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van der Aart J, Yaqub M, Kooijman EJM, Bakker J, Langermans JAM, Schuit RC, Hofman MBM, Christiaans JAM, Lammertsma AA, Windhorst AD, van Berckel BNM. Evaluation of the Novel PET Tracer [ 11C]HACH242 for Imaging the GluN2B NMDA Receptor in Non-Human Primates. Mol Imaging Biol 2020; 21:676-685. [PMID: 30306318 DOI: 10.1007/s11307-018-1284-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE There are currently no positron emission tomography (PET) radiotracers for the GluN2B (NR2B) binding sites of brain N-methyl-D-aspartate (NMDA) receptors. In rats, the GluN2B antagonist Ro25-6981 reduced the binding of N-((5-(4-fluoro-2-[11C]methoxyphenyl)pyridin-3-yl)methyl)cyclopentanamin ([11C]HACH242). This paper reports the evaluation of [11C]HACH242 PET in non-human primates at baseline and following administration of the GluN2B negative allosteric modulator radiprodil. PROCEDURES Eight 90-min dynamic [11C]HACH242 PET scans were acquired in three male anaesthetised rhesus monkeys, including a retest session of subject 1, at baseline and 10 min after intravenous 10 mg/kg radiprodil. Standardised uptake values (SUV) were calculated for 9 brain regions. Arterial blood samples were taken at six timepoints to characterise pharmacokinetics in blood and plasma. Reliable input functions for kinetic modelling could not be generated due to variability in the whole-blood radioactivity measurements. RESULTS [11C]HACH242 entered the brain and displayed fairly uniform uptake. The mean (± standard deviation, SD) Tmax was 17 ± 7 min in baseline scans and 24 ± 15 min in radiprodil scans. The rate of radioligand metabolism in plasma (primarily to polar metabolites) was high, with mean parent fractions of 26 ± 10 % at 20 min and 8 ± 5 % at 85 min. Radiprodil increased [11C]HACH242 whole-brain SUV in the last PET frame by 25 %, 1 %, 3 and 17 % for subjects 1, 2, 3 and retest of subject 1, respectively. The mean brain to plasma ratio was 5.4 ± 2.6, and increased by 39 to 110 % in the radiprodil condition, partly due to lower parent plasma radioactivity of -11 to -56 %. CONCLUSIONS The present results show that [11C]HACH242 has a suitable kinetic profile in the brain and low accumulation of lipophilic radiometabolites. Radiprodil did not consistently change [11C]HACH242 brain uptake. These findings may be explained by variations in cerebral blood flow, a low fraction of specifically bound tracer, or interactions with endogenous NMDA receptor ligands at the binding site. Further experiments of ligand interactions are necessary to facilitate the development of radiotracers for in vivo imaging of the ionotropic NMDA receptor.
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Affiliation(s)
- Jasper van der Aart
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands. .,Centre for Human Drug Research, Leiden, The Netherlands.
