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Saednia S, Emami S, Moslehi M, Hosseinimehr SJ. Insights into the development of 99mTc-radioligands for serotonergic receptors imaging: Synthesis, labeling, In vitro, and In vivo studies. Eur J Med Chem 2024; 270:116349. [PMID: 38555856 DOI: 10.1016/j.ejmech.2024.116349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 04/02/2024]
Abstract
Serotonergic (5-hydroxytryptamine; 5-HT) receptors play critical roles in neurological and psychological disorders such as schizophrenia, anxiety, depression, and Alzheimer's diseases. Therefore, it is particularly important to develop novel radioligands or modify the existing ones to identify the serotonergic receptors involved in psychiatric disorders. Among the 16 subtypes of serotonergic systems, only technetium-99m based radiopharmaceuticals have been evaluated for serotonin-1A (5-HT1A), serotonin-2A (5-HT2A), 5-HT1A/7 heterodimers and serotonin receptor neurotransmitter (SERT). This review focuses on recent efforts in the design, synthesis and evaluation of 99mTc-radioligands used for single photon emission computerized tomography (SPECT) imaging of serotonergic (5-HT) receptors. Additionally, the discussion will cover aspects such as chemical structure, in vitro/vivo stability, affinity toward serotonin receptors, blood-brain barrier permeation (BBB), and biodistribution study.
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Affiliation(s)
- Shahnaz Saednia
- Farabi Hospital, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Saeed Emami
- Department of Medicinal Chemistry and Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Masoud Moslehi
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Seyed Jalal Hosseinimehr
- Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran.
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2
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Fu H, Rong J, Chen Z, Zhou J, Collier T, Liang SH. Positron Emission Tomography (PET) Imaging Tracers for Serotonin Receptors. J Med Chem 2022; 65:10755-10808. [PMID: 35939391 DOI: 10.1021/acs.jmedchem.2c00633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) and 5-HT receptors (5-HTRs) have crucial roles in various neuropsychiatric disorders and neurodegenerative diseases, making them attractive diagnostic and therapeutic targets. Positron emission tomography (PET) is a noninvasive nuclear molecular imaging technique and is an essential tool in clinical diagnosis and drug discovery. In this context, numerous PET ligands have been developed for "visualizing" 5-HTRs in the brain and translated into human use to study disease mechanisms and/or support drug development. Herein, we present a comprehensive repertoire of 5-HTR PET ligands by focusing on their chemotypes and performance in PET imaging studies. Furthermore, this Perspective summarizes recent 5-HTR-focused drug discovery, including biased agonists and allosteric modulators, which would stimulate the development of more potent and subtype-selective 5-HTR PET ligands and thus further our understanding of 5-HTR biology.
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Affiliation(s)
- Hualong Fu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Jian Rong
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Zhen Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jingyin Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Thomas Collier
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
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3
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99mTc-Labeled human and camel lactoferrin for detection of Staphylococcus aureus infections. J Radioanal Nucl Chem 2018. [DOI: 10.1007/s10967-018-5924-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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4
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García G, Abet V, Alajarín R, Álvarez-Builla J, Delgado M, García-García L, Bascuñana-Almarcha P, Peña-Salcedo C, Kelly J, Pozo MA. N-(4-[(18)F]-fluoropyridin-2-yl)-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}carboxamides as analogs of WAY100635. New PET tracers of serotonin 5-HT(1A) receptors. Eur J Med Chem 2014; 85:795-806. [PMID: 25171752 DOI: 10.1016/j.ejmech.2014.07.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/24/2014] [Accepted: 07/25/2014] [Indexed: 10/25/2022]
Abstract
N-(4-[(18)F]-Fluoropyridin-2-yl)-N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-carboxamides were prepared by labeling their 4-nitropyridin-2-yl precursors through nitro substitution by the (18)F anion. In vitro and in vivo tests showed that the cyclohexanecarboxamide derivative is a reversible, selective and high affinity 5-HT1A receptor antagonist (IC50 = 0.29 nM, ki = 0.18 nM) with high brain uptake, slow brain clearance and stability to defluorination when compared with conventional standards. This PET radioligand is a promising candidate for an improved in vivo quantification of 5-HT1A receptors in neuropsychiatric disorders.
