Browsing by Author "Ay E."
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Item Synthesis and antimicrobial activities of two novel amino sugars derived from chloraloses(2010) Yenil N.; Ay E.; Ay K.; Oskay M.; Maddaluno J.The synthesis of 5-amino-5-deoxy-1,2-O-(S)-trichloroethylidene-β-l-arabinofuranose and 6-amino-6-deoxy-1,2-O-(S)-trichloroethylidene-α-d-glucofuranose is described by a simple three- or four-step route. Antibacterial potency of the new compounds was determined using an inhibition zone diameter test. The results show that these compounds have a broad-spectrum activity against Gram-positive, Gram-negative bacteria and Candida albicans. © 2010 Elsevier Ltd. All rights reserved.Item Determination of some chemical parameters and antimicrobial activity of traditional food: Mesir paste(2010) Oskay M.; Karaildirim T.; Ay E.; Ay K.The antimicrobial activities and some chemical properties of the traditional Turkish food called mesir paste were studied. Results of chemical analysis for moisture and volatiles, water-insoluble components, refractive index, soluble solids content, raw fiber, invert sugar, total ash, 5-hydroxymethylfurfural, acidity, and pH were calculated as 17.06%, 2.55%, 1.491, 80.2%, 0.70%, 40.54%, 0.13%, 44 mg/kg, 0.9% anhydrous citric acid, and 3.6, respectively. Mesir paste was extracted individually by six solvents with different polarity, and antimicrobial activities of each extracts were determined against 12 microbial strains, mostly food-borne, including pathogens, by the agar well diffusion method. All extracts obtained showed antimicrobial activity ranging from 8 mm to 40 mm, and the butanolic extract displayed stronger antimicrobial activity against all tested microorganisms; Gram-positive strains were found to be more sensitive than Gram-negative strains. Antimicrobial potency of n-butanol extracts of mesir paste was determined in term of minimal inhibitory concentration and minimal bactericidal concentration for the sensitive microorganisms. In addition, some commercial antibiotics such as ampicillin, gentamicin, and nystatin were used as positive controls to determine the sensitivity of the strains. © 2010, Mary Ann Liebert, Inc. and Korean Society of Food Science and Nutrition.Item The knoevenagel-doebner reaction on 1,2-O-(2,2,2-Trichloroethylidene) derivatives of D-Gluco- and D-Manno- furanose(2010) Kök G.; Karayildirim T.; Ay K.; Ay E.The synthesis of new α,β-unsaturated furanuronic acid derivatives of α-gluco- (3) β-gluco- (6) and β-manno-chloraloses (9) via a convenient one pot procedure using the Knoevenagel-Doebner reaction approach are described. The dialdofuranose derivatives were reacted with malonic acid under Knoevenagel-Doebner reaction conditions and (E)- α,β-unsaturated furanuronic acid derivatives were obtained. © 2010 licensee MDPI Basel Switzerland.Item Synthesis, characterization and non-isothermal decomposition kinetic of a new galactochloralose based polymer(2014) Kök G.; Ay K.; Ay E.; Doǧan F.; Kaya I.A glycopolymer, poly(3-O-methacroyl-5,6-O-isopropylidene-1,2-O-(S)- trichloroethylidene-α-d-galactofuranose) (PMIPTEG) was synthesized from the sugar-carrying methacrylate monomer, 3-O-methacroyl-5,6-O-isopropylidene-1, 2-O-(S)-trichloroethylidene-α-d-galactofuranose (MIPTEG) via conventional free radical polymerization with AIBN in 1,4-dioxane. The structures of glycomonomer and their polymers were confirmed by UV-vis, FT-IR, 1H NMR, 13C NMR, GPC, TG/DTG-DTA, DSC, and SEM techniques. SEM images showed that PMIPTEG had a straight-chain length structure. On the other hand, the thermal decomposition kinetics of polymer were investigated by means of thermogravimetric analysis in dynamic nitrogen atmosphere at different heating rates. The apparent activation energies for thermal decomposition of the PMIPTEG were calculated using the Kissinger, Kim-Park, Tang, Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Friedman methods and were found to be 100.15, 104.40, 102.0, 102.2, 103.2 and 99.6 kJ/mol, respectively. The most likely process mechanism related to the thermal decomposition stage of PMIPTEG was determined to be a Dn deceleration type in terms of master plots results. © 2013 Elsevier Ltd. All rights reserved.Item Syntheses of 1,2,3-triazole-bridged pyranose sugars with purine and pyrimidine nucleobases and evaluation of their anticancer potential(Taylor and Francis Inc., 2017) Halay E.; Ay E.; Şalva E.; Ay K.; Karayıldırım T.With the aim to create