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Bock L, Schultheiß SK, Maschauer S, Lasch R, Gradl S, Prante O, Zard SZ, Heinrich MR. Synthesis of 2‐(Chlorodifluoromethyl)indoles for Nucleophilic Halogen Exchange with [
18
F]Fluoride. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Leonard Bock
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
| | - Stefanie K. Schultheiß
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
| | - Simone Maschauer
- Department of Nuclear Medicine, Molecular Imaging and Radiochemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Schwabachanlage 12 91054 Erlangen Germany
| | - Roman Lasch
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
| | - Susanne Gradl
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
| | - Olaf Prante
- Department of Nuclear Medicine, Molecular Imaging and Radiochemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Schwabachanlage 12 91054 Erlangen Germany
| | - Samir Z. Zard
- Laboratoire de Synthèse Organique associé au CNRS Ecole Polytechnique 91128 Palaiseau France
| | - Markus R. Heinrich
- Department of Chemistry and Pharmacy, Pharmaceutical Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg Nikolaus-Fiebiger-Str. 10 91058 Erlangen Germany
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2
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Kroth H, Oden F, Molette J, Schieferstein H, Gabellieri E, Mueller A, Berndt M, Sreenivasachary N, Serra AM, Capotosti F, Schmitt-Willich H, Hickman D, Pfeifer A, Dinkelborg L, Stephens A. PI-2620 Lead Optimization Highlights the Importance of Off-Target Assays to Develop a PET Tracer for the Detection of Pathological Aggregated Tau in Alzheimer's Disease and Other Tauopathies. J Med Chem 2021; 64:12808-12830. [PMID: 34455780 DOI: 10.1021/acs.jmedchem.1c00861] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The first candidate PI-2014 was tested in healthy controls and subjects with Alzheimer's disease (AD). As PI-2014 displayed off-target binding to monoamine oxidase A (MAO-A), a new lead with improved binding to Tau and decreased MAO-A binding was required. For compound optimization, Tau binding assays based on both human AD brain homogenate and Tau-paired helical filaments were employed. Furthermore, two MAO-A screening assays based on (1) human-recombinant MAO-A and (2) displacement of 2-fluoro-ethyl-harmine from mouse brain homogenate were employed. Removing the N-methyl group from the tricyclic core resulted in compounds displaying improved Tau binding. For the final round of optimization, the cyclic amine substituents were replaced by pyridine derivatives. PI-2620 (2-(2-fluoropyridin-4-yl)-9H-pyrrolo[2,3-b:4,5-c']dipyridine) emerged as a best candidate displaying high Tau binding, low MAO-A binding, high brain uptake, and fast and complete brain washout. Furthermore, PI-2620 showed Tau binding on brain sections from corticobasal degeneration, progressive supranuclear palsy, and Pick's disease.
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Affiliation(s)
- Heiko Kroth
- AC Immune SA, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland
| | - Felix Oden
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
| | - Jerome Molette
- AC Immune SA, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland
| | | | | | - Andre Mueller
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
| | - Mathias Berndt
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
| | | | | | | | | | - David Hickman
- AC Immune SA, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland
| | - Andrea Pfeifer
- AC Immune SA, EPFL Innovation Park, Building B, 1015 Lausanne, Switzerland
| | - Ludger Dinkelborg
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
| | - Andrew Stephens
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353 Berlin, Germany
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3
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Clinical validity of increased cortical uptake of [ 18F]flortaucipir on PET as a biomarker for Alzheimer's disease in the context of a structured 5-phase biomarker development framework. Eur J Nucl Med Mol Imaging 2021; 48:2097-2109. [PMID: 33547556 PMCID: PMC8175307 DOI: 10.1007/s00259-020-05118-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 11/15/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE In 2017, the Geneva Alzheimer's disease (AD) Biomarker Roadmap initiative adapted the framework of the systematic validation of oncological diagnostic biomarkers to AD biomarkers, with the aim to accelerate their development and implementation in clinical practice. With this work, we assess the maturity of [18F]flortaucipir PET and define its research priorities. METHODS The level of maturity of [18F]flortaucipir was assessed based on the AD Biomarker Roadmap. The framework assesses analytical validity (phases 1-2), clinical validity (phases 3-4), and clinical utility (phase 5). RESULTS The main aims of phases 1 (rationale for use) and 2 (discriminative ability) have been achieved. [18F]Flortaucipir binds with high affinity to paired helical filaments of tau and has favorable kinetic properties and excellent discriminative accuracy for AD. The majority of secondary aims of phase 2 were fully achieved. Multiple studies showed high correlations between ante-mortem [18F]flortaucipir PET and post-mortem tau (as assessed by histopathology), and also the effects of covariates on tracer binding are well studied. The aims of phase 3 (early detection ability) were only partially or preliminarily achieved, and the aims of phases 4 and 5 were not achieved. CONCLUSION Current literature provides partial evidence for clinical utility of [18F]flortaucipir PET. The aims for phases 1 and 2 were mostly achieved. Phase 3 studies are currently ongoing. Future studies including representative MCI populations and a focus on healthcare outcomes are required to establish full maturity of phases 4 and 5.
