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Weinstein JJ, Moeller SJ, Perlman G, Gil R, Van Snellenberg JX, Wengler K, Meng J, Slifstein M, Abi-Dargham A. Imaging the Vesicular Acetylcholine Transporter in Schizophrenia: A Positron Emission Tomography Study Using [ 18F]-VAT. Biol Psychiatry 2024; 96:352-364. [PMID: 38309322 DOI: 10.1016/j.biopsych.2024.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/10/2024] [Accepted: 01/23/2024] [Indexed: 02/05/2024]
Abstract
BACKGROUND Despite longstanding interest in the central cholinergic system in schizophrenia (SCZ), cholinergic imaging studies with patients have been limited to receptors. Here, we conducted a proof-of-concept positron emission tomography study using [18F]-VAT, a new radiotracer that targets the vesicular acetylcholine transporter as a proxy measure of acetylcholine transmission capacity, in patients with SCZ and explored relationships of vesicular acetylcholine transporter with clinical symptoms and cognition. METHODS A total of 18 adult patients with SCZ or schizoaffective disorder (the SCZ group) and 14 healthy control participants underwent a positron emission tomography scan with [18F]-VAT. Distribution volume (VT) for [18F]-VAT was derived for each region of interest, and group differences in VT were assessed with 2-sample t tests. Functional significance was explored through correlations between VT and scores on the Positive and Negative Syndrome Scale and a computerized neurocognitive battery (PennCNB). RESULTS No group differences in [18F]-VAT VT were observed. However, within the SCZ group, psychosis symptom severity was positively associated with VT in multiple regions of interest, with the strongest effects in the hippocampus, thalamus, midbrain, cerebellum, and cortex. In addition, in the SCZ group, working memory performance was negatively associated with VT in the substantia innominata and several cortical regions of interest including the dorsolateral prefrontal cortex. CONCLUSIONS In this initial study, the severity of 2 important features of SCZ-psychosis and working memory deficit-was strongly associated with [18F]-VAT VT in several cortical and subcortical regions. These correlations provide preliminary evidence of cholinergic activity involvement in SCZ and, if replicated in larger samples, could lead to a more complete mechanistic understanding of psychosis and cognitive deficits in SCZ and the development of therapeutic targets.
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Affiliation(s)
- Jodi J Weinstein
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York; Department of Psychiatry, Columbia University Vagelos School of Medicine and New York State Psychiatric Institute, New York, New York.
| | - Scott J Moeller
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Greg Perlman
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Roberto Gil
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Jared X Van Snellenberg
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York; Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York; Department of Psychology, Stony Brook University, Stony Brook, New York
| | - Kenneth Wengler
- Department of Psychiatry, Columbia University Vagelos School of Medicine and New York State Psychiatric Institute, New York, New York; Department of Radiology, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Jiayan Meng
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Mark Slifstein
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York
| | - Anissa Abi-Dargham
- Department of Psychiatry and Behavioral Health, Stony Brook University Renaissance School of Medicine, Stony Brook, New York; Department of Psychiatry, Columbia University Vagelos School of Medicine and New York State Psychiatric Institute, New York, New York
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Qiu L, Jiang H, Zhou C, Tangadanchu VKR, Wang J, Huang T, Gropler RJ, Perlmutter JS, Benzinger TLS, Tu Z. Design, synthesis, and biological evaluation of multiple F-18 S1PR1 radiotracers in rodent and nonhuman primate. Org Biomol Chem 2024; 22:5428-5453. [PMID: 38884683 PMCID: PMC11238945 DOI: 10.1039/d4ob00712c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Here we report our design and synthesis of 28 new fluorine-containing compounds as potential F-18 radiotracers for CNS imaging of sphingosine-1-phosphate receptor 1 (S1PR1), and determination of their in vitro binding potency and selectivity toward S1PR1 over other S1PR subtypes. Nine potent and selective compounds, 7c&d, 9a&c, 12b, 15b, and 18a-c with IC50 values ranging from 0.6-12.3 nM for S1PR1 and weak binding toward S1PR2, 3, 4, and 5, were further 18F-radiolabeled to produce [18F]7c&d, [18F]9a&c, [18F]12b, [18F]15b, and [18F]18a-c. Multi-step F-18 radiochemistry procedures were investigated for radiosynthesis of [18F]7c&d and [18F]9a&c, and the presumed intermediates were synthesized and authenticated by analytic HPLC. We then performed nonhuman primate (NHP) PET brain imaging studies for eight radiotracers: [18F]7c&d, [18F]9a, [18F]12b, [18F]15b, and [18F]18a-c. Three radiotracers, [18F]7c, [18F]7d, and [18F]15b, had high NHP brain uptake with standardized uptake values (SUVs) at 2 h post-injection of 2.42, 2.84, and 2.00, respectively, and good brain retention. Our ex vivo biodistribution study in rats confirmed [18F]7d had a high brain uptake with no in vivo defluorination. Radiometabolic analysis of [18F]7c and [18F]7d in rat plasma and brain samples found that [18F]7c has a more favorable metabolic profile than [18F]7d. However, the trend of increased brain uptake precludes [18F]7c as a suitable PET radiotracer for imaging S1PR1 in the brain. Further structural optmization is warranted to identify a highly S1PR1-specific radiotracer with rapid brain uptake kinetics.
