1
|
Eastham K, Scattergood PA, Chu D, Boota RZ, Soupart A, Alary F, Dixon IM, Rice CR, Hardman SJO, Elliott PIP. Not All 3MC States Are the Same: The Role of 3MC cis States in the Photochemical N ∧N Ligand Release from [Ru(bpy) 2(N ∧N)] 2+ Complexes. Inorg Chem 2022; 61:19907-19924. [PMID: 36450138 DOI: 10.1021/acs.inorgchem.2c03146] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Ruthenium(II) complexes feature prominently in the development of agents for photoactivated chemotherapy; however, the excited-state mechanisms by which photochemical ligand release operates remain unclear. We report here a systematic experimental and computational study of a series of complexes [Ru(bpy)2(N∧N)]2+ (bpy = 2,2'-bipyridyl; N∧N = bpy (1), 6-methyl-2,2'-bipyridyl (2), 6,6'-dimethyl-2,2'-bipyridyl (3), 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole (4), 1-benzyl-4-(6-methylpyrid-2-yl)-1,2,3-triazole (5), 1,1'-dibenzyl-4,4'-bi-1,2,3-triazolyl (6)), in which we probe the contribution to the promotion of photochemical N∧N ligand release of the introduction of sterically encumbering methyl substituents and the electronic effect of replacement of pyridine by 1,2,3-triazole donors in the N∧N ligand. Complexes 2 to 6 all release the ligand N∧N on irradiation in acetonitrile solution to yield cis-[Ru(bpy)2(NCMe)2]2+, with resultant photorelease quantum yields that at first seem counter-intuitive and span a broad range. The data show that incorporation of a single sterically encumbering methyl substituent on the N∧N ligand (2 and 5) leads to a significantly enhanced rate of triplet metal-to-ligand charge-transfer (3MLCT) state deactivation but with little promotion of photoreactivity, whereas replacement of pyridine by triazole donors (4 and 6) leads to a similar rate of 3MLCT deactivation but with much greater photochemical reactivity. The data reported here, discussed in conjunction with previously reported data on related complexes, suggest that monomethylation in 2 and 5 sterically inhibits the formation of a 3MCcis state but promotes the population of 3MCtrans states which rapidly deactivate 3MLCT states and are prone to mediating ground-state recovery. On the other hand, increased photochemical reactivity in 4 and 6 seems to stem from the accessibility of 3MCcis states. The data provide important insights into the excited-state mechanism of photochemical ligand release by Ru(II) tris-bidentate complexes.
Collapse
Affiliation(s)
- Katie Eastham
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Paul A Scattergood
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Danny Chu
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Rayhaan Z Boota
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Adrien Soupart
- Laboratoire de Chimie et Physique Quantiques, UMR 5626 CNRS/Université Toulouse 3─Paul Sabatier, Université de Toulouse, 118 route de Narbonne, Toulouse 31062, France
| | - Fabienne Alary
- Laboratoire de Chimie et Physique Quantiques, UMR 5626 CNRS/Université Toulouse 3─Paul Sabatier, Université de Toulouse, 118 route de Narbonne, Toulouse 31062, France
| | - Isabelle M Dixon
- Laboratoire de Chimie et Physique Quantiques, UMR 5626 CNRS/Université Toulouse 3─Paul Sabatier, Université de Toulouse, 118 route de Narbonne, Toulouse 31062, France
| | - Craig R Rice
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Samantha J O Hardman
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Paul I P Elliott
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.,Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| |
Collapse
|
2
|
Romanov AS, Linnolahti M, Bochmann M. Synthesis and photophysical properties of linear gold(I) complexes based on a CCC carbene. Dalton Trans 2021; 50:17156-17164. [PMID: 34781337 PMCID: PMC8631002 DOI: 10.1039/d1dt03393j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction between allenylpyridine (L1) and (Me2S)AuCl resulted in the quantitative formation of the (Indolizy)gold chloride complex 1 (Indolizy = indolizin-2-ylidene). The reaction of 1 with carbazole in the presence of KOtBu affords the corresponding (Indolizy)Au(Cz) complex 2. Both compounds show high air- and temperature stability. The crystal structure of 2 confirmed the linear co-planar geometry. Complex 1 shows an intense low energy absorption of mixed character in the UV-vis spectrum, ascribed to intraligand and (M + Hal)L charge transfer processes, and exhibits bright yellow phosphorescence with an excited state lifetime of 62.8 μs in the crystal and a luminescence quantum yield up to 65%. On the other hand, the carbazolate complex 2 in a polystyrene matrix shows bright red delayed fluorescence at 617 nm with a sub-microsecond excited state lifetime and a quantum yield of 21.6%.
Collapse
Affiliation(s)
- Alexander S Romanov
- School of Chemistry, University of East Anglia, Earlham Road, Norwich, NR4 7TJ, UK. .,School of Chemistry, University of Manchester, Manchester, M13 9PL, UK.
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, FI-80101 Joensuu, Finland.
| | - Manfred Bochmann
- School of Chemistry, University of East Anglia, Earlham Road, Norwich, NR4 7TJ, UK.
| |
Collapse
|
3
|
Ricart-Ortega M, Berizzi AE, Catena J, Malhaire F, Muñoz L, Serra C, Lebon G, Goudet C, Llebaria A. Development and validation of a mass spectrometry binding assay for mGlu5 receptor. Anal Bioanal Chem 2020; 412:5525-5535. [PMID: 32564119 DOI: 10.1007/s00216-020-02772-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/03/2020] [Accepted: 06/12/2020] [Indexed: 10/24/2022]
Abstract
Mass spectrometry (MS) binding assays are a label-free alternative to radioligand or fluorescence binding assays, so the readout is based on direct mass spectrometric detection of the test ligand. The study presented here describes the development and validation of a highly sensitive, rapid, and robust MS binding assay for the quantification of the binding of the metabotropic glutamate 5 (mGlu5) negative allosteric modulator (NAM), MPEP (2-methyl-6-phenylethynylpyridine) at the mGlu5 allosteric binding site. The LC-ESI-MS/MS (liquid chromatography-electrospray ionization-tandem mass spectrometric) analytical method was established and validated with a deuterated analogue of MPEP as an internal standard. The developed MS binding assay described here allowed for the determination of MS binding affinity estimates that were in agreement with affinity estimates obtained from a tritiated MPEP radioligand saturation binding assay, indicating the suitability of this methodology for determining affinity estimates for compounds that target mGlu5 allosteric binding sites. Graphical abstract.