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4
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Kim H, Choe YS. High-yield synthesis of a tau PET radioligand and its nonradioactive ligand using an alternative protection and deprotection strategy. J Labelled Comp Radiopharm 2020; 64:150-158. [PMID: 33125755 DOI: 10.1002/jlcr.3894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/22/2020] [Accepted: 10/22/2020] [Indexed: 11/07/2022]
Abstract
Recently developed tau imaging radiopharmaceuticals show specific uptake in tau protein-rich regions in human brains without off-target binding. These radiopharmaceuticals and their nonradioactive reference ligands are generally obtained in low (radio)chemical yields. In the present study, we investigated high-yield synthesis of 18 F-RO948 ([18 F]1) and its nonradioactive ligand (1). The ligand 1 was synthesized by a Suzuki-Miyaura coupling reaction between 9-(4-methoxybenzyl)-9H-pyrrolo[2,3-b:4,5-c']dipyridin-2-yl trifluoromethanesulfonate (3) and 2-fluoro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (4), followed by oxidative removal of the para-methoxybenzyl (PMB) group with ceric ammonium nitrate (CAN). This two-step reaction gave 1 in 55.8% yield. The precursor for [18 F]1 was synthesized from 3 and 2-nitro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (6). The resulting PMB-protected precursor 8 was obtained in 74.5% yield. [18 F]1 was synthesized by radiofluorination of 8 (radiochemical conversion (RCC): 95.7 ± 1.7%), followed by deprotection of the PMB group with CAN. This one-pot, two-step radiochemical synthesis followed by HPLC purification gave [18 F]1 in high decay-corrected radiochemical yield (54-60%). The RCC of [18 F]fluoride to [18 F]1 in our two-step synthesis method was similar to that in a one-step radiofluorination reaction of a tert-butoxycarbonyl (BOC)-protected precursor 10 that proceeds with concomitant thermal deprotection of the BOC group. Taken together, the results of this study suggest that this high-yield synthesis method is useful for the synthesis of 18 F-labeled (NH)heteroarene compounds.
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Affiliation(s)
- Hyunjung Kim
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Yearn Seong Choe
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea
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5
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Gabellieri E, Capotosti F, Molette J, Sreenivasachary N, Mueller A, Berndt M, Schieferstein H, Juergens T, Varisco Y, Oden F, Schmitt-Willich H, Hickman D, Dinkelborg L, Stephens A, Pfeifer A, Kroth H. Discovery of 2-(4-(2-fluoroethoxy)piperidin-1-yl)-9-methyl-9H-pyrrolo[2,3-b:4,5-c']dipyridine ([18F]PI-2014) as PET tracer for the detection of pathological aggregated tau in Alzheimer's disease and other tauopathies. Eur J Med Chem 2020; 204:112615. [PMID: 32771872 DOI: 10.1016/j.ejmech.2020.112615] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/04/2020] [Accepted: 06/21/2020] [Indexed: 12/29/2022]
Abstract
The compound screening was initiated with a direct staining assay to identify compounds binding to Tau aggregates and not Abeta plaques using human brain sections derived from late stage Alzheimer's disease donors. The binding of Tau aggregate selective compounds was then quantitatively assessed with human brain derived paired helical filaments utilizing the label-free Back Scattering Interferometry assay. In vivo biodistribution experiments of selected fluorine-18 labeled compounds were performed in mice to assess brain uptake, brain washout, and defluorination. Compound 11 emerged as the most promising candidate, displaying high in vitro binding affinity and selectivity to neurofibrillary tangles. Fluorine-18 labeled compound 11 showed high brain uptake and rapid washout from the mouse brain with no observed bone uptake. Furthermore, compound 11 was able to detect Tau aggregates in tauopathy brain sections from corticobasal degeneration, progressive supranuclear palsy, and Pick's disease donors. Thus, 2-(4-(2-fluoroethoxy)piperidin-1-yl)-9-methyl-9H-pyrrolo[2,3-b:4,5-c']dipyridine (PI-2014, compound 11) was selected for characterization in a first-in-human study.
