The Eurasian National University named after L.N. Gumilyov will defend the thesis for the degree of Doctor of Philosophy (PhD) by Azhikhanova Zhanat Tobakhanovna on the topic «Phytochemical investigation of some plants of Kazakhstan» under the educational program «8D05306 – Chemistry».
The dissertation was carried out at the «Chemistry education department» of L.N. Gumilyov Eurasian National University.
The language of defense is kazakh
Official reviewers:
Burasheva Gaukhar Shakhmanovna – Doctor of Chemical Sciences, Professor, Non-Profit Joint-Stock Company “Al-Farabi Kazakh National University” (Almaty, Republic of Kazakhstan);
Nurmaganbetov Zhangeldi Seitovich – Candidate of Chemical Sciences, Associate Professor (Docent), LLP “Institute of Organic Synthesis and Coal Chemistry of the Republic of Kazakhstan” (Karaganda, Republic of Kazakhstan).
Temporary members of the Dissertation Council:
Eskalieva Balakyz Kymyzgalievna – Candidate of Chemical Sciences, Research Professor, Non-Profit Joint-Stock Company “Al-Farabi Kazakh National University”, Department of Chemistry and Technology of Organic Substances, Natural Compounds and Polymers (Almaty, Republic of Kazakhstan);
Numonov Sodik Rakhmonovich – Doctor of Natural Sciences, Scientific Research Institute “Chinese-Tajik Innovation Center for Natural Products” (Dushanbe, Republic of Tajikistan);
Ibataev Zharkyn Abykenovich – Candidate of Chemical Sciences, Docent, Non-Profit Joint-Stock Company “S. Seifullin Kazakh Agrotechnical Research University” (Astana, Republic of Kazakhstan).
Scientific advisors:
Baisalova Galiya Zhumamuratovna – Candidate of Chemical Sciences, Docent,, Acting Professor of the Department of Chemistry, Non-Profit Joint-Stock Company “L.N. Gumilyov Eurasian National University” (Astana, Republic of Kazakhstan);
Mehmet Ali Özler – Doctor of Philosophy (PhD), Associate Professor, Muğla Sitki Kochman University (Mugla, Republic of Türkiye).
The defense will take place on May 26, 2026, at 02:00 PM in the Dissertation Council for the training direction «8D053 – Physical and chemical sciences» under the educational program «8D05306 – Chemistry» of L.N. Gumilyov Eurasian National University. The meeting of the dissertation council will be held in both offline and online formats.
Link: https://clck.ru/3SzYSs
Address: Satpayev Street, 2, Room: 302., Astana.
Abstract (English): ABSTRACT of the thesis of Azhikhanova Zhanat Tobakhanovna on the topic «Phytochemical investigation of some plants of Kazakhstan», submitted for the degree of Doctor of Philosophy (PhD) educational program in "8D05306 - Chemistry" General description of the thesis. In this dissertation, wild-growing plants from the Ortau mountain massif of the Karaganda region in Central Kazakhstan were investigated. These include species belonging to the Lamiaceae family Phlomis tuberosa L. (tuberous Jerusalem sage), as well as the Asteraceae family a representative of the genus Achillea, species Achillea setacea Waldst. et Kit. (Bristly yarrow). During the study, the chemical and organic composition of phenolic compounds, essential oils, and vitamins extracted from the flowers, aerial parts (leaves and stems), and root parts of the plants were examined. From a biochemical perspective, under in vitro conditions, their abilities were studied and evaluated in terms of inhibiting lipid oxidation, neutralizing DPPH and ABTS⁺ radicals, exhibiting chelating activity (binding Fe²⁺ ions), and suppressing the activity of enzymes such as cholinesterase, α-amylase, urease, and tyrosinase. For the purpose of developing polymer materials from the stems of P. tuberosa, pure cellulose was isolated and its adsorption properties were investigated. Relevance of the research topic. The relevance of this study is determined by the high demand in modern medicine and the pharmaceutical industry for new sources of natural chemical compounds of plant origin. Phenolic compounds and essential oils (which include lactones and terpenes) obtained from plants are valuable ecological and safe sources of medicinal substances. Among such plants are P. tuberosa and A. setacea, which grow in the flora of Kazakhstan. Some of their species have been used in traditional folk medicine as antiseptic and anti-inflammatory agents, as well as for the treatment of digestive system