Collapse
Affiliation(s)
- Maria Ricart-Ortega
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain.,IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France
| | - Alice E Berizzi
- IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France
| | - Juanlo Catena
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain
| | - Fanny Malhaire
- IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France
| | - Lourdes Muñoz
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain.,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain
| | - Carmen Serra
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain.,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain
| | - Guillaume Lebon
- IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France
| | - Cyril Goudet
- IGF, CNRS, INSERM, University of Montpellier, 34094, Montpellier, France.
| | - Amadeu Llebaria
- MCS, Laboratory of Medicinal Chemistry & Synthesis, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain. .,SIMchem, Service of Synthesis of High Added Value Molecules, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18, 08034, Barcelona, Spain.
| |
Collapse
|
4
|
Qian M, Wouters E, Dalton JAR, Risseeuw MDP, Crans RAJ, Stove C, Giraldo J, Van Craenenbroeck K, Van Calenbergh S. Synthesis toward Bivalent Ligands for the Dopamine D 2 and Metabotropic Glutamate 5 Receptors. J Med Chem 2018; 61:8212-8225. [PMID: 30180563 DOI: 10.1021/acs.jmedchem.8b00671] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In this study, we designed and synthesized heterobivalent ligands targeting heteromers consisting of the metabotropic glutamate 5 receptor (mGluR5) and the dopamine D2 receptor (D2R). Bivalent ligand 22a with a linker consisting of 20 atoms showed 4-fold increase in affinity for cells coexpressing D2R and mGluR5 compared to cells solely expressing D2R. Likewise, the affinity of 22a for mGluR5 increased 2-fold in the coexpressing cells. Additionally, 22a exhibited a 5-fold higher mGluR5 affinity than its monovalent precursor 21a in cells coexpressing D2R and mGluR5. These results indicate that 22a is able to bridge binding sites on both receptors constituting the heterodimer. Likewise, cAMP assays revealed that 22a had a 4-fold higher potency in stable D2R and mGluR5 coexpressing cell lines than 1. Furthermore, molecular modeling reveals that 22a is able to simultaneously bind both receptors by passing between the TM5-TM6 interface and establishing six protein-ligand H-bonds.
Collapse
Affiliation(s)
- Mingcheng Qian
- Laboratory for Medicinal Chemistry (FFW) , Ghent University , Ottergemsesteenweg 460 , B-9000 Ghent , Belgium.,Laboratory of Toxicology , Ghent University , Ottergemsesteenweg 460 , B-9000 Ghent , Belgium
| | - Elise Wouters
- Laboratory of Toxicology , Ghent University , Ottergemsesteenweg 460 , B-9000 Ghent , Belgium
| | - James A R Dalton
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística, Institut de Neurociències , Universitat Autònoma de Barcelona , 08193 Bellaterra , Spain.,Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM , Universitat Autònoma de Barcelona , 08193 Bellaterra , Spain.,Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències , Universitat Autònoma de Barcelona , 08193 Bellaterra , Spain
| | - Martijn D P Risseeuw
- Laboratory for Medicinal Chemistry (FFW) , Ghent University , Ottergemsesteenweg 460 , B-9000 Ghent , Belgium
| | - René A J Crans
- Laboratory of Toxicology , Ghent University , Ottergemsesteenweg 460 , B-9000 Ghent , Belgium
| | - Christophe Stove
- Laboratory of Toxicology , Ghent University , Ottergemsesteenweg 460 , B-9000 Ghent , Belgium
| | - Jesús Giraldo
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Unitat de Bioestadística, Institut de Neurociències , Universitat Autònoma de Barcelona , 08193 Bellaterra , Spain.,Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM , Universitat Autònoma de Barcelona , 08193 Bellaterra , Spain.,Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències , Universitat Autònoma de Barcelona , 08193 Bellaterra , Spain
| | | | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry (FFW) , Ghent University , Ottergemsesteenweg 460 , B-9000 Ghent , Belgium
| |
Collapse
|
5
|
Gouda MA, Hussein BHM, Helal MH, Salem MA. A Review: Synthesis and Medicinal Importance of Nicotinonitriles and Their Analogous. J Heterocycl Chem 2018. [DOI: 10.1002/jhet.3188] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Moustafa A. Gouda
- Department of Chemistry, Faculty of Science and Arts, Ulla; Taibah University; Medina Saudi Arabia
- Department of Chemistry, Faculty of Science; Mansoura University; El-Gomhoria Street Mansoura 35516 Egypt
| | - Belal H. M. Hussein
- Department of Chemistry, Faculty of Science and Arts, Ulla; Taibah University; Medina Saudi Arabia
- Department of Chemistry, Faculty of Science; Suez Canal University; Ismailia Egypt
| | - Mohamed H. Helal
- Department of Chemistry, Faculty of Arts and Science; Northern Border University; Rafha Saudi Arabia
- Department of Chemistry, Faculty of Science; Al-Azhar University; 11284 Nasr City Cairo Egypt
| | - Mohammed A. Salem
- Department of Chemistry, Faculty of Science; Al-Azhar University; 11284 Nasr City Cairo Egypt
- Department of Chemistry, Faculty of Arts and Science; King Khalid University; Mohail Asir Saudi Arabia
| |
Collapse
|
6
|
Mu B, Mu L, Schibli R, Ametamey SM, Milicevic Sephton S. Improved Syntheses of the mGlu5 Antagonists MMPEP and MTEP Using Sonogashira Cross-Coupling. Pharmaceuticals (Basel) 2018; 11:ph11010024. [PMID: 29461503 PMCID: PMC5874720 DOI: 10.3390/ph11010024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 02/10/2018] [Accepted: 02/12/2018] [Indexed: 11/16/2022] Open
Abstract
The Sonogashira cross-coupling, a key step in the syntheses of the mGlu5 antagonists MMPEP and MTEP, provided an improved three-step method for the preparation of MMPEP in 62% overall yield. Using Spartan molecular modeling kit an explanation for the failure to employ analogues method in the synthesis of MTEP was sought. The DFT calculations indicated that meaningful isolated yields were obtained when the HOMO energy of the aryl halide was lower than the HOMO energy of the respective alkyne.