a library of compounds with potential bioactivities by combining special characteristics of two important groups such as nucleobases and carbohydrates, twenty 1,4-disubstituted-triazole nucleosides were synthesized in good yields (80-94%) using the copper catalyzed ‘Click’ reaction between azido-modified pento- or hexopyranoses and alkyne-bearing pyrimidine or purine nucleobases. Structural elucidation was made with the assistance of spectroscopic techniques such as FTIR, 1D-, 2D-NMR, and ESI-TOFMS. All the synthesized triazole nucleosides were evaluated for their cytotoxic activity against three human cancer cell lines (MDA-MB-231, Hep3B, PC-3) by using the MTT assay. Particularly, compounds 3a and 1b were identified as potential hits against Hep3B cell. © 2017 Taylor & Francis Group, LLC.Item Synthesis and antimicrobial evaluation of sulfanilamide- and carbohydrate-derived 1,4-disubstitued-1,2,3-triazoles via click chemistry(Birkhauser Boston, 2017) Ay K.; Ispartaloğlu B.; Halay E.; Ay E.; Yaşa İ.; Karayıldırım T.4-Sulfanilamido substitued-1,2,3-triazoles conjugated with monosaccharides (8–17) including d-glucose, d-galactose, d-mannose, and d-fructose were synthesized in good yields from azidosugars with propargyl sulfanilamides using copper catalyst 1,3-dipolar cycloaddition reaction (CuAAC). The structures of new compounds were elucidated by liquid chromatography-mass spectrometry, infrared, one-dimensional- and two-dimensional-nuclear magnetic resonance techniques. All of the new compounds were tested in vitro against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Klebsiella pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans for their antibacterial and antifungal activities. Experimental results showed antimicrobial activity with minimum inhibitory concentrations values a ranging from 0.078 to 5.0 mg/mL against test microorganisms. © 2017, Springer Science+Business Media New York.Item Synthesis of triazolylmethyl-linked nucleoside analogs via combination of azidofuranoses with propargylated nucleobases and study on their cytotoxicity(Springer New York LLC, 2018) Halay E.; Ay E.; Şalva E.; Ay K.; Karayıldırım T.[Figure not available: see fulltext.] Copper(I)-catalyzed azide–alkyne 1,3-dipolar cycloaddition reactions (CuAAC) between azidofuranoses and propargyl-nucleobases were carried out in the presence of CuSO4·5H2O and sodium ascorbate as catalytic system to provide the corresponding 1,4-disubstituted-1,2,3-triazole-bridged nucleoside analogs in good yields. Twelve new sugar-based triazolylmethyl-linked nucleoside analogs were synthesized and screened for their cytotoxic activity against MDA-MB-231, Hep3B, PC-3, SH-SY5Y, and HCT-116 cancer cell lines and control cell line (L929). Most of the compounds were moderately effective against all the cancer cell lines assayed. Particularly, among the tested compounds, 1,2,3-triazole-linked 5-fluorouracil–mannofuranose hybrid was found to be the most potent cytotoxic agent against HCT-116, Hep3B, SH-SY5Y cells with IC50 values of 35.6, 71.1, and 75.6 μM, respectively. None of the triazolylmethyl-linked nucleoside analogs exhibited cytotoxic effect against the control cells L929. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.Item Synthesis of 5-fluorouracil dimer containing 2-amino-thiazole group via click reaction; [2-amino-tiyazol grubu içeren 5-florourasil dimerinin klik tepkimesi yoluyla sentezi](TUBITAK, 2021) Öztürkoğlu G.; Ay E.; Alp H.; Ay K.Since cancer is one of the leading diseases that cause human deaths in the world, the synthesis of anticancer or new compounds with fewer side effects is important. 5-Fluorouracil (5-FU) is one of the oldest compounds used for chemotherapy. In this study, 1,2,3-triazole bridge containing compound 4, which could have potential anticancer properties, was synthesized via the click reaction from the 5-FU and 2-aminothiazole using the molecular hybridization approach. The structural elucidation of the new compound was carried out using modern spectroscopic methods such as FTIR,1H,13C,19F, COSY, HSQC, HMBC and TOF-MS. © 2021, TUBITAK. All rights reserved.Item Click Reactivity of Azide-Modified Polyvinyl Chloride as an Entry to Glycopolymer Scaffolds(Croatian Chemical Society, 2021) Ay E.; Yenil N.We report the synthesis of new carbohydrate/triazole polymers based on poly(viny chloride) (PVC). Azide incorporation into commercially available PVC was carried out using nucleophilic substitution and Cu-catalyzed