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https://www.readbyqxmd.com/read/27886621/evaluation-of-two-nucleophilic-syntheses-routes-for-the-automated-synthesis-of-6-18-f-fluoro-l-dopa
#1
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...
October 27, 2016: Nuclear Medicine and Biology
https://www.readbyqxmd.com/read/27847991/synthesis-and-pre-clinical-evaluation-of-a-new-class-of-high-affinity-18-f-labeled-psma-ligands-for-detection-of-prostate-cancer-by-pet-imaging
#2
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...
November 15, 2016: European Journal of Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/27730680/a-highly-efficient-copper-mediated-radioiodination-approach-using-aryl-boronic-acids
#3
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
https://www.readbyqxmd.com/read/27598109/synthesis-of-a-potent-aminopyridine-based-nnos-inhibitor-by-two-recent-no-carrier-added-18-f-labelling-methods
#4
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...
2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27540460/mechanistic-studies-and-radiofluorination-of-structurally-diverse-pharmaceuticals-with-spirocyclic-iodonium-iii-ylides
#5
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
https://www.readbyqxmd.com/read/27539841/18f-fluorosulfate-for-pet-imaging-of-the-sodium-iodide-symporter-synthesis-and-biological-evaluation-in-vitro-and-in-vivo
#6
Alex Khoshnevisan, Krisanat Chuamsaamarkkee, Mehdi Boudjemeline, Alex Jackson, Gareth E Smith, Anthony Gee, Gilbert O Fruhwirth, Philip Blower
PURPOSE: Anion transport by the human sodium/iodide symporter (hNIS) is an established target for molecular imaging and radionuclide therapy. Current radiotracers for positron emission tomography (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...
August 18, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/27377671/synthesis-and-biological-evaluation-of-iodoglucoazomycin-i-gaz-an-azomycin-glucose-adduct-with-putative-applications-in-diagnostic-imaging-and-radiotherapy-of-hypoxic-tumors
#7
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
https://www.readbyqxmd.com/read/27260779/fully-automated-radiosynthesis-of-n-1-18-f-fluoroethyl-tryptophan-and-study-of-its-biological-activity-as-a-new-potential-substrate-for-indoleamine-2-3-dioxygenase-pet-imaging
#8
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
https://www.readbyqxmd.com/read/27110797/development-of-a-new-radiofluorinated-quinoline-analog-for-pet-imaging-of-phosphodiesterase-5-pde5-in-brain
#9
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
https://www.readbyqxmd.com/read/27061216/automation-of-18-f-fluoroacetaldehyde-synthesis-application-to-a-recombinant-human-interleukin-1-receptor-antagonist-rhil-1ra
#10
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
https://www.readbyqxmd.com/read/26973098/metabolically-stabilized-68-ga-nota-bombesin-for-pet-imaging-of-prostate-cancer-and-influence-of-protease-inhibitor-phosphoramidon
#11
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
https://www.readbyqxmd.com/read/26748018/fully-automated-one-pot-two-step-synthesis-of-4-18-f-adam-a-potent-serotonin-transporter-imaging-agent
#12
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
https://www.readbyqxmd.com/read/26725469/preparation-characterization-and-evaluation-of-186-re-idarubicin-a-novel-agent-for-diagnosis-and-treatment-of-hepatocellular-carcinoma
#13
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
https://www.readbyqxmd.com/read/26652124/novel-bi-modal-h2dedpa-derivatives-for-radio-and-fluorescence-imaging
#14
Caterina F Ramogida, Lisa Murphy, Jacqueline F Cawthray, James D Ross, Michael J Adam, Chris Orvig
A novel pyridyl functionalized analog of the promising hexadentate (68)Ga(3+) chelate H2dedpa (N4O2, 1,2-[[6-carboxy-pyridin-2-yl]-methylamine]ethane) was successfully synthesized and characterized. This new bifunctional chelate (BFC) was used to prepare the first proof-of-principle bi-modal H2dedpa derivative for fluorescence and nuclear imaging. Two bi-modal H2dedpa derivatives were prepared: H2dedpa-propylpyr-FITC and H2dedpa-propylpyr-FITC-(N,N'-propyl-2-NI) (FITC=fluorescein, pyr=pyridyl functionalized, NI=nitroimidazole)...
November 19, 2015: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/26602273/synthesis-and-evaluation-of-n-methylthiophenyl-picolinamide-derivatives-as-pet-radioligands-for-metabotropic-glutamate-receptor-subtype-4
#15
Kun-Eek Kil, Pekka Poutiainen, Zhaoda Zhang, Aijun Zhu, Darshini Kuruppu, Shilpa Prabhakar, Ji-Kyung Choi, Bakhos A Tannous, Anna-Liisa Brownell
In recent years, mGlu4 has received great research attention because of the potential benefits of mGlu4 activation in treating numerous brain disorders, such as Parkinson's disease (PD). A specific mGlu4 PET radioligand could be an important tool in understanding the role of mGlu4 in both healthy and disease conditions, and also for the development of new drugs. In this study, we synthesized four new N-(methylthiophenyl)picolinamide derivatives 11-14. Of these ligands, 11 and 14 showed high in vitro binding affinity for mGlu4 with IC50 values of 3...