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Affiliation(s)
- Lin Qiu
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
| | - Hao Jiang
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
| | - Charles Zhou
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
| | | | - Jinzhi Wang
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
| | - Tianyu Huang
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
| | - Robert J Gropler
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
- Department of Neurology, Neuroscience, Physical Therapy and Occupational Therapy, Washington University School of Medicine, Saint Louis, Missouri, 63110, USA
| | - Tammie L S Benzinger
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
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3
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O'Donnell JL, Soda AK, Jiang H, Norris SA, Maiti B, Karimi M, Campbell MC, Moerlein SM, Tu Z, Perlmutter JS. PET Quantification of [ 18F]VAT in Human Brain and Its Test-Retest Reproducibility and Age Dependence. J Nucl Med 2024; 65:956-961. [PMID: 38604762 PMCID: PMC11149597 DOI: 10.2967/jnumed.123.266860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 03/13/2024] [Indexed: 04/13/2024] Open
Abstract
Molecular imaging of brain vesicular acetylcholine transporter provides a biomarker to explore cholinergic systems in humans. We aimed to characterize the distribution of, and optimize methods to quantify, the vesicular acetylcholine transporter-specific tracer (-)-(1-(8-(2-[18F]fluoroethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)-piperidin-4-yl)(4-fluorophenyl)methanone ([18F]VAT) in the brain using PET. Methods: Fifty-two healthy participants aged 21-97 y had brain PET with [18F]VAT. [3H]VAT autoradiography identified brain areas devoid of specific binding in cortical white matter. PET image-based white matter reference region size, model start time, and duration were optimized for calculations of Logan nondisplaceable binding potential (BPND). Ten participants had 2 scans to determine test-retest variability. Finally, we analyzed age-dependent differences in participants. Results: [18F]VAT was widely distributed in the brain, with high striatal, thalamic, amygdala, hippocampal, cerebellar vermis, and regionally specific uptake in the cerebral cortex. [3H]VAT autoradiography-specific binding and PET [18F]VAT uptake were low in white matter. [18F]VAT SUVs in the white matter reference region correlated with age, requiring stringent erosion parameters. Logan BPND estimates stabilized using at least 40 min of data starting 25 min after injection. Test-retest variability had excellent reproducibility and reliability in repeat BPND calculations for 10 participants (putamen, 6.8%; r > 0.93). We observed age-dependent decreases in the caudate and putamen (multiple comparisons corrected) and in numerous cortical regions. Finally, we provide power tables to indicate potential mean differences that can be detected between 2 groups of participants. Conclusion: These results validate a reference region for BPND calculations and demonstrate the viability, reproducibility, and utility of using the [18F]VAT tracer in humans to quantify cholinergic pathways.