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Affiliation(s)
- Gonzalo García
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Valentina Abet
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Ramón Alajarín
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain
| | - Julio Álvarez-Builla
- Departamento de Química Orgánica, Universidad de Alcalá, Alcalá de Henares, Madrid 28871, Spain.
| | - Mercedes Delgado
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Luis García-García
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Pablo Bascuñana-Almarcha
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain
| | - Carmen Peña-Salcedo
- Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain
| | - James Kelly
- Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain
| | - Miguel A Pozo
- CAI Cartografía Cerebral, Instituto Pluridisciplinar UCM, Paseo Juan XXIII, 1, Madrid 28040, Spain; Instituto Tecnológico PET, Calle Manuel Bartolomé Cossío 10, Madrid 28040, Spain.
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Chaturvedi S, Kaul A, Yadav N, Singh B, Mishra AK. Synthesis, docking and preliminary in vivo evaluation of serotonin dithiocarbamate as novel SPECT neuroimaging agent. MEDCHEMCOMM 2013. [DOI: 10.1039/c3md00044c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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6
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Choi JY, Kim CH, Jeon TJ, Kim BS, Yi CH, Woo KS, Seo YB, Han SJ, Kim KM, Yi DI, Lee M, Kim DG, Kim JY, Lee KC, Choi TH, An G, Ryu YH. Effective MicroPET imaging of brain 5-HT1Areceptors in rats with [18F]MeFWAY by suppression of radioligand defluorination. Synapse 2012; 66:1015-23. [DOI: 10.1002/syn.21607] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 08/21/2012] [Indexed: 11/11/2022]
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7
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Chiotellis A, Tsoukalas C, Pelecanou M, Pirmettis I, Papadopoulos M. Synthesis, characterization and biological evaluation of novel neutral fac-M(CO)3(SNO) complexes (M=Re, 99mTc) bearing the o-methoxyphenylpiperazine moiety. Appl Radiat Isot 2012; 70:957-64. [PMID: 22464790 DOI: 10.1016/j.apradiso.2012.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 12/07/2011] [Accepted: 03/01/2012] [Indexed: 10/28/2022]
Abstract
The synthesis, characterization and biological evaluation of two new neutral tricarbonyl fac-M(CO)(3)(SNO) (M=Re, (99m)Tc) bearing o-methoxyphenylpiperazine as pharmacophore and S-functionalized cysteine or penicillamine as chelators are reported. Competition binding tests showed good affinity for the 5-HT(1A) receptor (8 and 54 nM for 4a and 4b, respectively). Biodistribution studies in healthy animals showed high initial blood and liver uptake, fast blood and tissue depuration and negligible brain uptake.
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Affiliation(s)
- A Chiotellis
- Institute of Radioisotopes, Radiodiagnostic Products, National Centre for Scientific Research Demokritos, Athens, Greece
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Design, synthesis and in vitro evaluation of bridgehead fluoromethyl analogs of N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-N-(pyridin-2-yl)cyclohexanecarboxamide (WAY-100635) for the 5-HT1A receptor. Eur J Med Chem 2011; 46:5728-35. [DOI: 10.1016/j.ejmech.2011.06.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 06/10/2011] [Accepted: 06/16/2011] [Indexed: 11/19/2022]
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9
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Al Hussainy R, Verbeek J, van der Born D, Braker AH, Leysen JE, Knol RJ, Booij J, Herscheid J(KDM. Design, Synthesis, Radiolabeling, and in Vitro and in Vivo Evaluation of Bridgehead Iodinated Analogues of N-{2-[4-(2-Methoxyphenyl)piperazin-1-yl]ethyl}-N-(pyridin-2-yl)cyclohexanecarboxamide (WAY-100635) as Potential SPECT Ligands for the 5-HT1A Receptor. J Med Chem 2011; 54:3480-91. [DOI: 10.1021/jm1009956] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rana Al Hussainy
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Joost Verbeek
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Dion van der Born
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Anton H. Braker
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Josée E. Leysen
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Remco J. Knol
- Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Jan Booij
- Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - J. (Koos) D. M. Herscheid
- Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
