Person: GAZİOĞLU, IŞIL
Loading...
Status
Kurumdan Ayrılmıştır
Organizational Units
60 results
Search Results
Now showing 1 - 10 of 60
Publication Metadata only Effect of roasting on antioxidant and anticholinesterase capacities of coffee(2014-01-01) Yilmaz, Pelin Koseoglu; Hacibekiroglu, IŞIL; Kolak, Ufuk; GAZİOĞLU, IŞILThe aim of the study was to investigate the effect of the roasting degree on total phenolic and flavonoid contents, antioxidant and anticholinesterase activities of the hexane, acetone, ethanol and water extracts of coffee. The antioxidant capacity of the water extracts prepared according to the brewing procedure of Turkish coffee was measured for the first time by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and cupric ion reducing antioxidant capacity (CUPRAC) assays. The in vitro anticholinesterase activity of the coffee extracts and caffeine was determined for the first time. Water extracts of the coffee samples exhibited the highest 2,2--azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) cation radical scavenging, DPPH free radical scavenging and CUPRAC effects. The hexane extract of coffee roasted for 25 min showed the highest acetylcholinesterase inhibitory activity among the tested extracts. Caffeine, which is known to have therapeutic effect against Alzheimer-s disease, was found to possess almost the same anticholinesterase activity as galanthamine. The roasting degree had an irregular effect on the antioxidant and anticholinesterase activities of the coffee extracts. The caffeine contents in extracts of coffee roasted for 25 min, which had strong anticholinesterase effect, were determined by HPLC, and the water extract was found to possess the highest caffeine content.Publication Metadata only Synthesis, antioxidant activity and SAR study of novel spiro-isatin-based Schiff bases(2018-12-01) Sönmez, Fatih; ZENGİN KURT, BELMA; Küçükislamoğlu, Mustafa; Avcı, Davut; GAZİOĞLU, IŞIL; Güneşli, Zuhal; ZENGİN KURT, BELMA; GAZİOĞLU, IŞILA new series of 21 Schiff bases of spiro-isatin was synthesized, and their DPPH, CUPRAC and ABTS cation radical scavenging abilities were investigated for antioxidant activity. The results showed that all the synthesized compounds exhibited antioxidant activity for each assay. 5 & x30d;-(2,3-Dihydroxybenzylideneamino)spiro[[1,3] dioxolane-2,3 & x30d;-indoline]-2 & x30d;-on (5c) (IC50 = 4.49 mu M, for DPPH; IC50 = 0.39 mu M, for ABTS(.+); and A(0.50) = 0.42 mu M, for CUPRAC) showed significantly better ABTS, CUPRAC and DPPH radical scavenging ability than quercetin (IC50 = 8.69 mu M, for DPPH; IC50 = 15.49 mu M, for ABTS(.+); and A(0.50) = 18.47 mu M, for CUPRAC), which is used as a standard. SAR study showed that the synthesized compounds had higher ABTS(.+) activity than DPPH and CUPRAC activities. Moreover, the compounds (5c and 5d), containing two hydroxyl groups, exhibited the highest antioxidant activities for all assays. Quantum chemical calculations were also carried out to support SAR results.Publication Metadata only Biological activities and phenolic-flavonoid contents of bilberry extracts(2012-12-01T00:00:00Z) Hacibekiroǧlu, IŞIL; KOLAK, Ufuk; GAZİOĞLU, IŞILPublication Metadata only Synthesis, anticholinesterase activity and molecular modeling study of novel carbamate-substituted thymol/carvacrol derivatives(2017-02-15) KURT, Belma Zengin; Gazioglu, IŞIL; Dag, AYDAN; Salmas, Ramin Ekhteiari; Kayik, Gulru; Durdagi, Serdar; Sonmez, Fatih; ZENGİN KURT, BELMA; GAZİOĞLU, IŞIL; DAĞ, AYDANNew thymol and carvacrol derivatives with the carbamate moiety were synthesized and their inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were evaluated. 