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Carlotta Taddei, Salvatore Bongarzone, Antony Gee
The development of a fast and novel methodology to generate carbon-11 carbon monoxide ([11C]CO) from cyclotron-produced carbon-11 carbon dioxide ([11C]CO2) mediated by fluoride-activated disilane species is described. This methodology allows up to 74% conversion of [11C]CO2 to [11C]CO using commercially available reagents, readily available labware and mild reaction conditions (room temperature). As proof of utility, radiochemically pure [carbonyl-11C]N-benzylbenzamide was successfully synthesized from produced [11C]CO in up to 74% radiochemical yield (RCY) and > 99% radiochemical purity (RCP) in ≤ 10 min from end of [11C]CO2 delivery...
April 17, 2017: Chemistry: a European Journal
Enrico Raffaele Fantoni, Diego Dal Ben, Simonetta Falzoni, Francesco Di Virgilio, Simon Lovestone, Antony Gee
BACKGROUND: The P2X7 receptor has been shown to play a fundamental role in the initiation and sustenance of the inflammatory cascade. The development of a novel fluorine-18 PET tracer superior and with a longer half-life to those currently available is a promising step towards harnessing the therapeutic and diagnostic potential offered by this target. Inspired by the known antagonist A-804598, the present study outlines the design via molecular docking, synthesis and biological evaluation of the novel P2X7 tracer [(18)F]EFB...
December 2017: EJNMMI Research
Christian Brand, Valerie A Longo, Mike Groaning, Wolfgang A Weber, Thomas Reiner
PURPOSE: The folate receptor (FR) has emerged as an interesting diagnostic and therapeutic drug target with many potential applications in oncologic and inflammatory disorders. It was therefore the aim of this study to develop a folate-derived Ga-68-based positron emission tomography (PET) imaging tracer that is straightforward to radiolabel and could be broadly used in clinical studies. We validated its target binding affinity and specificity and compared it to [(99m)Tc]EC20, the folate single-photon emission computed tomography (SPECT) imaging tracer that has been most extensively studied clinically so far...
February 13, 2017: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
Archana Mukherjee, Suresh Subramanian, Rajwardhan Ambade, Bhaurao Avhad, Ashutosh Dash, Aruna Korde
Intra-arterial injection of (131)I Lipiodol is an effective treatment option for primary hepatocellular carcinoma as it delivers high radiation dose to liver tumor tissue with minimal accumulation in adjacent normal tissue. The present article demonstrates design, fabrication, and utilization of a semiautomated radiosynthesis module for preparation of (131)I labeled Lipiodol. The radiolabeling method was standardized for preparation of patient dose of (131)I labeled Lipiodol radiochemical yield (RCY); radiochemical purity (RCP) and pharmaceutical purity of the product were determined using optimized procedures...
February 2017: Cancer Biotherapy & Radiopharmaceuticals
Lauren Radford, Fabio Gallazzi, Lisa Watkinson, Terry Carmack, Ashley Berendzen, Michael R Lewis, Silvia S Jurisson, Dionysia Papagiannopoulou, Heather M Hennkens
INTRODUCTION: A somatostatin receptor (SSTR)-targeting antagonist peptide (sst2-ANT) was radiolabeled with (99m)Tc tricarbonyl via a tridentate [N,S,N]-type ligand (L) to develop a radiodiagnostic agent, (99m)TcL-sst2-ANT, for imaging of SSTR-expressing neuroendocrine tumors. METHODS: Receptor affinity was assessed in vitro with the nonradioactive analogue, ReL-sst2-ANT, via a challenge experiment in AR42J cells with (125)I-SS-14 as the competing radioligand. Preparation of (99m)TcL-sst2-ANT was achieved via reaction of [(99m)Tc(CO)3(H2O)3](+) with L-sst2-ANT...
April 2017: Nuclear Medicine and Biology
Pradeep K Garg, Rachid Nazih, Yanjun Wu, Ravi A Singh, Sudha Garg
We report the synthesis and preclinical evaluation of (11)C-labeled novel probe to target melanoma using Positron Emission Tomography (PET). METHODS: The target compound 4-(11)-Cmethoxy N-(2-diethylaminoethyl) benzamide (4-(11)C-MBZA) was prepared via the (11)C-methylation of 4-hydroxy N-(2-diethylaminoethyl) benzamide (4-HBZA). The in vitro binding was performed using B16F1 (Melanoma cells), MCF-10A (breast epithelial cells) and MDA-MB 231 (breast cancer cells). The internalization studies were conducted using B16F1 melanoma cells...
December 15, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Wenjie Zhang, Zhengxin Cai, Lin Li, Jim Ropchan, Keunpoong Lim, Nabil E Boutagy, Jing Wu, John C Stendahl, Wenhua Chu, Robert Gropler, Albert J Sinusas, Chi Liu, Yiyun Huang
Reactive oxygen species (ROS) play important roles in cell signaling and homeostasis. However, an abnormally high level of ROS is toxic, and is implicated in a number of diseases. Positron emission tomography (PET) imaging of ROS can assist in the detection of these diseases. For the purpose of clinical translation of [(18)F]6-(4-((1-(2-fluoroethyl)-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-5-methyl-5,6-dihydrophenanthridine-3,8-diamine ([(18)F]DHMT), a promising ROS PET radiotracer, we first manually optimized the large-scale radiosynthesis conditions and then implemented them in an automated synthesis module...