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Chiotellis A, Tsoukalas C, Pelecanou M, Pirmettis I, Papadopoulos M. New 99mTc(CO)3(NNO) complexes in the development of 5HT1A receptor imaging agents. RADIOCHIM ACTA 2011. [DOI: 10.1524/ract.2011.1835] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
In this work we report the synthesis, characterization and biological evaluation of two new neutral tricarbonyl fac-M(CO)3(NNO) (M=Re, 99mTc) derivatives of WAY-100635 as potential 99mTc agents for the in vivo imaging of 5HT1A receptors. The new pharmacophore NNO ligands are based on the picolylamine N,N-diacetic acid (PADA) ligand and their synthesis was achieved through the PADA anhydride, showing thus the applicability of this synthetic approach, developed in our laboratory, for the incorporation of bioactive amines in the PADA molecule and the development of target specific radiopharmaceuticals. The rhenium complexes were synthesized using [NEt4]2[Re(CO)3Br3] as a precursor and fully characterized by elemental analysis and spectroscopic methods. The analogous technetium-99m complexes were also prepared quantitatively using the [99mTc(CO)3(H2O)3]+ precursor and their structure corroborated by means of the rhenium complexes. The lipophilicity of the Tc complexes is in the range normally accepted for substances to be able to cross the BBB. Competition binding tests showed moderate affinity for the 5HT1A receptors, with IC50 values at the nanomolar range (30 and 116 nM). Biodistribution in healthy animals was characterized by high initial blood and liver uptake and fast blood and tissue depuration with excretion taking place mainly through the hepatobiliary system. None of the new complexes showed any significant brain uptake, suggesting that the ability of a compound to cross the BBB is determined by more factors than charge, lipophilicity and size.
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Affiliation(s)
- A. Chiotellis
- National Centre for Scientific Research “Demokritos“, Institute of Radioisotopes - Radiodiagnostic Produ, Athens, Griechenland
| | | | - M. Pelecanou
- National Centre for Scientific Research Demokritos, Institute of Biology, Athens, Griechenland
| | - I. Pirmettis
- National Centre for Scientific Research Demokritos, Institute of Radioisotopes - Radiodiagnostic Produ, Athens, Griechenland
| | - M. Papadopoulos
- National Centre for Scientific Research Demokritos, Institute of Radioisotopes - Radiodiagnostic Produ, Athens, Griechenland
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11
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Itsenko O, Blom E, Långström B, Kihlberg T. The Use of Lithium Amides in the Palladium-Mediated Synthesis of [Carbonyl-11C]Amides. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700255] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Møller M, Jakobsen S, Gjedde A. Parametric and regional maps of free serotonin 5HT1A receptor sites in human brain as function of age in healthy humans. Neuropsychopharmacology 2007; 32:1707-14. [PMID: 17251909 DOI: 10.1038/sj.npp.1301310] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Serotonin 5HT(1A)-binding sites can be detected in living human brain with the positron-emitting antagonist [(11)C]WAY-100635. Previous measurements of the availability of [(11)C]WAY-binding sites in normal aging are equivocal, in part because of the greatly variable binding of this ligand. To test the null hypothesis that the binding potential (pB) of 5HT(1A) sites remains constant with age; 19 healthy volunteers aged 23-73 years (8 women, 11 men) underwent positron emission tomography. To determine pBs, we applied a novel tissue reference method of analysis, Estimation of Reversible Ligand Binding and Receptor Density (ERLiBIiRD) (Gjedde, 2003; Rosa-Neto et al, 2004), which extrapolates measures of specific binding to an estimated steady-state. We compared these estimates in the two age groups with results obtained with the conventional Logan Plot and Simplified Reference Tissue Method (SRTM) applied to both regions of interest-based as parametric analyses. The regional distribution of specific binding of free sites [(11)C]WAY-100635 was similar to that reported in previous studies, with the highest pBs in limbic structures and the raphé nuclei. Although the results of the three methods differed, pBs in the elderly subjects consistently were lower than those of young subjects. Thus, the correlation between pB and age applied to regions-of-interest revealed significant decline of pB at the rate of 3 or 4% per decade, and a 10% decline of the global mean 5HT(1A) receptor-pB in elderly relative to young subjects. The results demonstrate that the number of available 5HT(1A)-binding sites declines with age.
