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Langmead CJ, Austin NE, Branch CL, Brown JT, Buchanan KA, Davies CH, Forbes IT, Fry VAH, Hagan JJ, Herdon HJ, Jones GA, Jeggo R, Kew JNC, Mazzali A, Melarange R, Patel N, Pardoe J, Randall AD, Roberts C, Roopun A, Starr KR, Teriakidis A, Wood MD, Whittington M, Wu Z, Watson J. Characterization of a CNS penetrant, selective M1 muscarinic receptor agonist, 77-LH-28-1. Br J Pharmacol 2008; 154:1104-15. [PMID: 18454168 DOI: 10.1038/bjp.2008.152] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE M1 muscarinic ACh receptors (mAChRs) represent an attractive drug target for the treatment of cognitive deficits associated with diseases such as Alzheimer's disease and schizophrenia. However, the discovery of subtype-selective mAChR agonists has been hampered by the high degree of conservation of the orthosteric ACh-binding site among mAChR subtypes. The advent of functional screening assays has enabled the identification of agonists such as AC-42 (4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl]-piperidine), which bind to an allosteric site and selectively activate the M(1) mAChR subtype. However, studies with this compound have been limited to recombinantly expressed mAChRs. EXPERIMENTAL APPROACH In this study, we have compared the pharmacological profile of AC-42 and a close structural analogue, 77-LH-28-1 (1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone) at human recombinant, and rat native, mAChRs by calcium mobilization, inositol phosphate accumulation and both in vitro and in vivo electrophysiology. KEY RESULTS Calcium mobilization and inositol phosphate accumulation assays revealed that both AC-42 and 77-LH-28-1 display high selectivity to activate the M1 mAChR over other mAChR subtypes. Furthermore, 77-LH-28-1, but not AC-42, acted as an agonist at rat hippocampal M1 receptors, as demonstrated by its ability to increase cell firing and initiate gamma frequency network oscillations. Finally, 77-LH-28-1 stimulated cell firing in the rat hippocampus in vivo following subcutaneous administration. CONCLUSIONS AND IMPLICATIONS These data suggest that 77-LH-28-1 is a potent, selective, bioavailable and brain-penetrant agonist at the M1 mAChR and therefore that it represents a better tool than AC-42, with which to study the pharmacology of the M1 mAChR.
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Affiliation(s)
- C J Langmead
- Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, Essex, UK.
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2
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Witherington J, Bordas V, Cooper DG, Forbes IT, Gribble AD, Ife RJ, Berkhout T, Gohil J, Groot PH. Conformationally restricted indolopiperidine derivatives as potent CCR2B receptor antagonists. Bioorg Med Chem Lett 2001; 11:2177-80. [PMID: 11514164 DOI: 10.1016/s0960-894x(01)00397-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [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: 11/24/2022]
Abstract
The preparation and biological evaluation of a series of indolopiperidine CCR2B receptor antagonists possessing a conformationally restricted C-5 linker chain in combination with a restricted piperidine ring are described. Compared to the parent compound 1, analogue 8 shows a dramatic improvement in selectivity against a range of 5-HT and dopaminergic receptors.
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Affiliation(s)
- J Witherington
- Department of Discovery Chemistry, GlaxoSmithKline Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, CM19 5AD, Essex, UK.