January 1, 2016: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/26526606/radiosynthesis-and-click-conjugation-of-ethynyl-4-18-f-fluorobenzene-an-improved-18-f-synthon-for-indirect-radiolabeling
#16
Maxine P Roberts, Tien Q Pham, John Doan, Cathy D Jiang, Trevor W Hambley, Ivan Greguric, Benjamin H Fraser
Reproducible methods for [(18)F]radiolabeling of biological vectors are essential for the development of new [(18)F]radiopharmaceuticals. Molecules such as carbohydrates, peptides and proteins are challenging substrates that often require multi-step indirect radiolabeling methods. With the goal of developing more robust, time saving, and less expensive procedures for indirect [(18)F]radiolabeling of such molecules, our group has synthesized ethynyl-4-[(18)F]fluorobenzene ([(18)F]2, [(18)F]EYFB) in a single step (14 ± 2% non-decay corrected radiochemical yield (ndc RCY)) from a readily synthesized, shelf stable, inexpensive precursor...
November 2015: Journal of Labelled Compounds & Radiopharmaceuticals
https://www.readbyqxmd.com/read/26341848/development-and-characterization-of-an-%C3%AE-v%C3%AE-6-specific-diabody-and-a-disulfide-stabilized-%C3%AE-v%C3%AE-6-specific-cys-diabody
#17
Jason B White, David L Boucher, Kirstin A Zettlitz, Anna M Wu, Julie L Sutcliffe
INTRODUCTION: This work describes the development and characterization of two antibody fragments that specifically target the α(v)β(6) integrin, a non-covalent diabody and a disulfide-stabilized cys-diabody. The diabodies were analyzed for their ability to bind both immobilized and cell surface-bound α(v)β(6). Radiolabeling was done using non-site-specific and site-specific conjugation approaches with N-succinimidyl 4-[(18)F]fluorobenzoate ([(18)F]-SFB) and the bifunctional chelator 1,4,7-triazacyclononane-triacetic acid maleimide (NOTA-maleimide) and copper-64 ([(64)Cu]), respectively...
December 2015: Nuclear Medicine and Biology
https://www.readbyqxmd.com/read/26189032/development-of-indazolylpyrimidine-derivatives-as-high-affine-ephb4-receptor-ligands-and-potential-pet-radiotracers
#18
Kristin Ebert, Jens Wiemer, Julio Caballero, Martin Köckerling, Jörg Steinbach, Jens Pietzsch, Constantin Mamat
Due to their essential role in the pathogenesis of cancer, members of the Eph (erythropoietin-producing hepatoma cell line-A2) receptor tyrosine kinase family represent promising candidates for molecular imaging. Thus, the development and preparation of novel radiotracers for the noninvasive imaging of the EphB4 receptor via positron emission tomography (PET) is described. First in silico investigations with the indazolylpyrimidine lead compound which is known to be highly affine to EphB4 were executed to identify favorable labeling positions for an introduction of fluorine-18 to retain the affinity...
September 1, 2015: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/26159661/automated-electrophilic-radiosynthesis-of-%C3%A2-%C3%A2-f-fbpa-using-a-modified-nucleophilic-ge-tracerlab-fxfdg
#19
Severin Mairinger, Johann Stanek, Thomas Wanek, Oliver Langer, Claudia Kuntner
We modified a commercially available synthesis module for nucleophilic [(18)F]fluorinations (TRACERlab(TM) FXFDG, GE Healthcare) to enable the reliable synthesis of 2-[(18)F]fluoro-4-borono-L-phenylalanine ([(18)F]FBPA) via direct electrophilic substitution of 4-borono-L-phenylalanine with [(18)F]F2 gas. [(18)F]FBPA was obtained with a RCY of 8.5±2.0% and a radiochemical purity of 98±1% in a total synthesis time of 72±7 min (n=22). The modified synthesis module might also be useful for the synthesis of other [(18)F]radiopharmaceuticals via electrophilic substitution reactions while still being suitable for nucleophilic substitution reactions...
October 2015: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/26094722/synthesis-and-bioevaluation-of-4-chloro-2-tert-butyl-5-2-1-2-18-f-fluroethyl-1h-1-2-3-triazol-4-yl-methyl-phenylmethoxy-3-2h-pyridazinone-as-potential-myocardial-perfusion-imaging-agent-with-pet
#20
Tiantian Mou, Zuoquan Zhao, Linyi You, Qian Wang, Wei Fang, Jie Lu, Cheng Peng, Xianzhong Zhang
This study reports the synthesis and characterization of 4-chloro-2-tert-butyl-5-[2-[[1-[2-[(18) F]fluroethyl]-1H-1,2,3-triazol-4-yl]methyl]phenylmethoxy]-3(2H)-pyridazinone ([(18) F]Fmp2) for myocardial perfusion imaging (MPI). The tosylate precursor and non-radioactive compound [(19) F]Fmp2 were synthesized and characterized by infrared, (1) H-NMR, (13) C-NMR, and mass spectra (MS). The radiotracer [(18) F]Fmp2 was obtained by one-step nucleophilic substitution of tosyl with (18) F, and evaluated as an MPI agent in vitro and in vivo...
June 30, 2015: Journal of Labelled Compounds & Radiopharmaceuticals
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