| | - Maqsood Yaqub
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands
| | - Esther J M Kooijman
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands
| | - Jaco Bakker
- Animal Science Department, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Jan A M Langermans
- Animal Science Department, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Robert C Schuit
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands
| | - Mark B M Hofman
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands
| | - Johannes A M Christiaans
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands
| | - Adriaan A Lammertsma
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands
| | - Bart N M van Berckel
- Department of Radiology & Nuclear Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam, The Netherlands
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Metaxas A, van Berckel BNM, Klein PJ, Verbeek J, Nash EC, Kooijman EJM, Renjaän VA, Golla SSV, Boellaard R, Christiaans JAM, Windhorst AD, Leysen JE. Binding characterization of N-(2-chloro-5-thiomethylphenyl)-N'-(3-[ 3 H] 3 methoxy phenyl)-N'-methylguanidine ([ 3 H]GMOM), a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist. Pharmacol Res Perspect 2019; 7:e00458. [PMID: 30784206 PMCID: PMC6381215 DOI: 10.1002/prp2.458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 12/01/2018] [Accepted: 12/06/2018] [Indexed: 01/18/2023] Open
Abstract
Labeled with carbon‐11, N‐(2‐chloro‐5‐thiomethylphenyl)‐N′‐(3‐methoxyphenyl)‐N′‐methylguanidine ([11C]GMOM) is currently the only positron emission tomography (PET) tracer that has shown selectivity for the ion‐channel site of N‐methyl‐D‐aspartate (NMDA) receptors in human imaging studies. The present study reports on the selectivity profile and in vitro binding properties of GMOM. The compound was screened on a panel of 80 targets, and labeled with tritium ([3H]GMOM). The binding properties of [3H]GMOM were compared to those of the reference ion‐channel ligand [3H](+)‐dizocilpine maleate ([3H]MK‐801), in a set of concentration‐response, homologous and heterologous inhibition, and association kinetics assays, performed with repeatedly washed rat forebrain preparations. GMOM was at least 70‐fold more selective for NMDA receptors compared to all other targets examined. In homologous inhibition and concentration‐response assays, the binding of [3H]GMOM was regulated by NMDA receptor agonists, albeit in a less prominent manner compared to [3H]MK‐801. Scatchard transformation of homologous inhibition data produced concave upward curves for [3H]GMOM and [3H]MK‐801. The radioligands showed bi‐exponential association kinetics in the presence of 100 μmol L−1l‐glutamate/30 μmol L−1 glycine. [3H]GMOM (3 nmol L−1 and 10 nmol L−1) was inhibited with dual affinity by (+)‐MK‐801, (R,S)‐ketamine and memantine, in both presence and absence of agonists. [3H]MK‐801 (2 nmol L−1) was inhibited in a monophasic manner by GMOM under baseline and combined agonist conditions, with an IC50 value of ~19 nmol L−1. The non‐linear Scatchard plots, biphasic inhibition by open channel blockers, and bi‐exponential kinetics of [3H]GMOM indicate a complex mechanism of interaction with the NMDA receptor ionophore. The implications for quantifying the PET signal of [11C]GMOM are discussed.
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Affiliation(s)
- Athanasios Metaxas
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Bart N M van Berckel
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Pieter J Klein
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Joost Verbeek
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Emily C Nash
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Esther J M Kooijman
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Véronique A Renjaän
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Sandeep S V Golla
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Ronald Boellaard
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Johannes A M Christiaans
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Josée E Leysen
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
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Klein PJ, Schuit RC, Metaxas A, Christiaans JAM, Kooijman E, Lammertsma AA, van Berckel BNM, Windhorst AD. Synthesis, radiolabeling and preclinical evaluation of a [ 11C]GMOM derivative as PET radiotracer for the ion channel of the N-methyl-D-aspartate receptor. Nucl Med Biol 2017; 51:25-32. [PMID: 28528265 DOI: 10.1016/j.nucmedbio.2017.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/29/2017] [Accepted: 05/04/2017] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Presently available PET ligands for the NMDAr ion channel generally suffer from fast metabolism. The purpose of this study was to develop a metabolically more stable ligand for the NMDAr ion channel, taking [11C]GMOM ([11C]1) as the lead compound. METHODS [11C]1, its fluoralkyl analogue [18F]PK209 ([18F]2) and the newly synthesized fluorovinyloxy analogue [11C]7b were evaluated ex vivo in male Wistar rats for metabolic stability. In addition, [11C]7b was subjected to a biodistribution study and its affinity (Ki) and lipophilicity (logD7.4) values were determined. RESULTS The addition of a vinyl chain in the fluoromethoxy moiety did not negatively alter the affinity of [11C]7b for the NMDAr, while lipophilicity was increased. Biodistribution studies showed higher uptake of [11C]7b in forebrain regions compared with cerebellum. Pre-treatment with MK-801 decreased the overall brain uptake significantly, but not in a region-specific manner. 45min after injection 78, 90 and 87% of activity in the brain was due to parent compound for [11C]1, [18F]2 and [11C]7b, respectively. In plasma, 26-31% of activity was due to parent compound. CONCLUSION Complete substitution of the alpha-carbon increased lipophilicity to more favorable values. Substitution of one or more hydrogens of the alpha-carbon atom in the methoxy moiety improved metabolic stability. In plasma, more parent compound was found for [18F]2 and [11C]7b then for [11C]1, although differences were not significant. At 45min, significantly more parent [18F]2 and [11C]7b was measured in the brain compared with [11C]1.