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Affiliation(s)
- John L O'Donnell
- Neurology, Washington University in Saint Louis, St. Louis, Missouri;
| | - Anil Kumar Soda
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Hao Jiang
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Scott A Norris
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Baijayanta Maiti
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Morvarid Karimi
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Meghan C Campbell
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Stephen M Moerlein
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
- Biochemistry and Molecular Biophysics, Washington University in Saint Louis, St. Louis, Missouri; and
| | - Zhude Tu
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
| | - Joel S Perlmutter
- Neurology, Washington University in Saint Louis, St. Louis, Missouri
- Radiology, Washington University in Saint Louis, St. Louis, Missouri
- Neuroscience, Physical, and Occupational Therapy, Washington University in Saint Louis, St. Louis, Missouri
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Hu B, Akula HK, Noh D, Mui YF, Slifstein M, Parsey R, Qu W. An improved synthesis of [ 18 F]VAT and its precursor. J Labelled Comp Radiopharm 2023; 66:384-392. [PMID: 37615234 PMCID: PMC10592132 DOI: 10.1002/jlcr.4059] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/25/2023]
Abstract
The vesicular acetylcholine transporter (VAChT) in the brain is an important presynaptic cholinergic biomarker, and neuroimaging studies of VAChT may provide in vivo information about psychiatric and neurologic conditions including Alzheimer's disease that are not accessible by other methods. The 18 F-labeled radiotracer, ((-)-(1-(-8-(2-[18 F]fluoroethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)piperidin-4-yl)(4-fluorophenyl)-methanone ([18 F]VAT, 1), was reported as a selective and high affinity ligand for the in vivo imaging of VAChT. The synthesis of [18 F]VAT has been reported in a two-step procedure with total 140 min, which includes preparation of 2-[18 F]fluoroethyltosylate and alkylation of benzovesamicol (-)-5 precursor with this radiosynthon using two different automated production modules consecutively. A multiple step synthetic route was employed for the synthesis of stereospecific precursor benzovesamicol (-)-5, which is difficult to be adapted for scale-up. To make the production of this tracer more amenable for clinical imaging, we present an improved total synthesis protocol to attain [18 F]VAT: (1) a tosylethoxy group being pre-installed tosylate precursor (-)-8 is synthesized to render a simple one-step radiofluorination under mild conditions; (2) The key optically active intermediate benzovesamicol (-)-5 was obtained via the regio- and enantio-enriched ring-opening amination of meso-epoxide 3 with 4-phenylpiperidine derivative 2 under catalysis of a chiral salenCo(III) catalyst 4b, which dramatically simplifies the synthetic route of the tosylate precursor (-)-8. [18 F]VAT 1 was prepared within ~65 min with desired chemical and radiochemical purities, via a fully automated procedure, using a commercial PET tracer production module. The final drug product was obtained as a sterile, pyrogen-free solution that conforms United States Pharmacopeia (USP) <823> requirements.
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Affiliation(s)
- Bao Hu
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- PET Research Core at Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Hari K. Akula
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- Department of Chemistry, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- PET Research Core at Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Doyoung Noh
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- PET Research Core at Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Yiu Fung Mui
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- PET Research Core at Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Mark Slifstein
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- PET Research Core at Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Ramin Parsey
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- PET Research Core at Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Wenchao Qu
- Department of Psychiatry and Behavioral Health, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- Department of Chemistry, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
- PET Research Core at Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
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5
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Mineur YS, Picciotto MR. How can I measure brain acetylcholine levels in vivo? Advantages and caveats of commonly used approaches. J Neurochem 2023; 167:3-15. [PMID: 37621094 PMCID: PMC10616967 DOI: 10.1111/jnc.15943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023]
Abstract
The neurotransmitter acetylcholine (ACh) plays a central role in the regulation of multiple cognitive and behavioral processes, including attention, learning, memory, motivation, anxiety, mood, appetite, and reward. As a result, understanding ACh dynamics in the brain is essential for elucidating the neural mechanisms underlying these processes. In vivo measurements of ACh in the brain have been challenging because of the low concentrations and rapid turnover of this neurotransmitter. Here, we review a number of techniques that have been developed to measure ACh levels in the brain in vivo. We follow this with a deeper focus on use of genetically encoded fluorescent sensors coupled with fiber photometry, an accessible technique that can be used to monitor neurotransmitter release with high temporal resolution and specificity. We conclude with a discussion of methods for analyzing fiber photometry data and their respective advantages and disadvantages. The development of genetically encoded fluorescent ACh sensors is revolutionizing the field of cholinergic signaling, allowing temporally precise measurement of ACh release in awake, behaving animals. Use of these sensors has already begun to contribute to a mechanistic understanding of cholinergic modulation of complex behaviors.
