Announcement about the defense of Ashurova Lola's Doctor of Philosophy (PhD) dissertation

Announcement about the defense of Ashurova Lola's Doctor of Philosophy (PhD) dissertation

I. General Information.

Dissertation topic and specialization code (name of the field of study for which the degree is awarded): “Chemical analysis of the plants Saponaria officinalis, S. griffithiana, and Dipsacus azureus”, 02.00.10 - Bioorganic chemistry (chemical sciences).

Dissertation topic registered number: B2025.2.PhD/K82

Supervisor: Nurmurod Sheraliyevich Ramazonov

Dissertation prepared institution: Institute of the Chemistry of Plant Substances named after Acad. S.Y. Yunusov. AS RUz.

Institution where Scientific Council operates, Scientific Council number: Institute of the Chemistry of Plant Substances named after Acad. S.Y. Yunusov. AS RUz., DSc. 02/30.01.2020.K/T.104.01.

The defense will take place on May 13, 2025 at 09:00 a.m.

Opponents: doctor of chemical sciences, Sabir Zaripbayevich Nishanbayev, Doctor of chemical sciences, senior researcher, doctor of chemical sciences, professor, Abdullazhanova Nodira Gulamzhanovna.

Lead organization: Samarkand State University

Dissertation direction: theoretical and practical.

II. The aim of this research.

The aim of this research is the isolation of metabolites from the plant species Saponaria officinalis, Saponaria griffithiana, and Dipsacus azureus, which grow in the flora of Uzbekistan, as well as the study of their chemical structures and biological activities.

III. Scientific novelty of the research work:

for the first time, the chemical composition of Saponaria officinalis, Saponaria griffithiana, and Dipsacus azureus, belonging to the genera Saponaria and Dipsacus, have been studied. As a result, a total of 12 metabolites were isolated, identified, and determined their structures.

from Saponaria officinalis, new compounds were isolated, including a saponin identified as 3β,16α-dihydroxy-23-oxo-oleanan-28,13β-olid, and a vitasteroid identified as 5β,6β-epoxy-20α,24β,25α-trihydroxy-1,3-dioxovita-2-enolid. Their structures were confirmed using physicochemical research methods.

additionally, from the aerial part of S. officinalis, four compounds grasillin, 5α-hydroxylaxogenin, hederagenin, and pinitol were identified for the first time.

the composition of essential oil components of S. officinalis and S. griffithiana was studied for the first time, with 38 and 32 compounds identified, respectively. Furthermore, the compound 1-(2-furyl)ethanol was identified in the essential oil for the first time.

pharmacological studies revealed that the saponin extract of D. azureus exhibits significant hypoglycemic and hypocholesterolemic effects.

IV. Implementation of research results.

Based on the results obtained from studying the chemical composition of plants belonging to the Saponaria and Dipsacus genera:

The chemical structures and physicochemical properties of new compounds, sapolid and 5β,6β-epoxy-20α,24β,25α-trihydroxy-1,3-dioxovita-2-enolid, isolated from Saponaria officinalis, have been determined. As a result, it was possible to describe the structure and properties of substances similar to the new compounds.

Research carried out under the scientific project № F-FA-2021-496 titled “Development of targeted molecular-directed cytostatics from natural compounds and their synthetic Derivatives,” part of the research plan of the Institute of Plant Chemistry, resulted in the isolation of several compounds from Saponaria genus plants. These compounds were tested for antibacterial and antifungal activity. Inhibitory effects on the growth of gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, were identified (as per the certificate of the Academy of Sciences of Uzbekistan, dated July 8, 2024, № 4/1255-1544). As a result, compounds with antimicrobial activity against Staphylococcus aureus and Bacillus subtilis were discovered.

The results of the research on the chemical composition and biological activity of Saponaria and Dipsacus genus plants have been published by foreign scientists in several high-impact journals: Journal of Drug Delivery Science and Technology (https://doi.org/10.1016/j.jddst.2024.105382, 2024, IF-4.5), Natural Product Research (https://doi.org/10.1080/14786419.2024.2358525, 2024, IF-1.9), Ximiya rastitelnogo sirya (doi:10.14258/jcprm.20240112489, 2024, IF-0.77), and Chemistry of Natural Compounds (doi.org/10.1007/s10600-022-03679-w, 2022, IF-0.83). These publications describe the chemical and quantitative characteristics of secondary metabolites isolated from the plants, as well as their antimicrobial, antifungal, and cytotoxic activities.

A monograph titled “Saponins”, co-authored by several researchers, has been published, providing detailed information on the chemistry, biological activities, and applications of saponins. This monograph is widely used in local universities and institutes, offering young scientists and researchers valuable insights into saponins.

 

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