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Affiliation(s)
- Pieter J Klein
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands.
| | - Robert C Schuit
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Athanasios Metaxas
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Johannes A M Christiaans
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Esther Kooijman
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Adriaan A Lammertsma
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Bart N M van Berckel
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
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Klein PJ, Chomet M, Metaxas A, Christiaans JAM, Kooijman E, Schuit RC, Lammertsma AA, van Berckel BNM, Windhorst AD. Synthesis, radiolabeling and evaluation of novel amine guanidine derivatives as potential positron emission tomography tracers for the ion channel of the N-methyl-d-aspartate receptor. Eur J Med Chem 2016; 118:143-60. [PMID: 27128179 DOI: 10.1016/j.ejmech.2016.04.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 04/06/2016] [Accepted: 04/07/2016] [Indexed: 11/25/2022]
Abstract
The N-Methyl-d-Aspartate receptor (NMDAR) is involved in many neurological and psychiatric disorders including Alzheimer's disease and schizophrenia. The aim of this study was to develop a positron emission tomography (PET) ligand to assess the bio-availability of the NMDAR ion channel in vivo. A series of tri-N-substituted diarylguanidines was synthesized and their in vitro binding affinities for the NMDAR ion channel assessed in rat forebrain membrane fractions. Compounds 21, 23 and 26 were radiolabeled with either carbon-11 or fluorine-18 and ex vivo biodistribution and metabolite studies were performed in Wistar rats. Biodistribution studies showed high uptake especially in prefrontal cortex and lowest uptake in cerebellum. Pre-treatment with MK-801, however, did not decrease uptake of the radiolabeled ligands. In addition, all three ligands showed fast metabolism.
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Affiliation(s)
- Pieter J Klein
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands.
| | - Marion Chomet
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Athanasios Metaxas
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Johannes A M Christiaans
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Esther Kooijman
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Robert C Schuit
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Adriaan A Lammertsma
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Bart N M van Berckel
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands
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Golla SSV, Klein PJ, Bakker J, Schuit RC, Christiaans JAM, van Geest L, Kooijman EJM, Oropeza-Seguias GM, Langermans JAM, Leysen JE, Boellaard R, Windhorst AD, van Berckel BNM, Metaxas A. Preclinical evaluation of [(18)F]PK-209, a new PET ligand for imaging the ion-channel site of NMDA receptors. Nucl Med Biol 2014; 42:205-12. [PMID: 25451213 DOI: 10.1016/j.nucmedbio.2014.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 09/17/2014] [Accepted: 09/23/2014] [Indexed: 12/20/2022]
Abstract
INTRODUCTION The present study was designed to assess whether [(18)F]PK-209 (3-(2-chloro-5-(methylthio)phenyl)-1-(3-([(18)F]fluoromethoxy)phenyl)-1-methylguanidine) is a suitable ligand for imaging the ion-channel site of N-methyl-D-aspartate receptors (NMDArs) using positron emission tomography (PET). METHODS Dynamic PET scans were acquired from male rhesus monkeys over 120min, at baseline and after the acute administration of dizocilpine (MK-801, 0.3mg/kg; n=3/condition). Continuous and discrete arterial blood samples were manually obtained, to generate metabolite-corrected input functions. Parametric volume-of-distribution (VT) images were obtained using Logan analysis. The selectivity profile of PK-209 was assessed in vitro, on a broad screen of 79 targets. RESULTS PK-209 was at least 50-fold more selective for NMDArs over all other targets examined. At baseline, prolonged retention of radioactivity was observed in NMDAr-rich cortical regions relative to the cerebellum. Pretreatment with MK-801 reduced the VT of [(18)F]PK-209 compared with baseline in two of three subjects. The rate of radioligand metabolism was high, both at baseline and after MK-801 administration. CONCLUSIONS PK-209 targets the intrachannel site with high selectivity. Imaging of the NMDAr is feasible with [(18)F]PK-209, despite its fast metabolism. Further in vivo evaluation in humans is warranted.
