1
|
Blower JE, Ma MT, Al-Salemee FAI, Gee AD. The Hantzsch reaction for nitrogen-13 PET: preparation of [ 13N]nifedipine and derivatives. Chem Commun (Camb) 2021; 57:4962-4965. [PMID: 33876157 PMCID: PMC8132178 DOI: 10.1039/d1cc00495f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/07/2021] [Indexed: 12/31/2022]
Abstract
Nitrogen-13 is an attractive but under-used PET radionuclide for labelling molecules of biological and pharmaceutical interest, complementing other PET radionuclides. Its short half-life (t1/2 = 9.97 min) imposes synthetic challenges, but we have expanded the hitherto limited pool of 13N labelling strategies and tracers by adapting the multicomponent Hantzsch condensation reaction to prepare a library of 13N-labelled 1,4-dihydropyridines from [13N]ammonia, including the widely-used drug nifedipine. This represents a key advance in 13N PET radiochemistry, and will serve to underpin the renewed interest in clinical opportunities offered by short-lived PET tracers.
Collapse
Affiliation(s)
- Julia E Blower
- King's College London, School of Biomedical Engineering and Imaging Sciences, Department of Imaging Chemistry and Biology, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK.
| | - Michelle T Ma
- King's College London, School of Biomedical Engineering and Imaging Sciences, Department of Imaging Chemistry and Biology, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK.
| | - Fahad A I Al-Salemee
- King's College London, School of Biomedical Engineering and Imaging Sciences, Department of Imaging Chemistry and Biology, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK.
| | - Antony D Gee
- King's College London, School of Biomedical Engineering and Imaging Sciences, Department of Imaging Chemistry and Biology, 4th Floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK.
| |
Collapse
|
2
|
Rotstein BH, Liang SH, Belov VV, Livni E, Levine DB, Bonab AA, Papisov MI, Perlis RH, Vasdev N. Practical Radiosynthesis and Preclinical Neuroimaging of [11C]isradipine, a Calcium Channel Antagonist. Molecules 2015; 20:9550-9. [PMID: 26016546 PMCID: PMC4870226 DOI: 10.3390/molecules20069550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 05/19/2015] [Accepted: 05/20/2015] [Indexed: 11/30/2022] Open
Abstract
In the interest of developing in vivo positron emission tomography (PET) probes for neuroimaging of calcium channels, we have prepared a carbon-11 isotopologue of a dihydropyridine Ca2+-channel antagonist, isradipine. Desmethyl isradipine (4-(benzo[c][1,2,5]oxadiazol-4-yl)-5-(isopropoxycarbonyl)-2,6-dimethyl-1,4-dihydropyridine-3-carboxylic acid) was reacted with [11C]CH3I in the presence of tetrabutylammonium hydroxide in DMF in an HPLC injector loop to produce the radiotracer in a good yield (6 ± 3% uncorrected radiochemical yield) and high specific activity (143 ± 90 GBq·µmol−1 at end-of-synthesis). PET imaging of normal rats revealed rapid brain uptake at baseline (0.37 ± 0.08% ID/cc (percent of injected dose per cubic centimeter) at peak, 15–60 s), which was followed by fast washout. After pretreatment with isradipine (2 mg·kg−1, i.p.), whole brain radioactivity uptake was diminished by 25%–40%. This preliminary study confirms that [11C]isradipine can be synthesized routinely for research studies and is brain penetrating. Further work on Ca2+-channel radiotracer development is planned.
Collapse
Affiliation(s)
- Benjamin H Rotstein
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
| | - Steven H Liang
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
| | - Vasily V Belov
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
- Department of Research, Shriners Hospitals for Children-Boston, 51 Blossom Street, Boston, MA 02114, USA.
| | - Eli Livni
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
| | - Dylan B Levine
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
- Department of Research, Shriners Hospitals for Children-Boston, 51 Blossom Street, Boston, MA 02114, USA.
| | - Ali A Bonab
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
- Department of Research, Shriners Hospitals for Children-Boston, 51 Blossom Street, Boston, MA 02114, USA.
| | - Mikhail I Papisov
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
- Department of Research, Shriners Hospitals for Children-Boston, 51 Blossom Street, Boston, MA 02114, USA.
| | - Roy H Perlis
- Department of Psychiatry and Center for Experimental Drugs and Diagnostics, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.