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Affiliation(s)
- Mette Møller
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark.
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13
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Lavén M, Itsenko O, Markides K, Långström B. Determination of metabolic stability of positron emission tomography tracers by LC–MS/MS: An example in WAY-100635 and two analogues. J Pharm Biomed Anal 2006; 40:943-51. [PMID: 16388927 DOI: 10.1016/j.jpba.2005.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2004] [Revised: 08/05/2005] [Accepted: 08/06/2005] [Indexed: 10/25/2022]
Abstract
A method is presented for determination of microsomal metabolic stability of potential positron emission tomography (PET) tracers by LC-MS/MS in the lower nm range. The PET tracers used for the study were the serotonin receptor antagonist WAY-100635 and two potential tracer analogues. The sensitivity permitted the substrates to be directly collected from PET radiolabelling batches, containing very low amounts of substance (0.3-7 microg), for subsequent metabolic stability incubations. Sample preparation was minimal, with addition of internal standard, acetonitrile and a fast centrifugation step, as a result of the low protein concentration of the microsome solutions. Linearity (R2 > or = 0.99), precision (inter-assay R.S.D. < 7%) and accuracy (bias < or = 8%) for the tested concentration range 0.5-5 nM proved to be well within accepted limits. No significant differences in metabolic rates were detected using substrates from cold (non-labelling) chemistry syntheses and PET labelling batches, indicating the validity of using substrates from the latter source. A para-methoxy-benzamide analogue (MeO-WAY) displayed a significantly lower rate of metabolism compared to WAY-100635, whereas a para-iodo-benzamide analogue was more susceptible to metabolic transformation. LC-MS/MS Analysis of formed metabolites from WAY-100635 and MeO-WAY suggested similar metabolic pathways, with hydroxylation, demethylation and dearylation reactions. The main metabolic route in humans, amide hydrolysis, was not observed with the rat liver microsome assay.
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Affiliation(s)
- M Lavén
- Department of Analytical Chemistry, Institute of Chemistry, Uppsala University, Box 599, 751 24 Uppsala, Sweden
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McCarron JA, Marchais-Oberwinkler S, Pike VW, Tarkiainen J, Halldin C, Sóvagó J, Gulyas B, Wikström HV, Farde L. Two C-Methyl Derivatives of [11C]WAY-100635 – Effects of an Amido α-Methyl Group on Metabolism and Brain 5-HT1A Receptor Radioligand Behavior in Monkey*. Mol Imaging Biol 2005; 7:209-19. [PMID: 15912425 DOI: 10.1007/s11307-005-4127-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE [carbonyl-11C]N-(2-(1-(4-(2-methoxyphenyl)-piperazinyl)ethyl)-N-pyridinyl)cyclohexanecarboxamide ([carbonyl-11C]WAY-100635) is an effective radioligand for imaging brain 5-HT1A receptors with positron emission tomography (PET). However, this radioligand has some drawbacks for deriving relative regional receptor densities, including rapid metabolism, which acts against accurate definition of an arterial input function for compartmental modeling, and very low nonspecific binding in brain, which detracts from the accuracy of modeling by a simplified reference tissue (cerebellum) approach. Here, in a search for a radioligand that overcomes these limitations, we investigated the effects of introducing a single methyl group at either of the carbon atoms alpha to the amide bond in [11C]WAY-100635. PROCEDURES Ligands with a methyl group on the alpha carbon of the cyclohexyl group (SWAY) or the alpha carbon of the C2H4 linker ((R,S)-JWAY) were synthesized and tested for binding affinity and intrinsic activity at 5-HT1A receptors. SWAY was labeled with carbon-11 (t1/2 = 20.4 minutes; beta+ = 99.8%) in its O-methyl group and (R,S)-JWAY in its carbonyl group. Each radioligand was evaluated by PET experiments in cynomolgus monkey. RESULTS SWAY and (R,S)-JWAY were found to be high-affinity antagonists at 5-HT1A receptors. After injection of [11C]SWAY into monkey, radioactivity uptake in brain reached a maximum of 3% at 4.5 minutes and decreased to 0.7% at 72 minutes. However, over the time span of the experiment, radioactivity concentrations in 5-HT1A receptor-rich brain regions were only fractionally higher than in cerebellum. Radioactivity represented by parent radioligand in plasma was 39% at 45 minutes. After injection of [11C](R,S)-JWAY alone, radioactivity uptake in brain reached a maximum of 4.8% at 2.5 minutes and decreased to 1.2% at 90 minutes. At this time, radioactivity concentration in 5-HT1A receptor-rich brain regions was markedly greater than in cerebellum. In another PET experiment, the monkey was predosed with WAY-100635 before [11C](R,S)-JWAY injection. At 90 minutes after injection, the ratio of radioactivity in 5-HT1A receptor-rich regions to that in cerebellum was reduced to near unity. Radioactivity represented by parent radioligand in plasma was 12% at 45 minutes. CONCLUSIONS [11C](R,S)-JWAY, but not [11C]SWAY, gives a sizeable 5-HT1A receptor-selective PET signal in monkey. The presence of a C-methyl group adjacent to the amide bond in SWAY or (R,S)-JWAY fails to counter metabolism.