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Affiliation(s)
| | | | - Jerome Molette
- AC Immune SA, EPFL Innovation Park, Building B, 1015, Lausanne, Switzerland
| | | | - Andre Mueller
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353, Berlin, Germany
| | - Mathias Berndt
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353, Berlin, Germany
| | - Hanno Schieferstein
- Formerly Piramal Imaging GmbH, Tegeler Strasse 6-7, 13353, Berlin, Germany; Merck KGaA, Frankfurter Strasse 250, 64293, Darmstadt, Germany
| | - Tanja Juergens
- AC Immune SA, EPFL Innovation Park, Building B, 1015, Lausanne, Switzerland
| | - Yvan Varisco
- AC Immune SA, EPFL Innovation Park, Building B, 1015, Lausanne, Switzerland
| | - Felix Oden
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353, Berlin, Germany
| | | | - David Hickman
- AC Immune SA, EPFL Innovation Park, Building B, 1015, Lausanne, Switzerland
| | - Ludger Dinkelborg
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353, Berlin, Germany
| | - Andrew Stephens
- Life Molecular Imaging GmbH, Tegeler Strasse 6-7, 13353, Berlin, Germany
| | - Andrea Pfeifer
- AC Immune SA, EPFL Innovation Park, Building B, 1015, Lausanne, Switzerland
| | - Heiko Kroth
- AC Immune SA, EPFL Innovation Park, Building B, 1015, Lausanne, Switzerland.
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6
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Kroth H, Oden F, Molette J, Schieferstein H, Capotosti F, Mueller A, Berndt M, Schmitt-Willich H, Darmency V, Gabellieri E, Boudou C, Juergens T, Varisco Y, Vokali E, Hickman DT, Tamagnan G, Pfeifer A, Dinkelborg L, Muhs A, Stephens A. Discovery and preclinical characterization of [ 18F]PI-2620, a next-generation tau PET tracer for the assessment of tau pathology in Alzheimer's disease and other tauopathies. Eur J Nucl Med Mol Imaging 2019; 46:2178-2189. [PMID: 31264169 PMCID: PMC6667408 DOI: 10.1007/s00259-019-04397-2] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 06/10/2019] [Indexed: 01/11/2023]
Abstract
PURPOSE Tau deposition is a key pathological feature of Alzheimer's disease (AD) and other neurodegenerative disorders. The spreading of tau neurofibrillary tangles across defined brain regions corresponds to the observed level of cognitive decline in AD. Positron-emission tomography (PET) has proved to be an important tool for the detection of amyloid-beta (Aβ) aggregates in the brain, and is currently being explored for detection of pathological misfolded tau in AD and other non-AD tauopathies. Several PET tracers targeting tau deposits have been discovered and tested in humans. Limitations have been reported, especially regarding their selectivity. METHODS In our screening campaign we identified pyrrolo[2,3-b:4,5-c']dipyridine core structures with high affinity for aggregated tau. Further characterization showed that compounds containing this moiety had significantly reduced monoamine oxidase A (MAO-A) binding compared to pyrido[4,3-b]indole derivatives such as AV-1451. RESULTS Here we present preclinical data of all ten fluoropyridine regioisomers attached to the pyrrolo[2,3-b:4,5-c']dipyridine scaffold, revealing compounds 4 and 7 with superior properties. The lead candidate [18F]PI-2620 (compound 7) displayed high affinity for tau deposits in AD brain homogenate competition assays. Specific binding to pathological misfolded tau was further demonstrated by autoradiography on AD brain sections (Braak I-VI), Pick's disease and progressive supranuclear palsy (PSP) pathology, whereas no specific tracer binding was detected on brain slices from non-demented donors. In addition to its high affinity binding to tau aggregates, the compound showed excellent selectivity with no off-target binding to Aβ or MAO-A/B. Good brain uptake and fast washout were observed in healthy mice and non-human primates. CONCLUSIONS Therefore, [18F]PI-2620 was selected for clinical validation.