diseases. However, the chemical composition of individual parts of these plants, including phenolic compounds, essential oils, and vitamins, has not yet been sufficiently studied from a scientific point of view. The treatment of diseases such as diabetes mellitus, neurodegenerative disorders, gastric ulcers, and oncological diseases some of which are caused by the bacterium Helicobacter pylori still remains an unresolved problem. In this regard, the identification of plant-derived chemical compounds with antidiabetic activity, the ability to inhibit enzymes, and to slow down or suppress oxidative processes in the body is of particular importance. In addition, it is important to develop new medicinal products based on these compounds, as well as ointments for the treatment of skin diseases. The scientific literature also insufficiently addresses the use of the stems of P. tuberosa as a renewable source for obtaining natural polymeric materials based on cellulose for environmental purposes. In this context, the perennial herbaceous plant Phlomis tuberosa L., which grows in the central region of Kazakhstan, can be considered a promising and sustainable source of lignocellulosic biomass. Therefore, special attention should be paid to studying the structure and adsorption properties of cellulose-based polymeric materials derived from plant raw materials, as well as their application for environmental purposes in effective and commercially accessible water purification technologies. Aim of the dissertation work: To study the chemical composition and biological activity of wild plants growing in Kazakhstan (P. tuberosa and A. setacea) and to develop beneficial products based on them. Research objectives: 1. Obtaining extracts and essential oils from the flowers, aerial parts, and roots of P. tuberosa and A. setacea, as well as determining their chemical composition, including phenolic compounds and vitamins, using modern physicochemical methods (GC-MS, HPLC). 2. Isolation of natural cellulose from the stems of P. tuberosa and the development of polymer composite materials based on it; studying the structural, morphological (SEM, TEM), crystalline (XRD), and adsorption (UV-Vis) properties of the obtained materials. 3. Investigation of the biological activity of the obtained extracts and essential oils in vitro, in particular their antioxidant properties (ability to slow down or inhibit oxidative processes in the body), antidiabetic activity, as well as their ability to inhibit the enzymes cholinesterase, urease, and tyrosinase. Object of the research: Individual organs of wild-growing plants P. tuberosa and A. setacea from the flora of Kazakhstan, growing in the same region and representing ecologically adapted species belonging to the hemicryptophyte life form. In addition, the object of the study includes polymer composite materials based on cellulose isolated from the stems of P. tuberosa. Research methods:). Extracts from the flowers, aerial parts, and roots of the plants were obtained using ultrasound-assisted extraction, while essential oils were obtained by hydrodistillation. The chemical composition, including the content of phenolic compounds and vitamins in the extracts, was determined by HPLC, and the component composition of the essential oils was analyzed by GC-MS. Biochemical studies were carried out in vitro, evaluating antioxidant, antidiabetic, anticholinesterase, antiurease, and antityrosinase activities. The structural properties (XRD), morphology (SEM, TEM), and adsorption characteristics (UV-Vis) of a biodegradable polymer material based on cellulose isolated from the stems of P. tuberosa using the organosolv method were also investigated. Scientific novelty of the thesis: 1. For the first time, chlorogenic, ferulic, and ellagic acids, apigenin, and other chemical compounds, as well as vitamins (B₃, C, and E), were identified in individual organs of the studied plants. In addition, the chemical composition of the essential oil obtained from the flowers of P. tuberosa was established. 2. For the first time, an important chemical compound cellulose was obtained from the stems of P. tuberosa using known chemical reactions. Based on this, a composite polymer material was developed. Its adsorption capacity was investigated as an adsorbent in the process of adsorption of synthetic dyes a key phenomenon in surface chemistry and a theoretical model of this adsorption process was also developed. 