Dosimetric investigation of radiaton damage centers induced by gamma radiaton in some anticancer drugs and natural amino acid derrivatives using EPR technique

This thesis consists of two parts. In the first part; the behaviour of the free radicals induced by gamma irradiation in four different anticancer drugs studied by Electron Paramagnetic Resonance Spectroscopy (EPR) to characterize the amounts and stability of these radicals, on the absorbed dose. Samples of drugs were irradiated by gamma rays at room temperature in the dose range of 0-20 kGy. While the EPR (Electron Paramagnetic Resonance) spectra of unirradiated drug samples show no signal, signals dependent on the irradiation dose observed with irradiated samples. Firstly microwave saturation of the irradiated samples was studied at room temperature. Several mathematical functions were tried to describe the dose-response curves obtained for irradiated samples and best functions describing the curves were determined. Correlation coefficients between absorbed doses and their corresponding EPR signals were identified from EPR signals. Storage at room temperature over 12 months was performed. The evolutions of the percentage of signal intensities were calculated. In the second part; four different powder crystals of amino acid derrivatives were irradiated with gamma rays. Paramagnetic centers resuleted in the samples were determined. EPR spectra of the samples were determined by Mc Kelvey simulation program. Paramagnetic centers, hyperfine structure constanst and g values were calculated.