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Affiliation(s)
| | - Felix Oden
- Life Molecular Imaging, GmbH, Berlin, Germany
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7
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Huang YY, Chiu MJ, Yen RF, Tsai CL, Hsieh HY, Chiu CH, Wu CH, Hsin LW, Tzen KY, Cheng CY, Ma KH, Shiue CY. An one-pot two-step automated synthesis of [18F]T807 injection, its biodistribution in mice and monkeys, and a preliminary study in humans. PLoS One 2019; 14:e0217384. [PMID: 31260447 PMCID: PMC6602418 DOI: 10.1371/journal.pone.0217384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/11/2019] [Indexed: 12/22/2022] Open
Abstract
[18F]T807 is a potent tau protein imaging agent. In order to fulfill the demand from preclinical and clinical studies, we developed an automated one-pot two-step synthesis of this potent tau imaging agent and studied its stability, and dosimetry in mice and monkeys. We also conducted a preliminary study of this imaging agent in humans. Using this one-pot two-step method, the radiochemical yield (RCY) of [18F]T807 was 20.5 ± 6.1% (n = 15) at the end of bombardment (EOB) in a synthesis time of 70±5 min. The chemical and radiochemical purities were >90% and the specific activities were 151 ± 52 GBq/μmol. The quality of [18F]T807 synthesized by this method met the U.S. Pharmacopoeia (USP) criteria. The stability test showed that the [18F]T807 injection was stable at room temperature for up to 4 h after the end of synthesis (EOS). The estimated effective dose of the [18F]T807 injection extrapolated from monkeys was 19 μSv/MBq (n = 2), while the estimated effective doses of the [18F]T807 injection extrapolated from fasted and non-fasted mice were 123 ± 27 (n = 3) and 94 ± 19 (n = 4) μSv/MBq, respectively. This one-pot two-step automated method produced the [18F]T807 injection with high reproducibility and high quality. PET imaging and radiation dosimetry evaluation in mice and Formosan rock monkeys suggested that the [18F]T807 injection synthesized by this method is suitable for use in human PET imaging studies. Thus, this method could fulfill the demand for the [18F]T807 injection in both preclinical and clinical studies of tauopathies, especially for nearby study sites without cyclotrons.
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Affiliation(s)
- Ya-Yao Huang
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Jang Chiu
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- Departments of Neurology, National Taiwan University Hospital, Taipei, Taiwan
- Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
- Department of Psychology, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Biomedical Engineering and Bio-informatics, National Taiwan University, Taipei, Taiwan
| | - Ruoh-Fang Yen
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chia-Ling Tsai
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Hao-Yu Hsieh
- School of Pharmacy, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
| | - Ching-Hung Chiu
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi-Han Wu
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Ling-Wei Hsin
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- School of Pharmacy, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
| | - Kai-Yuan Tzen
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Cheng-Yi Cheng
- PET Center, Department of Nuclear Medicine, Tri-Service General Hospital, Neihu, Taipei, Taiwan
| | - Kuo-Hsing Ma
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
| | - Chyng-Yann Shiue
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- PET Center, Department of Nuclear Medicine, Tri-Service General Hospital, Neihu, Taipei, Taiwan
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8
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Dahl K, Garcia A, Stephenson NA, Vasdev N. "In-loop" 18 F-fluorination: A proof-of-concept study. J Labelled Comp Radiopharm 2019; 62:292-297. [PMID: 31083778 DOI: 10.1002/jlcr.3751] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 02/04/2023]
Abstract
There is a great demand to develop more cost-efficient and robust manufacturing processes for fluorine-18 (18 F) labelled compounds and radiopharmaceuticals. Herein, we present to our knowledge the first radiofluorination "in-loop," where [18 F]triflyl fluoride was used as the labelling agent. Initial development of the "in-loop" [18 F]fluorination method was optimized by reacting [18 F]triflyl fluoride with 1,4-dinitrobenzene to form [18 F]1-fluoro-4-nitrobenzene. This methodology was then applied for the syntheses of two well-known radiopharmaceuticals, namely, [18 F]T807 for imaging of tau protein and [18 F]FEPPA for imaging the translocator protein 18 KDa. Both radiotracers were synthesized and formulated using an automated radiosynthesis module with nondecay corrected radiochemical yields of 27% and 29% (relative [18 F]F- ), respectively. The overall syntheses times for [18 F]T807 and [18 F]FEPPA were 65 and 55 minutes, respectively. In these cases, our "in-loop" radiofluorination methodology enabled us to obtain equal or superior yields compared with conventional reactions in a vial. The radiochemical purities were more than 99%, and the molar activities were more than 350 GBq/μmol at the end-of-synthesis for both radiotracers. This novel method is simple, efficient, and allows for a reliable production of radiofluorinated compounds and radiopharmaceuticals.
