Yazar "Osmanoglu, Yunus Emre" seçeneğine göre listele

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    Öğe
    Conformational, IR, NMR, and EPR analysis of ifosfamide by density functional theory calculation
    (Springer Wien, 2017) Osmanoglu, Yunus Emre; Tokatli, Ahmet; Sutcu, Kerem; Osmanoglu, Semsettin; Ucun, Fatih
    The optimized molecular structure, vibrational frequencies, H-1 and C-13 NMR chemical shifts, and EPR hyperfine splittings of 3-(2-chloroethyl)-2-[(2-chloroethyl) amino] tetrahydro-2H-1,3,2-oxazaphosphorine-2-oxide (ifosfamide) have been investigated using density functional theory (B3LYP) method with 6-31+G(d, p) basis set for the first time. The calculated optimized geometric parameters (bond lengths and bond angles), vibrational frequencies, NMR chemical shifts, and EPR hyperfine splittings were seen to be in a well agreement with the corresponding experimental data. The experimentalEPRspectrumof themoleculewas recorded after c-irradiation. From the comparison of the calculated and experimental results the formed radical was attributed to a carbon atom-centered radical occurred upon the loss of a chlorine atom due to breakage of the weak C-Cl bonds. So we mentioned that the free electron is transferred to a carbon atom through intramolecular rearrangement while the molecular charge changes to neutral situation, giving NHC alpha H2C beta H2 radical.
  • [ X ]
    Öğe
    Dosimetric Identification of Gamma-Irradiated Progesterone and Propranolol Hydrochloride by Electron Paramagnetic Resonance Spectroscopy
    (Springer Wien, 2023) Suetcue, Kerem; Osmanoglu, Yunus Emre
    In this study, radiation sensitivities of progesterone and propranolol hydrochloride samples irradiated with gamma in the 0-25 kGy dose range, which are widely used in medicine, were investigated by electron paramagnetic (EPR) resonance spectroscopy. Since the microwave saturation behavior of free radicals contributing to the spectra may be different, curves of signal intensities of the irradiated samples were obtained in the range of 0-15 mW depending on the microwave power. By using irradiated samples at dose values of 1, 5, 10, 15, 20 and 25 kGy, dose-response curves of the samples were obtained and the most appropriate mathematical functions and correlation coefficients were calculated. In addition, the extinction curves of the signal intensities of the samples were determined to test the stability of the free radicals formed in the irradiated samples at room temperature.
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    Öğe
    EPR Investigation of Gamma-Irradiated Tiopronin
    (Springer Wien, 2024) Sutcu, Kerem; Osmanoglu, Yunus Emre
    This research delves into the radiation sensitivities of tiopronin when exposed to gamma irradiation within the 2-20 kGy dose range. This particular drug sample is commonly employed in the treatment of severe homozygous cystinuria. The paramagnetic species detected within tiopronin were ascribed to the presence of the -HNCHCOOH- radical. The g factor and hyperfine constants for H atoms were computed as follows: a alpha = 1.60 mT, a beta = 1.11 mT, aN = 0.87 mT, and g = 2.0225 +/- 0.0005. In the spectra recorded across different microwave power ranges, it was found that all signals exhibited the most favorable correlations with polynomial and logarithmic functions. It was established that the experimental data within the spectra recorded across the 2-20 kGy dose range exhibited a high degree of compatibility with power and polynomial functions. Obtaining EPR signals in the spectra recorded at high temperatures and after approximately 3 months showed that stable radicals were formed in the structure as a result of irradiation.
  • [ X ]
    Öğe
    Study of Dose-Response and Radical Decay Curves of Gamma Irradiated Norfloxacin Using EPR Spectroscopy
    (Amer Inst Physics, 2017) Sutcu, Kerem; Osmanoglu, Yunus Emre
    this study, Electron Paramagnetic Resonance (EPR) spectra of unirradiated and gamma-irradiated at doses of 1, 5, 10, 12 and 15 kGy norlioxacin (NOF) were investigated. Before irradiation no EPR signal were observed. After irradiation a weak singlet signal at g = 2.0039 were obtained at room temperature. In order to describe the variation of EPR signal intensity with absorbed radiation dose, several mathematical equations were tried. Increasing irradiation dose up to 15 kGy has increased the signal intensity of the central signal however, no significant changes were observed in g spectroscopic splitting factor. The stability of signal intensity of irradiated NOF was studied over a storage period of 200 days. According to analyses conducted, EPR spectroscopy can be used to distinguish irradiated and unirradiated samples from each other.