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Affiliation(s)
- Julie A McCarron
- MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, London, W12 0NN, UK.
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Garcia R, Xavier C, Paulo A, Santos I, Kniess T, Bergmann R, Wüst F. Synthesis and biological evaluation ofS-[11C]methylated mercaptoimidazole piperazinyl derivatives as potential radioligands for imaging 5-HT1Areceptors by positron emission tomography (PET). J Labelled Comp Radiopharm 2005. [DOI: 10.1002/jlcr.924] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Mundwiler S, Kündig M, Ortner K, Alberto R. A new [2 + 1] mixed ligand concept based on [99(m)Tc(OH2)3(CO)3]+: a basic study. Dalton Trans 2004:1320-8. [PMID: 15252624 DOI: 10.1039/b400220b] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mixed ligand fac-tricarbonyl complexes of the general formula [M(L1)(L2)(CO)3](M = Re, 99(m)Tc, L1= imidazole, benzyl isocyanide, L2 = 1H-imidazole-4-carboxylic acid, pyridine-2,4-dicarboxylic acid, pyridine-2,5-dicarboxylic acid) have been prepared starting from the precursors [M(OH2)3(CO)3]+. The complexes can be obtained in good yield and purity in a two-step procedure by first attaching the bidentate ligand followed by addition of the monodentate. 99mTc compounds can also be prepared at the tracer level in one-pot procedures with L1 and L2 being concomitantly present. This [2 + 1] approach allows the labeling of bioactive molecules containing a monodentate or a bidentate donor site. Examples given in here are N-(tert-butoxycarbonyl)glycyl-N-(3-(imidazol-1-yl)propyl)phenylalaninamide, 5-((3-(imidazol-1-yl)propyl)aminomethyl)-2'-deoxyuridine and 4-(5-isonitrilpentyl)-1-(2-methoxyphenyl)-piperazine as L1 and N-((6-carboxypyridine-3-yl)methyl)glycylphenylalanine as L2. The corresponding second ligand can be used to influence the physico-chemical properties of the conjugate. The crystal structures of [99Tc(OH2)(imc)(CO)3], [Re(OH2)(2,4-dipic)(CO)3], [Re(bic)(2,4-dipic)(CO)3] and [Re(im)(2,5-dipic)(CO)3] are reported.