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Affiliation(s)
- Sandeep S V Golla
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Pieter J Klein
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Jaco Bakker
- Biomedical Primate Research Centre, Rijswijk, the Netherlands
| | - Robert C Schuit
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Johannes A M Christiaans
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Leo van Geest
- Biomedical Primate Research Centre, Rijswijk, the Netherlands
| | - Esther J M Kooijman
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Gisela M Oropeza-Seguias
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | | | - Josée E Leysen
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Ronald Boellaard
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Bart N M van Berckel
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands
| | - Athanasios Metaxas
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands.
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Jarho EM, Venäläinen JI, Poutiainen S, Leskinen H, Vepsäläinen J, Christiaans JAM, Forsberg MM, Männistö PT, Wallén EAA. 2(S)-(Cycloalk-1-enecarbonyl)-1-(4-phenyl-butanoyl)pyrrolidines and 2(S)-(aroyl)-1-(4-phenylbutanoyl)pyrrolidines as prolyl oligopeptidase inhibitors. Bioorg Med Chem 2007; 15:2024-31. [PMID: 17215128 DOI: 10.1016/j.bmc.2006.12.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 12/08/2006] [Accepted: 12/22/2006] [Indexed: 11/19/2022]
Abstract
In order to replace the P2-P1 amide group, different 1-cycloalkenyls and 2-aryls were studied in the place of the P1 pyrrolidine group of a 4-phenylbutanoyl-L-Pro-pyrrolidine structure, which is a well-known prolyl oligopeptidase inhibitor SUAM-1221. The 1-cyclopentenyl and the 2-thienyl groups gave novel compounds, which were equipotent with the corresponding pyrrolidine-analog SUAM-1221. It was shown that the P2-P1 amide group of POP inhibitors can be replaced by an alpha,beta-unsaturated carbonyl group or the aryl conjugated carbonyl group.
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Affiliation(s)
- Elina M Jarho
- Department of Pharmaceutical Chemistry, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
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Jarho EM, Venäläinen JI, Juntunen J, Yli-Kokko AL, Vepsäläinen J, Christiaans JAM, Forsberg MM, Järvinen T, Männistö PT, Wallén EAA. An introduction of a pyridine group into the structure of prolyl oligopeptidase inhibitors. Bioorg Med Chem Lett 2006; 16:5590-3. [PMID: 16919454 DOI: 10.1016/j.bmcl.2006.08.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 08/03/2006] [Accepted: 08/03/2006] [Indexed: 10/24/2022]
Abstract
A series of ionizable prolyl oligopeptidase inhibitors were developed through the introduction of a pyridyl group to the P3 position of the prolyl oligopeptidase inhibitor structure. The study was performed on previously developed prolyl oligopeptidase inhibitors with proline mimetics at the P2 position. The 3-pyridyl group resulted in equipotent compounds as compared to the parent compounds. It was shown that the pyridyl group improves water solubility and, in combination with a 5(R)-tert-butyl-l-prolyl group at the P2 position, good lipophilicity can be achieved.
