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    Determination of free radical on polycrystal of 4,4?-bis(chloroacetyl)diphenylether: An ESR study
    (Elsevier Science Bv, 2013) Ceylan, Yusuf; Usta, Ayhan; Usta, Keziban; Durmaz, Fatih; Coskun, Ahmet
    4,4'-Bis(chloroacetyl)diphenylether was synthesized and its polycrystal form was produced. This polycrystal sample was irradiated by gamma rays (Co-60) for 72 h. The ESR method was used to observe formation of free radical on the sample. ESR signal was not recorded from the non-irradiated sample, but the irradiated polycrystal sample exhibited complex ESR spectra. The measurements were carried out in the temperature range of 120-450 K. It was observed that the shape of the spectrum was dependent on the temperature. Two identical radicals were determined on the irradiated sample. Respectively, the spin density, hyperfine, and g values were found to be rho(Ha) = 0.53, rho(Hb) = 0.23, a(Cl) = 1.263 mT, a(Ha) = 1.486 mT, a(Hb) = 0.637 mT, and g(1) = 2.0115 for the Radical rho(Hx) = 0.22, rho(Hy) = 0.14, a(Cl) = 0.905 mT, a(Hx) = 0.615 mT, a(Hy) = 0.391 mT, and g(2) = 2.0383 for the Radical II. (C) 2013 Elsevier B.V. All rights reserved.
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    A newly synthesized thiazole derivative as a fluoride ion chemosensor: Naked-eye, spectroscopic, electrochemical and NMR studies
    (Pergamon-Elsevier Science Ltd, 2014) Sariguney, Ahmet Burak; Saf, Ahmet Ozgur; Coskun, Ahmet
    2,3-Indoledione 3-thiosemicarbazone (TSCI) and a novel compound 3-(2-(4-(4-phenoxyphenyl)thiazol-2-yl)hydrazono)indolin-2-one (FTHI) were synthesized with high yield and characterized by spectroscopic techniques. The complexation behaviors of TSCI and FTHI for various anionic species (F-, Cl-, Br-, l(-), NO2-, NO3-, BzO(-), HSO4-, ClO4-) in CH3CN were investigated and compared by UV-vis spectroscopy, cyclic voltammetry and H-1 NMR titration techniques. FTHI showed high degree of selectivity for fluoride over other anions. This selectivity could be easily observed by the naked eye, indicating that FTHI is potential colorimetric sensor for fluoride anion. (C) 2014 Elsevier B.V. All rights reserved.
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    Oxidation of cyanobenzocycloheptatrienes: Synthesis, photooxygenation reaction and carbonic anhydrase isoenzymes inhibition properties of some new benzotropone derivatives
    (Pergamon-Elsevier Science Ltd, 2014) Guney, Murat; Coskun, Ahmet; Topal, Fevzi; Dastan, Arif; Gulcin, Ilhami; Supuran, Claudiu T.
    The oxidation of some cyanocycloheptatrienes with CrO3 and pyridine was investigated and a few new nitrile functionalised benzotropone derivatives were obtained. Photooxygenation reaction of these products was also studied. The structures of the formed products were determined on the basis of NMR spectroscopy and the formation mechanism of unusual products was discussed. Human carbonic anhydrase isoenzymes I, and II (hCA I and hCA II) inhibition properties of nitrile functionalized new benzotropone derivatives were also studied. Both CA isozymes were inhibited in the low micromolar range by these nitrile functionalized benzotropone analogues. The newly synthesized benzotropone derivatives showed inhibition constants in the sub-micromolar range (2.51-4.06 mu M). The best hCA I inhibition was observed in 5H-benzocycloheptene-7-carbonitrile (K-1: 2.88 +/- 0.86 mu M). On the other hand, 5-oxo-5H-benzocycloheptatriene-7-carbonitrile showed the powerful inhibitory effect against hCA II (K-i: 2.51 +/- 0.34 mu M). (C) 2014 Elsevier Ltd. All rights reserved.
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    Synthesis and Antimicrobial Activity of Some 2-aminothiazole and 2-aminothiadiazine Derivatives
    (Wiley, 2018) Sariguney, Ahmet Burak; Kocabas, Erdal; Erci, Fatih; Torlak, Emrah; Coskun, Ahmet
    In this study, some thiazole and thiadiazine ring bearing compounds were synthesized, characterized by spectroscopic techniques, and evaluated as potential antimicrobial agents. Their antimicrobial activities evaluated by broth microdilution method and expressed as minimum inhibitory concentration; against Escherichia coli, Salmonella typhimurium, Bacillus cereus, and Staphylococcus aureus. From these compounds, Compounds 2, 5, and 9 have been found to selectively inhibit Gram positives.
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    Synthesis, Antibacterial and Cytotoxic Activities of New Thiazole Based Pyrrolidine Derivatives
    (Biointerface Research Applied Chemistry, 2021) Kocabas, Erdal; Sariguney, Ahmet Burak; Erci, Fatih; Cakir-Koc, Rabia; Kocabas, Hilal Ozen; Torlak, Emrah; Coskun, Ahmet
    In this study, some thiazole-based pyrrolidine derivatives were synthesized, characterized by FT-IR and H-1 NMR spectroscopic techniques, and evaluated as potential antibacterial agents. Their antibacterial activities were evaluated by broth microdilution method and expressed as minimum inhibitory concentration; against Escherichia coli, Salmonella typhimurium, Bacillus cereus, and Staphylococcus aureus. Cytotoxicity studies of synthesized compounds were also conducted to minimize the toxic effects on healthy mammalian cells. From synthesized compounds, 4-F-phenyl derivative compound (11) has been found to inhibit Gram-positive bacteria with minimum toxicity selectively.