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Affiliation(s)
- Stefan Mundwiler
- Institute of Inorganic Chemistry, University of Zürich, 8057 Zürich, Switzerland
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Bernard J, Ortner K, Spingler B, Pietzsch HJ, Alberto R. Aqueous synthesis of derivatized cyclopentadienyl complexes of technetium and rhenium directed toward radiopharmaceutical application. Inorg Chem 2003; 42:1014-22. [PMID: 12588133 DOI: 10.1021/ic0204575] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Half-sandwich complexes of the type [(RCOCp)M(CO)(3)] with M = Re and (99(m))Tc were synthesized from [M(OH(2))(3)(CO)(3)](+) in water. The R group can be an organic residue or a receptor binding biomolecule with a spacer to cyclopentadienyl (Cp). This provides a general route to Cp complexes of technetium without the need for starting from [TcBr(CO)(5)]. The X-ray structure of [(C(6)H(5)CH(2)COC(5)H(4))Tc(CO)(3)] has been elucidated. The compound crystallizes in the monoclinic space group P2(1)/c with a = 16.1454(9), b = 7.6300(6), and c = 12.3922(7) A and beta = 107.792(6) degrees. We have chosen a serotonergic receptor ligand (WAY) as an example for the derivatization of Cp with a bioactive molecule. WAY is linked to Cp by an aliphatic chain of variable length. The half-sandwich complexes were prepared from water and organic solvents. The structure of [(WAY4-Cp)Re(CO)(3)] could be elucidated. The compound crystallizes in the monoclinic space group P2(1)/c with a = 15.7112(6), b = 6.8775(3), and c = 25.5217(12) A and beta = 103.778(5) degrees. Quantification of inhibition constants gave a clear structure-activity relationship. A single methylene group between the receptor binding site and the half-sandwich complex gave an IC(50) of 217 nM for HT(1A), whereas a butylene linker resulted in retention of the inhibition constant with an IC(50) of 6 nM with respect to underivatized WAY. For use as radiopharmaceuticals, the compounds have also been prepared with (99m)Tc in quantitative yield.
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Affiliation(s)
- Jonathan Bernard
- Institute of Inorganic Chemistry, University of Zürich, CH-8057 Zürich, Switzerland
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Lu SY, Hong J, Pike VW. Synthesis of NCA [carbonyl-11C]amides by direct reaction ofin situ generated [11C]carboxymagnesium halides with amines under microwave-enhanced conditions. J Labelled Comp Radiopharm 2003. [DOI: 10.1002/jlcr.786] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Papagiannopoulou D, Pirmettis I, Tsoukalas C, Nikoladou L, Drossopoulou G, Dalla C, Pelecanou M, Papadopoulou-Daifotis Z, Papadopoulos M, Chiotellis E. Oxotechnetium 99mTcO[SN(R)S][S] complexes as potential 5-HT1A receptor imaging agents. Nucl Med Biol 2002; 29:825-32. [PMID: 12453592 DOI: 10.1016/s0969-8051(02)00343-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of 99mTcO[SN(R)S][S] complexes carrying the 1-(2-methoxyphenyl)piperazine moiety on the tridentate ligand [SN(R)S] was synthesized. For structural characterization and for in vitro binding assays the analogous oxorhenium complexes were prepared. As demonstrated by appropriate competition binding tests in rat hippocampal preparations, all oxorhenium analogues showed affinity for the 5-HT(1A) receptor binding sites with IC(50) values at the nanomolar range (IC(50)= 5.8-103 nM). All 99mTcO[SN(R)S]/[S] complexes showed significant brain uptake in rats at 2 min p.i. (0.24-1.31% ID). However, a clear correlation between distribution of radioactivity in the brain and distribution of 5-HT(1A) receptors could not be established.
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Affiliation(s)
- D Papagiannopoulou
- Institute of Radioisotopes-Radiodiagnostic Products, National Center for Scientific Research Demokritos, 15310 Ag. Paraskevi, Athens, Greece
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20
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Wald J, Alberto R, Ortner K, Candreia L. Aqueous One-Pot Synthesis of Derivatized Cyclopentadienyl-Tricarbonyl Complexes of (99m) Tc with an In Situ CO Source: Application to a Serotonergic Receptor Ligand. Angew Chem Int Ed Engl 2002; 40:3062-6. [PMID: 12203650 DOI: 10.1002/1521-3773(20010817)40:16<3062::aid-anie3062>3.0.co;2-o] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2001] [Indexed: 11/12/2022]
Abstract
Instant radiopharmaceuticals-just add [(99m) TcO4 ](-) in water! Half-sandwich complexes of the type [(RCOCp)(99m) Tc(CO)3 ] (e.g. 1) were synthesized in a single step in water from [(99m) TcO4 ](-) . The acidification of the Cp ring by a carbonyl substituent and the use of K2 [H3 BCO2 ] as a reducing agent and in situ source of CO are instrumental in the synthesis.