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Affiliation(s)
- Yann S. Mineur
- Department of Psychiatry, Yale University School of Medicine, 34 Park Street, 3 Floor Research, New Haven, CT 06508, USA
| | - Marina R. Picciotto
- Department of Psychiatry, Yale University School of Medicine, 34 Park Street, 3 Floor Research, New Haven, CT 06508, USA
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6
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Qiu L, Jiang H, Zhou C, Wang J, Yu Y, Zhao H, Huang T, Gropler R, Perlmutter JS, Benzinger TLS, Tu Z. Discovery of a Promising Fluorine-18 Positron Emission Tomography Radiotracer for Imaging Sphingosine-1-Phosphate Receptor 1 in the Brain. J Med Chem 2023; 66:4671-4688. [PMID: 36926861 PMCID: PMC11037415 DOI: 10.1021/acs.jmedchem.2c01752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Sphingosine-1-phosphate receptor 1 (S1PR1) is recognized as a novel therapeutic and diagnostic target in neurological disorders. We recently transferred the S1PR1 radioligand [11C]CS1P1 into clinical investigation for multiple sclerosis. Herein, we reported the design, synthesis and evaluation of novel F-18 S1PR1 radioligands. We combined the structural advantages of our two lead S1PR1 radioligands and synthesized 14 new S1PR1 compounds, then performed F-18 radiochemistry on the most promising compounds. Compound 6h is potent (IC50 = 8.7 nM) and selective for S1PR1. [18F]6h exhibited a high uptake in macaque brain (SUV > 3.0) and favorable brain washout pharmacokinetics in positron emission tomography (PET) study. PET blocking and displacement studies confirmed the specificity of [18F]6h in vivo. Radiometabolite analysis confirmed no radiometabolite of [18F]6h entered into the brain to confound the PET measurement. In summary, [18F]6h is a promising radioligand to image S1PR1 and worth translational clinical investigation for humans with brain disorders.
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Affiliation(s)
- Lin Qiu
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Hao Jiang
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Charles Zhou
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Jinzhi Wang
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Yanbo Yu
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Haiyang Zhao
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Tianyu Huang
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Robert Gropler
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Joel S Perlmutter
- Department of Neurology, Radiology, Neuroscience, Physical Therapy and Occupational Therapy, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Tammie L S Benzinger
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, Saint Louis, Missouri 63110, United States
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7
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Singh P, Singh D, Srivastava P, Mishra G, Tiwari AK. Evaluation of advanced, pathophysiologic new targets for imaging of CNS. Drug Dev Res 2023; 84:484-513. [PMID: 36779375 DOI: 10.1002/ddr.22040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/12/2022] [Accepted: 12/31/2022] [Indexed: 02/14/2023]
Abstract
The inadequate information about the in vivo pathological, physiological, and neurological impairments, as well as the absence of in vivo tools for assessing brain penetrance and the efficiency of newly designed drugs, has hampered the development of new techniques for the treatment for variety of new central nervous system (CNS) diseases. The searching sites such as Science Direct and PubMed were used to find out the numerous distinct tracers across 16 CNS targets including tau, synaptic vesicle glycoprotein, the adenosine 2A receptor, the phosphodiesterase enzyme PDE10A, and the purinoceptor, among others. Among the most encouraging are [18 F]FIMX for mGluR imaging, [11 C]Martinostat for Histone deacetylase, [18 F]MNI-444 for adenosine 2A imaging, [11 C]ER176 for translocator protein, and [18 F]MK-6240 for tau imaging. We also reviewed the findings for each tracer's features and potential for application in CNS pathophysiology and therapeutic evaluation investigations, including target specificity, binding efficacy, and pharmacokinetic factors. This review aims to present a current evaluation of modern positron emission tomography tracers for CNS targets, with a focus on recent advances for targets that have newly emerged for imaging in humans.
