Various methods were experimented to obtain complex of L-asparagine with99mTc. The VII state of Tc was reduced with direct reduction by SnCl2 and complex compound could not be obtained. For this reason, ligand exchange with99mTc-gluconate complex was tried and 20% yield was obtained.99mTc-pyrophosphate complex was carred out as second ligand exchanger and 50% yield was obtained in this experiment. Optimum conditions for ligand exchange with pyrophosphate are pH 11,50°C temperature, 60 minutes for reaction time and 278: 1 for pyrophosphate concentration to SnCl2 ratio.
Sertraline is an antidepressant drug. Sertraline was labeled with 131I by using iodogen method. Labeling yield was 85–90% and specific activity was approximately 64.75 GBq/mmol. The purification of radioiodinated Sertraline was performed by Sep Pak C-18 plus and the radiochemical purity was determined to be over 99%. Biodistribution studies were carried out by male Albino Wistar rats. The percentage of injected radioactivity per gram of tissue was calculated, and these data versus time curves were generated for organs and brain regions. The results showed that 131I labeled Sertraline may be a promising radiopharmaceutical for the investigation of serotonin 5-HT receptor functions of brain.
Chlordiazepoxide (CDZ) was labeled with 131I and investigated its radiopharmaceutical potential as a benzodiazepine receptor agent. Iodogen was used as iodination agent. Labeling yields were determined by radio-ITLC (instant thin layer chromatography) and paper electrophoresis. Labeling yield was approximately 90%. Purification was performed by Sep-Pak C-18 plus. Biodistribution studies were carried out by albino Wistar rats. 131I labeled chlordiazepoxide which is the 62.2 GBq/mmol specific activity was administered by tail vein into the rats. Rats were sacrificed by ether narcotization at certain time intervals and the organs were removed. The brains were dissected into their components. Their activities were counted by a gamma-counter. The activity per gram tissue was calculated and time–activity curves were generated.
Ornidazole (1-(3-chloro-2-hydroxypropyl)-2-methyl-5-nitroimidazole) was labeled with iodine-131 by using iodogen method. Quality
controls were performed by instant thin layer chromatography (ITLC) and electrophoresis methods. Labeling yield was 91%. Iodination
was carried out by substitution of chloride by iodine-131. Structure was confirmed by1H-NMR.
Authors:F. Yurt Lambrecht, K. Durkan, and E. Bayrak
Bombesin (BNN)-like peptides have very high binding affinity for the gastrin-releasing peptide (GRP) receptor. The goal of
the current study was to optimize the labeling conditions of a new 99mTc-radiolabeled BNN-like peptide based on the bifunctional chelating ligand HYNIC using different co-ligands (EDDA and tricine).
The radiolabeling conditions (pH, amount of co-ligand, amount of stannous chloride, temperature and reaction time) for newly-formed
99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were optimized and evaluated by RHPLC and RTLC. Radiochemical yields for 99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were 98.0 ± 1.7 and 97.5 ± 2.5%, respectively. When EDDA was used as co-ligand, the labeling of 99mTc-EDDA-HYNIC-Q-Litorin was optimal in the following reaction mixture: HYNIC-peptide: EDDA: 10 μg/5 mg, pH 3, SnCl2 concentration: 12 μg/0.1 mL, reaction temperature: 100 °C, reaction time: 15 min. Besides, the optimum conditions were HYNIC-peptide:tricine:
10 μg/50 mg, pH 5, SnCl2 concentration: 12 μg/0.1 mL, reaction temperature: 100 °C, reaction time: 15 min for preparing 99mTc-tricine-HYNIC-Q-Litorin. The manufactured 99mTc-HYNIC-Q-Litorin conjugates may offer new possibilities for imaging cancer cells expressing bombesin receptors.
Cefuroxime axetil, a cephalosporin antibiotic used to treat bacterial infections, was investigated to label with 99mTc. Radiolabeling of cefuroxime axetil was carried out by using stannous chloride method. Effects of pH and stannous chloride
amount on the radiolabeling yield were investigated. The radiochemical purity of 99mTc-cefuroxime axetil was determined by thin layer radio chromatography (TLRC), electrophoresis and high performance liquid
chromatography. The maximum radiolabeling yield was 98±1%.
Authors:B. Seyitoglu, F. Yurt Lambrecht, and K. Durkan
Apigenin (4′,5,7-trihydroxyflavone), one of the most common flavonoids, has been shown to possess a variety of biological
activities including tumor growth inhibition and chemopreventation. In the present study, apigenin was labeled with 131I using iodogen method and investigated of its bioactivity. Radiolabeling yield is 98±0.2%, as determined by radio thin layer
chromatography (RTLC), electrophoresis and radio high performance liquid chromatography (RHPLC). Besides, structure analysis
of synthesized cold iodoapigenin complex were assessed with LCMS/MS and 1H-NMR. Results of in vitro study indicated a high stability (3 hours) in human serum. Biodistrubition studies are performed
in male and female albino Wistar rats. Biodistribution data related to the male rats showed significant uptake in the small
intestine. The female rats biodistribution results indicated that the uptake of 131I-apigenin was high in the intestine and uterus.
Authors:H. Enginar, P. Ünak, F. Yurt, and F. Zümrüt Biber
An oestrogen derivative 3,17-a-oestradiolyl propyl 1,4,8,11-tetraazacyclotetradecanyl-1-(4-methylbenzoic acid)ester (ESTCPTA) that is 3,17-a-oestradiolyl propinol coupled to 1-(4-methylbenzoic acid)1,4,8,11-tetraazacyclotetradecane (CPTA) was synthesized in five steps. The product was purified by recrystallization in ethyl alcohol, and analysed by NMR and IR spectroscopy. ESTCPTA was labeled with 99mTc and radio thin layer chromatography (RTLC) and radio-paper electrophoresis were used to determine the radiochemical yields. Specific activity was approximately 23.7 GBq/mmol and the labeling yield was over 95%. The biodistribution studies were performed on female Albino Wistar rats. The rats were sacricified by ether narcotization at certain time intervals and the activity of the organs was counted by a gamma counter. The activity per gram tissue was calculated and time activity curves were generated.
Authors:H. Enginar, P. Unak, F. Yurt Lambrecht, and F. Biber
An estrogen derivative 1-(3, 17-α-estradiolyl propin-1-yl-3-(1,4,8,11-tetraazacyclotetradecyl)-propanate (ESTACPA) was synthesized.
The product was purified by HPLC and characterized by NMR and IR spectroscopy. The synthesized compound was labeled with 99mTc. The biodistribution studies were performed on female Albino Wistar rats. The rats were sacrificed and their organs were
removed. The radioactivities of the organs were counted using a gamma-counter. The activity per gram tissue was calculated
and time versus activity curves were generated. The 99mTc-ESTACPA uptake by the uterus and ovary such as ER-rich tissues, were observed. The pancreas and stomach also showed a significant
Authors:P. Ünak, F. Yurt Lambrecht, F. Biber, and S. Darcan
This study was designed to evaluate iodine concentrations in drinking water samples using isotope dilution analysis (IDA)
in the Aegean region of Turkey A total of 76 drinking water samples from rural and urban areas in regional cities were analyzed.
The mean iodine concentration was 78±27 μg/l and iodine concentration ranges were within 69±26 μg/l and 103±6 μg/l.