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Affiliation(s)
- Kenneth Dahl
- Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Armando Garcia
- Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Nickeisha A Stephenson
- Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Chemistry, University of the West Indies, Mona, Kingston, Jamaica.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Neil Vasdev
- Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
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9
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Gao M, Wang M, Glick-Wilson BE, Meyer JA, Peters JS, Territo PR, Green MA, Hutchins GD, Zarrinmayeh H, Zheng QH. Synthesis and initial in vitro characterization of a new P2X7R radioligand [18F]IUR-1602. Appl Radiat Isot 2019; 144:10-18. [DOI: 10.1016/j.apradiso.2018.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/29/2018] [Accepted: 11/13/2018] [Indexed: 11/25/2022]
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10
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Brendel M, Yousefi BH, Blume T, Herz M, Focke C, Deussing M, Peters F, Lindner S, von Ungern-Sternberg B, Drzezga A, Bartenstein P, Haass C, Okamura N, Herms J, Yakushev I, Rominger A. Comparison of 18F-T807 and 18F-THK5117 PET in a Mouse Model of Tau Pathology. Front Aging Neurosci 2018; 10:174. [PMID: 29930508 PMCID: PMC5999706 DOI: 10.3389/fnagi.2018.00174] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 05/22/2018] [Indexed: 11/16/2022] Open
Abstract
Positron-emission-tomography (PET) imaging of tau pathology has facilitated development of anti-tau therapies. While members of the arylquinoline and pyridoindole families have been the most frequently used tau radioligands so far, analyses of their comparative performance in vivo are scantly documented. Here, we conducted a head-to-head PET comparison of the arylquinoline 18FT807 and the pyridoindole 18FTHK5117 PET in a mouse model of tau pathology. PET recordings were obtained in groups of (N = 5–7) P301S and wild-type (WT) mice at 6 and 9 months of age. Volume-of-interest based analysis (standard-uptake-value ratio, SUVR) was used to calculate effect sizes (Cohen’s d) for each tracer and age. Statistical parametric mapping (SPM) was used to assess regional similarity (dice coefficient) of tracer binding alterations for the two tracers. Immunohistochemistry staining of neurofibrillary tangles was performed for validation ex vivo. Significantly elevated 18F-T807 binding in the brainstem of P301S mice was already evident at 6 months (+14%, p < 0.01, d = 1.64), and increased further at 9 months (+23%, p < 0.001, d = 2.70). 18F-THK5117 indicated weaker increases and effect sizes at 6 months (+5%, p < 0.05, d = 1.07) and 9 months (+10%, p < 0.001, d = 1.49). Regional similarity of binding of the two tracers was high (71%) at 9 months. 18F-T807 was more sensitive than 18F-THK5117 to tau pathology in this model, although both tracers present certain obstacles, which need to be considered in the design of longitudinal preclinical tau imaging studies.
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Affiliation(s)
- Matthias Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Behrooz H Yousefi
- Department of Nuclear Medicine, Technical University of Munich, Munich, Germany.,Neuroimaging Center, Technische Universität München, Munich, Germany
| | - Tanja Blume
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Michael Herz
- Department of Nuclear Medicine, Technical University of Munich, Munich, Germany
| | - Carola Focke
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Maximilian Deussing
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Finn Peters
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | | | - Alexander Drzezga
- Department of Nuclear Medicine, University of Cologne, Cologne, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Biomedical Center, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Nobuyuki Okamura
- Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Igor Yakushev
- Department of Nuclear Medicine, Technical University of Munich, Munich, Germany.,Neuroimaging Center, Technische Universität München, Munich, Germany
| | - Axel Rominger
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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11
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Gao M, Wang M, Glick-Wilson BE, Meyer JA, Peters JS, Territo PR, Green MA, Hutchins GD, Zarrinmayeh H, Zheng QH. Synthesis and preliminary biological evaluation of a novel P2X7R radioligand [ 18F]IUR-1601. Bioorg Med Chem Lett 2018; 28:1603-1609. [PMID: 29628324 DOI: 10.1016/j.bmcl.2018.03.044] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 02/27/2018] [Accepted: 03/17/2018] [Indexed: 01/02/2023]
Abstract
The reference standard IUR-1601 ((S)-N-(2-chloro-3-(trifluoromethyl)benzyl)-1-(2-fluoroethyl)-5-oxopyrrolidine-2-carboxamide) was synthesized from tert-butyl (S)-5-oxopyrrolidine-2-carboxylate, fluoroethylbromide, and 2-chloro-3-(trifluoromethyl)benzylamine with overall chemical yield 12% in three steps. The target tracer [18F]IUR-1601 ((S)-N-(2-chloro-3-(trifluoromethyl)benzyl)-1-(2-[18F]fluoroethyl)-5-oxopyrrolidine-2-carboxamide) was synthesized from desmethyl-GSK1482160 with 2-[18F]fluoroethyl tosylate, prepared from 1,2-ethylene glycol-bis-tosylate and K[18F]F/Kryptofix2.2.2, in two steps and isolated by HPLC combined with SPE in 1-3% decay corrected radiochemical yield. The radiochemical purity was >99%, and the molar activity at end of bombardment (EOB) was 74-370 GBq/μmol. The potency of IUR-1601 in comparison with GSK1482160 was determined by a radioligand competitive binding assay using [11C]GSK1482160, and the binding affinity Ki values for IUR-1601 and GSK1482160 are 4.31 and 5.14 nM, respectively.
