L.N. Gumilyov Eurasian National University, a dissertation defense for the degree of Doctor of Philosophy (PhD) by Kozhantayeva Akmaral on the topic «Phytochemical study of some plants of the Onagraceae L. Family» to 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:
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);
Tuleuov Borash Igilikovich – Academician of the National Academy of Sciences of the Republic of Kazakhstan, Doctor of Chemical Sciences, Professor, Joint-Stock Company “International Research and Production Center ‘Phytochemistry’ RK”, Head of the Laboratory of Steroid Compounds Chemistry (Karaganda, Republic of Kazakhstan).
Temporary members of the Dissertation Council:
Kurzina Irina Alexandrovna – Doctor of Physical and Mathematical Sciences, Associate Professor, Head of the Department, National Research Tomsk State University (Tomsk, Russian Federation);
Seitmova Gulnaz Absattarovna – Doctor of Philosophy (PhD), Research Professor, Non-Profit Joint-Stock Company “Al-Farabi Kazakh National University,” Associate Professor of the Department of Chemistry and Technology of Organic Substances, Natural Compounds and Polymers (Almaty, Republic of Kazakhstan);
Zhanzhaksina Almira Shaikhslamovna – Doctor of Philosophy (PhD), Senior Lecturer, Non-Profit Joint-Stock Company “S. Seifullin Kazakh Agrotechnical Research University” (Astana, Republic of Kazakhstan).
Scientific advisors:
Yerbolat Ordabekovich Tashenov – Doctor of Philosophy (PhD), Acting Associate Professor of the Department of Chemistry, Non-Profit Joint-Stock Company “L.N. Gumilyov Eurasian National University” (Astana, Republic of Kazakhstan);
Gulmira Ozek – Doctor of Philosophy (PhD), Professor, Anadolu University, Faculty of Pharmacy, Department of Pharmacognosy (Eskishehir, Republic of Türkiye).
The defense will take place on February 26, 2026, at 03:00 PM in the Dissertation Council for the training direction «8D053 – Physical and chemical sciences» in the specialty «8D05306 – Chemistry» of L.N. Gumilyov Eurasian National University. The meeting of the Dissertation Council will be held in offline and online formats.
Link: https://inlnk.ru/QwY71x
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Abstract (English): General description of the work. The dissertation is devoted to the phytochemical investigation of Circaea lutetiana and Chamaenerion latifolium, representatives of the family Onagraceae L. The study determined the component composition of the plant material and carried out chromatographic and spectroscopic identification of biologically active compounds in the extracts. The biological activity of the extracts was evaluated based on their antioxidant and antimicrobial properties. In addition, the profile of volatile constituents was established using GC–MS, and the possibility of obtaining biocompatible silver nanoparticles via a green synthesis approach employing Circaea lutetiana extract was examined. The main findings of the research are presented in a series of published scientific articles focused on the phytochemical profiling of the studied plants and the assessment of their biological activity. Relevance of the research topic. The biological diversity of Kazakhstan’s flora, comprising more than six thousand plant species, holds significant scientific and practical value for the search for environmentally safe sources of biologically active compounds. Plants of the family Onagraceae L. are widely used in traditional medicine as therapeutic agents for various diseases and represent valuable sources of bioactive substances. The combined action of these compounds contributes to enhanced biocompatibility and pharmacological activity. Therefore, the investigation of the phytochemical composition of representatives of this family, as well as the assessment of their pharmacological potential, constitutes a relevant and promising direction of scientific research. Research purpose: Phytochemical investigation of Circaea lutetiana and Chamaenerion latifolium plants belonging to the Onagraceae L. family. Research Objectives: 1. To obtain a complex of biologically active compounds by extracting the aerial parts of Circaea lutetiana and Chamaenerion latifolium using polar and non-polar solvents. 2. To determine the qualitative composition of volatile components in the non-polar extracts of the aerial parts of the studied plants using gas chromatography–mass spectrometry (GC–MS). 