3. For the first time, the ability of methanolic and hexane extracts, as well as essential oils obtained from different parts of the studied plants, to inhibit the enzymes urease, tyrosinase, α-glucosidase, α-amylase, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) was investigated. Validity and reliability of the research results: All experiments were carried out using modern, well-validated laboratory equipment and instruments ensuring high measurement accuracy. The research methods and materials used in this work comply with the requirements of international standards and regulatory documents. The determination of the chemical composition of phenolic compounds in the extracts, essential oils, and their biological activity was performed using validated methods approved by the pharmacopoeias of the Republic of Turkey and the Republic of Kazakhstan. The results obtained in this study demonstrate the potential application of the studied plants in addressing pharmaceutical and environmental challenges in applied chemistry in the future. In particular, the membrane produced from the isolated cellulose is considered a composite material that aligns with the principles of “green” chemistry environmentally safe, efficient, and commercially accessible developed within the framework of the rational use of Kazakhstan’s natural resources. Main provisions submitted for defense: 1. For the first time, chlorogenic, ferulic, and ellagic acids, apigenin, and other chemical compounds, as well as vitamins (B₃, C, and E), were identified in individual organs of the studied plants. In addition, the chemical composition of the essential oil isolated from the flowers of P. tuberosa was established. 2. For the first time, high-purity cellulose was isolated from the stems of P. tuberosa, and the structural, morphological, and adsorption properties of the polymer material based on it were investigated. The mechanism of interaction between methylene blue and cellulose was theoretically substantiated using molecular dynamics (MD) modeling. The obtained composite membranes are considered environmentally safe materials that effectively purify water contaminated with methylene blue. 3. For the first time, it was established that the methanolic extract of P. tuberosa flowers exhibits ABTS⁺ radical scavenging activity with an IC₅₀ of 48.35 ± 0.84 µg/mL, while the hexane extract of P. tuberosa roots shows stronger α-glucosidase inhibition (IC₅₀ = 103.2 ± 0.99 µg/mL) compared to the standard drug acarbose (IC₅₀ = 128.5 ± 0.62 µg/mL). Practical significance of the thesis: The results of this study will contribute to the development of applied chemistry in our country, particularly in fields such as medicine, pharmaceuticals, and dermatology, through the creation of commercially accessible, import-substituting new medicinal and cosmetic products. In addition, the cellulose obtained from the stems of P. tuberosa can serve as a basis for the production of technical products used in water purification systems. Connection of the research work with scientific projects: The research was funded by the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP14871259) and was carried out jointly during 2022–2024. Author’s Personal Contribution: The author’s personal contribution consisted of planning the experiments and carrying out both theoretical and experimental research. The author mastered modern physicochemical analysis methods used in the study, performed statistical processing of the research data, and participated directly in the discussion and interpretation of the results as well as in drawing conclusions. The writing of the dissertation text, the preparation of the statements submitted for defense, and the publication of scientific articles in first-quartile impact-factor journals as the first author were carried out independently by the candidate. Publications: Based on the results of the dissertation work, 6 scientific papers were published. Among them, 2 articles were published in Scientific Reports (Q1, 89th percentile), indexed in the Web of Science and Scopus databases; 1 article was published in Engineered Science (Q1, 97th percentile), indexed