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Affiliation(s)
- Priya Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Deepika Singh
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Pooja Srivastava
- Division of Cyclotron and Radiopharmaceuticals Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Gauri Mishra
- Department of Zoology, Swami Shraddhananad College, University of Delhi, Alipur, Delhi, India
| | - Anjani K Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
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Norris SA, Tian L, Williams EL, Perlmutter JS. Transient dystonia correlates with parkinsonism after 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine in nonhuman primates. DYSTONIA 2023; 2:11019. [PMID: 37711667 PMCID: PMC10501383 DOI: 10.3389/dyst.2023.11019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
Unilateral internal carotid artery 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) infusion in non-human primates produces transient contralateral hemi-dystonia followed by stable contralateral hemi-parkinsonism; the relationship between dystonia and parkinsonism remains unclear. We hypothesized that transient dystonia severity following MPTP correlates with parkinsonism severity. In male Macaca nemestrina (n = 3) and M. fascicularis (n = 17) we administered unilateral intra-carotid MPTP, then correlated validated blinded ratings of transient peak dystonia and delayed parkinsonism. We also correlated dystonia severity with post-mortem measures of residual striatal dopamine and nigral neuron counts obtained a mean 53 ± 15 days following MPTP, after resolution of dystonia but during stable parkinsonism. Median latency to dystonia onset was 1 day, and peak severity 2.5 days after MPTP; total dystonia duration was 13.5 days. Parkinsonism peaked a median of 19.5 days after MPTP, remaining nearly constant thereafter. Peak dystonia severity highly correlated with parkinsonism severity (r[18] = 0.82, p < 0.001). Residual cell counts in lesioned nigra correlated linearly with peak dystonia scores (r[18] = -0.68, p=<0.001). Dystonia was not observed in monkeys without striatal dopamine depletion (n = 2); dystonia severity correlated with striatal dopamine depletion when residual nigral cell loss was less than 50% ([11] r = -0.83, p < 0.001) but spanned a broad range with near complete striatal dopamine depletion, when nigral cell loss was greater than 50%. Our data indicate that residual striatal dopamine may not reflect dystonia severity. We speculate on mechanisms of transient dystonia followed by parkinsonism that may be studied using this particular NHP MPTP model to better understand relationships of transient dystonia to nigrostriatal injury and parkinsonism.
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Affiliation(s)
- S. A. Norris
- Department of Neurology, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Radiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - L. Tian
- Department of Neurology, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - E. L. Williams
- Department of Neurology, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - J. S. Perlmutter
- Department of Neurology, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Radiology, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Neuroscience, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Physical Therapy, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Occupational Therapy, School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
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Abstract
Positron emission tomography (PET) has revealed key insights into the pathophysiology of movement disorders. This paper will focus on how PET investigations of pathophysiology are particularly relevant to Parkinson disease, a neurodegenerative condition usually starting later in life marked by a varying combination of motor and nonmotor deficits. Various molecular imaging modalities help to determine what changes in brain herald the onset of pathology; can these changes be used to identify presymptomatic individuals who may be appropriate for to-be-developed treatments that may forestall onset of symptoms or slow disease progression; can PET act as a biomarker of disease progression; can molecular imaging help enrich homogenous cohorts for clinical studies; and what other pathophysiologic mechanisms relate to nonmotor manifestations. PET methods include measurements of regional cerebral glucose metabolism and blood flow, selected receptors, specific neurotransmitter systems, postsynaptic signal transducers, and abnormal protein deposition. We will review each of these methodologies and how they are relevant to important clinical issues pertaining to Parkinson disease.
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Affiliation(s)
- Baijayanta Maiti
- Department of Neurology, Washington University in St. Louis, St Louis, MO.