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Affiliation(s)
- Elina M Jarho
- Department of Pharmaceutical Chemistry, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
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Venäläinen JI, Garcia-Horsman JA, Forsberg MM, Jalkanen A, Wallén EAA, Jarho EM, Christiaans JAM, Gynther J, Männistö PT. Binding kinetics and duration of in vivo action of novel prolyl oligopeptidase inhibitors. Biochem Pharmacol 2006; 71:683-92. [PMID: 16405869 DOI: 10.1016/j.bcp.2005.11.029] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 11/24/2005] [Accepted: 11/29/2005] [Indexed: 10/25/2022]
Abstract
Prolyl oligopeptidase (POP) is a serine protease that specifically hydrolyses small peptides at the carboxyl end of the proline residue. POP has gained pharmaceutical interest, since its inhibitors have been shown to have antiamnesic properties in rat. We examined the effect of the 2(S)-substituents CN and COCH(2)OH at the P1 site of the parent inhibitors isophthalic acid 2(S)-(cyclopentanecarbonyl)pyrrolidine-l-prolyl-pyrrolidine amide and 4-phenylbutanoyl-l-prolyl-pyrrolidine and bulky 5-t-butyl group at the P2 site l-prolyl residue of the parent inhibitor 4-phenylbutanoyl-l-prolyl-pyrrolidine on the binding kinetics to the enzyme. In addition, we studied the duration of POP inhibition in the rat tissues in vivo after i.p. administration. CN and COCH(2)OH substituents at the P1 site pyrrolidine group were found to greatly increase the affinity of the inhibitor and the enzyme-inhibitor complex half-life. In addition, 5-t-butyl group at the P2 site l-prolyl residue increased the dissociation half-life of the enzyme-inhibitor complex, without much affecting the inhibitory potency. The duration of the inhibition in the rat tissues followed the inhibition kinetic properties in that the compounds with fast dissociation produced shorter inhibition in the rat tissues than the compounds with slow dissociation. The duration of POP inhibition of compounds was evidently not governed by their serum clearance. The fact that the in vivo pharmacodynamic behaviour of POP inhibitors can be predicted by their in vitro-properties may be of importance when designing therapeutically useful POP inhibitors.
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Affiliation(s)
- Jarkko I Venäläinen
- Department of Pharmacology and Toxicology, University of Kuopio, P.O. Box 1627, Kuopio FI-70211, Finland.
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Jarho EM, Wallén EAA, Christiaans JAM, Forsberg MM, Venäläinen JI, Männistö PT, Gynther J, Poso A. Dicarboxylic Acid Azacycle l-Prolyl-pyrrolidine Amides as Prolyl Oligopeptidase Inhibitors and Three-Dimensional Quantitative Structure−Activity Relationship of the Enzyme−Inhibitor Interactions. J Med Chem 2005; 48:4772-82. [PMID: 16033257 DOI: 10.1021/jm0500020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of dicarboxylic acid azacycle l-prolyl-pyrrolidine amides was synthesized, and their inhibitory activity against prolyl oligopeptidase (POP) from porcine brain was tested. Three different azacycles were tested at the position beyond P3 and six different dicarboxylic acids at the P3 position. l-Prolyl-pyrrolidine and l-prolyl-2(S)-cyanopyrrolidine were used at the P2-P1 positions. The IC(50) values ranged from 0.39 to 19000 nM. The most potent inhibitor was the 3,3-dimethylglutaric acid azepane l-prolyl-2(S)-cyanopyrrolidine amide. Molecular docking (GOLD) was used to analyze binding interactions between different POP inhibitors of this type and the POP enzyme. The data set consisted of the novel inhibitors, inhibitors published previously by our group, and well-known reference compounds. The alignments were further analyzed using comparative molecular similarity indices analysis. The binding of the inhibitors was consistent at the P1-P3 positions. Beyond the P3 position, two different binding modes were found, one that favors lipophilic structures and one that favors nonhydrophobic structures.
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Affiliation(s)
- Elina M Jarho
- Department of Pharmaceutical Chemistry, P.O. Box 1627, FI-70211 Kuopio, Finland.