December 9, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Marc Pretze, Dominic Franck, Falk Kunkel, Erich Foßhag, Carmen Wängler, Björn Wängler
Two different strategies for the nucleophilic radiosynthesis of [(18)F]F-DOPA were evaluated regarding their applicability for an automated routine production on an Ecker&Ziegler Modular-Lab Standard module. Initially, we evaluated a promising 5-step synthesis based on a chiral, cinchonidine-derived phase-transfer catalyst (cPTC) being described to give the product in high radiochemical yields (RCY), high specific activities (AS) and high enantiomeric excesses (ee). However, the radiosynthesis of [(18)F]F-DOPA based on this strategy showed to be highly complex, giving the intermediate products as well as the final product in insufficient yields for automatization...
February 2017: Nuclear Medicine and Biology
James Kelly, Alejandro Amor-Coarasa, Anastasia Nikolopoulou, Dohyun Kim, Clarence Williams, Shashikanth Ponnala, John W Babich
PURPOSE: Current clinical imaging of PSMA-positive prostate cancer by positron emission tomography (PET) mainly features (68)Ga-labeled tracers, notably [(68)Ga]Ga-PSMA-HBED-CC. The longer half-life of fluorine-18 offers significant advantages over Ga-68, clinically and logistically. We aimed to develop high-affinity PSMA inhibitors labeled with fluorine-18 as alternative tracers for prostate cancer. METHODS: Six triazolylphenyl ureas and their alkyne precursors were synthesized from the Glu-urea-Lys PSMA binding moiety...
April 2017: European Journal of Nuclear Medicine and Molecular Imaging
Pu Zhang, Rongqiang Zhuang, Zhide Guo, Xinhui Su, Xiaoyuan Chen, Xianzhong Zhang
A convenient and quantitative radioiodination method by copper-mediated cross-coupling of aryl boronic acids was developed. The mild labeling conditions, ready availability of the boronic acid substrate, simple operation, broad functional group tolerance and excellent radiochemical yield (RCY) make this a practical strategy for radioiodine labeling without further purification.
November 14, 2016: Chemistry: a European Journal
Christian Drerup, Johannes Ermert, Heinz H Coenen
Nitric oxide (NO), an important multifunctional signaling molecule, is produced by three isoforms of NO-synthase (NOS) and has been associated with neurodegenerative disorders. Selective inhibitors of the subtypes iNOS (inducible) or nNOS (neuronal) are of great interest for decoding neurodestructive key factors, and (18)F-labelled analogues would allow investigating the NOS-function by molecular imaging with positron emission tomography. Especially, the highly selective nNOS inhibitor 6-((3-((3-fluorophenethylamino)methyl)phenoxy)methyl)-4-methylpyridin-2-amine (10) lends itself as suitable compound to be (18)F-labelled in no-carrier-added (n...
September 1, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Benjamin H Rotstein, Lu Wang, Richard Y Liu, Jon Patteson, Eugene E Kwan, Neil Vasdev, Steven H Liang
Synthesis of non-activated electron-rich and sterically hindered (18)F-arenes remains a major challenge due to limitations of existing radiofluorination methodologies. Herein, we report on our mechanistic investigations of spirocyclic iodonium(III) ylide precursors for arene radiofluorination, including their reactivity, selectivity, and stability with no-carrier-added [(18)F]fluoride. Benchmark calculations at the G2[ECP] level indicate that pseudorotation and reductive elimination at iodine(III) can be modeled well by appropriately selected dispersion-corrected density functional methods...
July 1, 2016: Chemical Science
Alex Khoshnevisan, Krisanat Chuamsaamarkkee, Mehdi Boudjemeline, Alex Jackson, Gareth E Smith, Antony D Gee, Gilbert O Fruhwirth, Philip J Blower
Anion transport by the human sodium-iodide symporter (hNIS) is an established target for molecular imaging and radionuclide therapy. Current radiotracers for PET of hNIS expression are limited to (124)I(-) and (18)F-BF4(-) We sought new (18)F-labeled hNIS substrates offering higher specific activity, higher affinity, and simpler radiochemical synthesis than (18)F-BF4(-) METHODS: The ability of a range of anions, some containing fluorine, to block (99m)TcO4(-) uptake in hNIS-expressing cells was measured. SO3F(-) emerged as a promising candidate...
January 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Piyush Kumar, Hassan R H Elsaidi, Bohdarianna Zorniak, Evelyn Laurens, Jennifer Yang, Veena Bacchu, Monica Wang, Leonard I Wiebe
Iodoglucoazomycin (I-GAZ; N-(2-iodo-3-(6-O-glucosyl)propyl)-2-nitroimidazole), a non-glycosidic nitroimidazole-6-O-glucose adduct, was synthesized, radioiodinated, and evaluated as a substrate of glucose transporter 1 (GLUT1) for radiotheranostic (therapy+diagnostic) management of hypoxic tumors. Nucleophilic iodination of the nosylate synthon of I-GAZ followed by deprotection afforded I-GAZ in 74 % overall yield. I-GAZ was radioiodinated via 'exchange' labeling using [(123/131) I]iodide (50-70 % RCY) and then purified by Sep-Pak™ (>96 % RCP)...
