Announcement about the defense of the Doctor of Philosophy (PhD) thesis of Azizov Doniyor Zokirjanovich

I. General information.

The topic of the dissertation, specialty code (the name of the branch where the academic degree is awarded): «Arabinogalactans of Ferula kuhistanica and F. tenuisecta », 02.00.10 - Bioorganic chemistry (chemical sciences).

Dissertation topic registered number: В2022.4. PhD/K574.

Scientific supervisor: Rakhmanberdyeva Rano Karimovna, doctor of sciences in chemistry.

Name of the institution where the dissertation was completed: Institute of the Chemistry of Plant Substances.

Name of the institution where the scientific council works, Number of the scientific council: Institute of the Chemistry of Plant Substances, DSc.02/30.01.2020.K/T.104.01.

Official opponents: Normakhamatov Nodirali Sakhobatalievich, doctor of sciences in chemistry; Karimov Abdurashid Musaxonovich, doctor of sciences in chemistry.

Leading organization: National University of Uzbekistan

Dissertation direction: theoretical and practical.

II. The aim of the dissertation work is to isolate and study various groups of polysaccharides from F. kuhistanica and F. tenuisecta, determine the physicochemical properties, monosaccharide composition and establish the structure of arabinogalactans, identify the relationship between the structural features of polysaccharides and the biological activity they exhibit.

III. The scientific novelty of the research. The content of various groups of polysaccharides in the aerial parts of F. kuhistanica and F. tenuisecta was determined for the first time.

The optimal period for the harvesting of raw materials F. kuhistanica has been established. It is shown that the main polysaccharides in the aerial part of the plant are water-soluble polysaccharides and pectin substances. For the first time, homogeneous arabinogalactans AGF and AG-Ften were obtained from the water-soluble polysaccharide of F.kuhistanica and F. tenuisecta. It has been shown that they are branched polysaccharides with a main polymer chain consisting of (1→6) β-galactopyranose residues, where α-arabinofuranose residues and its 1,5-linked oligomers, as well as β-GlcpA4OMe-(1→6)-β-Galp-(1→fragments. It has been established for the first time that a small portion of the main chain of the F. kuhistanica arabinogalactan macromolecule carries β-galactopyranose residues in the C-2 position. It has been proven that the studied arabinogalactans belong to arabino-3,6-galactans. The prebiotic activity of water-soluble polysaccharides and pectin substances of F. kuhistanica and F. tenuisecta, as well as the antimicrobial activity of water-soluble polysaccharides of F. tenuisecta roots were revealed.

IV. Implementation of the research results. Based on the results of scientific research, a technical specification for a method for obtaining a water-soluble polysaccharide F. kuhistanica "Arbifilan" (Ts 03535440-031:2020) was developed and approved.

Spectral data and data on the chemical structure of F. kuhistanica arabinogalactan have been used in foreign scientific publications to determine the structure of polysaccharides: J. Biol. Macromol. 2023, V. 235, 123816  https://doi.org/10.1016/j.ijbiomac. 2023.123816 IF 8,025; Food Bioscience, 2022, V. 47, 101780 (https://doi.org/10.1016/j.fbio.2022.1017 IF-5,318; Polymers 15(9):1999, 2023 DOI:10.3390/polim15091999, https://www.mdpi.com/2073-4360/15/9/1999# IF-5,0; Pharmaceutical sciences, 2022;25(3) DOI: 10.21626/vestnik/2022-3/08, https://www.kursk-vestnik.ru/jour/article/view/1069/ 581, IF-3.784]; Carbohyd. Res. 2023, v. 529, 108828, https://ssrn.com/abstract=4406065.