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Venäläinen JI, Juvonen RO, Garcia-Horsman JA, Wallén EAA, Christiaans JAM, Jarho EM, Gynther J, Männistö PT. Slow-binding inhibitors of prolyl oligopeptidase with different functional groups at the P1 site. Biochem J 2005; 382:1003-8. [PMID: 15217351 PMCID: PMC1133977 DOI: 10.1042/bj20040992] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2004] [Accepted: 06/24/2004] [Indexed: 11/17/2022]
Abstract
POP (prolyl oligopeptidase) specifically hydrolyses a number of small proline-containing peptides at the carboxy end of the proline residue and POP inhibitors have been shown to have cognition-enhancing properties. It has been noted that certain functional groups at the P1 site of the inhibitor, which correspond to the substrate residue on the N-terminal side of the bond to be cleaved, increase the inhibitory potency. However, detailed mechanistic and kinetic analysis of the inhibition has not been studied. In the present study, we examined the effect of different functional groups at the P1 site of the parent inhibitor isophthalic acid bis-(L-prolylpyrrolidine) amide on the binding kinetics to POP. Addition of CHO, CN or COCH(2)OH groups to the P1 site increased the inhibitory potency by two orders of magnitude (K(i)=11.8-0.1 nM) and caused a clear slow-binding inhibition. The inhibitor containing a CHO group had the lowest association rate constant, k(on)=(2.43+/-0.12) x 10(5) M(-1) x s(-1), whereas the inhibitor with a CN group exhibited the fastest binding, k(on)=(12.0+/-0.08)x10(5) M(-1) x s(-1). In addition, the dissociation rate was found to be crucially dependent on the type of the functional group. Compounds with COCH(2)OH and CHO groups had much longer half-lives of dissociation (over 5 h) compared with the compound with the CN group (25 min), although the K(i) values of the compounds were relatively similar. A possibility to optimize the duration of inhibition by changing the functional group at the P1 site is important when planning therapeutically useful POP inhibitors.
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Affiliation(s)
- Jarkko I Venäläinen
- Department of Pharmacology and Toxicology, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland.
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Jarho EM, Venäläinen JI, Huuskonen J, Christiaans JAM, Garcia-Horsman JA, Forsberg MM, Järvinen T, Gynther J, Männistö PT, Wallén EAA. A cyclopent-2-enecarbonyl group mimics proline at the P2 position of prolyl oligopeptidase inhibitors. J Med Chem 2004; 47:5605-7. [PMID: 15509157 DOI: 10.1021/jm049503w] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
With the aim to replace the natural amino acid proline by a proline mimetic structure, a cyclopent-2-enecarbonyl moiety was studied at the P2 position of prolyl oligopeptidase (POP) inhibitors. The cyclopent-2-enecarbonyl moiety proved to be an excellent proline mimetic at the P2 position of POP inhibitors. The replacement is particularly useful when increased lipophilicity is needed.
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Affiliation(s)
- Elina M Jarho
- Department of Pharmaceutical Chemistry, University of Kuopio, P.O. Box 1627, FI-70211 Kuopio, Finland.
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Wallén EAA, Christiaans JAM, Jarho EM, Forsberg MM, Venäläinen JI, Männistö PT, Gynther J. New prolyl oligopeptidase inhibitors developed from dicarboxylic acid bis(l-prolyl-pyrrolidine) amides. J Med Chem 2003; 46:4543-51. [PMID: 14521416 DOI: 10.1021/jm030811o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Isophthalic acid bis(l-prolyl-pyrrolidine) amide is a very potent prolyl oligopeptidase inhibitor, but it has a log P value of -0.2, which is very low for a compound targeted to the brain. Therefore, these types of compounds were further modified to improve the structure-activity relationships, with the focus on increasing the log P value. The inhibitory activity against prolyl oligopeptidase from pig brain was tested in vitro. The most promising compounds resulted from replacing the pyrrolidinyl group at the P5 site by cycloalkyl groups, such as cyclopentyl and cyclohexyl groups, and by a phenyl group. These compounds are slightly more potent, and they have a significantly higher log P value. The potency of these compounds was further increased by replacing the pyrrolidinyl group at the P1 site by 2(S)-cyanopyrrolidinyl and 2(S)-(hydroxyacetyl)pyrrolidinyl groups.
