WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Conference Object Citation - WoS: 1The Effects of Novel Telomerase Activators on Human Adipose-Derived Mesenchymal Stem Cell (had-Msc) Proliferation and Osteogenic Differentiation(Georg Thieme Verlag Kg, 2022) Kuru, G.; Küçüksolak, Melis; Pulat, G.; Karaman, O.; Bedir, Erdal[No Abstract Available]Conference Object Citation - WoS: 1Secondary Metabolites From Endophytic Fungus Penicilium Roseopurpureum and Investigation of Their Cytotoxic Activities(Georg Thieme Verlag, 2022) Dizmen, Berivan; Üner, Göklem; Küçüksolak, Melis; Ballar Kırmızıbayrak, Petek; Bedir, Erdal[No Abstract Available]Conference Object Citation - WoS: 1Phytochemical Studies on Mastic Gum of Pistacia Lentiscus Var. Chia Collected From Karaburun Peninsula and Neuroprotective Activities of the Isolates(Georg Thieme Verlag, 2022) Demir, Mehmet; Üner, Göklem; Mu, Kurt; Aygün, M.; Ballar Kırmızıbayrak, Petek; Bedir, Erdal[No Abstract Available]Conference Object Short Lecture "method Development for Pilot Production of Astragaloside Vii"(Georg Thieme Verlag, 2022) Kurt, Mustafa Ünver; Tağ, Özgür; Bedir, ErdalBased on the promising immunostimulant effect comparable to commercialized adjuvants Alum and Quillaja saponins (including QS-21) [1], [2], [3], our team has been prompted to carry out advance studies for developing Astragaloside VII (AST VII) ([Fig. 1]) as a new vaccine adjuvant or an immunotherapeutic agent. Hence, one of the most critical challenges is establishing efficient isolation and purification processes to obtain AST VII on a large scale. Thus, this study aimed to develop a production methodology for AST VII from Turkish Astragalus species.Conference Object Short Lecture Novel Neuroprotective Metabolites Produced Via Biotransformation of Cyclocephagenol by Alternaria Eureka 1e1bl1(Georg Thieme Verlag, 2022) Küçüksolak, Melis; Üner, Göklem; Ballar Kırmızıbayrak, Petek; Bedir, ErdalNeurodegeneration refers to the loss of structure/function of neurons leading to neurological diseases including Alzheimerʼs and Parkinsonʼs. The discovery of novel therapeutics against neurodegenerative diseases has been an area of intense research as neurodegenerative diseases are a huge burden on society and the economy [1]. Numerous studies reported that natural products have the potential to prevent and treat neurodegeneration. Among these studies, the neuroprotective activities of cycloartane-type saponins are noteworthy [2], [3]. In our preliminary studies, the neuroprotective activity of cyclocephagenol, an aglycone of cyclocephaloside I from Astragalus microcephalus [4], was screened for H2O2-induced injury in SH-SY5Y cells. Based on the promising bioactivity of cyclocephagenol, the aims of this study were: i) to perform microbial transformation studies on cyclocephagenol using Alternaria eureka followed by isolation and structural characterization of the metabolites; ii) to investigate neuroprotective activities of the metabolites; iii) to understand structure-activity relationships towards neuroprotection.Conference Object A New Iminol Derivative From Streptomyces Cacaoi in New Fermentation Conditions(Georg Thieme Verlag, 2022) Gezer, Emre; Küçüksolak, Melis; Bilgi, Eyüp; Bedir, ErdalMarine-derived organisms have varied secondary metabolism due to their adaptation to extreme conditions of marine environments. This fact has made marine-derived Actinobacteria promising sources of new/novel compounds. In addition, the expression of secondary metabolite gene clusters is typically under the control of environmental conditions that cause many of the biosynthetic gene clusters to be silent under laboratory conditions. Thus, the determination of proper fermentation conditions becomes crucial for discovering new molecules.Conference Object Citation - WoS: 1Immunomodulatory Mechanisms of Astragalus Saponins(Wiley, 2021) Yakuboğulları, Nilgün; Çağır, Ali; Bedir, Erdal; Sağ, DuyguArticle Citation - WoS: 19Citation - Scopus: 21Telomerase Activators From 20(27)-Octanor Via Biotransformation by the Fungal Endophytes(Academic Press, 2021) Duman, Seda; Ekiz, Güner; Yılmaz, Sinem; Yusufoğlu, Hasan; Ballar Kırmızıbayrak, Petek; Bedir, ErdalCycloastragenol [20(R),24(S)-epoxy-3 beta,6 alpha,16 beta,25-tetrahydroxycycloartane] (CA), the