Collapse
Affiliation(s)
- Boshuai Mu
- Center of Radiopharmaceutical Sciences of ETH, PSI and USZ, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
| | - Linjing Mu
- Center of Radiopharmaceutical Sciences of ETH, PSI and USZ, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
- Department of Nuclear Medicine, University Hospital Zurich, Ramistrasse 101, 8003 Zurich, Switzerland.
| | - Roger Schibli
- Center of Radiopharmaceutical Sciences of ETH, PSI and USZ, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
- Department of Nuclear Medicine, University Hospital Zurich, Ramistrasse 101, 8003 Zurich, Switzerland.
| | - Simon M Ametamey
- Center of Radiopharmaceutical Sciences of ETH, PSI and USZ, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
| | - Selena Milicevic Sephton
- Center of Radiopharmaceutical Sciences of ETH, PSI and USZ, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
- Department of Nuclear Medicine, University Hospital Zurich, Ramistrasse 101, 8003 Zurich, Switzerland.
- Molecular Imaging Chemistry Laboratory, Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Box 65 Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK..
| |
Collapse
|
7
|
Christopher JA, Orgován Z, Congreve M, Doré AS, Errey JC, Marshall FH, Mason JS, Okrasa K, Rucktooa P, Serrano-Vega MJ, Ferenczy GG, Keserű GM. Structure-Based Optimization Strategies for G Protein-Coupled Receptor (GPCR) Allosteric Modulators: A Case Study from Analyses of New Metabotropic Glutamate Receptor 5 (mGlu5) X-ray Structures. J Med Chem 2018; 62:207-222. [DOI: 10.1021/acs.jmedchem.7b01722] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- John A. Christopher
- Heptares Therapeutics Ltd., BioPark, Welwyn Garden City, Hertfordshire AL7 3AX, U.K
| | - Zoltán Orgován
- Medicinal Chemistry Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 2 Magyar tudósok körútja, Budapest H-1117, Hungary
| | - Miles Congreve
- Heptares Therapeutics Ltd., BioPark, Welwyn Garden City, Hertfordshire AL7 3AX, U.K
| | - Andrew S. Doré
- Heptares Therapeutics Ltd., BioPark, Welwyn Garden City, Hertfordshire AL7 3AX, U.K
| | - James C. Errey
- Heptares Therapeutics Ltd., BioPark, Welwyn Garden City, Hertfordshire AL7 3AX, U.K
| | - Fiona H. Marshall
- Heptares Therapeutics Ltd., BioPark, Welwyn Garden City, Hertfordshire AL7 3AX, U.K
| | - Jonathan S. Mason
- Heptares Therapeutics Ltd., BioPark, Welwyn Garden City, Hertfordshire AL7 3AX, U.K
| | - Krzysztof Okrasa
- Heptares Therapeutics Ltd., BioPark, Welwyn Garden City, Hertfordshire AL7 3AX, U.K
| | - Prakash Rucktooa
- Heptares Therapeutics Ltd., BioPark, Welwyn Garden City, Hertfordshire AL7 3AX, U.K
| | | | - György G. Ferenczy
- Medicinal Chemistry Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 2 Magyar tudósok körútja, Budapest H-1117, Hungary
| | - György M. Keserű
- Medicinal Chemistry Research Group, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 2 Magyar tudósok körútja, Budapest H-1117, Hungary
| |
Collapse
|
8
|
Simic M, Paunovic N, Boric I, Randjelovic J, Vojnovic S, Nikodinovic-Runic J, Pekmezovic M, Savic V. Functionalised isocoumarins as antifungal compounds: Synthesis and biological studies. Bioorg Med Chem Lett 2016; 26:235-9. [DOI: 10.1016/j.bmcl.2015.08.086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/26/2015] [Accepted: 08/29/2015] [Indexed: 02/01/2023]
|
9
|
Wu N, Melan CFC, Stevenson KA, Fleischel O, Guo H, Habib F, Holmberg RJ, Murugesu M, Mosey NJ, Nierengarten H, Petitjean A. Systematic study of the synthesis and coordination of 2-(1,2,3-triazol-4-yl)-pyridine to Fe(ii), Ni(ii) and Zn(ii); ion-induced folding into helicates, mesocates and larger architectures, and application to magnetism and self-selection. Dalton Trans 2015; 44:14991-5005. [DOI: 10.1039/c5dt00233h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The 2-pyridyl–1,2,3-triazole chelate was found to display unique coordination properties.