in the Scopus database; and 1 publication appeared in journals included in the list recommended by the Committee for CQASHE. The research results were presented and discussed at international scientific conferences held in the CIS countries and Kazakhstan. Author’s Contribution: The author’s main contribution to the published scientific works includes planning and organizing chemical experiments, conducting research, and processing and analyzing data. In addition, the preparation of graphical materials and diagrams, as well as writing and editing the text, was carried out with the direct participation of the researcher. The materials presented at scientific conferences involved the researcher’s work in summarizing, data processing, conducting research, writing the text, and being the first author. 1. Azhikhanova, Zh., Emin. M. D., Megbenu, H.K., Kucukaydin, S.,Таs-Kucukaydin, M., Ваisalova, G., Shaimardan, M., Nuraje, N., Ali. M. Özler. Phytochemical profiling and various biological activites of Phlomis tuberosa L // Scientific Reports. - 2025. - V.15:7293. (15р) Q1; 89%. https://doi.org/10.1038/s41598-024-80456-5 The article is indexed in the Web of Science Core Collection and Scopus databases. At the time of its publication in 2025, the journal Scientific Reports had an Impact Factor of 3.9 (2024) and was ranked in Quartile Q1 in the multidisciplinary sciences category. The journal also had a CiteScore of 6.7 for 2024, with percentile ranking in the multidisciplinary field – 89. 2. Azhikhanova Zh, Megbenu H.K, Zhengis A, Baisalova, G., Shaimardan, M., Aldongarov, A., Karibayev, M., Ali. M. Özler & Nuraje N. Bio-based cellulose membrane from Phlomis tuberosa L. for methylene blue dye removal from wastewater and molecular interaction mechanisms // Scientific Reports. - 2026. V.16:2028. (13р) Q1; 89%. DOI:10.1038/s41598-025-31751-2 The article is indexed in the Web of Science Core Collection and Scopus databases. At the time of its publication in 2025, the journal Scientific Reports had an Impact Factor of 3.9 (2024) and was ranked in Quartile Q1 in the multidisciplinary sciences category. The journal also had a CiteScore of 6.7 for 2024, with percentile ranking in the multidisciplinary field – 89. 3. Azhikhanova, Zh., Emin. M. D., Megbenu, H.K., Kucukaydin, S., Tas- Kucukaydin, M., Baisalova, G., Shaimardan, M., Seiilgazy, M., Adekenov, S., Nuraje, N., Phytochemical Study of Achillea setacea Waldst. et Kit. with Anticholinesterase, Antidiabetic, Anti-Urease, and Anti-Tyrosinase Activities // Engineered Science- 2024. - V.31:1256. (10р) Q1; 97%. https://dx.doi.org/10.30919/es1256 The article is indexed in the Scopus database. At the time of its publication in 2024, the journal Engineered Science had a 2023 CiteScore of 14.9, with percentiles as follows: 98 in Applied Mathematics, 96 in General Mechanical Engineering, 93 in Energy Engineering and Energy Technology, 93 in Physical and Theoretical Chemistry, 91 in Artificial Intelligence, 91 in General Materials Science, and 91 in Chemistry (Miscellaneous). 4. Megbenu H.K, Azhikhanova, Zh., Ingkar, G., Rakhimgaliyev, N., Mels, A., Kenzheshov, A., Askarov, A., Shaimardan, M. & Nuraje, N. Catalytic Dehydration of Biomass-Derived Feedstocks to Obtain 5-Hydroxymethylfurfural and Furfural // Eurasian Journal of Chemistry, 2024. 29, 2(114), 96 105. БҒСБК ұсынған журналдар. https://doi.org/10.31489/2959-0663/2-24-1 The research results and main conclusions were presented and discussed at the following international conferences: 1. Витамины Phlomis tuberosa L. МОБИ-ХимФарма (Молекулярные и Биологические аспекты Химии, Фармацевтики и Фармакологии). VII Междисциплинарной конференции (Москва, 2021. – С. 69). 2. Химическое изучение видов Аchillea L. Химия и технология растительных веществ - XII Всероссийская научная конференция «Утилизация и рециклинг отходов производства и потребления» (Киров, 2022). Volume and structure of the dissertation. The dissertation consists of an introduction, a list of symbols and abbreviations, the main section, a conclusion, a list of references, and appendices. The work comprises 99 pages, including 42 figures, 11 tables, 5 equations, and a list of 135 references.
Conclusion of the Research Ethics Committee
Defense of the dissertation: https://youtu.be/o7mSrKDKrNs?si=Zr8dUXqFy1SXOVXp