reaction of the resulting PVC-N3 using three alkynylcontaining acetonide-protected monosaccharides (based on D-glucose and D-galactose) provided a set of PVC-based polymers incorporating a triazolyl linkage with monosaccharide moieties present on the periphery. Modified polymers were characterized by using Fourier transform infrared (FT-IR), Nuclear Magnetic Resonance (1H-NMR and 13C-NMR) spectroscopy, together with thermogravimetric and surface morphological analysis. © 2021 Croatian Chemical Society. All rights reserved.Item Preparation and characterization of dialdehyde cellulose/polylactic acid blends; [Dialdehit selüloz/polilaktik asit blendlerinin hazırlanması ve karakterizasyonu](TUBITAK, 2021) Şirin K.; Seziş Ü.G.; Ay E.In recent years, the demand for naturally derived synthetic materials to protect the environment has increased. Cellulosic polymers are renewable, biodegradable, eco-friendly, and possess high strength and stiffness. As a result of the researches, the use of polylactic acid (PLA) instead of petroleum-based polymers stands out as an alternative. In this study, dialdehyde cellulose (DAC)/polylactic acid (PLA) mixtures were prepared. DAC was prepared by peroxide oxidation from microcrystalline cellulose. Firstly, DAC was blended with PLA. In addition to having hydrophilic properties of DAC, polyethylene glycol (PEG) was added to increase compatibility between PLA and DAC, as PLA was known to have hydrophobic properties.The blends were characterized by infrared spectroscopy (FT-IR) and thermal analysis (TGA and DTG) techniques. Besides, scanning electron microscopy (SEM) images of the polymer blends obtained were interpreted. © 2021, TUBITAK. All rights reserved.Item Thermal, Chemical and Mechanical Properties of Regenerated Bacterial Cellulose Coated Cotton Fabric(Taylor and Francis Ltd., 2022) Kilinc M.; Ay E.; Kut D.Bacterial cellulose is a raw material that is used in many industrial areas such as textile due to its properties and an alternative to plant cellulose whose usage is increasing day by day. In this research, dissolved bacterial cellulose was used as a coating material. After the coating process, samples were immersed in three different coagulation baths to provide regeneration of the coated material. TGA, FTIR, SEM-EDX, air permeability, tensile test, thermal comfort (alambeta), and water vapor transmission (permetest) analyses were carried out to compare the mechanical, chemical, and thermal properties between raw fabric and treated fabrics. Because of chemical analysis, it was observed that the structures are similar to each other. In terms of thermal stability, it has been determined that the samples that have been coated are more durable than the raw fabric. The tensile test revealed that there was a decrease between 15.05% and 41,62% in the strength of coated materials. According to the results of air permeability, alambeta, and permetest, a decrease in air permeability values, an increase in relative water vapor permeability, and thermal conductivity values were observed with the increase of the remaining coating material in the fabric. © 2021 Taylor & Francis.Item Synthesis of 1,2,3-triazole group-containing isomannide-based aromatic new polyurethanes(Springer Science and Business Media Deutschland GmbH, 2022) Bayrak F.; Ay E.; Oral A.; Karayıldırım T.; Ay K.Ten new carbohydrate-based aromatic polyurethanes have been synthesized using isomannide and/or a new 1,2,3-triazole isomannide derivative, IV, as the diol source in the polymerization reactions. As the isocyanate source, 1,4-phenylene diisocyanate or 2,4-toluene diisocyanate was used. To synthesize compound IV, isomannide was tosylated, the tosyl groups were substituted with azide, the triazole ring was formed by reaction with 2,4-pentane dione and finally carbonyl groups were converted into oximes. The synthesis of copolymers and terpolymers was performed using different proportions of diisocyanate and diol sources in DMF. The structural elucidation of the synthesized compounds and polymers was performed using spectroscopic techniques such as FTIR, 1D- and 2D-NMR and HRMS. The thermal behaviour and molecular weight distribution of polymers were analyzed by thermal gravimetric analysis and gel permeation chromatography, respectively. The surface properties of the polymers were analyzed using scanning electron microscopy. A comparative study on thermal behaviour of the synthesized polymers showed that polymers containing