Collapse
Affiliation(s)
- Nan Wu
- Department of Chemistry
- Queen's University
- Kingston
- Canada
| | | | | | | | - Huan Guo
- Department of Chemistry
- Queen's University
- Kingston
- Canada
| | - Fatemah Habib
- Department of Chemistry
- University of Ottawa
- Ottawa K1N6N5
- Canada
| | | | | | | | - Hélène Nierengarten
- Service de Spectrométrie de masse de l'Institut de Chimie de Strasbourg
- 67000 Strasbourg
- France
| | | |
Collapse
|
10
|
Gregory KJ, Nguyen ED, Malosh C, Mendenhall JL, Zic JZ, Bates BS, Noetzel MJ, Squire EF, Turner EM, Rook JM, Emmitte KA, Stauffer SR, Lindsley CW, Meiler J, Conn PJ. Identification of specific ligand-receptor interactions that govern binding and cooperativity of diverse modulators to a common metabotropic glutamate receptor 5 allosteric site. ACS Chem Neurosci 2014; 5:282-95. [PMID: 24528109 DOI: 10.1021/cn400225x] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A common metabotropic glutamate receptor 5 (mGlu5) allosteric site is known to accommodate diverse chemotypes. However, the structural relationship between compounds from different scaffolds and mGlu5 is not well understood. In an effort to better understand the molecular determinants that govern allosteric modulator interactions with mGlu5, we employed a combination of site-directed mutagenesis and computational modeling. With few exceptions, six residues (P654, Y658, T780, W784, S808, and A809) were identified as key affinity determinants across all seven allosteric modulator scaffolds. To improve our interpretation of how diverse allosteric modulators occupy the common allosteric site, we sampled the wealth of mGlu5 structure-activity relationship (SAR) data available by docking 60 ligands (actives and inactives) representing seven chemical scaffolds into our mGlu5 comparative model. To spatially and chemically compare binding modes of ligands from diverse scaffolds, the ChargeRMSD measure was developed. We found a common binding mode for the modulators that placed the long axes of the ligands parallel to the transmembrane helices 3 and 7. W784 in TM6 not only was identified as a key NAM cooperativity determinant across multiple scaffolds, but also caused a NAM to PAM switch for two different scaffolds. Moreover, a single point mutation in TM5, G747V, altered the architecture of the common allosteric site such that 4-nitro-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (VU29) was noncompetitive with the common allosteric site. Our findings highlight the subtleties of allosteric modulator binding to mGlu5 and demonstrate the utility in incorporating SAR information to strengthen the interpretation and analyses of docking and mutational data.
Collapse
Affiliation(s)
- Karen J. Gregory
- Drug Discovery
Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
The copper-catalyzed azide-alkyne cycloaddition (CuAAC) is a highly effective method for the selective incorporation of deuterium atom into the C-5 position of the 1,2,3-triazole structure. Reactions of alkynes and azides can be conveniently carried out in a biphasic medium of CH(2)Cl(2)/D(2)O, using the CuSO(4)/Na ascorbate system. The mildness of the method renders it applicable to substrates of relatively high complexity, such as nucleosides. Good yields and high levels of deuterium incorporation were observed. A reaction conducted in equimolar H(2)O and D(2)O showed 2.7 times greater incorporation of hydrogen atom as compared to deuterium. This is consistent with the H(+) and D(+) ion concentrations in H(2)O and D(2)O, respectively. With appropriately deuterated precursors, partially to fully deuterated triazoles were assembled where the final deuterium atom was incorporated in the triazole-forming step.
Collapse
Affiliation(s)
- Hari K. Akula
- Department of Chemistry, The City College and The City University of New York, 160 Convent Avenue, New York, NY 10031-9198
| | - Mahesh K. Lakshman
- Department of Chemistry, The City College and The City University of New York, 160 Convent Avenue, New York, NY 10031-9198
| |
Collapse
|
12
|
Gichinga MG, Olson JP, Butala E, Navarro HA, Gilmour BP, Mascarella SW, Carroll FI. Synthesis and Evaluation of Metabotropic Glutamate Receptor Subtype 5 Antagonists Based on Fenobam(). ACS Med Chem Lett 2011; 2:882-884. [PMID: 22523618 DOI: 10.1021/ml200162f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
In an effort to discover potent and selective metabotropic glutamate receptor subtype 5 (mGluR5) antagonists, 15 tetrahydropyrimidinone analogues of 1-(3-chlorophenyl)-3-(1-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl)-urea (fenobam) were synthesized. These compounds were evaluated for antagonism of glutamate-mediated mobilization of internal calcium in an mGluR5 in vitro efficacy assay. The IC(50) value for 1-(3-chlorophenyl)-3-(1-methyl-4-oxo-1,4,5,6-tetrahydropyridine)urea (4g) was essentially identical to that of fenobam.
Collapse
Affiliation(s)
- Moses G. Gichinga
- Center for Organic and Medicinal
Chemistry, Research Triangle Institute,
P.O. Box 12194, Research
Triangle Park, North Carolina 27709, United States
| | - Jeremy P. Olson
- Center for Organic and Medicinal
Chemistry, Research Triangle Institute,
P.O. Box 12194, Research
Triangle Park, North Carolina 27709, United States
| | - Elizabeth Butala
- Center for Organic and Medicinal
Chemistry, Research Triangle Institute,
P.O. Box 12194, Research
Triangle Park, North Carolina 27709, United States
| | - Hernán A. Navarro
- Center for Organic and Medicinal
Chemistry, Research Triangle Institute,
P.O. Box 12194, Research
Triangle Park, North Carolina 27709, United States
| | - Brian P. Gilmour
- Center for Organic and Medicinal
Chemistry, Research Triangle Institute,
P.O. Box 12194, Research
Triangle Park, North Carolina 27709, United States
| | - S. Wayne Mascarella
- Center for Organic and Medicinal
Chemistry, Research Triangle Institute,
P.O. Box 12194, Research
Triangle Park, North Carolina 27709, United States
| | - F. Ivy Carroll
- Center for Organic and Medicinal
Chemistry, Research Triangle Institute,
P.O. Box 12194, Research
Triangle Park, North Carolina 27709, United States
| |
Collapse
|
13
|
Potent mGluR5 antagonists: pyridyl and thiazolyl-ethynyl-3,5-disubstituted-phenyl series. Bioorg Med Chem Lett 2011; 21:3243-7. [PMID: 21546249 DOI: 10.1016/j.bmcl.2011.04.047] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/11/2011] [Accepted: 04/12/2011] [Indexed: 11/21/2022]
Abstract
We report the synthesis of four series of 3,5-disubstituted-phenyl ligands targeting the metabotropic glutamate receptor subtype 5: (2-methylthiazol-4-yl)ethynyl (1a-j,), (6-methylpyridin-2-yl)ethynyl (2a-j), (5-methylpyridin-2-yl)ethynyl (3a-j,), and (pyridin-2-yl)ethynyl (4a-j,). The compounds were evaluated for antagonism of glutamate-mediated mobilization of internal calcium in an mGluR5 in vitro assay. All compounds were found to be full antagonists and exhibited low nanomolar to subnanomolar activity.