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3
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Wood MD, Reavill C, Trail B, Wilson A, Stean T, Kennett GA, Lightowler S, Blackburn TP, Thomas D, Gager TL, Riley G, Holland V, Bromidge SM, Forbes IT, Middlemiss DN. SB-243213; a selective 5-HT2C receptor inverse agonist with improved anxiolytic profile: lack of tolerance and withdrawal anxiety. Neuropharmacology 2001; 41:186-99. [PMID: 11489455 DOI: 10.1016/s0028-3908(01)00054-5] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [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: 11/25/2022]
Abstract
SB-243213 (5-methyl-1-[[-2-[(2-methyl-3-pyridyl)oxy]-5-pyridyl]carbamoyl]-6-trifluoromethylindoline hydrochloride) is a new, selective 5-hydroxytryptamine (5-HT)2C receptor inverse agonist. SB-243213 has high affinity for the human 5-HT2C receptor (pK(i) 9.37) and greater than a 100-fold selectivity over a wide range of neurotransmitter receptors, enzymes and ion channels. In in vitro functional studies, SB-243213 acted as an inverse agonist at the human 5-HT2C receptor with a pK(b) of 9.8. In in vivo studies, SB-243213 was a potent inhibitor of central 5-HT2C receptor-mediated function in rats, blocking meta-chlorophenylpiperazine-induced hypolocomotion with an ID50 of 1.1 mg/kg p.o. and a long duration of action (>8 h). In rats, SB-243213 exhibited anxiolytic-like activity in both the social interaction and Geller-Seifter conflict tests. Importantly, unlike diazepam, chronic administration of SB-243213 did not result in the development of either tolerance to the anxiolytic-like effects or withdrawal anxiogenesis. Furthermore, in rodents, SB-243213 did not affect seizure threshold, did not increase body weight or induce catalepsy, but attenuated the haloperidol-induced catalepsy. SB-243213 did not affect amphetamine-, MK-801- or phencyclidine-induced hyperactivity. In conclusion, SB-243213 may possess an improved anxiolytic profile compared to benzodiazepines. SB-243213 also modulates dopaminergic transmission, lacks pro-psychotic properties and may have utility in the treatment of schizophrenia and motor disorders.
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Affiliation(s)
- M D Wood
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow Essex, CM19 5AW, UK.
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4
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Bromidge SM, Dabbs S, Davies S, Duckworth DM, Forbes IT, Jones GE, Jones J, King FD, Saunders DV, Blackburn TP, Holland V, Kennett GA, Lightowler S, Middlemiss DN, Riley GJ, Trail B, Wood MD. 1-[2-[(Heteroaryloxy)heteroaryl]carbamoyl]indolines: novel and selective 5-HT2C receptor inverse agonists with potential as antidepressant/anxiolytic agents. Bioorg Med Chem Lett 2000; 10:1863-6. [PMID: 10969986 DOI: 10.1016/s0960-894x(00)00364-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [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: 11/27/2022]
Abstract
Bisaryl ethers have been identified with excellent 5-HT2C affinity and selectivity over both 5-HT2A and 5-HT2B receptors. Compounds such as 11, 27 and 38 have potent oral activity in a centrally mediated pharmacodynamic model of 5-HT2C function and their potential as novel non-sedating anxiolytic and antidepressants is under investigation.
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Affiliation(s)
- S M Bromidge
- SmithKline Beecham Pharmaceuticals, Discovery Research, Harlow, Essex, UK.
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5
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Forbes IT, Cooper DG, Dodds EK, Hickey DM, Ife RJ, Meeson M, Stockley M, Berkhout TA, Gohil J, Groot PH, Moores K. CCR2B receptor antagonists: conversion of a weak HTS hit to a potent lead compound. Bioorg Med Chem Lett 2000; 10:1803-6. [PMID: 10969972 DOI: 10.1016/s0960-894x(00)00347-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [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: 11/25/2022]
Abstract
A weak HTS hit at the CCR2B receptor has been converted into a potent antagonist by array SAR studies. Selectivity over the closely related CCR5 receptor is also achieved.
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Affiliation(s)
- I T Forbes
- Department of Discovery Chemistry, SmithKline Beecham Pharmaceuticals, Harlow, Essex, UK.
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6
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Bromidge SM, Davies S, Duckworth DM, Forbes IT, Jones GE, Jones J, King FD, Blackburn TP, Holland V, Kennett GA, Lightowler S, Middlemiss DN, Riley GJ, Trail B, Wood MD. 1-[2-[(Heteroarylmethoxy)aryl]carbamoyl]indolines are selective and orally active 5-HT2C receptor inverse agonists. Bioorg Med Chem Lett 2000; 10:1867-70. [PMID: 10969987 DOI: 10.1016/s0960-894x(00)00365-6] [Citation(s) in RCA: 13] [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: 11/29/2022]
Abstract
Bisarylmethoxyethers have been identified with nanomolar 5-HT2C affinity and selectivity over both 5-HT2A and 5-HT2B receptors. Compounds such as 1, 2, 8, 12, 14 and 18 have potent oral activity in a centrally mediated pharmacodynamic model of 5-HT2C function and their therapeutic potential is currently under further investigation.