3. To identify the qualitative and quantitative composition of phenolic compounds and flavonoids in the polar extracts by high-performance liquid chromatography with ultraviolet detection and electrospray ionization followed by mass spectrometric analysis (HPLC-UV-ESI/MS). 4. To evaluate the antioxidant activity of the plant extracts using the DPPH and FRAP assays, as well as to determine their antibacterial properties under in vitro conditions. 5. To explore the possibility of obtaining biologically active and biocompatible silver nanoparticles via “green” synthesis using Circaea lutetiana extract and to characterize their physicochemical properties. Object of the research: Plant raw materials obtained from the aerial parts (flowers, leaves, stems) of representatives of the Onagraceae family – Circaea lutetiana, growing in the Pavlodar region within the territory of Bayanaul National Park, and Chamaenerion latifolium, found in the Big Almaty Gorge. Main provisions submitted for defense: 1. It has been established that the lipophilic composition of the nonpolar extracts obtained from the aerial parts of Chamaenerion latifolium and Circaea lutetiana is species- and organ-specific: Chamaenerion latifolium is characterized by the predominance of long-chain aliphatic hydrocarbons, with total contents of 31.34% in leaves and 48.16% in stems, whereas fatty acid esters dominate in the extracts of Circaea lutetiana, reaching up to 30.80%; triterpenoids were detected in both species at levels of 2.25–3.79%. 2. It has been shown that the polar extracts of Chamaenerion latifolium and Circaea lutetiana, analyzed by HPLC–UV–ESI/MS, are characterized by distinct phenolic profiles: the ethanolic extract of Chamaenerion latifolium is dominated by gallic acid (35.00 mg/g), chlorogenic acid (26.80 mg/g), and quercetin-3-glucoside (71.90 mg/g), whereas the extract of Circaea lutetiana is characterized by the predominance of gallic acid (15.10 mg/g), p-coumaric acid (14.60 mg/g), and caffeic acid (9.80 mg/g). 3. It has been established that the ethanolic extract obtained from the aerial parts of Chamaenerion latifolium exhibits high antioxidant and antimicrobial activity: the IC50 values are 21.31 ± 0.65 μg/mL in the DPPH assay and 18.13 ± 0.15 μg/mL in the FRAP assay, while the in vitro inhibition zones against various microorganisms range from 8.53 to 14.27 mm. These biological effects are directly associated with the high content of phenolic compounds (TPC 267.48 ± 3.44 mg GAE/g) and flavonoids (TFC 24.18 ± 1.06 mg QE/g). 4. It has been shown that the polyphenol – rich ethanolic extract of Circaea lutetiana effectively enables the “green” synthesis of silver nanoparticles through the combined reducing and stabilizing action of plant – derived biomolecules, resulting in the formation of spherical AgNPs with particle sizes of 2.7–4.9 nm (average diameter 3.84 ± 0.62 nm). The synthesized nanoparticles exhibit significantly higher in vitro antibacterial activity against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae compared to the corresponding plant extracts, indicating a synergistic enhancement of biological activity upon the transition of phytochemical compounds into a nanostructured form. Scientific Novelty: 1. For the first time, a comprehensive phytochemical investigation of Circaea lutetiana and Chamaenerion latifolium growing in the natural regions of Kazakhstan (Bayanaul and the Big Almaty Gorge) has been conducted using modern chromatographic and spectroscopic methods. 2. Chamaenerion latifolium has been introduced into scientific circulation for the first time as a renewable plant resource. Sixty-five volatile components were identified in the hexane extract of this plant using gas chromatography–mass spectrometry, while seventy-nine major volatile compounds were identified in the Circaea lutetiana sample. 