| | - Joel S Perlmutter
- Department of Neurology, Washington University in St. Louis, St Louis, MO; Department of Radiology, Washington University in St. Louis, St Louis, MO; Department of Neuroscience, Washington University in St. Louis, St Louis, MO; Department of Physical Therapy, Washington University in St. Louis, St Louis, MO; Department of Occupational Therapy, Washington University in St. Louis, St Louis, MO
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10
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Yue X, Luo Z, Liu H, Kaneshige K, Parsons SM, Perlmutter JS, Tu Z. Radiosynthesis and evaluation of a fluorine-18 labeled radioligand targeting vesicular acetylcholine transporter. Bioorg Med Chem Lett 2018; 28:3425-3430. [PMID: 30274694 DOI: 10.1016/j.bmcl.2018.09.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 09/21/2018] [Accepted: 09/22/2018] [Indexed: 12/28/2022]
Abstract
Vesicular acetylcholine transporter (VAChT) is a reliable biomarker for assessing the loss of cholinergic neurons in the brain that is associated with cognitive impairment of patients. 5-Hydrotetralin compound (±)-5-OH-VAT is potent (Ki = 4.64 ± 0.32 nM) and selective for VAChT (>1800-fold and 398-fold for σ1 and σ2 receptor, respectively) with favorable hydrophilicity (LogD = 1.78), while (-)-5-OH-VAT originally serves as the radiolabeling precursor of (-)-[18F]VAT, a promising VAChT radiotracer with a logD value of 2.56. To evaluate (-)-5-OH-[18F]VAT as a radiotracer for VAChT, we performed in vitro binding assay to determine the potency of the minus enantiomer (-)-5-OH-VAT and plus enantiomer (+)-5-OH-VAT, indicating that (-)-5-OH-VAT is a more potent VAChT enantiomer. Radiosynthesis of (-)-5-OH-[18F]VAT was explored using three strategies. (-)-5-OH-[18F]VAT was achieved with a good yield (24 ± 6%) and high molar activity (∼37 GBq/µmol, at the end of synthesis) using a microwave assisted two-step one-pot procedure that started with di-MOM protected nitro-containing precursor (-)-6. MicroPET studies in the brain of nonhuman primate (NHP) suggest that (-)-5-OH-[18F]VAT readily penetrated the blood brain barrier and specifically accumulated in the VAChT-enriched striatum with improved washout kinetics from striatum compared to [18F]VAT. Nevertheless, the lower target to non-target ratio may limit its use for in vivo measurement of the VAChT level in the brain.
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Affiliation(s)
- Xuyi Yue
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Zonghua Luo
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Hui Liu
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Kota Kaneshige
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, United States
| | - Stanley M Parsons
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, United States
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States; Department of Neurology, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St Louis, MO 63110, United States.
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11
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Luo Z, Liu H, Jin H, Gu J, Yu Y, Kaneshige K, Perlmutter JS, Parsons SM, Tu Z. Exploration of Sulfur-Containing Analogues for Imaging Vesicular Acetylcholine Transporter in the Brain. ChemMedChem 2018; 13:1978-1987. [PMID: 30071131 PMCID: PMC6422167 DOI: 10.1002/cmdc.201800411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/29/2018] [Indexed: 11/09/2022]
Abstract
Sixteen new sulfur-containing compounds targeting the vesicular acetylcholine transporter (VAChT) were synthesized and assessed for in vitro binding affinities. Enantiomers (-)-(1-(3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)piperidin-4-yl)(4-(methylthio)phenyl)methanone [(-)-8] and (-)-(4-((2-fluoroethyl)thio)phenyl)(1-(3-hydroxy-1,2,3,4-tetrahydronaph-thalen-2-yl)piperidin-4-yl)methanone [(-)-14 a] displayed high binding affinities, with respective Ki values of 1.4 and 2.2 nm for human VAChT, moderate and high selectivity for human VAChT over σ1 (≈13-fold) and σ2 receptors (>420-fold). Radiosyntheses of (-)-[11 C]8 and (-)-[18 F]14 a were achieved using conventional methods. Ex vivo autoradiography and biodistribution studies in Sprague-Dawley rats indicated that both radiotracers have the capacity to penetrate the blood-brain barrier, with high initial brain uptake at 5 min and rapid washout. The striatal region had the highest accumulation for both radiotracers. Pretreating the rats with the VAChT ligand (-)-vesamicol decreased brain uptake for both radiotracers. Pretreating the rats with the σ1 ligand YUN-122 (N-(4-benzylcyclohexyl)-2-(2-fluorophenyl)acetamide) also decreased brain uptake, suggesting these two radiotracers also bind to the σ1 receptor in vivo. The microPET study of (-)-[11 C]8 in the brain of a non-human primate showed high striatal accumulation that peaked quickly and washed out rapidly. Although preliminary results indicated these two sulfur-containing radiotracers have high binding affinities for VAChT with rapid washout kinetics from the striatum, their σ1 receptor binding properties limit their potential as radiotracers for quantifying VAChT in vivo.