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Affiliation(s)
- S M Bromidge
- SmithKline Beecham Pharmaceuticals, Discovery Research, Harlow, Essex, UK.
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7
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Bromidge SM, Dabbs S, Davies DT, Davies S, Duckworth DM, Forbes IT, Gaster LM, Ham P, Jones GE, King FD, Mulholland KR, Saunders DV, Wyman PA, Blaney FE, Clarke SE, Blackburn TP, Holland V, Kennett GA, Lightowler S, Middlemiss DN, Trail B, Riley GJ, Wood MD. Biarylcarbamoylindolines are novel and selective 5-HT(2C) receptor inverse agonists: identification of 5-methyl-1-[[2-[(2-methyl-3-pyridyl)oxy]- 5-pyridyl]carbamoyl]-6-trifluoromethylindoline (SB-243213) as a potential antidepressant/anxiolytic agent. J Med Chem 2000; 43:1123-34. [PMID: 10737744 DOI: 10.1021/jm990388c] [Citation(s) in RCA: 72] [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: 11/30/2022]
Abstract
The evolution, synthesis, and biological activity of a novel series of 5-HT(2C) receptor inverse agonists are reported. Biarylcarbamoylindolines have been identified with excellent 5-HT(2C) affinity and selectivity over 5-HT(2A) receptors. In addition, (pyridyloxypyridyl)carbamoylindolines have been discovered with additional selectivity over the closely related 5-HT(2B) receptor. Compounds from this series are inverse agonists at the human cloned 5-HT(2C) receptor, completely abolishing basal activity in a functional assay. The new series have reduced P450 inhibitory liability compared to a previously described series of 1-(3-pyridylcarbamoyl)indolines (Bromidge et al. J. Med. Chem. 1998, 41, 1598) from which they evolved. Compounds from this series showed excellent oral activity in a rat mCPP hypolocomotion model and in animal models of anxiety. On the basis of their favorable biological profile, 32 (SB-228357) and 40 (SB-243213) have been selected for further evaluation to determine their therapeutic potential for the treatment of CNS disorders such as depression and anxiety.
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Affiliation(s)
- S M Bromidge
- SmithKline Beecham Pharmaceuticals, Discovery Research, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW, UK.
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8
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Lovell PJ, Bromidge SM, Dabbs S, Duckworth DM, Forbes IT, Jennings AJ, King FD, Middlemiss DN, Rahman SK, Saunders DV, Collin LL, Hagan JJ, Riley GJ, Thomas DR. A novel, potent, and selective 5-HT(7) antagonist: (R)-3-(2-(2-(4-methylpiperidin-1-yl)ethyl)pyrrolidine-1-sulfonyl) phen ol (SB-269970). J Med Chem 2000; 43:342-5. [PMID: 10669560 DOI: 10.1021/jm991151j] [Citation(s) in RCA: 215] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P J Lovell
- SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW, U.K.
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9
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Bromidge SM, Dabbs S, Davies DT, Davies S, Duckworth DM, Forbes IT, Gadre A, Ham P, Jones GE, King FD, Saunders DV, Thewlis KM, Vyas D, Blackburn TP, Holland V, Kennett GA, Riley GJ, Wood MD. Model studies on a synthetically facile series of N-substituted phenyl-N'-pyridin-3-yl ureas leading to 1-(3-pyridylcarbamoyl) indolines that are potent and selective 5-HT(2C/2B) receptor antagonists. Bioorg Med Chem 1999; 7:2767-73. [PMID: 10658582 DOI: 10.1016/s0968-0896(99)00228-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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: 11/17/2022]
Abstract
A model series of 5-HT2C antagonists have been prepared by rapid parallel synthesis. These N-substituted phenyl-N'-pyridin-3-yl ureas were found to have a range of 5-HT2C receptor affinities and selectivities over the closely related 5-HT2A receptor. Extrapolation of simple SAR, derived from this set of compounds, to the more active but synthetically more complex 1-(3-pyridylcarbamoyl)indoline series allowed us to target optimal substitution patterns and identify potent and selective 5-HT(2C/2B) antagonists.