Collapse
|
14
|
|
15
|
Zhang P, Zou MF, Rodriguez AL, Conn PJ, Newman AH. Structure-activity relationships in a novel series of 7-substituted-aryl quinolines and 5-substituted-aryl benzothiazoles at the metabotropic glutamate receptor subtype 5. Bioorg Med Chem 2010; 18:3026-35. [PMID: 20382541 DOI: 10.1016/j.bmc.2010.03.053] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 03/18/2010] [Accepted: 03/23/2010] [Indexed: 10/19/2022]
Abstract
The metabotropic glutamate receptor subtype 5 (mGluR5) has been implicated in numerous neuropsychiatric disorders including addiction. We have discovered that the rigid diaryl alkyne template, derived from the potent and selective noncompetitive mGluR5 antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP), can serve to guide the design of novel quinoline analogues and pharmacophore optimization has resulted in potent mGluR5 noncompetitive antagonists (EC(50) range 60-100 nM) in the quinoline series.
Collapse
Affiliation(s)
- Peng Zhang
- Medicinal Chemistry Section, National Institute on Drug Abuse-Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA
| | | | | | | | | |
Collapse
|
16
|
Kulkarni SS, Zou MF, Cao J, Deschamps JR, Rodriguez AL, Conn PJ, Newman AH. Structure-activity relationships comparing N-(6-methylpyridin-yl)-substituted aryl amides to 2-methyl-6-(substituted-arylethynyl)pyridines or 2-methyl-4-(substituted-arylethynyl)thiazoles as novel metabotropic glutamate receptor subtype 5 antagonists. J Med Chem 2009; 52:3563-75. [PMID: 19445453 DOI: 10.1021/jm900172f] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The metabotropic glutamate receptor subtype 5 (mGluR5) has been implicated in anxiety, depression, pain, mental retardation, and addiction. The potent and selective noncompetitive mGluR5 antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP, 1) has been a critically important tool used to further elucidate the role of mGluR5 in these CNS disorders. In an effort to provide novel and structurally diverse selective mGluR5 antagonists, we previously described a set of analogues with moderate activity wherein the alkyne bond was replaced with an amide group. In the present report, extended series of both amide and alkyne-based ligands were synthesized. MGluR5 binding and functional data were obtained that identified (1) several novel alkynes with comparable affinities to 1 at mGluR5 (e.g., 10 and 20-23), but (2) most structural variations to the amide template were not well tolerated, although a few potent amides were discovered (e.g., 55 and 56). Several of these novel analogues show drug-like physical properties (e.g., cLogP range = 2-5) that support their use for in vivo investigation into the role of mGluR5 in CNS disorders.
Collapse
Affiliation(s)
- Santosh S Kulkarni
- Medicinal Chemistry Section, National Institute on Drug Abuse-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | | | | | | | | | | | | |
Collapse
|
17
|
Yamada S, Toshimitsu A, Takahashi Y. A significant substituent effect on the regioselectivity in addition of alkynes to 3-substituted pyridines. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.01.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
18
|
Carroll FI. Antagonists at metabotropic glutamate receptor subtype 5: structure activity relationships and therapeutic potential for addiction. Ann N Y Acad Sci 2008; 1141:221-32. [PMID: 18991960 DOI: 10.1196/annals.1441.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
As a result of intensive investigation, particularly in the pharmaceutical industry, a number of potent and selective metabotropic glutamate receptor subtype 5 (mGluR5) antagonists have been discovered. The structure activity relationship studies that led to the discovery of these mGluR5 antagonists are presented in this review. Results from studies on selected mGluR5 antagonists in animal models that simulate drug reward, reinforcement, and relapse appear promising. The comorbidity between drug abuse and anxiety and depression make drugs active in these disorders of great interest. Clinical studies showed that the mGluR5 antagonist fenobam was an active anxiolytic drug. Several new mGluR5 antagonists produced anxiolytic and antidepressant-like effects in animal models of these disorders. The results from the clinical and animal studies provide information for new approaches to finding mechanistically distinct pharmacotherapies to help patients achieve and maintain abstinence from cocaine, methamphetamine, opiates, ethanol, and nicotine (smoking).
Collapse
Affiliation(s)
- F Ivy Carroll
- Center for Organic and Medicinal Chemistry, Research Triangle Institute, Research Triangle Park, NC 27709-2194, USA.