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Affiliation(s)
- J Wald
- Institute of Inorganic Chemistry, University of Zürich Winterthurerstrasse 190, 8057 Zürich, Switzerland, Fax: (+41) 1-635-68-03
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21
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Pike VW, Halldin C, Wikström HV. Radioligands for the study of brain 5-HT1A receptors in vivo. PROGRESS IN MEDICINAL CHEMISTRY 2002; 38:189-247. [PMID: 11774795 DOI: 10.1016/s0079-6468(08)70094-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- V W Pike
- Chemistry and Engineering Group, MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, Ducane Road, London W12 ONN, UK
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22
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Sandell J, Halldin C, Chou YH, Swahn CG, Thorberg SO, Farde L. PET-examination and metabolite evaluation in monkey of [(11)C]NAD-299, a radioligand for visualisation of the 5-HT(1A) receptor. Nucl Med Biol 2002; 29:39-45. [PMID: 11786274 DOI: 10.1016/s0969-8051(01)00272-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
NAD-299 is a selective 5-HT(1A) receptor antagonist that is currently developed as a putative antidepressant drug. [(11)C]NAD-299 was examined in the cynomolgus monkey brain with positron emission tomography (PET). After radioligand injection high accumulation of radioactivity was observed in the frontal and temporal cortex and the raphe nuclei, regions known to contain a high density of 5-HT(1A) receptors. Peak equilibrium appeared already at about 10 min after i.v. injection. Pre-treatment with a high dose of the antagonist WAY-100635 reduced the amount of radioactivity in the cortex and the raphe to the level of the cerebellum. A strong pre-treatment effect could also be achieved using pindolol, a partial agonist at the 5-HT(1A)-receptors. The appearance of labeled metabolites in monkey plasma was measured with HPLC. At 45 minutes after injection 49% (range 27-55%, n = 5) of radioactivity in monkey plasma represented unchanged radioligand. [(11)C]NAD-299 was metabolized to more polar labeled metabolites of which one has the same chromatographic mobility as the descyclobutyl analogue of NAD-299 (NAD-272). The results indicate that [(11)C]NAD-299 has potential as a PET radioligand for studies of 5-HT(1A) receptors in the primate brain.
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Affiliation(s)
- Johan Sandell
- Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-171 76 Stockholm, Sweden.
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Wald J, Alberto R, Ortner K, Candreia L. Aqueous One-Pot Synthesis of Derivatized Cyclopentadienyl-Tricarbonyl Complexes of99mTc with an In Situ CO Source: Application to a Serotonergic Receptor Ligand. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20010817)113:16<3152::aid-ange3152>3.0.co;2-i] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Sandell J, Halldin C, Pike VW, Chou YH, Varnäs K, Hall H, Marchais S, Nowicki B, Wikström HV, Swahn CG, Farde L. New halogenated [11C]WAY analogues, [11C]6FPWAY and [11C]6BPWAY--radiosynthesis and assessment as radioligands for the study of brain 5-HT1A receptors in living monkey. Nucl Med Biol 2001; 28:177-85. [PMID: 11295428 DOI: 10.1016/s0969-8051(00)00181-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
[Carbonyl-(11)C]WAY-100635 ([(11)C]WAY) is an established radioligand for the study of brain serotonin(1A) (5-HT(1A)) receptors in living animals and humans with positron emission tomography (PET). There is a recognised need to develop halogenated ligands for 5-HT(1A) receptors, either for labelling with longer-lived fluorine-18 for more widespread application with PET or with iodine-123 for application with single photon emission tomography (SPET). Here we used autoradiography and PET to assess two new halogenated analogues of WAY, namely 6BPWAY and 6FPWAY [N-(2-(1-(4-(2-methoxyphenyl)-piperazinyl)ethyl))-N-(2-(6-bromo-/fluoro-pyridinyl))cyclohexanecarboxamide] as prospective radioligands, initially using carbon-11 as the radiolabel. Labelling of 6BPWAY and 6FPWAY with carbon-11 was accomplished by acylation of the corresponding