PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Citation - WoS: 14Citation - Scopus: 15Biotransformation of Ruscogenins by Cunninghamella Blakesleeana Nrrl 1369 and Neoruscogenin by Endophytic Fungus Neosartorya Hiratsukae(Elsevier Ltd., 2018) Özçınar, Özge; Tağ, Özgür; Yusufoğlu, Hasan; Kıvçak, Bijen; Bedir, ErdalBiotransformation of steroidal ruscogenins (neoruscogenin and ruscogenin) was carried out with Cunninghamella blakesleeana NRRL 1369 and endophytic fungus Neosartorya hiratsukae yielding mainly P450 monooxygenase products together with a glycosylated compound. Fermentation of ruscogenins (75:25, neoruscogenin-ruscogenin mixture) with C. blakesleeana yielded 8 previously undescribed hydroxylated compounds. Furthermore, microbial transformation of neoruscogenin by endophytic fungus N. hiratsukae afforded three previously undescribed neoruscogenin derivatives. While hydroxylation at C-7, C-12, C-14, C-21 with further oxidation at C-1 and C-7 were observed with C. blakesleeana, N. hiratsukae biotransformation provided C-7 and C-12 hydroxylated compounds along with C-12 oxidized and C-1(O) glycosylated derivatives. The structures of the metabolites were elucidated by 1-D (1H, 13C and DEPT135) and 2-D NMR (COSY, HMBC, HMQC, NOESY, ROESY) as well as HR-MS analyses.Article Citation - WoS: 27Citation - Scopus: 30Biotransformation of Cyclocanthogenol by the Endophytic Fungus Alternaria Eureka 1e1bl1(Elsevier Ltd., 2018) Ekiz, Güner; Duman, Seda; Bedir, ErdalThe microbial transformation of cyclocanthogenol (CCG), Astragalus sp. originated sapogenin, by the endophytic fungus Alternaria eureka 1E1BL1 isolated from Astragalus angustifolius was investigated. Hydroxylation, oxidation, epoxidation, O-methylation, ring-expansion and methyl migration reactions were observed on the triterpenoid skeleton. As a result, eight metabolites were isolated and the structures of the previously undescribed compounds were established by 1-D, 2-D NMR and HR-MS analyses.Article Citation - WoS: 13Citation - Scopus: 13Cycloartane-Type Sapogenol Derivatives Inhibit Nf?b Activation as Chemopreventive Strategy for Inflammation-Induced Prostate Carcinogenesis(Elsevier Ltd., 2018) Debeleç Bütüner, Bilge; Öztürk, Mert Burak; Tağ, Özgür; Akgün, İsmail Hakkı; Yetik Anacak, Günay; Bedir, Erdal; Korkmaz, Kemal SamiChronic inflammation is associated to 25% of cancer cases according to epidemiological data. Therefore, inhibition of inflammation-induced carcinogenesis can be an efficient therapeutic approach for cancer chemoprevention in drug development studies. It is also determined that anti-inflammatory drugs reduce cancer incidence. Cell culture-based in vitro screening methods are used as a fast and efficient method to investigate the biological activities of the biomolecules. In addition, saponins are molecules that are isolated from natural sources and are known to have potential for tumor inhibition. Studies on the preparation of analogues of cycloartane-type sapogenols (9,19-cyclolanostanes) have so far been limited. Therefore we have decided to direct our efforts toward the exploration of new anti-tumor agents prepared from cycloastragenol and its production artifact astragenol. The semi-synthetic derivatives were prepared mainly by oxidation, condensation, alkylation, acylation, and elimination reactions. After preliminary studies, five sapogenol analogues, two of which were new compounds (2 and 3), were selected and screened for their inhibitory activity on cell viability and NFκB signaling pathway activity in LNCaP prostate cancer cells. We found that the astragenol derivatives 1 and 2 as well as cycloastragenol derivatives 3, 4, and 5 exhibited strong inhibitory activity on NFκB signaling leading the repression of NFκB transcriptional activation and suppressed cell proliferation. The results suggested that these molecules might have significant potential for chemoprevention of prostate carcinogenesis induced by inflammatory NFκB signaling pathway.Article Citation - WoS: 19Citation - Scopus: 20Specialized Metabolites From the Aerial Parts of Centaurea Polyclada Dc.(Elsevier Ltd., 2017) Demir, Serdar; Karaalp, Canan; Bedir, ErdalThe genus Centaurea L. (Asteraceae) is represented by 200 taxa in the flora of Turkey and several Centaurea species are used as herbal remedies against different conditions. Previous phytochemical investigations on this genus generally revealed the isolation of sesquiterpene lactones and flavonoid derivatives. In our continuous search on Centaurea genus, a phytochemical study was performed on Centaurea polyclada DC., an endemic of West Anatolia. Previously undescribed two sesquiterpene-amino acid conjugates, an elemane and an eudesmane derivative were isolated from the aerial parts of Centaurea polyclada, together with eight known compounds; two elemane derivatives, three flavonoids, a lignan, a phenolic glucoside and a phenylpropanoid glucoside. Structural elucidation of the compounds was based on spectroscopic evidence, including 1D and 2D NMR and high-resolution mass spectrometry, chemical degradation results and reference data comparison. Sesquiterpene-amino acid conjugates are representatives of an unusual group of sesquiterpenes, and elemane-amino acid conjugates are herein reported for the first time in nature.Article Citation - WoS: 11Citation - Scopus: 11Secondary Metabolites From Astragalus Karjaginii Boriss and the Evaluation of Their Effects on Cytokine Release and Hemolysis(Elsevier Ltd., 2017) Aslanipour, Behnaz; Gülcemal, Derya; Nalbantsoy, Ayşe; Yusufoğlu, Hasan; Bedir, ErdalA new cycloartane sapogenol and a new cycloartane xyloside were isolated from Astragalus karjaginii BORISS along with thirteen known compounds. The structures of the new compounds were established as 3-oxo-6α,16β,24(S),25-tetrahydroxycycloartane (1) and 6-O-β-D-xylopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane (2) by 1D- and 2D-NMR experiments as well as ESIMS and HRMS analyses. The presence of the keto function at position 3 was reported for the first time for cyclocanthogenol sapogenin of Astragalus genus. In vitro immunomodulatory effects of the new compounds (1 and 2) along with the n-BuOH and MeOH extracts of A. karjaginii at two different doses (3 and 6 μg) were tested on human whole blood for in vitro cytokine release (IL-2, IL-17A and IFN-γ) and hemolytic activities. The results confirmed that compound 2, a monodesmosidic saponin, had the strongest effect on the induction of both IL-2 (6 μg, 6345.41 ± 0.12 pg/mL (× 5), P < 0.001) and a slight effect upon IL-17A (3 μg, 5217.85 ± 0.72 pg/mL, P < 0.05) cytokines compared to the other test compounds and positive controls (AST VII: Astragaloside VII; and QS-21: Quillaja saponin 21). All tested extracts and molecules also induced release of IFN-γ remarkably ranging between 5031.95 ± 0.05 pg/mL, P < 0.001 for MeOH extract (6 μg) and 5877.08 ± 0.06 pg/mL, P < 0.001 for compound 1 (6 μg) compared to QS-21 (6 μg, 5924.87 ± 0.1 pg/mL, P < 0.001). Administration of AST VII and other test compounds did not cause any hemolytic activity, whereas QS-21 resulted a noteworthy hemolysis.