a higher amount of compound IV displayed better thermal stability. The average molecular weights of copolymers were observed to vary from 7,900 (PUR-3) to 21,000 (PUR-4) whereas for terpolymers, values of 19,000 (PUR-5), 5,100 (PUR-6), 22,000 (PUR-8) and 28,000 (PUR-9) were found. The diisocyanate source was found to have more effect on the surface properties of polymers than the diol source: when 2,4-toluene diisocyanate was used in polymer synthesis, the resultant polymers had a spongy morphology with cavities while a polymer matrix containing spheres and platelets was obtained when 1,4-toluene diisocyanate was used. Graphical abstract: [Figure not available: see fulltext.] © 2021, Iran Polymer and Petrochemical Institute.Item Synthesis of new poly(1,2,3-triazolyl-benzenesulfonamide)s via step-growth polymerization and characterization of their structures(Springer Science and Business Media B.V., 2023) Ay E.In this article, three new poly(1,2,3-triazolyl-benzenesulfonamide)s (4-6) were synthesized from the new molecule 4-azido-N-(prop-2ʹ-yn-1ʹ-yl)benzenesulfonamide (3). The synthesis and step-growth click polyaddition reaction of a new AB-type monomer containing terminal alkyne and azide groups were described. Copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) and Huisgen click polymerization were performed to prepare sulfonamide, a derivative of poly(1,2,3-triazole)s. The CuAAC polymerization regioselectively led to 1,4-disubstituted triazole ring and hence to a stereoregular polymer. In contrast, the thermal polymerization also produced 1,5-disubstituted triazole units. The structure of the new poly(1,2,3-triazolyl-benzenesulfonamide)s (4-6) obtained from (4-azido-N-(prop-2ʹ-yn-1ʹ-yl)benzenesulfonamide) were characterized by FTIR, 1H-, and 13C- NMR spectroscopy. The resulting polymers had weight-average molecular weights in the 7,700-58,650 range and were determined by Gel Permeation Chromatography (GPC). The resulting polymers 4, 5 and 6, lossing about 50% of their weights, showed a decomposition temperature of 406, 474, and 451 °C in a nitrogen atmosphere, respectively. The glass transition temperature of all polymers were at 128 °C. In addition, the surface morphology was studied via Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS). This paper is dedicated to the 100th Annivesary of Repuclic of Türkiye. © 2023, The Polymer Society, Taipei.Item Influence of synthesis procedures on the preparation of strontium titanate nanoparticles and photocatalytic application for methylene blue degradation(Springer Science and Business Media B.V., 2023) Ay E.; Aktaş P.S.SrTiO3 is a well-known photocatalyst with various applications, such as antibacterial agents, self-cleaning surfaces, and water and air conditioning. With the increased environmental pollution, SrTiO3 is one of the most studied perovskite photocatalysts, exhibiting pronounced photocatalytic activity for removing chemical pollutants and water splitting. In the present work, pure Strontium titanate (ST) nanoparticles were successfully prepared using high-energy ball milling and Pechini techniques and characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier Transform Infrared spectroscopy (FTIR), scanning and transmission electron microscopy, respectively. Structural parameters were evaluated by Rietveld refinement analysis from XRD data, which confirmed the cubic system of SrTiO3 with Pm-3 m space group. Scanning electron microscope results showed that ST1 samples consisted of agglomerated and irregular-shaped structures between 20 and 40 nm, and in ST2, the particles were round-shaped and had an average size of 150 nm. The obtained nanoparticles were used for photocatalytic methylene blue (MB) degradation, and synthesis methods' influence on catalytic activity was investigated. The photocatalytic studies examining the decoloration of MB dye reveal the function of smaller particles in increasing the rate of reactions. The degradation rate constant of MB on the ST1 (Pechini-synthesized sample) and ST2 (high energy ball milled sample) is 0.0145 and 0.0112 min−1, respectively. The better photocatalytic activity of the ST1 demonstrated 93% degradation of dye under the solar light simulator. The photocatalytic reaction data provided well a first-order kinetic model. Graphical abstract: [Figure not available: see fulltext.]