| | - Neil Vasdev
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
| |
Collapse
|
3
|
Dollé F, Hinnen F, Valette H, Fuseau C, Duval R, Péglion JL, Crouzel C. Synthesis of two optically active calcium channel antagonists labelled with carbon-11 for in vivo cardiac PET imaging. Bioorg Med Chem 1997; 5:749-64. [PMID: 9158874 DOI: 10.1016/s0968-0896(97)00024-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
(+/-)-S11568 (1, 3-ethyl-5-methyl-(+/-)-2-[(2-(2-aminoethoxy)ethoxy) methyl]-4-(2,3-dichlorophenyl)-6-methyl-1,4-dihydropyridine-3, 5-dicarboxylate), has an in vitro profile of high potency and of high selectivity for the low-voltage dependent. L-type calcium channel. In in vitro binding studies, it displaced specifically bound (-)-[3H]PN 200-110 (isradipine (2), the reference molecule for in vitro studies) from cardiac and vascular smooth muscle preparations with potencies of 5.6 and 51 nM, respectively. It also appears as a pure pharmacological antagonist acting at a single channel L-type and free of any interaction at the benzothiazepine binding site such as amlodipine (3). Both enantiomers of S11568 have in vitro activities, the dextro isomer S12967 ((+)-1) being 6 to 18-fold less potent than the levo one S12968 ((-)-1). Two couples of optically active labelling precursors of S11568, ((-)-10/(+)-10 and (-)-14/(+)-14) have been synthesized using a modified Hantzsch's dihydropyridine synthesis. In both cases, the enantiomers were separated by preparative chiral HPLC. They both have been independently labelled with carbon-11, using [11C]diazomethane or [11C]iodomethane to give multimilliCurie quantities of (-)-1 (S12968) and (+)-1 (S12967) with high specific activities (500-1000 mCi/mumol, 18.5-37.0 GBq/mumol). Both enantiomers appear suitable for PET experiments: their myocardial concentration increases after a bolus injection to reach a maximum in 2 min and then remains on a plateau with a slight downslope while the blood concentration falls rapidly. Myocardial uptake was threefold higher than lung uptake, leading to a good contrast on PET images. The present preliminary biological results obtained in Beagle dogs showed that both enantiomers have similar myocardial kinetics and in vivo affinity for the left ventricular myocardium.
Collapse
Affiliation(s)
- F Dollé
- Service Hospitalier Frédéric Joliot, CEA, Orsay, France
| | | | | | | | | | | | | |
Collapse
|
4
|
Ishiwata K, Seki H, Ishii K, Ishii S, Nozaki T, Senda M. Synthesis and in vivo evaluation of [11C]semotiadil, a benzothiazine calcium antagonist. Appl Radiat Isot 1994; 45:439-43. [PMID: 8186770 DOI: 10.1016/0969-8043(94)90108-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A carbon-11 labeled benzothiazine calcium antagonist, (+)-(R)-2-[5-methoxy-2-[3-[methyl[2-[(3,4- methylenedioxy)phenoxy]ethyl]amino]propoxy]phenyl]-4-methyl-2H-1,4- benzothiazin-3(4H)-one (semotiadil), and its enantiomer were prepared by N-methylation of the corresponding norderivatives with 11CH3I: decay-corrected radiochemical yields of 16-27% based on 11CH3I, radiochemical, chemical and optical purity of > 99%, sp. act. of 11-50 GBq/mumol and preparation time of 35-40 min. In mice, saturable and stereo-selective uptake in the hippocampus, striatum and hypothalamus was observed. The potential of the compound to visualize the regional brain calcium channels in vivo by positron emission tomography was indicated; however, no promising sign was found in the myocardium.
Collapse
Affiliation(s)
- K Ishiwata
- Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Japan
| | | | | | | | | | | |
Collapse
|
5
|
Valette H, Crouzel C, Syrota A, Fuseau C, Bourachot ML. Canine myocardial dihydropyridine binding sites: a positron emission tomographic study with the calcium channel inhibitor 11C-S11568. Life Sci 1994; 55:1471-7. [PMID: 7968214 DOI: 10.1016/0024-3205(94)00688-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The in vivo determination of the density of dihydropyridine (DHP) binding sites will allow the assessment of pathophysiological changes associated with heart disease. The calcium channel antagonist S 11568: (+/-)(amino-7 dioxa-2,5 heptyl)-2(dichloro -2,3 phenyl) -4 methyl-6dihydro -1,4 pyridine has an in vitro profile of high potency and of high selectivity for the L-type Ca2+ channel. S 11568 was labelled by a reaction between 11C-diazomethane and the precursor 6-(7-amino-2,5-dioxa heptyl)-4-(2,3-dichloro phenyl)-5-(ethoxycarbonyl)-2 methyl-1,4 dihydro nicotinic acid. (+)-PN 200 110, a DHP with in vitro high affinity for the L-type Ca2+ channel, was also radiolabeled. Positron emission tomographic (PET) studies of both 11C-DHP myocardial uptake were performed in Beagle dogs. 11C-(+)-PN 200 110 had a rapid wash-out from myocardium. In contrary, after a bolus injection, 11C-S 11568 myocardial concentration increased to reach a maximum in 1-2 minutes and then remained in a plateau with a slight downslope while the blood concentration fell rapidly. Myocardial uptake was 2 to 4 fold higher than lung uptake, leading to a good contrast on PET images. Pre-treatment with unlabeled S 11568 (2 mumol/kg or 6 mumol/kg over 15 minutes) reduced myocardial uptake by 60% and 80%, respectively. Specific binding was estimated during a displacement experiment: bolus of unlabeled S 11568: 1 mumol/kg followed by a continuous infusion of 3 mumol/kg over 2 hours. It was found to represent 80% of the total binding. To assess influence of S 11568 on coronary blood flow and therefore on the myocardial tracer delivery, coronary blood flow was measured using 15O-H2O and PET at baseline and following bolus injections of 0.4, 0.8, 2 mumol/kg of S 11568. Only the higher dose increased coronary blood flow. This is the in vivo demonstration of the binding characteristics to myocardial tissue of a DHP ligand. Such properties make S 11568 suitable for PET experiments. The studies of DHP binding sites will provided new insights concerning physiological situations as well as heart disease.
Collapse
Affiliation(s)
- H Valette
- Service Hospitalier Frédéric Joliot, DRIPP-CEA, Orsay, France
| | | | | | | | | |
Collapse
|