3. Phenolic and flavonoid compounds in the plant extracts of Chamaenerion latifolium and Circaea lutetiana were identified using HPLC coupled with UV–ESI/MS detection. Analysis of the chromatographic profile of the ethanolic and ethyl acetate extracts of Chamaenerion latifolium revealed the presence of major groups of biologically active compounds. For the first time, a complete quantitative characterization of the key constituents was performed, including phenolic acids—gallic acid (35.00 mg/g), chlorogenic acid (26.80 mg/g), caffeic acid (4.40 mg/g), and p-coumaric acid (2.70 mg/g)—as well as flavonoids such as quercetin-3-glucoside (71.90 mg/g) and rutin (8.80 mg/g). Furthermore, to assess the biological significance of the identified polyphenolic complex, the antioxidant activity of the plant extracts was investigated using the DPPH and FRAP assays. It was established that the ethanolic extract of C. latifolium exhibits high activity (DPPH: IC50 = 21.31 ± 0.65 μg/mL; FRAP: IC50 = 18.13 ± 0.15 μg/mL). For the ethanolic extract of Circaea lutetiana, the major phenolic acids identified included gallic acid (15.1 mg/g), caffeic acid (9.80 mg/g), chlorogenic acid (10.5 mg/g), p-coumaric acid (14.6 mg/g), and rosmarinic acid (0.29 mg/g), along with the flavonoids rutin (1.20 mg/g) and quercetin-3-glucoside (0.10 mg/g) 4. For the first time, the extract of Circaea lutetiana was used for the green synthesis of silver nanoparticles (AgNPs), which exhibited a spherical morphology and ultra-small sizes of 2.70–4.95 nm according to TEM analysis. Their face-centered cubic structure (XRD), the stability of the colloidal system (ζ-potential = –25.62 to –28.19 mV), as well as the presence of a bio-organic layer on the surface (FT-IR, XPS), were established. The antibacterial activity of the synthesized silver nanoparticles was determined in vitro against both Gram-positive and Gram-negative strains, with inhibition zones reaching 5.12–5.86 mm, exceeding the activity of the initial plant extracts. Practical significance of the study. The practical significance of the work lies in establishing the antioxidant and antibacterial activity of Chamaenerion latifolium plant extracts, which confirms their promise for use in pharmacological screening and biomedical research. Silver nanoparticles synthesized via a green synthesis approach using Circaea lutetiana extract exhibit stability, biocompatibility, and pronounced antibacterial activity, thereby demonstrating their potential for application in antimicrobial protective materials and biomedical technologies. Author’s personal contribution. The identification of the research direction, formulation of the aim and objectives, search and analysis of scientific literature relevant to the dissertation topic, collection of plant materials, development of the theoretical foundation, and full execution of the experimental section were all carried out with the direct involvement of the author. Additionally, the author personally processed and scientifically analyzed the obtained results and prepared them for publication in international scientific journals. Publications: Based on the results and conclusions of the dissertation research, nine scientific works have been published, including seven articles in international peer-reviewed journals indexed in Scopus and Web of Science with a non-zero impact factor, one article in a journal recommended by the Committee for Quality Assurance under the Ministry of Science and Higher Education, Kazakhstan, and one paper presented at an international conference. List of publications based on the research results: 1. Kozhantayeva A.; Iskakova Zh.; Ibrayeva M.; Sapiyeva A.; Arkharbekova M.; Tashenov Y.;. Phytochemical Insights and Therapeutic Potential of Chamaenerion angustifolium and Chamaenerion latifolium // Molecules. – 2025. – V. 30, Iss. 5. – P. 1186. The article has been indexed in the Web of Science Core Collection and Scopus databases. At the time of its publication in 2025, the journal «Molecules» had an Impact Factor for 2024 of 4,6 and was ranked in Q2 in the categories of Multidisciplinary Chemistry as well as Biochemistry and Molecular Biology. It had a CiteScore for 2024 of 7,4 with the following percentiles: Chemistry (miscellaneous) – 81, Organic Chemistry – 87, Physical and Theoretical Chemistry – 82, Analytical Chemistry – 83, Pharmaceutical Science – 83, Drug Discovery – 81, and Molecular Medicine – 78. 2. Kozhantayeva A.; Tursynova N.; Kolpek A.; Aibuldinov Y.; Tursynova A.; Mashan T.; Mukazhanova Zh.; Ibrayeva M.; Zeinuldina A.; Nurlybayeva A.; Iskakova Zh.; Tashenov Y. Phytochemical Profiling, Antioxidant and Antimicrobial Potentials of Ethanol and Ethyl Acetate Extracts of Chamaenerion latifolium // Pharmaceuticals. – 2024. – V. 17, Iss. 8. – P. 96. The article has been indexed in the Web of Science Core Collection and Scopus databases. At the time of its publication in 2024, the journal «Pharmaceuticals» had an Impact Factor for 2023 of 4,3 and was ranked in Q2 in the category of Medicinal Chemistry and Q1 in Pharmacology and Pharmacy. It had a CiteScore for 2023 of 6.1, with the following percentiles: Pharmaceutical Science – 69, Drug Discovery – 58, and Molecular Medicine – 53. 