5-isopropyl-2-methylphenyl(3-fluorophenyl)carbamate (29) was found to be the most potent AChE inhibitor with IC50 values of 2.22 mu M, and 5-isopropyl-2-methylphenyl (4-fluorophenyl)carbamate (30) exhibited the strongest inhibition against BuChE with IC50 value of 0.02 mu M. Additionally, the result of H4IIE hepatoma cell toxicity assay for compounds 18, 20, 29, 30 and 35 showed negligible cell death at 0.07-10 mu M. Moreover in order to better understand the inhibitory profiles of these molecules, molecular modeling studies were applied. Binding poses of studied compounds at the binding pockets of AChE and BuChE targets were determined. Predicted binding energies of these compounds as well as structural and dynamical profiles of molecules at the target sites were estimated using induced fit docking (IFD) algorithms and post-processing molecular dynamics (MD) simulations methods (i.e., Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) approaches). (C) 2016 Elsevier Ltd. All rights reserved.Publication Metadata only Synthesis and Antibacterial Activity of New Sulfonamide Derivatives Containing Thiazolidine Ring(2020-03-01T00:00:00Z) Dandin, Gülnur; ZENGİN KURT, BELMA; GAZİOĞLU, IŞIL; ZENGİN KURT, BELMA; GAZİOĞLU, IŞILPublication Metadata only SIMULTANEOUS DETERMINATION OF FEBUXOSTAT AND MONTELUKAST IN HUMAN PLASMA BY USING FABRIC PHASE SORPTIVE EXTRACTION AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHY(2021-09-17T00:00:00Z) GAZİOĞLU, IŞIL; TEKKELİ, ŞERİFE EVRİM; Kabir, Abuzar; Aslan, Ceylin; GAZİOĞLU, IŞIL; TEKKELİ, ŞERİFE EVRİMPublication Metadata only Evaluation of Metabolites Produced by Fungal Biotransformation of Apigenin and Fisetin and Their Cytotoxic Activities(2020-03-01T00:00:00Z) GAZİOĞLU, IŞIL; Erdoğan, Oğuz; YANIKOĞLU, RABİA SARE; ÖZTÜRK, DİLEK; GAZİOĞLU, IŞIL; YANIKOĞLU, RABİA SARE; ÖZTÜRK CİVELEK, DİLEKPublication Metadata only Identification of Biotransformed Products of Some Terpenoids by Aspergillus flavus, A. niger and Cunnignhamella elegans(2018-04-28) GAZİOĞLU, IŞIL; GAZİOĞLU, IŞILPublication Metadata only Fabric phase sorptive extraction combined with high performance liquid chromatography for the determination of favipiravir in human plasma and breast milk(2023-01-01) TIRIS G.; Gazioglu I.; Furton K. G.; Kabir A.; Locatelli M.; TIRIS, GİZEM; GAZİOĞLU, IŞILA fast procedure obtained by the combination of fabric phase extraction (FPSE) with high performance liquid chromatography (HPLC) has been developed and validated for the quantification of favipiravir (FVP) in human plasma and breast milk. A sol-gel polycaprolactone-block-polydimethylsiloxane-block-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated on 100% cellose cotton fabric was selected as the most efficient membrane for FPSE in human plasma and breast milk samples. HPLC-UV analysis were performed using a RP C18 column under isocratic conditions. Under these optimezed settings, the overall chromatographic analysis time was limited to only 5 min without encountering any observable matrix interferences. Following the method validation pro-cedure, the herein assay shows a linear calibration curve over the range of 0.2-50 mu g/mL and 0.5-25 mu g/mL for plasma and breast milk, respectively. The method sensitivities in terms of limit of detection (LOD) and limit of quantification (LOQ), validated in both the matrices, have been found to be 0.06 and 0.2 mu g/mL for plasma and 0.15 and 0.5 mu g/mL for milk, respectively. Intraday and interday precision and trueness, accordingly to the International Guidelines, were validated and were below 3.61% for both the matrices. The herein method was further tested on real samples in order to highlight the applicability and the advantage for therapeutic drug monitoring (TDM) applications. To the best of our knowledge, this is the first validated FPSE-HPLC-UV method in human plasma and breast milk for TDM purposes applied on real samples. The validated method provides fast, simple, cost reduced, and sensitive assay for the direct quantification of favipiravir in real biological matrices, also appliyng a well-known rugged and cheap instrument configuration.Publication Metadata only Investigating the toxicity of biotransformation products of limonene in Aspergillus flavus culture(2019-03-14) GAZİOĞLU, IŞIL; Sutherland, John; GAZİOĞLU, IŞIL