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Affiliation(s)
- Erik A A Wallén
- Department of Pharmaceutical Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland.
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Wallén EAA, Christiaans JAM, Saarinen TJ, Jarho EM, Forsberg MM, Venäläinen JI, Männistö PT, Gynther J. Conformationally rigid N-acyl-5-alkyl-L-prolyl-pyrrolidines as prolyl oligopeptidase inhibitors. Bioorg Med Chem 2003; 11:3611-9. [PMID: 12901906 DOI: 10.1016/s0968-0896(03)00363-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the N-acyl-L-prolyl-pyrrolidine type of prolyl oligopeptidase inhibitors the L-prolyl group was replaced by different 5-alkyl-L-prolyl groups, resulting in a series of N-acyl-5-alkyl-L-prolyl-pyrrolidines. Since N-amides of 5-alkyl-L-prolines are conformationally more rigid than those of L-proline, the main objective was to make more rigid prolyl oligopeptidase inhibitors. In the series of compounds where the N-acyl group was a Boc group, the 5(R)-tert-butyl group increased the potency strongly. A similar effect was not observed for the 5(S)-tert-butyl group. In the series of compounds where the N-acyl group was a 4-phenylbutanoyl group, the 5(R)-tert-butyl, 5(R)-methyl and 5(S)-methyl groups did not have an effect on the potency [the 5(S)-tert-butyl group was not tested in this series]. As an additional effect, the 5-tert-butyl groups increased the log P of the compounds 1.5 log units, which might be beneficial when targeting the compounds to the brain.
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Affiliation(s)
- Erik A A Wallén
- Department of Pharmaceutical Chemistry, University of Kuopio, PO Box 1627, FIN-70211, Kuopio, Finland.
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Wallén EAA, Christiaans JAM, Forsberg MM, Venäläinen JI, Männistö PT, Gynther J. Dicarboxylic acid bis(L-prolyl-pyrrolidine) amides as prolyl oligopeptidase inhibitors. J Med Chem 2002; 45:4581-4. [PMID: 12238937 DOI: 10.1021/jm020966g] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
New dicarboxylic acid bis(L-prolyl-pyrrolidine) amides were synthesized, and their inhibitory activity against prolyl oligopeptidase from pig brain was tested in vitro. As compared with earlier described prolyl oligopeptidase inhibitors, these new compounds have in common an L-prolyl-pyrrolidine moiety, but the typical lipophilic acyl end group is replaced by another L-prolyl-pyrrolidine moiety connected symmetrically with a short dicarboxylic acid linker. These compounds are a new type of peptidomimetic prolyl oligopeptidase inhibitor.
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Affiliation(s)
- Erik A A Wallén
- Department of Pharmaceutical Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland.
