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Journal of Labelled Compounds & Radiopharmaceuticals

Vegard Torp Lien, Jo Klaveness, Dag Erlend Olberg
Cabozantinib is an FDA approved kinase inhibitor for the treatment of medullary thyroid cancer and advanced renal cell carcinoma, which exerts its therapeutic effect by inhibiting, among others, the tyrosine kinase c-Met. Non-invasive imaging techniques are becoming increasingly important clinically to ensure drug efficacy, staging, monitoring and patient stratification. PET isotope labelled tyrosine kinase inhibitors have, for the same reason, potential as PET tracers for imaging of various cancers. Based on cabozantinib, we synthesized the novel boronic acid pinacol ester 4 as a labelling precursor, where the boronic ester moiety replaces the fluorine native to this kinase inhibitor...
September 18, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Pyeong Seok Choi, Jun Young Lee, Joung Hoon Park, Sang Wook Kim
(68) Ga is a positron-emitting radionuclide that can be combined with bifunctional chelating agents and bioactive substances for use as positron-emission tomography (PET) diagnostic agents. HBED-CC is an acyclic chelating agent that is rapidly labeled with (68) Ga under mild conditions. To target cancer cells, bioactive substances can be conjugated to the carboxyl terminus of HBED-CC. Because folic acid strongly binds to folate receptors that are overexpressed on the surfaces of many types of cancer cells, it was coupled with HBED-CC through a small polyethylene glycol-based linker (EDBE) to generate an active, receptor-selective targeting system...
September 13, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Constantin Mamat, Matthew Gott, Jörg Steinbach
The increasing application of positron emission tomography (PET) and single photon emission computer tomography (SPECT) in radiopharmacy and nuclear medicine has stimulated the development of a multitude of novel and versatile bioorthogonal conjugation techniques. Currently, there is particular interest in radiolabeling biologically active, high molecular weight compounds like peptides, proteins or antibodies, but also for the labeling of small organic compounds. An enormous challenge in radiolabeling these biologically active molecules is that the introduction of radiohalogens like fluorine-18 as well as various radiometals proceeds under harsh conditions, which could destroy the biomolecule...
September 11, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Falguni Basuli, Xiang Zhang, Pedro Brugarolas, Daniel S Reich, Rolf E Swenson
4-aminopyridine (4-AP) is a clinically approved drug to improve motor symptoms in multiple sclerosis. A fluorine-18 labeled derivative of this drug, 3-[(18) F]fluoro-4-aminopyridine, is currently under investigation for PET imaging demyelination. Herein, the Yamada-Curtius reaction has been successfully applied for the preparation of this PET radioligand with a better radiochemical yield and improved specific activity. The overall radiochemical yield was 5-15% (n = 12, uncorrected) with a specific activity of 37-148 GBq/μmol (end of synthesis, EOS) in a 90 min synthesis time...
September 4, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Yinsheng Zhang
In order to make a detailed characterization of the mechanism of inhibition and selectivity of a novel fatty acid amide hydrolase inhibitor PF-622, three tritium isotopomers were prepared. [(3) H]PF-622a labeled at the piperazine ring B and [(3) H]PF-622b labeled at both the ring B and phenyl ring A were synthesized via catalytic H(hydrogen)-T(tritium) exchange, utilizing 1 equiv. and excess of Crabtree's catalyst, respectively. The preparation of [(3) H]PF-622c labeled only at the phenyl ring A was achieved via tritiodebromination of the bromide precursor, using Pd(PPh3 )4 as a catalyst...
September 4, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Kenneth Dahl, Johan Ulin, Magnus Schou, Christer Halldin
A new method for the reduction of no-carrier-added [(11) C]carbon dioxide ([(11) C]CO2 ) into [(11) C]carbon monoxide ([(11) C]CO) is described, in which the reductant (zinc) is supported on fused silica particles. Using this setup, which allows for a reduction temperature (485°C) well above the melting point for zinc (420°C), radiochemical yields (RCY) of up to 96% (decay-corrected) were obtained. A slight decrease in RCY was observed upon repeated [(11) C]CO productions (93±3%, n = 20). The methodology is convenient, efficient, and provides a straightforward path to no-carrier-added (NCA) production of [(11) C]CO...