August 5, 2016: ChemMedChem
Jean Henrottin, Christian Lemaire, Dominique Egrise, Astrid Zervosen, Benoit Van den Eynde, Alain Plenevaux, Xavier Franci, Serge Goldman, André Luxen
INTRODUCTION: Indoleamine 2,3-dioxygenase (IDO) catalyzes the initial step in the catabolism of l-tryptophan along the kynurenine pathway and exerts immunosuppressive properties in inflammatory and tumor tissues by blocking locally T-lymphocyte proliferation. Recently, 1-(2-[(19)F]fluoroethyl)-dl-tryptophan (1-[(19)F]FE-dl-Trp) was reported as a good and specific substrate of this enzyme. Herein, the radiosynthesis of its radioactive isotopomer (1-[(18)F]FE-dl-Trp, dl-[(18)F]5) is presented along with in vitro enzymatic and cellular uptake studies...
June 2016: Nuclear Medicine and Biology
Jianrong Liu, Barbara Wenzel, Sladjana Dukic-Stefanovic, Rodrigo Teodoro, Friedrich-Alexander Ludwig, Winnie Deuther-Conrad, Susann Schröder, Jean-Michel Chezal, Emmanuel Moreau, Peter Brust, Aurélie Maisonial-Besset
Phosphodiesterases (PDEs) are enzymes that play a major role in cell signalling by hydrolysing the secondary messengers cyclic adenosine monophosphate (cAMP) and/or cyclic guanosine monophosphate (cGMP) throughout the body and brain. Altered cyclic nucleotide-mediated signalling has been associated with a wide array of disorders, including neurodegenerative disorders. Recently, PDE5 has been shown to be involved in neurodegenerative disorders such as Alzheimer's disease, but its precise role has not been elucidated yet...
2016: Pharmaceuticals
Olivia Morris, Adam McMahon, Herve Boutin, Julian Grigg, Christian Prenant
[(18) F]Fluoroacetaldehyde is a biocompatible prosthetic group that has been implemented pre-clinically using a semi-automated remotely controlled system. Automation of radiosyntheses permits use of higher levels of [(18) F]fluoride whilst minimising radiochemist exposure and enhancing reproducibility. In order to achieve full-automation of [(18) F]fluoroacetaldehyde peptide radiolabelling, a customised GE Tracerlab FX-FN with fully programmed automated synthesis was developed. The automated synthesis of [(18) F]fluoroacetaldehyde is carried out using a commercially available precursor, with reproducible yields of 26% ± 3 (decay-corrected, n = 10) within 45 min...
June 15, 2016: Journal of Labelled Compounds & Radiopharmaceuticals
Susan Richter, Melinda Wuest, Cody N Bergman, Stephanie Krieger, Buck E Rogers, Frank Wuest
Peptide receptor-based targeted molecular imaging and therapy of cancer is on the current forefront of nuclear medicine preclinical research and clinical practice. The frequent overexpression of gastrin-releasing peptide (GRP) receptors in prostate cancer stimulated the development of radiolabeled bombesin derivatives as high affinity peptide ligands for selective targeting of the GRP receptor. In this study, we have evaluated a novel (68)Ga-labeled bombesin derivative for PET imaging of prostate cancer in vivo...
April 4, 2016: Molecular Pharmaceutics
Cheng-Yi Cheng, Ta-Kai Chou, Chyng-Yann Shiue
INTRODUCTION: N,N-dimethyl-2-(2-amino-4-[(18)F]fluorophenylthio)benzylamine (4-[(18)F]-ADAM, 2) is a potent serotonin transporter (SERT) imaging agent. In order to fulfill the demand of clinical studies, we have developed a fully automated one-pot two-step synthesis of this potent SERT imaging agent. METHODS: The 4-[(18)F]-ADAM (2) was synthesized using a commercially available GE TRACERlab FN module. Briefly, the precursor, N,N-dimethyl-2-(2,4-dinitrophenylthio) benzylamine (1) in DMSO was reacted with K[(18)F]/K2...
April 2016: Applied Radiation and Isotopes
O A El-Kawy, H M Talaat
Hepatocellular carcinoma is a widely prevalent cancer, and hence, the development of radiopharmaceuticals for its management is an important issue. In the current investigation, the complexation of idarubicin with (186) Re was studied. Optimum labelling conditions were found to be 4 mg idarubicin, 1.5 mg stannous chloride dihydrate and ~70 MBq Re-186 at pH 7. The complex showed ~97.6% RCY value at 20 min and remained stable up to 24 h in the presence of 2.5 mg ascorbic acid. Molecular docking was performed to evaluate the complex binding to its target DNA-human topoisomerase II complex...
February 2016: Journal of Labelled Compounds & Radiopharmaceuticals
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