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Affiliation(s)
- Mingzhang Gao
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Min Wang
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Barbara E Glick-Wilson
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Jill A Meyer
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Jonathan S Peters
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Paul R Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Mark A Green
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Gary D Hutchins
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Hamideh Zarrinmayeh
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Qi-Huang Zheng
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA.
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12
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Chen Q, Du Y, Zhang K, Liang Z, Li J, Yu H, Ren R, Feng J, Jin Z, Li F, Sun J, Zhou M, He Q, Sun X, Zhang H, Tian M, Ling D. Tau-Targeted Multifunctional Nanocomposite for Combinational Therapy of Alzheimer's Disease. ACS NANO 2018; 12:1321-1338. [PMID: 29364648 DOI: 10.1021/acsnano.7b07625] [Citation(s) in RCA: 163] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Alzheimer's disease (AD) remains an incurable disease and lacks efficient diagnostic methods. Most AD treatments have focused on amyloid-β (Aβ) targeted therapy; however, it is time to consider the alternative theranostics due to accumulated findings of weak correlation between Aβ deposition and cognition, as well as the failures of Phase III clinical trial on Aβ targeted therapy. Recent studies have shown that the tau pathway is closely associated with clinical development of AD symptoms, which might be a potential therapeutic target. We herein construct a methylene blue (MB, a tau aggregation inhibitor) loaded nanocomposite (CeNC/IONC/MSN-T807), which not only possesses high binding affinity to hyperphosphorylated tau but also inhibits multiple key pathways of tau-associated AD pathogenesis. We demonstrate that these nanocomposites can relieve the AD symptoms by mitigating mitochondrial oxidative stress, suppressing tau hyperphosphorylation, and preventing neuronal death both in vitro and in vivo. The memory deficits of AD rats are significantly rescued upon treatment with MB loaded CeNC/IONC/MSN-T807. Our results indicate that hyperphosphorylated tau-targeted multifunctional nanocomposites could be a promising therapeutic candidate for Alzheimer's disease.
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Affiliation(s)
- Qing Chen
- Department of Nuclear Medicine and PET/CT Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou, Zhejiang 310009, P.R. China
| | - Yang Du
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, P.R. China
| | - Kai Zhang
- Department of Nuclear Medicine and PET/CT Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou, Zhejiang 310009, P.R. China
| | - Zeyu Liang
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, P.R. China
| | - Jinquan Li
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, P.R. China
| | - Hao Yu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, P.R. China
| | - Rong Ren
- College of Chemical & Biological Engineering, Zhejiang University , Hangzhou, Zhejiang 310027, P.R. China
| | - Jin Feng
- Department of Nuclear Medicine and PET/CT Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou, Zhejiang 310009, P.R. China
| | - Zhiming Jin
- Jiangsu Huayi Technology Limited Company , Changshu, Jiangsu 215522, P.R. China
| | - Fangyuan Li
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, P.R. China
- Key Laboratory of Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering & Instrument Science, Zhejiang University , Hangzhou, Zhejiang 310058, P.R. China
| | - Jihong Sun
- Department of Radiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University , Hangzhou, Zhejiang 310016, P.R. China
| | - Min Zhou
- Department of Nuclear Medicine and PET/CT Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou, Zhejiang 310009, P.R. China
| | - Qinggang He
- College of Chemical & Biological Engineering, Zhejiang University , Hangzhou, Zhejiang 310027, P.R. China
| | - Xiaolian Sun
- Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Hong Zhang
- Department of Nuclear Medicine and PET/CT Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou, Zhejiang 310009, P.R. China
- Collaborative Innovation Center for Brain Science, Fudan University , Shanghai 200032, P.R. China
| | - Mei Tian
- Department of Nuclear Medicine and PET/CT Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University , Hangzhou, Zhejiang 310009, P.R. China
- Collaborative Innovation Center for Brain Science, Fudan University , Shanghai 200032, P.R. China
| | - Daishun Ling
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, P.R. China
- Key Laboratory of Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering & Instrument Science, Zhejiang University , Hangzhou, Zhejiang 310058, P.R. China
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13
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Bartels B, Cueni P, Muri D, Koerner M. Development of a safe and scalable route towards a tau PET tracer precursor. Bioorg Med Chem 2018; 26:970-976. [PMID: 29074348 DOI: 10.1016/j.bmc.2017.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/06/2017] [Accepted: 10/11/2017] [Indexed: 11/16/2022]
Abstract
A scalable 5-step synthesis of the diazacarbazole derivative 1 used as tau PET tracer precursor is reported. Key features of this synthesis include a Buchwald-Hartwig amination, a Pd catalyzed CH activation and a Suzuki-Miyaura cross-coupling.