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Affiliation(s)
- S M Bromidge
- SmithKline Beecham Pharmaceuticals Discovery Research, New Frontiers Science Park, Harlow, Essex, UK.
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10
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Thomas DR, Gittins SA, Collin LL, Middlemiss DN, Riley G, Hagan J, Gloger I, Ellis CE, Forbes IT, Brown AM. Functional characterisation of the human cloned 5-HT7 receptor (long form); antagonist profile of SB-258719. Br J Pharmacol 1998; 124:1300-6. [PMID: 9720804 PMCID: PMC1565501 DOI: 10.1038/sj.bjp.0701946] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.7] [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] [Indexed: 11/09/2022] Open
Abstract
1. The functional profile of the long form of the human cloned 5-HT7 receptor (designated h5-HT7(a)) was investigated using a number of 5-HT receptor agonists and antagonists and compared with its binding profile. Receptor function was measured using adenylyl cyclase activity in washed membranes from HEK293 cells stably expressing the recombinant h5-HT7(a) receptor. 2. The receptor binding profile, determined by competition with [3H]-5-CT, was consistent with that previously reported for the h5-HT7(a) receptor. The selective 5-HT7 receptor antagonist SB-258719 ((R)-3,N-Dimethyl-N-[1-methyl-3-(4-methylpiperidin-1-yl)propyl]ben zene sulfonamide) displayed high affinity (pKi 7.5) for the receptor. 3. In the adenylyl cyclase functional assay, 5-CT and 8-OH-DPAT were both full agonists compared to 5-HT and the rank order of potency for agonists (5-CT > 5-HT > 8-OH-DPAT) was the same in functional and binding studies. 4. Risperidone, methiothepin, mesulergine, clozapine, olanzapine, ketanserin and SB-258719 antagonised surmountably 5-CT-stimulated adenylyl cyclase activity. Schild analysis of the antagonism by SB-258719 gave a pA2 of 7.2+/-0.2 and slope not significantly different from 1, consistent with competitive antagonism. 5. The same antagonists also inhibited basal adenylyl cyclase activity with a rank order of potency in agreement with those for antagonist potency and binding affinity. Both SB-258719 and mesulergine displayed apparent partial inverse agonist profiles compared to the other antagonists tested. These inhibitory effects of antagonists appear to be 5-HT7 receptor-mediated and to reflect inverse agonism. 6. It is concluded that in this expression system, the h5-HT7(a) receptor shows the expected binding and functional profile and displays constitutive activity, revealing inverse agonist activity for a range of antagonists.
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Affiliation(s)
- D R Thomas
- Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex
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11
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Bromidge SM, Dabbs S, Davies DT, Duckworth DM, Forbes IT, Ham P, Jones GE, King FD, Saunders DV, Starr S, Thewlis KM, Wyman PA, Blaney FE, Naylor CB, Bailey F, Blackburn TP, Holland V, Kennett GA, Riley GJ, Wood MD. Novel and selective 5-HT2C/2B receptor antagonists as potential anxiolytic agents: synthesis, quantitative structure-activity relationships, and molecular modeling of substituted 1-(3-pyridylcarbamoyl)indolines. J Med Chem 1998; 41:1598-612. [PMID: 9572885 DOI: 10.1021/jm970741j] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [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: 02/07/2023]
Abstract
The synthesis, biological activity, and molecular modeling of a novel series of substituted 1-(3-pyridylcarbamoyl)indolines are reported. These compounds are isosteres of the previously published indole urea 1 (SB-206553) and illustrate the use of aromatic disubstitution as a replacement for fused five-membered rings in the context of 5-HT2C/2B receptor antagonists. By targeting a region of space previously identified as sterically allowed at the 5-HT2C receptor but disallowed at the 5-HT2A receptor, we have identified a number of compounds which are the most potent and selective 5-HT2C/2B receptor antagonists yet reported. 46 (SB-221284) was selected on the basis of its overall biological profile for further evaluation as a novel, potential nonsedating anxiolytic agent. A CoMFA analysis of these compounds produced a model with good predictive value and in addition good qualitative agreement with both our 5-HT2C receptor model and our proposed binding mode for this class of ligands within that model.
