Browsing by Author "Halay E."

Now showing 1 - 7 of 7
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    The newest member of the family of chloralose: Synthesis of β -ribochloralose and some derivatives
    (2013) Ay K.; Halay E.
    Treatment of D-ribose with chloral in the presence of acid catalyst gives 1,2-O-(S)-trichloroethylidene-α-D-ribofuranose (1) (β-ribochloralose) . Some derivatives of this product (1) were synthesized to be used as an intermediate in carbohydrate chemistry. Tricyclic orthoester structure (3, 77%) was obtained from the reaction of 1 with potassium t-butoxide. This novel orthoester is expected to be useful as a glycosyl donor in the formations of new ribofuranoside units. 3-O-Methyl-ribochloralose (5) was synthesized in 75% yield via the methylation of 1. 5-O-Tosyl-ribochloralose (6, 61%) was prepared with monotosylation reaction of 1. Treatment of 6 with NaN3 in DMF gives a 5-azido-5-deoxy-ribochloralose (7) in 77% yield. The azidosugar (7) was reduced to 5-amino-5-deoxy-ribochloralose (8, 72%) with triphenylphosphine according to Staudinger's reduction procedure. © 2013 Kadir Ay and Erkan Halay.
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    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.
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    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.
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    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.
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    Formulation, characterization, cytotoxicity and Salmonella/microsome mutagenicity (Ames) studies of a novel 5-fluorouracil derivative
    (Elsevier B.V., 2018) Köksal Karayildirim Ç.; Kotmakçi M.; Halay E.; Ay K.; Başpinar Y.
    5-Fluorouracil is one of the first line drugs for the systemic therapy of solid tumors like breast, colorectal, oesophageal, stomach, pancreatic, head and neck. It could be shown that sugars can improve the absorption across cell membranes and can help to bypass some pharmacokinetic problems. Carbohydrates as most common organic molecules are an important issue of plant and animal metabolisms. They are non toxic and have important duties in the body like participating in DNA and RNA synthesis and being responsible for energy production. In addition, they have many hydroxyl, aldehyde and ketone groups that attract attention for synthesis as a potential drug derivative. 1,2,3,-Triazole compounds have also important role in heterocyclic chemistry because of their pharmaceutical properties and their high reactivity, which could be used as a building block for complex chemical compounds. In this study, following the “Click Reaction” of 5-FU and tetra-O-acetylglycose the 5-fluorouracil derivative 1-[{1′-(2″,3″,4″,6″-tetra-O-acetyl-β-D-glycopyronosyl)-1′H-1′,2′,3′-triazole-4′-yl} methyl]5-fluorouracil was synthesized. Following, a micellar formulation of 5-Fluorouracil derivative was prepared and characterized in terms of particle size, polydispersity index, zeta potential, refractive index and pH. Furthermore, the cytotoxicity and mutagenicity of the 5-fluorouracil derivative was investigated using an in vitro cell culture model and the AMES test. According to the results of this study, the novel 5-fluorouracil derivative could be a drug candidate for the therapy of cancer and needs further in vivo investigations. © 2018 The Authors
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    Radiolabeling and in vitro evaluation of a new 5-fluorouracil derivative with cell culture studies
    (John Wiley and Sons Ltd, 2019) Ilem-Ozdemir D.; Atlihan-Gundogdu E.; Ekinci M.; Halay E.; Ay K.; Karayildirim T.; Asikoglu M.
    The clinical impact and accessibility of 99mTc tracers for cancer diagnosis would be greatly enhanced by the availability of a new, simple, and easy labeling process and radiopharmaceuticals. 5-Fluorouracil is an antitumor drug, which has played an important role for the treatment of breast carcinoma. In the present study, a new derivative of 5-Fluorouracil was synthesized as (1-[{1′-(1′′-deoxy-2′′,3′′:4′′,5′′-di-O-isopropylidene-β-D-fructopyranose-1′′-yl)-1′H-1′,2′, 3′-triazol-4′-yl}methyl]-5-fluorouracil) (E) and radiolabeled with 99mTc. It was analyzed by radio thin layer chromatography for quality control and stability. The radiolabeled complex was subjected to in vitro cell-binding studies to determine healthy and cancer cell affinity using HaCaT and MCF-7 cells, respectively. In addition, in vitro cytotoxicity studies of compound E were performed with HaCaT and MCF-5 cells. The radiochemical purity of the [99mTc]TcE was found to be higher than 90% at room temperature up to 6 hours. The radiolabeled complex showed higher specific binding to MCF-7 cells than HaCaT cells. IC50 values of E were found 31.5 ± 3.4 μM and 20.7 ± 2.77 μM for MCF-7 and HaCaT cells, respectively. The results demonstrated the potential of a new radiolabeled E with 99mTc has selective for breast cancer cells. © 2019 John Wiley & Sons, Ltd.
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    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.