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Affiliation(s)
- Bjoern Bartels
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland
| | - Philipp Cueni
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland
| | - Dieter Muri
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland
| | - Matthias Koerner
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland.
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14
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Salabert AS, Fontan C, Fonta C, Alonso M, Loukh N, Delisle MB, Tafani M, Payoux P. Radiosynthesis of [ 18F]AV1451 in pharmaceutical conditions and its biological characteristics. Appl Radiat Isot 2017; 128:101-107. [PMID: 28689157 DOI: 10.1016/j.apradiso.2017.06.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 11/30/2022]
Abstract
In this study, we describe the radiosynthesis of [18F]AV1451 in terms of its pharmaceutical quality and characterise its physical and biological properties. We performed an in vitro serum stability study in fresh human plasma and a plasma protein binding study. The radiochemical yield was 24% (decay corrected), and the product met all regulatory quality requirements. We found that this compound is stable in fresh human plasma and binds tightly to plasma proteins, especially lipoproteins.
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Affiliation(s)
- Anne-Sophie Salabert
- "Toulouse Neuro-imaging Centre" Research Unit (UMR 1214) INSERM, Toulouse, France; Radiopharmacy Department, Toulouse University Hospital, Toulouse, France.
| | - Charlotte Fontan
- Radiopharmacy Department, Toulouse University Hospital, Toulouse, France.
| | - Caroline Fonta
- Brain & Cognition Research Centre (CERCO UMR 5549), Toulouse, France.
| | - Mathieu Alonso
- Radiopharmacy Department, Toulouse University Hospital, Toulouse, France.
| | - Najat Loukh
- "Toulouse Neuro-imaging Centre" Research Unit (UMR 1214) INSERM, Toulouse, France; Neuropathology, Toulouse University Hospital, Toulouse, France.
| | - Marie Bernadette Delisle
- "Toulouse Neuro-imaging Centre" Research Unit (UMR 1214) INSERM, Toulouse, France; Neuropathology, Toulouse University Hospital, Toulouse, France.
| | - Mathieu Tafani
- "Toulouse Neuro-imaging Centre" Research Unit (UMR 1214) INSERM, Toulouse, France; Radiopharmacy Department, Toulouse University Hospital, Toulouse, France.
| | - Pierre Payoux
- "Toulouse Neuro-imaging Centre" Research Unit (UMR 1214) INSERM, Toulouse, France; Department of Nuclear Medicine, Toulouse University Hospital, Toulouse, France.
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15
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Mossine AV, Brooks AF, Henderson BD, Hockley BG, Frey KA, Scott PJH. An updated radiosynthesis of [ 18F]AV1451 for tau PET imaging. EJNMMI Radiopharm Chem 2017; 2:7. [PMID: 29503848 PMCID: PMC5824695 DOI: 10.1186/s41181-017-0027-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 05/29/2017] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND [18F]AV1451 is a commonly used radiotracer for imaging tau deposits in Alzheimer's disease (AD) and related non-AD tauopathies. Existing radiosyntheses of [18F]AV1451 require complex purifications to provide doses suitable for use in clinical imaging studies. To address this issue, we have modified the synthesis of [18F]AV1451 to use only 0.5 mg precursor, optimized the Boc-deprotection step and developed a simplified method for HPLC purification of the radiotracer. RESULTS An optimized [18F]AV1451 synthesis using a TRACERLab FXFN module led to high radiochemical yield (202 ± 57 mCi per synthesis) and doses with excellent radiochemical purity (98 ± 1%) and good specific activity (2521 ± 623 Ci/mmol). CONCLUSION An updated and operationally simple synthesis of [18F]AV1451 has been developed that is fully automated and prepares radiotracer doses suitable for use in clinical tau PET studies.