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Affiliation(s)
- Zonghua Luo
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Hui Liu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Hongjun Jin
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jiwei Gu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Yanbo Yu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Kota Kaneshige
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Neurology, Neuroscience, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Stanley M Parsons
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
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12
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Yue X, Dhavale DD, Li J, Luo Z, Liu J, Yang H, Mach RH, Kotzbauer PT, Tu Z. Design, synthesis, and in vitro evaluation of quinolinyl analogues for α-synuclein aggregation. Bioorg Med Chem Lett 2018; 28:1011-1019. [PMID: 29482941 PMCID: PMC5870887 DOI: 10.1016/j.bmcl.2018.02.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 02/09/2018] [Accepted: 02/14/2018] [Indexed: 12/19/2022]
Abstract
Here we report the synthesis and in vitro evaluation of 25 new quinolinyl analogues for α-synuclein aggregates. Three lead compounds were subsequently labeled with carbon-11 or fluorine-18 to directly assess their potency in a direct radioactive competitive binding assay ng both α-synuclein fibrils and tissue homogenates from Alzheimer's disease (AD) cases. The modest binding affinities of these three radioligands toward α-synuclein were comparable with results from the Thioflavin T fluorescence assay. However, all three ligand also showed modest binding affinity to the AD homogenates and lack selectivity for α-synuclein. The structure-activity relationship data from these 25 analogues will provide useful information for design and synthesis of new compounds for imaging α-synuclein aggregation.
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Affiliation(s)
- Xuyi Yue
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Dhruva D Dhavale
- Department of Neurology, Washington University School of Medicine, St Louis, MO, United States
| | - Junfeng Li
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Zonghua Luo
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Jialu Liu
- Department of Neurology, Washington University School of Medicine, St Louis, MO, United States
| | - Hao Yang
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Robert H Mach
- Department of Radiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
| | - Paul T Kotzbauer
- Department of Neurology, Washington University School of Medicine, St Louis, MO, United States
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St Louis, MO, United States.
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13
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Jin H, Yue X, Liu H, Han J, Flores H, Su Y, Parsons SM, Perlmutter JS, Tu Z. Kinetic modeling of [ 18 F]VAT, a novel radioligand for positron emission tomography imaging vesicular acetylcholine transporter in non-human primate brain. J Neurochem 2018; 144:791-804. [PMID: 29315563 DOI: 10.1111/jnc.14291] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 12/16/2017] [Accepted: 12/19/2017] [Indexed: 01/06/2023]
Abstract
Molecular imaging of vesicular acetylcholine transporter (VAChT) in the brain provides an important cholinergic biomarker for the pathophysiology and treatment of dementias including Alzheimer's disease. In this study, kinetics modeling methods were applied and compared for quantifying regional brain uptake of the VAChT-specific positron emission tomography radiotracer, ((-)-(1-(-8-(2-fluoroethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)piperidin-4-yl)(4-fluorophenyl)-methanone) ([18 F]VAT) in macaques. Total volume distribution (VT ) estimates were compared for one-tissue compartment model (1TCM), two-tissue compartment model (2TCM), Logan graphic analysis (LoganAIF) and multiple linear analysis (MA1) with arterial blood input function using data from three macaques. Using the cerebellum-hemispheres as the reference region with data from seven macaques, three additional models were compared: reference tissue model (RTM), simplified RTM (SRTM), and Logan graphic analysis (LoganREF). Model selection criterion indicated that a) 2TCM and SRTM were the most appropriate kinetics models for [18 F]VAT; and b) SRTM was strongly correlated with 2TCM (Pearson's coefficients r > 0.93, p < 0.05). Test-retest studies demonstrated that [18 F]VAT has good reproducibility and reliability (TRV < 10%, ICC > 0.72). These studies demonstrate [18 F]VAT is a promising VAChT positron emission tomography tracer for quantitative assessment of VAChT levels in the brain of living subjects.