secondary amine precursors with [carbonyl-(11)C]cyclohexanecarbonyl chloride. After incubation of human brain crysections with [(11)C]6BPWAY or [(11)C]6FPWAY, the highest accumulation of radioactivity was observed in cortical areas and the hippocampal formation. Both radioligands had high nonspecific binding. There was a rapid accumulation of radioactivity in the monkey brain after intravenous injection of [(11)C]6BPWAY and [(11)C]6FPWAY. High accumulation of radioactivity was observed in the frontal and temporal cortex and the raphe nuclei, areas known to contain a high density of 5-HT(1A) receptors. The ratios of radioactivity in receptor-rich temporal cortex to that in receptor-poor cerebellum at peak equilibrium were 1.9 (at 10 min) and 3.0 at (at 20 min) for [(11)C]6BPWAY and [(11)C]6FPWAY, respectively. In pretreatment experiments with high doses of unlabelled WAY, the level of radioactivity in the frontal and temporal cortex and the raphe nuclei was reduced to the same level as in the cerebellum. Radioactive metabolites of [(11)C]6FPWAY appeared at a rate similar to those for [(11)C]WAY, with 17% of the radioactivity in plasma represented by unchanged radioligand after 40 min. Radioactive metabolites of [(11)C]6BPWAY appeared much more slowly. At 40 min after injection 45% of the radioactivity in plasma still represented unchanged radioligand. The results indicate that 6-pyridinyl radiohalogented analogues of WAY are new leads to radioligands for PET or SPET.
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Affiliation(s)
- J Sandell
- Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-171 76, Stockholm, Sweden.
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Vandecapelle M, De Vos F, Dumont F, Audenaert K, Leysen D, Dierckx RA, Slegers G. Synthesis and preliminary in vivo evaluation of 4-[123I]iodo-N-{2-[4-(6-trifluoromethyl-2-pyridinyl)-1-piperazinyl]ethyl}benzamide, a potential SPECT radioligand for the 5-HT1A receptor. J Labelled Comp Radiopharm 2001. [DOI: 10.1002/jlcr.434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cliffe IA. A retrospect on the discovery of WAY-100635 and the prospect for improved 5-HT(1A) receptor PET radioligands. Nucl Med Biol 2000; 27:441-7. [PMID: 10962248 DOI: 10.1016/s0969-8051(00)00109-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Abstract. An outline is given of the developments that led to the identification of [O-methyl-(11)C]WAY-100635 (4) as the first useful PET ligand for imaging serotonin(1A) (5-HT(1A)) receptors in the living human brain. Recent attempts to develop 5-HT(1A) receptor radioligands superior to 4 are reviewed, and [carbonyl-(11)C]WAY-100635 (6) has been shown to be the best currently available radioligand for human studies. Of other (11)C-radiolabelled compounds, [O-methyl-(11)C](R,S)-CPC-222 (9), DWAY (8), and [(11)C]NAD-299 (14) all demonstrate specific binding to 5-HT(1A) receptors in animals and warrant further expedited studies in humans. The trans-fluorocyclohexane, 12, and fluorobenzene, [(18)F]p-MPPF 13, are highlighted as examples of promising (18)F-labelled ligands.
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Affiliation(s)
- I A Cliffe
- Department of Chemistry, Vernalis Research, Oakdene Court, 613 Reading Road, Winnersh, Workingham RG41 5UA, United Kingdom.
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Abstract
This paper summarizes our work on WAY-100635 and analogues, labeled either with carbon-11 or fluorine-18, as potential radioligands for the 5-hydroxytryptamine(1A) (5-HT(1A)) neuroreceptors. Other facets of our work include: (1) human studies with [O-methyl-(11)C]WAY-100634, the major radioactive metabolite of [O-methyl-(11)C]WAY-100635, and with [(11)C]CPC 222; (2) use of a human liver metabolism model to screen in vitro potential metabolic problems in humans; (3) modification of the "dry method" to prepare [carbonyl-(11)C]WAY-100635; and (4) validation studies in humans with [carbonyl-(11)C]WAY-100635.
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Affiliation(s)
- S Houle
- Vivian M Rakoff PET Centre, Centre for Addiction and Mental Health, Toronto, Canada.
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