Plants of the Crassulaceae family are natural accumulators of many medicinal secondary metabolites (SM). This article describes the study of morphophysiological, anatomic and phytochemical responses of immature plants of Rhodiolla semenovii under water deficit and (or) cold-stress conditions. Changes in biomass production due to water content in plant tissues such as a decrease in water deficit and an increase in cold stress were revealed. A significant decrease in the efficiency of the photosynthetic apparatus under stress conditions was noted, based on the parameters quantum efficiency of Photosystem II and electron transport rate and energy dissipated in Photosystem II. The greatest decrease in efficiency was pointed out in conditions of water shortage. The anatomical modulations of root and shoot of R. semenovii under stress conditions were found. For the first time, a detailed study of the chemical composition of the ethanol extract of root and shoot of R. semenovii under stress was carried out using gas chromatography–mass spectrometry. The qualitative and quantitative composition of SM associated with acclimation to the effects of abiotic stresses was determined. Both nonspecific and specific phytochemical changes caused by the action of water deficiency and cold treatment were identified. It has been shown that the antioxidant system in plant tissues is complex, multicomponent, depending on a number of natural and climatic factors. Further research should be focused on the use of abiotic stressors for the targeted synthesis of bioactive SMs valuable for pharmaceutical use.

The chemical composition of Sedum ewersii Ledeb., a plant indigenous to Kazakhstan and traditionally utilized in folk medicine, was comprehensively investigated, with a focus on its various plant parts. Fresh samples collected in May 2023 from the Almaty region underwent hydrodistillation to extract volatile components, followed by analysis using gas chromatography coupled with mass spectrometric detection, which identified a total of 71 compounds across different plant parts, including the root (underground part), root (aerial part), leaf, stem, and flowering aerial part. The predominant biologically active compound identified across all plant parts was Ethyl α-D-glucopyranoside. Monoterpenes, recognized as primary secondary metabolites, were notably abundant in each plant part, with varying compositions: the root (underground part) contained 28.58% aliphatic monoterpenes, 54.41% oxygenated monoterpenoids, 1.42% diterpenoids, and 15.59% other compounds; the root (aerial part) exhibited 1.34% aliphatic monoterpenes, 31.28% oxygenated monoterpenoids, 6.16% diterpenoids, and 61.22% other compounds; the stem and leaves showed 3.06% aliphatic monoterpenes, 21.49% oxygenated monoterpenoids, 17.99% diterpenoids, and 57.46% other compounds; and the flowering aerial part displayed 8.20% aliphatic monoterpenes, 53.18% oxygenated monoterpenoids, 23.75% diterpenoids, and 14.87% other compounds. Diterpenes, particularly Phytol, were prominently present in the leaf, stem, and flowering aerial parts. Additionally, a diverse array of organic acids, ketones, and phenolic compounds were identified across the plant parts, each potentially offering distinct pharmacological benefits. The presence of exclusive compounds in specific plant parts, such as Dihydroxyacetone in the root (aerial part), underscored the pharmacological diversity of S. ewersii. This study provides valuable insights into the chemical diversity and pharmacological potential of S. ewersii, suggesting promising applications in pharmaceutical and medicinal fields. Further research aimed at elucidating the individual and synergistic pharmacological effects of these compounds is crucial to fully harness the therapeutic benefits of this plant.

The article presents the features of the anatomical and morphological structure of the vegetative organs of Rheum wittrokii Lundstr. and the results of its qualitative and quantitative phytochemical analyses. The structure of the leaf shows the presence of calcium oxalate druses, which are located mainly under the layer of columnar mesophyll, along the Central part of the leaf blade. Druses in the spongy parenchyma are clearly distinguished and have an almost spherical shape with a peculiar needle-like structure. In the main vein, sections of the sclerenchymic lining are adjacent to the conducting bundle. The covering tissue of the roots has a secondary structure and is represented by a three-layer periderm. In the cells of the main parenchyma of the cortex, numerous calcium oxalate druses are found, which have a round-crystal configuration and are collected in small groups. The vessels of the root xylem are large with ladder and mesh perforation. Features of the main stem parenchyma are its larger, rounded-oblong or oval shape with slightly thickened cell walls. The revealed anatomical features can be used in the case of the diagnosis of medicinal plant raw materials. The study of the chemical composition, the study of biological activity and the development of new herbal medicines is relevant. As a result of studying the chemical composition of the ethanol extract of Rheum wittrokii obtained by extracting 96% ethanol, 8 main components were identified. Rhizomes are dominated by chrysophanic acid with an identification probability of 41.4%. The presence of components was found: chrysarobin, chrysophanic acid, emodin-3-methyl ether, emodin-1,3,8-trihydroxy-6-methylanthracene-9,10-dione, which are directly involved in the body’s metabolism, providing antioxidant, antiseptic and anti-cancer effects, and also help in the removal of toxins from the body, which has a beneficial effect on the liver, increasing the level of glycogen.