3. Iskakova Zh.; Kozhantayeva A.; Temirbekova A.; Mukhtubayeva S.; Bissenova G.; Tekebayeva Zh.; Almagambetov K.; Tashenov Y.; and Sarmurzina Z. Green Synthesis of Silver Nanoparticles Using Circaea lutetiana Ethanolic Extract: Phytochemical Profiling, Characterization, and Antimicrobial Evaluation // International Journal of Molecular Sciences. – 2025. V. 26, Iss. 12. – P. 5505. The article has been indexed in the Web of Science Core Collection and Scopus databases. At the time of its publication in 2025, the journal «Journal of Molecular Sciences» had an Impact Factor for 2024 of 4,9 and was ranked Q1 in Biochemistry and Molecular Biology and Q2 in Multidisciplinary Chemistry. It had a CiteScore for 2024 of 9,0 with the following percentiles: Organic Chemistry – 90, Inorganic Chemistry – 85, Spectroscopy – 85, Physical and Theoretical Chemistry – 84, Computer Science Applications – 84, Molecular Biology – 79, and Catalysis – 70. 4. Kozhantayeva A.; Tashenov Y.; Tosmaganbetova K.; Tazhkenova G.; Mashan T.; Bazarkhankyzy A.; Iskakova Zh.; Sapiyeva A.; Gabbassova A. Circaea lutetiana (L) plant and its chemical composition // Rasayan Journal of Chemistry. – 2022. – V. 15, Iss. 3. – P. 1653 – 1659. The article is indexed in the Scopus database. At the time of its publication in 2022, the CiteScore of the journal «Rasayan Journal of Chemistry» for 2021 was 2.0. The journal has the following percentile indicators by scientific fields: General Pharmacology, Toxicology, and Pharmaceutics – 52; General Energy – 44; General Chemistry – 43; General Chemical Engineering – 41; Biochemistry – 20. 5. Kozhantayeva A.; Rakhmadiyeva S.; Ozek G. Investigation of polyphenolic compounds of Chamaenerion latifolium (L.) plant // Rasayan Journal of Chemistry. – 2020. – V. 13, Iss. 4. – P. 2474 – 2482. The article is indexed in the Scopus database. At the time of its publication in 2020, the CiteScore of the journal «Rasayan Journal of Chemistry» for 2019 was 1,8. The journal has the following percentile indicators by scientific fields: General Energy – 56; General Pharmacology, Toxicology, and Pharmaceutics – 51; General Chemical Engineering – 46; General Chemistry – 45; Biochemistry – 20. 6. Iskakova Zh.; Kozhantayeva A.; Tazhkenova G.; Mashan T.; Tosmaganbetova K.; Tashenov Y. Investigation of Chemical Constituents of Chamaenerion latifolium L. // Anti-Inflammatory and Anti-Allergy Agents in Medicinal Chemistry. – 2022. – V. 21, Iss. 3. – P. 173 – 178. The article is indexed in the Scopus database. At the time of its publication in 2022, the «Anti Inflammatory and Anti Allergy Agents in Medicinal Chemistry» journal had a CiteScore of 2,3 for 2021. The journal’s percentile rankings by scientific discipline are as follows: Pharmacology – 31; Immunology and Allergy – 25; Immunology – 20. 7. Kozhantayeva A.; Rakhmadiyeva S.; Ozek G. Evaluation of metal content of Сircaea lutetiana (l) plant // Journal of Chemical Technology and Metallurgy. – 2022. – V. 57, Iss. 1. – P. 114 – 118. The article is indexed in the Scopus database. At the time of its publication in 2022, the CiteScore of the journal Journal of Chemical Technology and Metallurgy for 2021 was 1.4. The journal has the following percentile indicators by scientific fields: Industrial and Manufacturing Design – 38; General Chemical Engineering – 31. In publications recommended by the authorized body: 8. Kozhantayeva A.; Rakhmadiyeva S. Research of polyphenolic compounds of Circaea lutetiana l. // Chem. Bull. Kazakh Nat. Univ. – 2020. – V. 98., Iss.3. P. 18 – 27. List of presentations at international conferences: 9. Kozhantayeva A.G., Rakhmadiyeva S.B., Baigaziyeva A.T. Study of biologically active compounds of Chamaenerion latifolium (L.) // Proceedings of the X International Birimzhanov Congress on Chemistry and Chemical Technology. – Almaty: Al-Farabi Kazakh National University, 2019.
Conclusion of the Research Ethics Committee
Defense of the dissertation: https://youtu.be/aAFPhYe2ogM?si=A7RosGOJ4Z1jDpAt