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Affiliation(s)
- Hongjun Jin
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Xuyi Yue
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hui Liu
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Junbin Han
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hubert Flores
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Yi Su
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Stanley M Parsons
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California, USA
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Neuroscience, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
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14
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Yue X, Jin H, Liu H, Luo Z, Zhang X, Kaneshige K, Flores HP, Perlmutter JS, Parsons SM, Tu Z. Synthesis, resolution, and in vitro evaluation of three vesicular acetylcholine transporter ligands and evaluation of the lead fluorine-18 radioligand in a nonhuman primate. Org Biomol Chem 2018; 15:5197-5209. [PMID: 28590490 DOI: 10.1039/c7ob00854f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The vesicular acetylcholine transporter (VAChT) is a reliable biomarker for assessing cholinergic dysfunction associated with dementia. We recently reported three new potent and selective carbon-11 labeled VAChT radiotracers. Herein, we report the resolution with a Chiralcel OD column of three additional fluorine containing VAChT ligands in which a fluoroethoxy or fluoroethylamino moiety was substituted for the methoxy group. An in vitro competitive binding assay showed that (-)-7 had high potency for VAChT (Ki-VAChT = 0.31 ± 0.03 nM) and excellent selectivity for VAChT versus σ receptors (Ki-σ1 = 1870 ± 250 nM, Ki-σ2 = 5480 ± 140 nM). Three different radiolabeling approaches were explored; the radiosynthesis of (-)-[18F]7 was successfully accomplished via a stepwise two-pot, three-step method with moderate yield (11 ± 2%) and high radiochemical purity (>98%). PET imaging studies in a nonhuman primate indicated that (-)-[18F]7 rapidly entered the brain and accumulated in the VAChT-enriched striatum. The uptake of (-)-[18F]7 in the target striatal area peaked at 10 min and displayed improved clearance kinetics compared to the VAChT tracer [18F]VAT, which has been approved by the Food and Drug Administration (FDA) for first-in-man studies. These studies justify further investigation of (-)-[18F]7 and exploration of the structure-activity relationships of these fluoroethoxy and fluoroethylamino analogs.
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Affiliation(s)
- Xuyi Yue
- Department of Radiology, Washington University School of Medicine, St Louis, MO, USA.
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15
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Abstract
As the field of PET has expanded and an ever-increasing number and variety of compounds have been radiolabeled as potential in vivo tracers of biochemistry, transporters have become important primary targets or facilitators of radiotracer uptake and distribution. A transporter can be the primary target through the development of a specific high-affinity radioligand: examples are the multiple high-affinity radioligands for the neuronal membrane neurotransmitter or vesicular transporters, used to image nerve terminals in the brain. The goal of a radiotracer might be to study the function of a transporter through the use of a radiolabeled substrate, such as the application of 3-O-[11C]methyl]glucose to measure rates of glucose transport through the blood-brain barrier. In many cases, transporters are required for radiotracer distributions, but the targeted biochemistries might be unrelated: an example is the use of 2-deoxy-2-[18F]FDG for imaging glucose metabolism, where initial passage of the radiotracer through cell membranes requires the action of specific glucose transporters. Finally, there are transporters such as p-glycoprotein that function to extrude small molecules from tissues, and can effectively work against successful uptake of radiotracers. The diversity of structures and functions of transporters, their importance in human health and disease, and their role in therapeutic drug disposition suggest that in vivo imaging of transporter location and function will continue to be a point of emphasis in PET radiopharmaceutical development. In this review, the variety of transporters and their importance for in vivo PET radiotracer development and application are discussed. Transporters have thus joined the other major protein targets such as G-protein coupled receptors, ligand-gated ion channels, enzymes, and aggregated proteins as of high interest for understanding human health and disease.
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Affiliation(s)
- Michael R Kilbourn
- Department of Radiology, University of Michigan Medical School, Ann Arbor, MI.
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16
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van der Born D, Pees A, Poot AJ, Orru RVA, Windhorst AD, Vugts DJ. Fluorine-18 labelled building blocks for PET tracer synthesis. Chem Soc Rev 2017; 46:4709-4773. [DOI: 10.1039/c6cs00492j] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review presents a comprehensive overview of the synthesis and application of fluorine-18 labelled building blocks since 2010.
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Affiliation(s)
- Dion van der Born
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Anna Pees
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Alex J. Poot
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Romano V. A. Orru
- Department of Chemistry and Pharmaceutical Sciences and Amsterdam Institute for Molecules
- Medicines & Systems (AIMMS)
- VU University Amsterdam
- Amsterdam
- The Netherlands
| | - Albert D. Windhorst
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
| | - Danielle J. Vugts
- Department of Radiology & Nuclear Medicine
- VU University Medical Center
- 1081 HV Amsterdam
- The Netherlands
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