| |
Collapse
|
19
|
Wang JQ, Tueckmantel W, Zhu A, Pellegrino D, Brownell AL. Synthesis and preliminary biological evaluation of 3-[(18)F]fluoro-5-(2-pyridinylethynyl)benzonitrile as a PET radiotracer for imaging metabotropic glutamate receptor subtype 5. Synapse 2008; 61:951-61. [PMID: 17787003 DOI: 10.1002/syn.20445] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The metabotropic glutamate receptor subtype 5 (mGluR5) has been reported to be implicated in various neurological disorders in the central nervous system. To investigate physiological and pathological functions of mGluR5, noninvasive imaging in a living body with PET technology and an mGluR5-specific radiotracer is urgently needed. Here, we report the synthesis of 3-[(18)F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([(18)F]FPEB) through a convenient thermal reaction as a highly specific PET radiotracer for mGluR5. The precursor and standard compounds were prepared by a coupling reaction catalyzed by palladium. Radiosynthesis of [(18)F]FPEB was performed using nitro as a leaving group replaced by [(18)F]fluoride under conventional heating condition. Biodistribution, metabolite, and microPET studies were performed using Sprague-Dawley rats. Upto 30 mCi of [(18)F]FPEB was obtained with a radiochemical yield of 5% and a specific activity of 1900 +/- 200 mCi/mumol at the end of syntheses. Biodistribution showed rapid clearance from the blood pool and fast and steady accumulation of radioactivity into the brain. Metabolite studies indicated that only 22% of [(18)F]FPEB remained in the blood system 10 min after administration, and that a metabolite existed which was much more polar than the parent tracer. MicroPET studies demonstrated that [(18)F]FPEB accumulated specifically in mGluR5-rich regions of the brain such as striatum and hippocampus, and that blockade with 2-methyl-6-(2-phenylethynyl)pyridine (MPEP) and 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) substantially reduced the activity uptake in these regions. Selectivity was investigated by blockage with 6-amino-N-cyclohexyl-N,3-dimethylthiazolo[3,2-a]benzimidazole-2-caroxamide (YM-298198), a specific antagonist for mGluR1. [(18)F]FPEB was prepared conveniently and showed high specificity and selectivity toward mGluR5. It possesses the potential to be used in human studies to evaluate mGluR5 functions in various neurological disorders.
Collapse
Affiliation(s)
- Ji-Quan Wang
- Experimental PET Laboratory, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | | | | | | | | |
Collapse
|
20
|
Galatsis P, Yamagata K, Wendt JA, Connolly CJ, Mickelson JW, Milbank JB, Bove SE, Knauer CS, Brooker RM, Augelli-Szafran CE, Schwarz RD, Kinsora JJ, Kilgore KS. Synthesis and SAR comparison of regioisomeric aryl naphthyridines as potent mGlu5 receptor antagonists. Bioorg Med Chem Lett 2007; 17:6525-8. [DOI: 10.1016/j.bmcl.2007.09.083] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 09/24/2007] [Accepted: 09/25/2007] [Indexed: 10/22/2022]
|
21
|
Milbank JBJ, Knauer CS, Augelli-Szafran CE, Sakkab-Tan AT, Lin KK, Yamagata K, Hoffman JK, Zhuang N, Thomas J, Galatsis P, Wendt JA, Mickelson JW, Schwarz RD, Kinsora JJ, Lotarski SM, Stakich K, Gillespie KK, Lam WW, Mutlib AE. Rational design of 7-arylquinolines as non-competitive metabotropic glutamate receptor subtype 5 antagonists. Bioorg Med Chem Lett 2007; 17:4415-8. [PMID: 17590335 DOI: 10.1016/j.bmcl.2007.06.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 06/04/2007] [Accepted: 06/05/2007] [Indexed: 11/16/2022]
Abstract
Rational replacement of the alkyne linker of mGluR5 antagonist MPEP gave 7-arylquinolines. SAR optimization gave an orally active compound with high affinity for the MPEP binding site.
Collapse
Affiliation(s)
- Jared B J Milbank
- Pfizer Global Research and Development, Michigan Laboratories, 2800 Plymouth Road, Ann Arbor, MI 48105, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Yang F, Wu Y. Facile Synthesis of Substituted Alkynes by Cyclopalladated Ferrocenylimine Catalyzed Cross-Coupling of Arylboronic Acids/Esters with Terminal Alkynes. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700065] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
23
|
Jaeschke G, Porter R, Büttelmann B, Ceccarelli SM, Guba W, Kuhn B, Kolczewski S, Huwyler J, Mutel V, Peters JU, Ballard T, Prinssen E, Vieira E, Wichmann J, Spooren W. Synthesis and biological evaluation of fenobam analogs as mGlu5 receptor antagonists. Bioorg Med Chem Lett 2007; 17:1307-11. [PMID: 17196387 DOI: 10.1016/j.bmcl.2006.12.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Revised: 12/01/2006] [Accepted: 12/03/2006] [Indexed: 11/29/2022]
Abstract
Optimization of affinity and microsomal stability led to identification of the potent, metabolically stable fenobam analog 4l. Robust in vivo efficacy of 4l was demonstrated in four different models of anxiety. Additionally, a ligand based pharmacophore alignment of fenobam and MPEP is proposed.
Collapse
Affiliation(s)
- Georg Jaeschke
- Pharmaceutical Division, Discovery Research, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Chen Y, Nong Y, Goudet C, Hemstapat K, de Paulis T, Pin JP, Conn PJ. Interaction of novel positive allosteric modulators of metabotropic glutamate receptor 5 with the negative allosteric antagonist site is required for potentiation of receptor responses. Mol Pharmacol 2007; 71:1389-98. [PMID: 17303702 DOI: 10.1124/mol.106.032425] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exciting advances have been made in the discovery of selective positive allosteric modulators of the metabotropic glutamate receptor (mGluR) mGluR5. These compounds may provide a novel approach that could be useful in the treatment of certain central nervous system disorders. However, because of their low potencies, previously described mGluR5 potentiators are not useful for functional studies in native preparations. In addition, binding sites at which these compounds act have not been identified. It has been suggested that two allosteric potentiators, 3,3'-difluorobenzaldazine and 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB), act by binding to the same allosteric site as the negative allosteric modulators of mGluR5 such as 2-methyl-6-(phenylethynyl)pyridine (MPEP). However, another mGluR5 potentiator, N-{4-chloro-2-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)m-ethyl]phenyl}-2-hydroxybenzamide, does not bind to this site, bringing this hypothesis into question. We have synthesized a series of CDPPB analogs and report that these compounds bind to the MPEP site with affinities that are closely related to their potencies as mGluR5 potentiators. Furthermore, allosteric potentiation is antagonized by a neutral ligand at the MPEP site and reduced by a mutation of mGluR5 that eliminates MPEP binding. Together, these data suggest that interaction with the MPEP site is important for allosteric potentiation of mGluR5 by CDPPB and related compounds. In addition, whole-cell patch-clamp studies in midbrain slices reveal that a highly potent analog of CDPPB, 4-nitro-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (VU-29), selectively potentiates mGluR5 but not mGluR1-mediated responses in midbrain neurons, whereas a previously identified allosteric potentiator of mGluR1 has the opposite effect.
