Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
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Book Part Astragalus sp.(CRC Press, 2023) Yakuboğulları, Nilgün; Bedir, ErdalAstragalus is one of the largest genera in Turkey and is widely distributed worldwide. The phytochemical studies on Turkish Astragalus species have presented 112 new compounds besides 63 known compounds. The overriding basis for biological activity studies is the traditional use of Astragalus roots in the Southeastern Region of Turkey to cure leukemia. As the isolated compounds did not show cytotoxic properties, a hypothesis that the biological activity of Astragalus saponins might result from the activation of the immune system came up. While Astragalus polysaccharides are used for their strong immunomodulatory activities in Chinese medicine, there are a few articles revealing the immunostimulatory properties of Astragalus saponins. Here, we summarized the compounds isolated from Turkish Astragalus species and concentrated on the immunomodulatory activities of these compounds to put forward their potential as saponin-based vaccine adjuvants. © 2024 selection and editorial matter, Ufuk Koca-Caliskan; individual chapters, the contributors.Article Optimization of Precursor and Elicitor Utilization in Batch Cultures of Astragalus Trojanus Stev.(2018) Nartop, Pınar; Gürel, Aynur; Akgün, İsmail Hakkı; Bedir, ErdalElicitor and precursor applications are commonly used to induce secondary metabolism in plant cell cultures. In this study, methyl jasmonate, jasmonic acid, salicylic acid and pectin were used as elicitors and ?-sitosterol was used as a precursor in batch cultures of Astragalus trojanus in order to trigger astragaloside IV and cycloastragenol productions. Growth parameters (fresh and dry weights and dry weight percentages) of batch cultures were also evaluated in order to understand the effects of elicitors and precursor on primary metabolism. All elicitors and precursor used in this study triggered metabolite production at different stages of culture period. The highest astragaloside IV accumulation (0.9435 µg/mg) was detected in medium supplemented with 50 µM methyl jasmonate at the 14th day of culture period, whereas the highest cycloastragenol concentration (0.3626 µg/mg) was found in medium supplemented with 50 µM jasmonic acid at the 28th day of culture period. Large scale cultivation was also performed and 0.3759 µg/mg astragaloside IV was detected in medium supplemented with 50 µM methyl jasmonate at the 14th day.Article Astragalus Trojanus Stev. Batch Cultures: Cycloartane-Type Metabolite Accumulation in Response To Ph, Sucrose and Casein Hydrolysate(Hacettepe Üniversitesi, 2019) Nartop, Pınar; Gürel, Aynur; Akgün, İsmail Hakkı; Bedir, ErdalI n this study, two grams of callus regenerated from stem and leaf explants of Astragalus trojanus Stev. were cultured in Woody Plant Medium (WPM) supplemented with 1 mg/L 2,4-D for four weeks and used as inoculum in order to investigate the effects of working volume and media composition. The highest biomass was obtained in 250 mL flask with astragaloside IV (1.66 µg/mg) and cycloastragenol (0.19 µg/mg) accumulation. Different concentrations of sucrose and casein hydrolysate (1 and 2 g/L) were also tested and the effect of pH was also investigated. Biomass accumulation cannot be enhanced, however, astragaloside IV and cycloastragenol content was ascended. The highest astragaloside IV (95.23 µg/mg) and cycloastragenol (5.93 mg/mg) accumulations were obtained at pH 6.8 and 2 g/L casein hydrolysate, respectively