. © 2023, Akadémiai Kiadó, Budapest, Hungary.Item Synthesis of new 1,2,3-triazolo-nucleoside analogues with 2-propargylamino pyrimidines via click reactions(Taylor and Francis Ltd., 2023) Ay E.In this study, it was reported that twelve nucleoside analogues were synthesized by click reactions. The reactions were carried out between the azide derivatives of D-glucopyranose, D-galactopyranose, D-ribofuranose and 2-propargylamino pyrimidine derivatives (5 and 7) that are synthesized via a different route for the first time. In the first step, N-propargyl guanidine was obtained with the reaction of 1H-pyrazole-1-carboxamidine hydrochloride and propargyl amine, then condensation of N-propargyl guanidine and β-diketone (4 and 6) resulted in 2-propargylamino pyrimidines (5 and 7) for the first time in good yields (85%). Finally, click reactions were performed with azidosugars (8a-8f) and 2-propargylamino pyrimidine derivatives and produced twelve new nucleoside analogues in good yields. (9a-9f, 10a-10f, 65-73% yields). The chemical structures of the new derivatives were elucidated spectroscopic techniques, such as FT-IR, 1H NMR, 19F NMR, 13C NMR and TOF-ESI-MS. © 2022 Taylor & Francis Group, LLC.Item Phenolic Compounds, Fatty Acid Contents, and Antibacterial Properties of Ozonated and Non-Ozonated Tobacco Seed Oils(Taylor and Francis Ltd., 2024) Yemiş F.; Alp H.; Ay E.; Tepe M.; Ay K.In this study, the fatty acid content, phenolic compounds, and antimicrobial activity of seed oils from Ege Özbaş (EO), Sarıbağlar 407 (S407) and Akhisar 98 (A98) tobacco plants grown in the Aegean region were investigated. The ozonation process altered fatty acid and phenolic compound compositions and affected antimicrobial activities against Gram-positive and Gram-negative bacteria in the oils. Tobacco seed oils (TSOs) were extracted via cold pressing (CP) and Soxhlet extraction (SE). Fatty acids and phenolic compounds were analyzed using GC-FID and LC-MS/MS, respectively. Non-ozonated oils averaged 73% linoleic acid, 13% oleic acid, 9% palmitic acid, and 3% stearic acid, while ozonated oils contained 41% linoleic acid, 18% oleic acid, 22% palmitic acid, and 11% stearic acid. The presence of 33 phenolic compounds was investigated and 22 common phenolic compounds were detected in both ozonated and non-ozonated TSOs, including gallic acid, protocatechuic acid, chlorogenic acid, 3-hydroxybenzoic acid, (-)-epicatechin, 2,5-dihydroxybenzoic acid, caffeic acid, verbascoside, luteolin-7-glucoside, hesperidin, and rosmarinic acid. The increased antimicrobial activity of fatty acids and phenolic compounds following ozonation suggests the potential for developing creams to treat skin diseases and wounds caused by antibiotic-resistant pathogens, and to reduce the effects of aging skin wrinkles. © 2024 International Ozone Association.Item Heterocyclic-based Schiff base material designed as optochemical sensor for the sensitive detection of chlorinated solvent vapours(Springer Science and Business Media B.V., 2024) Halay E.; Capan I.; Capan R.; Ay E.; Acikbas Y.Herein, a newly synthesized intermediate, piperazine-based Schiff base (PBSB) gas sensor was fabricated by the Schiff base condensation of amino functionalized methylpiperazine with aromatic aldehyde containing nitro substituent. This organic sensor material was structurally identified with spectroscopic techniques such as FTIR, HRMS, 1H- and 13C-NMR. The designed sensor candidate was explored for its optical response to chlorinated volatile organic compounds, namely trichloroethylene, dichloromethane and chloroform in the light of structure–property relationship investigation by using surface plasmon resonance (SPR) technique. The results showed that Schiff bases could be candidates for chlorinated vapour sensing materials with their good response and reversibility. Concordantly, compound PBSB exhibited good response against chlorinated solvent vapours aided by the electron-withdrawing group on benzene ring that promoted better intermolecular interactions and opened up a new strategy to create a novel set of responsive materials for gas sensing applications. In addition, the adsorption kinetics of SPR data obtained from PBSB spun film on exposure to these chlorinated vapours at different concentrations was also evaluated using the Elovich Model. The values of the initial adsorption rate, a and Elovich constant, b were analysed depending on the concentration values and the highest values were obtained for dichloromethane between 372.92 and 4377.53 ppm/mm2. Graphical abstract: (Figure presented.) © The Author(s) 2024.