Collapse
Affiliation(s)
- Yelin Chen
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232-6600, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Yang F, Cui X, Li YN, Zhang J, Ren GR, Wu Y. Cyclopalladated ferrocenylimines: efficient catalysts for homocoupling and Sonogashira reaction of terminal alkynes. Tetrahedron 2007. [DOI: 10.1016/j.tet.2006.12.064] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
26
|
Orita A, Taniguchi H, Otera J. One-Shot Double Elimination Process: A Practical and Concise Protocol for Diaryl Acetylenes. Chem Asian J 2006; 1:430-7. [PMID: 17441079 DOI: 10.1002/asia.200600073] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A variety of diaryl acetylenes were obtained in good yields when lithium hexamethyldisilazide was added to a solution of arylmethyl sulfone, aryl aldehyde, and chlorodiethylphosphate in THF. In this one-shot process, a number of transformations such as aldol reaction, phosphorylation of aldolate, and double elimination of the resulting beta-substituted sulfone proceeded successively to afford the desired acetylenes. The one-shot process was accelerated by the substitution of halogen atoms on the phenyl groups, and unsymmetrically substituted diaryl acetylenes were obtained without contamination of the dehalogenated products. Diaryl acetylenes with other substituents such as CF3, ethoxycarbonyl, dimethylamino, TMS-acetylene groups, as well as pyridinyl and thienyl moieties were also accessible with this method. However, methoxy-substituted compounds were obtained in moderate yields under the same conditions, but the yields were increased when lithium diisopropylamide was used instead.
Collapse
Affiliation(s)
- Akihiro Orita
- Department of Applied Chemistry, Okayama University of Science, Ridai-cho, Okayama 700-0005, Japan.
| | | | | |
Collapse
|
27
|
Bach P, Nilsson K, Wållberg A, Bauer U, Hammerland LG, Peterson A, Svensson T, Osterlund K, Karis D, Boije M, Wensbo D. A new series of pyridinyl-alkynes as antagonists of the metabotropic glutamate receptor 5 (mGluR5). Bioorg Med Chem Lett 2006; 16:4792-5. [PMID: 16839764 DOI: 10.1016/j.bmcl.2006.06.079] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 06/21/2006] [Accepted: 06/24/2006] [Indexed: 11/25/2022]
Abstract
Synthesis and some structure-activity relationships for a new series of propargyl ethers as mGluR5 antagonists are reported.
Collapse
Affiliation(s)
- Peter Bach
- Department of Medicinal Chemistry, AstraZeneca R&D Mölndal, Pepparedsleden 1, S-431 83 Mölndal, Sweden.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Illa O, Bagan X, Cazorla AM, Lyon C, Baceiredo A, Branchadell V, Ortuño RM. Reaction of C-Silylated α-Diazophosphines as Nucleophiles toward Carbonyl Compounds: A Mechanistic Study and Application to the Synthesis of Alkynes and α-Hydroxyphosphonamides. J Org Chem 2006; 71:5320-7. [PMID: 16808522 DOI: 10.1021/jo060663k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Diversely substituted alpha-hydroxyphosphonamides and alkynes have been efficiently synthesized through the reaction of C-silylated alpha-diazophosphines with different types of aldehydes (2 equiv) in a neutral medium under very mild conditions. The reaction with some chiral aldehydes is highly diastereoselective leading to phosphonamides as single diastereomers. The novel reaction is influenced by electronic and steric effects being precluded for aromatic aldehydes containing electron-releasing substituents on the phenyl ring and for bulky aliphatic aldehydes. The mechanistic studies of these processes, which are highly exothermic, provide evidence for a nucleophilic attack of the diazophosphine to the aldehyde leading to a betaine that rapidly rearranges to a diazomethylenephosphorane, which has been detected or captured in some instances. The diazomethylenephosphorane reacts with a second molecule of aldehyde according to a Wittig-type condensation, and the rate-determining step of the whole process is believed to be the decomposition of the resultant oxaphosphetane to afford the hydroxyphosphonamide and a diazocumulene. Finally, this intermediate loses molecular nitrogen giving a transient carbene that rapidly evolves toward the alkyne.
Collapse
Affiliation(s)
- Ona Illa
- Departament de Química, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | | | | | | | | | | | | |
Collapse
|
29
|
de Paulis T, Hemstapat K, Chen Y, Zhang Y, Saleh S, Alagille D, Baldwin RM, Tamagnan GD, Conn PJ. Substituent Effects ofN-(1,3-Diphenyl-1H-pyrazol-5-yl)benzamides on Positive Allosteric Modulation of the Metabotropic Glutamate-5 Receptor in Rat Cortical Astrocytes. J Med Chem 2006; 49:3332-44. [PMID: 16722652 DOI: 10.1021/jm051252j] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CDPPB [3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide] was recently described as the first centrally active, positive allosteric modulator of rat and human metabotropic glutamate receptor (mGluR) mGluR5 subtype. We explored the structural requirements for potentiation of glutamate-induced calcium release in naturally expressed mGluR5 in cultured rat astrocytes and increasing affinity for the allosteric antagonist binding site by evaluating 50 analogues of CDPPB. In the fluorometric calcium assay, CDPPB exhibited an EC50 value of 77 +/- 15 nM in potentiating mGluR5-mediated responses in cortical astrocytes and a Ki value of 3760 +/- 430 nM in displacing [3H]methoxyPEPy binding in membranes of cultured HEK-293 cells expressing rat mGluR5. The structure-activity relationships showed that electronegative aromatic substituents in the para-position of the benzamide moiety of CDPPB increase potency. Both binding and functional activities were further increased with a halogen atom in the ortho-position of the 1-phenyl ring. These effects of substitution do not match those of either aromatic ring of MPEP [2-methyl-6-(phenylethynyl)pyridine] for the antagonist allosteric binding site. Combination of the optimal substituents and aromatic positions resulted in 4-nitro-N-(1-(2-fluorophenyl)-3-phenyl-1H-pyrazol-5-yl)benzamide (VU-1545) showing Ki = 156 +/- 29 nM and EC50 = 9.6 +/- 1.9 nM in the binding and functional assays, respectively.