principle sapogenol of many cycloartane-type glycosides found in Astragalus genus, is currently the only natural product in the anti-aging market as telomerase activator. Here, we report biotransformation of 20(27)-octanor-cycloastragenol (1), a thermal degradation product of CA, using Astragalus species originated endophytic fungi, viz. Penicillium roseopurpureum, Alternaria eureka, Neosartorya hiratsukae and Camarosporium laburnicola. Fifteen new biotransformation products (2-16) were isolated, and their structures were established by NMR and HRESIMS. Endophytic fungi were found to be capable of performing hydroxylation, oxidation, ring cleavage-methyl migration, dehydrogenation and Baeyer-Villiger type oxidation reactions on the starting compound (1), which would be difficult to achieve by conventional synthetic methods. In addition, the ability of the metabolites to increase telomerase activation in Hekn cells was evaluated, which showed from 1.08 to 12.4-fold activation compared to the control cells treated with DMSO. Among the compounds tested, 10, 11 and 12 were found to be the most potent in terms of telomerase activation with 12.40-, 7.89- and 5.43-fold increase, respectively (at 0.1, 2 and 10 nM concentrations, respectively).Article Citation - WoS: 12Citation - Scopus: 12Isolation of Rosmarinic Acid and Methyl Rosmarinate as Lipoxygenase Inhibitors From Salvia Palaestina Benth. by Activity-Guided Fractionation(Elsevier, 2021) İçen, Mehmet Sina; Gürbüz, İlhan; Bedir, Erdal; Günbatan, Tuğba; Demirci, FatihSalvia palaestina aqueous and methanol extracts were prepared from the aerial parts, which were evaluated for the in vitro anti-inflammatory properties using the lipoxygenase (LO) enzyme inhibition assay. While the aqueous extract showed no activity at test concentrations, a significant (p < 0.001) lipoxygenase inhibition was detected for the methanol extract with 29% inhibition. Activity guided fractionation was carried out on the methanol extract via liquid-liquid partitioning using n-hexane, dichloromethane, ethyl acetate, and n-butanol. The ethyl acetate fraction showed statistically the best inhibition among the sub-fractions with 70% inhibition (p < 0.0001). The compounds responsible for the activity were purified, and their structures were established as rosmarinic acid, and methyl rosmarinate by spectroscopic methods. IC50 values of rosmarinic acid, and methyl rosmarinate were calculated as 0.21 and 0.02 ?M, respectively. In conclusion, the in vitro anti-inflammatory potential of S. palaestina was associated to rosmarinic acid, and methyl rosmarinate, for the first time to the best of our knowledge. © 2021 SAABArticle Citation - WoS: 5Citation - Scopus: 7Five New Cardenolides Transformed From Oleandrin and Nerigoside by Alternaria Eureka 1e1bl1 and Phaeosphaeriasp. 1e4cs-1 and Their Cytotoxic Activities(Elsevier Ltd., 2021) Karakoyun, Çiğdem; Küçüksolak, Melis; Bilgi, Eyüp; Doğan, Gamze; Çömlekçi, Yiğit Ege; Bedir, ErdalBiotransformation of oleandrin (1) and nerigoside (2) by endophytic fungi; Alternaria eureka 1E1BL1 and Phaeospheria sp. 1E4CS-1, has led to the isolation of five new metabolites (3, 5, 6, 7 and 8) together with a known compound (4). The structures of the biotransformation products were elucidated by 1D-, 2D NMR and HR-MS. Phaeospheria sp. mainly provided monooxygenation reactions on the A and B rings, whereas A. eureka afforded both monooxygenated and desacetylated derivatives of the substrates. Cytotoxic activity of the compounds was tested against a non-cancerous (HEK-293) and four cancer (PANC-1, MIA PaCa-2, DU 145 and A549) cell lines by MTT cell viability assay. All compounds were less cytotoxic than oleandrin, which had IC50 values ranging between 2.7 and 41.9 nM. Two of the monohydroxylated metabolites, viz. 7(?)-hydroxy oleandrin (3) and 1(?)-hydroxy oleandrin (7), were also potent with IC50 values from 18.45 to 39.0 nM, while desacetylated + monohydroxylated, or dihydroxylated products had much lower cytotoxicity. Additionally, the lesser activity of 2 and its metabolite (6) possessing diginose as sugar residue inferred that oleandrose moiety is important for the toxicity of oleandrin as well as hydrophobicity of the steroid core. © 2020 Phytochemical Society of Europe