastrallus immarginatus (P. W. J. Muller, 1821), G. laevigatus (A. G. Olivier, 1970), Priobium carpini (Herbst, 1793), Oligomerus brunneus (Olivier, 1790), O. retowskii Schilsky, 1898, Dorcatoma chrysomelina Sturm, 1837, Ptinomorphus regalis (Duftschmid, 1825), Xyletinus pectinatus (Fabricius, 1792).

Comparative ecological analysis of the trematode fauna of fishes of the reservoirs cascade on the Kura River within Azerbaijan

Y.V. Shakaraliyeva — 2025-07-24

In 2007-2022, in four reservoirs forming a cascade on the Kura River, 1243 fish of 30 species were examined for trematode infection using the method of complete parasitological dissection. For this purpose, 283 fish of 21 species were examined in the Shamkir Reservoir, 276 fish of 21 species in the Yenikend Reservoir, 341 fish of 25 species in the Mingechevir Reservoir, and 343 fish of 26 species in the Varvara Reservoir. As a result of the conducted research, 39 species of trematodes were found, of which 11 species parasitize in the lenses of the eyes, 9 species in the intestines, 4 species in the muscles and under the skin, one species each in the bloodstream, vitreous body, stomach, oral cavity and esophagus, urinary bladder, ureters, and kidneys, heart, brain, skin and fins, muscles and mesentery, walls of the swim bladder and kidneys, scales; 2 species at the metacercaria stage live in various tissues of fish, and in the adult stage – In the intestines of predatory fish. Among the found trematodes, 14 species use fish only as a definitive host, 23 species parasitize in fish only at the larval stage, completing their development in fish-eating birds, 2 species use various fish as a second intermediate host, and predatory fish as a definitive host. When comparing the studied reservoirs, it turned out that the greatest number of trematode species was found in fish from the relatively small Varvara Reservoir, where fish were infected with 27 trematode species. This is due to the fact that most of this reservoir is shallow, has a weak current and a lot of aquatic vegetation, which creates favorable conditions for the development of mollusks – the first intermediate hosts of trematodes, and also attracts fish-eating birds, which are the final hosts of many species of fish trematodes. Next in terms of the number of fish trematode species is the Mingechevir Reservoir, where 25 species were found in fish. It is the largest among the reservoirs we studied and has large areas with a slow current. In the fish of the Shamkir Reservoir, which is the second largest, 20 trematode species were noted, and in the relatively small Yenikend Reservoir, where there is a fast current, 17 species of fish trematodes were recorded. In each reservoir, the species composition of fish trematodes is richer in those areas where there is no fast current, overgrowing with aquatic vegetation is observed and fish-eating birds are present. It turned out that in reservoirs located close to each other, same species are found more often than in reservoirs located far from each other. Since previous studies, which were conducted by different authors in the 1950s, 1970s and 2000s, the species composition of fish trematodes in reservoirs that form a cascade on the Kura River has been significantly enriched. Among the trematodes found, 14 species are pathogenic for fish and 2 species are dangerous to humans.

Photoperiod-induced changes in total nitrogen and soluble protein content in soybean leaves

I.M. Raievska — 2025-07-24

Soybean (Glycine max (L.) Merr.) is a short-day plant highly sensitive to photoperiod, with this sensitivity largely regulated by maturity (E) genes. These genes influence a wide range of developmental processes, including flowering time, morphological traits, hormone levels, and carbon and nitrogen metabolism. Adaptation to photoperiod involves coordinated changes in morphology, physiology, and biochemistry, ensuring timely transition to reproductive development and optimal crop formation. Field experiments were conducted at the experimental plots of the Department of Physiology and Biochemistry of Plants and Microorganisms of V. N. Karazin Kharkiv National University. This study investigated the effects of photoperiod duration on total nitrogen and soluble protein content in the leaves of near-isogenic soybean lines of the Clark variety, differing in E1–E4 gene combinations. Short-day lines (Clark variety (e1E2E3E4e5E7), line L63-3016 (e1E2E3e4e5E7), line L 80-5879 (E1e2e3E4e5E7) and photoperiod-insensitive lines (L63-3117 (e1e2E3E4e5E7), L71-920 (e1e2e3E4e5E7) were grown under natural long-day conditions (16 h) until the V3 stage. Half of the plants were then exposed to short-day conditions (9 h) for 14 days using blackout treatments. Leaf samples were collected at four time points (before the start of the short day effect, during the short day effect - 7 and 14 days, a week after the short photoperiod effect) to assess total nitrogen and soluble protein levels. The results showed that dominant alleles of E1 and E2 delayed the transition to the reproductive phase and significantly affected nitrogen and protein accumulation. Specifically, E1 reduced total nitrogen under both photoperiods, while E2 increased it under long-day conditions. Both E1 and E2 lowered soluble protein content under short-day exposure. No significant effects of E3 and E4 were observed. These results demonstrate that the regulation of nitrogen metabolism and protein synthesis in soybean is closely modulated by the interaction between photoperiod and maturity gene expression.

Flora of the projected Mzhasnkyi National Nature Park (Kharkiv Region). Part 1: Pinewood complex

H.M. Bondarenko — 2025-07-24

In the territory of the Kharkiv Region, pine forests are understudied, and only small areas of pine forests are protected. At the same time, there are risks for the pine forests and their biodiversity associated with a high level of economic activity, recreational load, and over the past 3 years, with active combat activity. This encourages research and preservation of the most valuable areas of pine forests in the territory of the Kharkiv Region. To protect the valley complexes of the Mozh River, including pine forests, a project for organizing the Mzhansky National Nature Park was proposed. From 2023 to 2024, the flora of the designated park was studied using the route reconnaissance method. It was established that the flora of the studied territory consists of 529 species, subspecies and hybrids of vascular plants. The phytobiota is represented by 81 families, among which the leading ones are Asteraceae, Poaceae, Cyperaceae, Fabaceae, Rosaceae, Caryophyllaceae, Lamiaceae, Brassicaceae, Plantaginaceae s.l., Apiaceae, Boraginaceae, and Ranunculaceae. The analysis of the flora by the main edaphic factors showed that the hygromorphes spectrum is dominated by groups of hygromesophytes (24.3%), mesophytes (23.4%), and submesophytes (23.0%). Compared with other studied forests in the Kharkiv Region, the studied territory is characterized by more humid and diverse conditions. In terms of nitrate content, general salt regime and substrate acidity, the studied territory has typical conditions for forests in the Kharkiv region. According to the results of the analysis of the flora synanthropization, it was established that the degree of transformation is 51.1%, which is less than similar indicators of other local floras in the Kharkiv Region. Transformation occurs mainly due to apophytes (31.1%). At least 106 alien plant species occurred, more than half of which are of Mediterranean or North American origin. Among them are new species to the Kharkiv Region: Commelina communis, Bidens connata, and Sedum album. During the research, 40 protected plant species were revealed. Among them, 30 are protected at the regional level (Bistorta officinalis, Comarum palustre, Dryopteris carthusiana, Paris quadrifolia, Pyrola rotundifolia, Thelypteris palustris, etc.), 10 are included in the Red Book of Ukraine (Botrychium lunaria, Epipactis helleborine, Neottia ovata, Pulsatilla pratensis, Stipa borysthenica, etc.) and 3 species are included in Resolution 6 of the Bern Convention (Jurinea cyanoides, Pulsatilla patens, and Salvinia natans). Several rare species in the region that do not have a protected status were also identified (Carex remota, Luzula pilosa, Peucedanum palustre, etc.). A significant proportion of rare and protected species are at the southern limit of their distribution, therefore they are particularly vulnerable in the study area.