Collapse
Affiliation(s)
- Tomas de Paulis
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Büttelmann B, Peters JU, Ceccarelli S, Kolczewski S, Vieira E, Prinssen EP, Spooren W, Schuler F, Huwyler J, Porter RHP, Jaeschke G. Arylmethoxypyridines as novel, potent and orally active mGlu5 receptor antagonists. Bioorg Med Chem Lett 2006; 16:1892-7. [PMID: 16439120 DOI: 10.1016/j.bmcl.2005.12.088] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 12/27/2005] [Accepted: 12/28/2005] [Indexed: 10/25/2022]
Abstract
Optimisation of affinity, chemical stability, metabolic stability and solubility led from a chemically labile HTS hit 1 to mGlu5 receptor antagonists (24-26) with high affinity for the allosteric MPEP binding site, improved microsomal metabolic stability and anxiolytic-like activity in vivo as assessed by the Vogel conflict drinking test.
Collapse
Affiliation(s)
- Bernd Büttelmann
- Pharma Division, Discovery Chemistry, F. Hoffman-La Roche Ltd, CH-4070 Basel, Switzerland
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Iso Y, Grajkowska E, Wroblewski JT, Davis J, Goeders NE, Johnson KM, Sanker S, Roth BL, Tueckmantel W, Kozikowski AP. Synthesis and Structure−Activity Relationships of 3-[(2-Methyl-1,3-thiazol-4-yl)ethynyl]pyridine Analogues as Potent, Noncompetitive Metabotropic Glutamate Receptor Subtype 5 Antagonists; Search for Cocaine Medications. J Med Chem 2006; 49:1080-100. [PMID: 16451073 DOI: 10.1021/jm050570f] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent genetic and pharmacological studies have suggested that the metabotropic glutamate receptor subtype 5 (mGluR5) may represent a druggable target in identifying new therapeutics for the treatment of various central nervous system disorders including drug abuse. In particular, considerable attention in the mGluR5 field has been devoted to identifying ligands that bind to the allosteric modulatory site, distinct from the site for the primary agonist glutamate. Both 2-methyl-6-(phenylethynyl)pyridine (MPEP) and its analogue 3-[(2-methyl-4-thiazolyl)ethynyl]pyridine (MTEP) have been shown to be selective and potent noncompetitive antagonists of mGluR5. Because of results presented in this study showing that MTEP prevents the reinstatement of cocaine self-administration caused by the presentation of environmental cues previously associated with cocaine availability, we have prepared a series of analogues of MTEP with the aim of gaining a better understanding of the structural features relevant to its antagonist potency and with the ultimate aim of investigating the effects of such compounds in blunting the self-administration of cocaine. These efforts have led to the identification of compounds showing higher potency as mGluR5 antagonists than either MPEP or MTEP. Two compounds 19 and 59 exhibited functional activity as mGluR5 antagonists that are 490 and 230 times, respectively, better than that of MTEP.
Collapse
Affiliation(s)
- Yasuyoshi Iso
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Rodriguez AL, Nong Y, Sekaran NK, Alagille D, Tamagnan GD, Conn PJ. A close structural analog of 2-methyl-6-(phenylethynyl)-pyridine acts as a neutral allosteric site ligand on metabotropic glutamate receptor subtype 5 and blocks the effects of multiple allosteric modulators. Mol Pharmacol 2005; 68:1793-802. [PMID: 16155210 DOI: 10.1124/mol.105.016139] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The metabotropic glutamate receptor subtype 5 (mGlu5) activates calcium mobilization via binding of glutamate, the major excitatory neurotransmitter in the central nervous system. Allosteric modulation of the receptor has recently emerged as a promising alternative method of regulation to traditional regulation through orthosteric ligands. We now report three novel compounds that bind to the allosteric 2-methyl-6-(phenylethynyl)-pyridine (MPEP) site on mGlu5 but have only partial inhibition or no functional effects on the mGlu5 response. Two of these compounds, 2-(2-(3-methoxyphenyl)ethynyl)-5-methylpyridine (M-5MPEP) and 2-(2-(5-bromopyridin-3-yl)ethynyl)-5-methylpyridine (Br-5MPEPy), act as partial antagonists of mGlu5 in that they only partially inhibit the response of this receptor to glutamate. The third compound, 5-methyl-6-(phenylethynyl)-pyridine (5MPEP), acts as a neutral allosteric site ligand that binds to the MPEP site and has no effects alone. However, 5MPEP blocks the effects of both the allosteric antagonist MPEP and potentiators 3,3'-difluorobenzaldazine and 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB). This compound also blocks depolarization effects of both MPEP and CDPPB in neurons in the subthalamic nucleus. These novel compounds provide valuable new insight into the pharmacology of allosteric sites on G protein-coupled receptors and provide valuable new tools for determining the effects of allosteric site ligands in native systems.
Collapse
Affiliation(s)
- Alice L Rodriguez
- Department of Pharmacology and Program in Translational Neuropharmacology, Vanderbilt University Medical Center, 23rd Ave. South at Pierce, 417-D Preston Research Bldg., Nashville, Tennessee 37232-6600, USA
| | | | | | | | | | | |
Collapse
|