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Affiliation(s)
- Andrew V. Mossine
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI 48109 USA
| | - Allen F. Brooks
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI 48109 USA
| | - Bradford D. Henderson
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI 48109 USA
| | - Brian G. Hockley
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI 48109 USA
| | - Kirk A. Frey
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI 48109 USA
| | - Peter J. H. Scott
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI 48109 USA
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16
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Synthesis and preliminary biological evaluation of radiolabeled 5-BDBD analogs as new candidate PET radioligands for P2X4 receptor. Bioorg Med Chem 2017; 25:3835-3844. [PMID: 28554730 DOI: 10.1016/j.bmc.2017.05.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 05/10/2017] [Accepted: 05/15/2017] [Indexed: 01/01/2023]
Abstract
P2X4 receptor has become an interesting molecular target for treatment and PET imaging of neuroinflammation and associated brain diseases such as Alzheimer's disease. This study reports the first design, synthesis, radiolabeling and biological evaluation of new candidate PET P2X4 receptor radioligands using 5-BDBD, a specific P2X4 receptor antagonist, as a scaffold. 5-(3-Hydroxyphenyl)-1-[11C]methyl-1,3-dihydro-2H-benzofuro[3,2-e][1,4]diazepin-2-one (N-[11C]Me-5-BDBD analog, [11C]9) and 5-(3-Bromophenyl)-1-[11C]methyl-1,3-dihydro-2H-benzofuro[3,2-e][1,4]diazepin-2-one (N-[11C]Me-5-BDBD, [11C]8c) were prepared from their corresponding desmethylated precursors with [11C]CH3OTf through N-[11C]methylation and isolated by HPLC combined with SPE in 30-50% decay corrected radiochemical yields with 370-1110GBq/µmol specific activity at EOB. 5-(3-[18F]Fluorophenyl)-1,3-dihydro-2H-benzofuro[3,2-e][1,4]diazepin-2-one ([18F]F-5-BDBD, [18F]5a) and 5-(3-(2-[18F]fluoroethoxy)phenyl)-1,3-dihydro-2H-benzofuro[3,2-e][1,4]diazepin-2-one ([18F]FE-5-BDBD, [18F]11) were prepared from their corresponding nitro- and tosylated precursors by nucleophilic substitution with K[18F]F/Kryptofix 2.2.2 and isolated by HPLC-SPE in 5-25% decay corrected radiochemical yields with 111-740GBq/µmol specific activity at EOB. The preliminary biological evaluation of radiolabeled 5-BDBD analogs indicated these new radioligands have similar biological activity with their parent compound 5-BDBD.
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17
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Wang M, Gao M, Xu Z, Zheng QH. Synthesis of [11C]HG-10-102-01 as a new potential PET agent for imaging of LRRK2 enzyme in Parkinson’s disease. Bioorg Med Chem Lett 2017; 27:1351-1355. [DOI: 10.1016/j.bmcl.2017.02.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 12/17/2022]
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18
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Gao M, Wang M, Zheng QH. Synthesis of carbon-11-labeled isonicotinamides as new potential PET agents for imaging of GSK-3 enzyme in Alzheimer’s disease. Bioorg Med Chem Lett 2017; 27:740-743. [DOI: 10.1016/j.bmcl.2017.01.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 01/12/2017] [Accepted: 01/13/2017] [Indexed: 12/29/2022]
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19
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Holt DP, Ravert HT, Dannals RF. Synthesis and quality control of [(18) F]T807 for tau PET imaging. J Labelled Comp Radiopharm 2016; 59:411-5. [PMID: 27427174 DOI: 10.1002/jlcr.3425] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 11/06/2022]
Abstract
The detailed synthesis and quality control of [(18) F]T807, radiotracer for tau protein aggregate imaging, are described. The radiotracer synthesis was accomplished in an average of 48 min with an average specific activity at end-of-synthesis of over 4.4 TBq/µmole (120 Ci/µmole) and an average radiochemical yield of 32%. Compliance with all standard US Pharmacopeia Chapter <823> acceptance tests was observed.
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Affiliation(s)
- Daniel P Holt
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hayden T Ravert
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Robert F Dannals
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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20
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Wang M, Gao M, Xu Z, Zheng QH. Synthesis of a PET tau tracer [(11)C]PBB3 for imaging of Alzheimer's disease. Bioorg Med Chem Lett 2015; 25:4587-92. [PMID: 26323870 DOI: 10.1016/j.bmcl.2015.08.053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 08/17/2015] [Accepted: 08/20/2015] [Indexed: 11/17/2022]
Abstract
The authentic standard PBB3 and its precursor N-desmethyl-PBB3 as well as TBS-protected N-desmethyl-PBB3 precursor for radiolabeling were synthesized from 5-bromo-2-nitropyridine, acrolein diethyl acetal, 6-methoxy-2-methylbenzothiazole, and diethylchlorophosphate with overall chemical yield 1% in six steps, 2% in five steps, and 1% in six steps, respectively. [(11)C]PBB3 was prepared from either desmethyl-PBB3 or TBS-protected desmethyl-PBB3 with [(11)C]CH3OTf through N-[(11)C]methylation and isolated by HPLC combined with SPE in 20-25% and 15-20% radiochemical yield, respectively, based on [(11)C]CO2 and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the specific activity at EOB was 370-1110 GBq/μmol with a total synthesis time of ~40-min from EOB.
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Affiliation(s)
- Min Wang
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Mingzhang Gao
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA
| | - Zhidong Xu
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei 071002, China
| | - Qi-Huang Zheng
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, Room 202, Indianapolis, IN 46202, USA.
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