The article examines the current status of populations of Phedimus hybridus (L.) ‘t Hart (also known as Sedum hybridum L. and Aizopsis hybrida (L.) Grulich) and Hylotelephium ewersii (Ledeb.) H. Ohba (formerly Sedum ewersii Ledeb.) in the Kok-Zhailau Gorge, part of the flora of the Ile Alatau. The study explores the biology of these species, including their population dynamics and life forms, as well as their ecological responses to specific ecological-cenotic conditions. P. hybridus is valued in traditional medi-cine for its diverse therapeutic properties, such as anti-inflammatory effects, stimulation of the nervous system, antidepressant and wound-healing actions, and inhibition of leukocytosis. In contrast, H. ewersiiis commonly cultivated as an ornamental plant. The article also includes a taxonomic, ecological, and geographical analysis of the flora associated with the populations of P. hybridus and H. ewersii in the Kok-Zhailau Gorge. The flora of the studied populations of P. hybridus and H. ewersii in the Big Almaty Gorge, Kok-Zhailau Tract, and Kazachka River areas of the Ile Alatau comprises 146 species across 78 genera and 39 families. The main ecological groups of plants within the P. hybridus and H. ewersiipopulations are shown: mesophytes – 105 species (71.9%), mesoxerophytes – 30 species (20.5%), and mesohygrophytes – 11 species (7.5%). The analysis revealed different levels of representation of geo-graphical elements in the flora of the populations of P. hybridus and H. ewersii in the Kok-Zhailau tract of the Trans-Ili Alatau, which emphasizes the heterogeneity of the flora.

The article describes the natural soil conditions of Sedum hybridum L. and Sedum ewersii Ledeb—populations area based on the results of field and laboratory soil studies of soils. Soil types, morphological features, chemical composition, nutrient elements, amount of humus, absorbed bases and salt composition, and mechanical composition of soils are determined. The following soil types were identified during field studies: Kokzhailau Gorge (population 1) – chernozem, Turgeni Gorge (population 2) – chernozem, near Kastek River (population 3) – chestnut soil. The humus content in the 0-80 cm layer of chernozem (population 1) of Kokzhailiau gorge is very high, ranging from 5.55-12.81%, the reaction of the soil medium is within pH 7.10-7.40, i.e. CO2 content ranges from 0.16 to 0.34. On chernozems of Turgeni gorge (population 2) humus content in 0-60 cm layer is very high, within 5.90-20.88%, reaction of soil medium within pH 6.15-7.07, amount of CO2 within 0.21-0.34.On chestnut soils near the Kastek River (population 3), the humus content in the 0-73 cm layer was in the range of 1.57-6.92%, the pH ranged from 7.13-8.23, i.e. it was alkaline, the CO2 content was in the range of 0.16 - 0.34. The composition of salts in the chernozems of the Kokzhailau gorge: CO3 - not detected; HCO3- - 0,24- 0,48 ; Cl- – 0.04; CO4- – 0,12-0,92; Sa+ – 0,29-0,49; Mg 2+ – 0,20-0,98; Na+ – 0,05-0,06; To+ – 0,05-0,23; The amount of salts is 0.060-0.083%. It was found that the soils of all 3 populations are not saline, since the amount of salts does not exceed the salinity limit.Keywords: population, soil, profile, humus, salt.

The article is devoted to the study of the current state of populations of the species Hylotelephium ewersii (Ledeb.) H. Ohba (formerly Sedum ewersii Ledeb.) and Phedimus hybridus (L.) 't Hart (also known as Sedum hybridum L. and Aizopsis hybrida (L.) Grulich) in the floristic composition of the coenopopulations of these species in the Ile Alatau. The article presents a study and analysis of the biology of the populations of H. ewersii and P. hybridus in the Kastek Gorge of the Ile Alatau, the diversity of their life forms, and ecological reactions in specific ecological-cenotic conditions. Seasonal rhythms of development of H. ewersii and P. hybridus showed their stability and high adaptability to the conditions of the landscape mountain zone of the Ile Alatau. The studies made it possible to identify the adaptations of natural cenopopulations of H. ewersii and P. hybridus to long-term, sustainable existence in conditions of a sharply continental climate and to assess their current state. The article presents a taxonomic, ecological, and geographical analysis of the flora of the populations of H. ewersii and P. hybridus. The studied species H. ewersii and P. hybridus have a life form of herbaceous succulent-leafy terrestrial-creeping polycarpics with a rosette-less sympodial model of shoot formation, where, according to the position of the renewal buds, the studied species belong to the chamaephyte biomorph Key words: Hylotelephium ewersii, Phedimus hybridus, population, coenopopulation, Kastek Gorge, Ile Alatau