September 4, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Robert H Mach, Robert R Luedtke
The dopamine D2-like receptors (i.e., D2/3 receptors) have been the most extensively studied CNS receptor with PET. The three different radiotracers which have been used in these studies are [(11) C]raclopride, [(18) F]fallypride, and [(11) C]PHNO. Since these radiotracers have a high affinity for both dopamine D2 and D3 receptors, the density of dopamine receptors in the CNS is reported as the D2/3 binding potential, which reflects a measure of the density of both receptor subtypes. Although the development of D2- and D3-selective PET radiotracers has been an active area of research for many years, this by and large presents an unmet need in the area of translational PET imaging studies...
August 31, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Fraser Graeme Edgar, Hanne D Hansen, Sebastian Leth-Petersen, Anders Ettrup, Jesper L Kristensen, Gitte M Knudsen, Matthias M Herth
An agonist PET tracer is of key interest for the imaging of the 5-HT2A receptor, as exemplified by the previously reported success of [(11) C]Cimbi-36. Fluorine-18 holds several advantages over carbon-11, making it the radionuclide of choice for clinical purposes. In this respect, a (18) F-labelled agonist 5-HT2A receptor (5-HT2A R) tracer is highly sought after. Herein we report a two-step, one-pot labelling methodology of two tracer candidates. Both ligands display high in vitro affinities for the 5-HT2A R...
August 30, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Yan Chong, Jin Chang, Wenwen Zhao, Yong He, Yuqiao Li, Huabei Zhang, Chuanmin Qi
Four novel F-18 labeled quinazoline derivatives with low lipophilicity, [(18) F]4-(2-fluoroethoxy)-6,7-dimethoxyquinazoline ([(18) F]I), [(18) F]4-(3-((4-(2-fluoroethoxy)-7-methoxyquinazolin-6-yl)oxy)propyl)morpholine ([(18) F]II), [(18) F]4-(2-fluoroethoxy)-7-methoxy-6-(2-methoxyethoxy)quinazoline ([(18) F]III) and [(18) F]4-(2-fluoroethoxy)-6,7-bis(2-methoxyethoxy)quinazoline ([(18) F]IV), were synthesized via a two-step radiosynthesis procedure with an overall radiochemical yield of 10-38% (without decay correction) and radiochemical purities of > 98%...
August 18, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
M H Sanad, F A Marzook, Gehan M Saleh
Nizatidine has been labeled using [(125/123) I] with chloramine-T (Ch-T) as oxidizing agent. Factors such as the amount of oxidizing agent, amount of substrate, pH, reaction temperature and reaction time, have been systematically studied to optimize the iodination. Biodistribution studies indicate the suitability of radioiodinated nizatidine as a novel tracer to image stomach ulcer. Radioiodinated nizatidine may be considered a highly selective radiotracer for peptic ulcer imaging.
August 18, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Ronghui Lin, David C Hoerr, Larry E Weaner, Rhys Salter
Canagliflozin (Invokana®, JNJ-28431754) is an orally bioavailable and selective SGLT2 (subtype 2 sodium-glucose transport protein) inhibitor approved for the treatment of type 2 diabetes. Herein we report the synthesis of (13) C and (14) C-labeled canagliflozin. Stable isotope-labeled [(13) C6 ]canagliflozin was synthesized in four steps starting from [(13) C6 ]-labeled glucose. [(14) C]-Labeled canagliflozin was synthesized by incorporation of [(14) C] into the benzylic position between the thiophene and benzene rings of the compound...
August 18, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
David C Labaree, Jim R Ropchan, Nabeel Nabulsi, Yiyun Huang
We report herein a modification to a component of the GE Radiochemistry System that increases the yield and reliability of [(11) C]CN(-) production from [(11) C]carbon dioxide.
August 18, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Zhiming Chen, Gang Wang, Minhao Xie, Heyun Huang, Erming Wu, Yang Wang
We have developed a new set of lyophilized kits, composed of three different kits, for the instant preparation of no-carrier-added (nca) (131) I-MIBG in the clinic. We here discussed the formulation of the kits, optimization of radiolabelling, quality control of radiolabeled (131) I-MIBG and studies of animal biodistribution. The nca (131) I-MIBG injection could be prepared within 30 min in the clinic with the help of the lyophilized kits. The radiochemical purity and specific activity (SA) could achieve above 98% and 6700 MBq/mg respectively...
August 17, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
E Fontana, V Cenacchi, F Pivetti, A Pignatti, T Pazzi, L Bondanza, M Pazzi
A eight steps preparation of (14) C-labelled CHF6001, a potent PDE4 inhibitor in the treatment of respiratory diseases, is described. An overall yield of approximately 9% was obtained starting from copper[(14) C]cyanide. The synthesis of a stable labelled version of CHF6001 is also reported using the commercially available trideuterated bromomethylcyclopropane as starting material.