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Wallén EAA, Christiaans JAM, Saario SM, Forsberg MM, Venäläinen JI, Paso HM, Männistö PT, Gynther J. 4-Phenylbutanoyl-2(S)-acylpyrrolidines and 4-phenylbutanoyl-L-prolyl-2(S)-acylpyrrolidines as prolyl oligopeptidase inhibitors. Bioorg Med Chem 2002; 10:2199-206. [PMID: 11983517 DOI: 10.1016/s0968-0896(02)00061-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
New 4-phenylbutanoyl-2(S)-acylpyrrolidines and 4-phenylbutanoyl-L-prolyl-2(S)-acylpyrrolidines were synthesized. Their inhibitory activity against prolyl oligopeptidase from pig brain was tested in vitro. In the series of 4-phenylbutanoyl-2(S)-acylpyrrolidines, the cyclopentanecarbonyl and benzoyl derivatives were the best inhibitors having IC(50) values of 30 and 23 nM, respectively. This series of compounds shows that the P1 pyrrolidine ring, which is common in most POP inhibitors, can be replaced by either a cyclopentyl ring or a phenyl ring, causing only a slight decrease in the inhibitory activity. In the series of 4-phenylbutanoyl-L-prolyl-2(S)-acylpyrrolidines the cyclopentanecarbonyl and benzoyl derivatives were not as active as in the series of 4-phenylbutanoyl-2(S)-acylpyrrolidines. The hydroxyacetyl derivative did however show high inhibitory activity. This compound is structurally similar to JTP-4819, which is one of the most potent prolyl oligopeptidase inhibitors. The acyl group in the two series of new compounds seems to bind to different sites of the enzyme, since the second series of new compounds did not show the same cyclopentanecarbonyl or benzoyl specificity as the first series.
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Affiliation(s)
- Erik A A Wallén
- Department of Pharmaceutical Chemistry, University of Kuopio, PO Box 1627, FIN-70211 Kuopio, Finland.
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Kovalainen JT, Christiaans JAM, Ropponen R, Poso A, Peräkylä M, Vepsäläinen J, Laatikainen R, Gynther J. A Proton Relay Process as the Mechanism of Activation of the Histamine H3-Receptor Determined by 1H NMR and ab Initio Quantum Mechanical Calculations. J Am Chem Soc 2000. [DOI: 10.1021/ja993322f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Jari T. Kovalainen
- Contribution from the Department of Pharmaceutical Chemistry, Department of Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Johannes A. M. Christiaans
- Contribution from the Department of Pharmaceutical Chemistry, Department of Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Risto Ropponen
- Contribution from the Department of Pharmaceutical Chemistry, Department of Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Antti Poso
- Contribution from the Department of Pharmaceutical Chemistry, Department of Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Mikael Peräkylä
- Contribution from the Department of Pharmaceutical Chemistry, Department of Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Jouko Vepsäläinen
- Contribution from the Department of Pharmaceutical Chemistry, Department of Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Reino Laatikainen
- Contribution from the Department of Pharmaceutical Chemistry, Department of Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Jukka Gynther
- Contribution from the Department of Pharmaceutical Chemistry, Department of Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
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Kovalainen JT, Wegelius E, Christiaans JAM, Huuskonen J, Gynther J. 2(S)-Amino-3-[1H-imidazol-4(5)-yl]propyl cyclohexylmethyl ether dihydrochloride and 2(S)-amino-3-[1H-imidazol-4(5)-yl]propyl 4-bromobenzyl ether dihydrochloride. Acta Crystallogr C 2000. [DOI: 10.1107/s0108768100005292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Christiaans JAM, Windhorst AD, van der Goot H, Timmerman H. Synthesis and in vitro pharmacology of a series of hybrid molecules possessing 1,4-dihydropyridine calcium-channel blocking activity and histamine H2-agonistic properties. Eur J Med Chem 1994. [DOI: 10.1016/0223-5234(94)90150-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Christiaans JAM, Windhorst AD, Groenenberg PM, van der Goot H, Timmerman H. Synthesis and in vitro pharmacology of new 1,4-dihydropyridines. 1. 2-(ω-Aminoalkylthiomethyl)-1,4-dihydropyridines as potent calcium channel blockers. Eur J Med Chem 1993. [DOI: 10.1016/0223-5234(93)90038-g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Christiaans JAM, van der Goot H, Timmerman H. Synthesis and in vitro pharmacology of a series of new 1,4-dihydropyridines. 2. Diethyl 4-[2-(ω-aminoalkoxy)phenyl]-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylates and their corresponding isothioureas as tools for determining structure-activity relationships. Eur J Med Chem 1993. [DOI: 10.1016/0223-5234(93)90048-j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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