August 1, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Lonneke Rotteveel, Alex J Poot, Uta Funke, Aleksandra Pekošak, Ulrike Filp, Adriaan A Lammertsma, Albert D Windhorst
The multitude of biologically active compounds requires the availability of a broad spectrum of radiolabeled synthons for the development of positron emission tomography (PET) tracers. The aim of this study was to synthesize 1-iodo-2-[(11) C]methylpropane and 2-methyl-1-[(11) C]propanol and investigate the use of these reagents in further radiosynthesis reactions. 2-methyl-1-[(11) C]propanol was obtained with an average radiochemical yield of 46 ± 6% d.c. and used with fluorobenzene as starting material. High conversion rates of 85 ± 4 % d...
July 29, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Carmine Marzano, Steen Jacobsen, Cristian Salinas, Sac Pham Tang, Dirk Bender, Jan Passchier, Christophe Plisson
Oxytocin is known to be implicated in a variety of functions, such as learning, stress, anxiety, feeding and pain perception. Oxytocin is also important for social memory and attachment, human bonding, sexual and maternal behaviour, and aggression. Human disorders characterized by aberrant social interactions, such as autism and schizophrenia, may also involve abnormal oxytocin levels. GSK712043, GSK711320 and GSK664004, three antagonists exhibiting sub-nanomolar affinity for the human oxytocin receptor (hOTR) and high selectivity over vasopressin receptors were successfully labelled with carbon-11 with suitable yields (0...
July 3, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
O Morris, M A Elsawy, M Fairclough, K J Williams, A Mcmahon, J Grigg, D Forster, A F Miller, A Saiani, C Prenant
Positron emission tomography (PET) and fluorescence labelling have been used to assess the pharmacokinetics, biodistribution and eventual fate of a hydrogel-forming nonapeptide, FEFKFEFKK (F9), in healthy mice, using (18) F-labelled and fluorescein isothiocyanate (FITC)-labelled F9 analogues. F9 was site-specifically radiolabelled with 2-[(18) F]fluoro-3-pyridinecarboxaldehyde ([(18) F]FPCA) via oxime bond formation. [(18) F]FPCA-F9 in vivo fate was evaluated both as a solution, following intravenous administration, and as a hydrogel when subcutaneously injected...
August 2017: Journal of Labelled Compounds & Radiopharmaceuticals
B Lugato, S Stucchi, S Ciceri, M N Iannone, E A Turolla, L Giuliano, C Chinello, S Todde, P Ferraboschi
As an effort to improve (18) F-radiolabeling of biomolecules in method robustness and versatility, we report the synthesis and radiolabeling of a new azido precursor potentially useful for the so-called "click reaction," in particular the ligand-free version of the copper(I)-catalyzed alkyne-azide cycloaddition. The new azido precursor may help to overcome problems sometimes exhibited by most of the currently used analogues, as it is safe to handle and it displays long-term chemical stability, thus facilitating the development of new radiolabeling procedures...
August 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Jens Wiemer, Jörg Steinbach, Jens Pietzsch, Constantin Mamat
The visualization of Eph receptors, which are overexpressed in various tumor entities, using selective small molecule Eph inhibitors by means of positron emission tomography is a promising approach for tumor imaging. N-(Pyrimidinyl)indazolamines represent a class of compounds, which are known to have high affinity especially for the EphB4 receptor. Radiofluorination of these compounds could provide a highly specific imaging agent and was investigated using a classical nucleophilic introduction of [(18) F]fluoride as well as a less common nucleophilic ring-opening reaction of azetidinium salts...
August 2017: Journal of Labelled Compounds & Radiopharmaceuticals
Malliga R Iyer, Resat Cinar, Nathan J Coffey, Robert J Chorvat, George Kunos
JD5037 (1) is a potent and selective, peripherally acting inverse agonist of the cannabinoid (CB1 R) receptor. Peripheral CB1 receptor antagonists/inverse agonists have great potential in the treatment of metabolic disorders like type 2 diabetes, obesity, and nonalcoholic steatohepatitis. We report the synthesis of octadeuterated [(2) H8 ]-JD5037 (S, S) (8) along with its (S, R) diastereomer (13) from commercially available L-valine-d8 starting material. The [(2) H8 ]-JD5037 compound will be used to quantitate unlabeled JD5037 during clinical ADME studies and will be used as an LC-MS/MS bioanalytical standard...
August 2017: Journal of Labelled Compounds & Radiopharmaceuticals
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