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MESH Headings
- Animals
- Anti-Anxiety Agents/chemical synthesis
- Anti-Anxiety Agents/chemistry
- Anti-Anxiety Agents/metabolism
- Anti-Anxiety Agents/pharmacology
- Conditioning, Operant/drug effects
- Conflict, Psychological
- Indoles/chemical synthesis
- Indoles/chemistry
- Indoles/metabolism
- Indoles/pharmacology
- Male
- Models, Molecular
- Motor Activity/drug effects
- Pyridines/chemical synthesis
- Pyridines/chemistry
- Pyridines/metabolism
- Pyridines/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptor, Serotonin, 5-HT2B
- Receptor, Serotonin, 5-HT2C
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/metabolism
- Serotonin Antagonists/chemical synthesis
- Serotonin Antagonists/chemistry
- Serotonin Antagonists/metabolism
- Serotonin Antagonists/pharmacology
- Social Behavior
- Structure-Activity Relationship
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Affiliation(s)
- S M Bromidge
- SmithKline Beecham Pharmaceuticals, Discovery Research, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW, England
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12
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Forbes IT, Dabbs S, Duckworth DM, Jennings AJ, King FD, Lovell PJ, Brown AM, Collin L, Hagan JJ, Middlemiss DN, Riley GJ, Thomas DR, Upton N. (R)-3,N-dimethyl-N-[1-methyl-3-(4-methyl-piperidin-1-yl) propyl]benzenesulfonamide: the first selective 5-HT7 receptor antagonist. J Med Chem 1998; 41:655-7. [PMID: 9513592 DOI: 10.1021/jm970519e] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- I T Forbes
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, Harlow, Essex, England
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13
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Bromidge SM, Duckworth M, Forbes IT, Ham P, King FD, Thewlis KM, Blaney FE, Naylor CB, Blackburn TP, Kennett GA, Wood MD, Clarke SE. 6-Chloro-5-methyl-1-[[2-[(2-methyl-3-pyridyl)oxy]-5-pyridyl]carbamoyl]- indoline (SB-242084): the first selective and brain penetrant 5-HT2C receptor antagonist. J Med Chem 1997; 40:3494-6. [PMID: 9357513 DOI: 10.1021/jm970424c] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- S M Bromidge
- SmithKline Beecham Pharmaceuticals, Discovery Research, Harlow, Essex, England
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14
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Kennett GA, Wood MD, Bright F, Trail B, Riley G, Holland V, Avenell KY, Stean T, Upton N, Bromidge S, Forbes IT, Brown AM, Middlemiss DN, Blackburn TP. SB 242084, a selective and brain penetrant 5-HT2C receptor antagonist. Neuropharmacology 1997; 36:609-20. [PMID: 9225286 DOI: 10.1016/s0028-3908(97)00038-5] [Citation(s) in RCA: 410] [Impact Index Per Article: 15.2] [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: 02/04/2023]
Abstract
SB 242084 has a high affinity (pKi 9.0) for the cloned human 5-HT2C receptor and 100- and 158-fold selectivity over the closely related cloned human 5-HT2B and 5-HT2A subtypes respectively. SB 242084 had over 100-fold selectivity over a range of other 5-HT, dopamine and adrenergic receptors. In studies of 5-HT-stimulated phosphatidylinositol hydrolysis using SH-SY5Y cells stably expressing the cloned human 5-HT2C receptor, SB 242084 acted as an antagonist with a pKb of 9.3, which closely resembled its corresponding receptor binding affinity. SB 242084 potently inhibited m-chlorophenylpiperazine (mCPP, 7 mgkg i.p. 20 min pre-test)-induced hypolocomotion in rats, a model of in vivo central 5-HT2C receptor function, with an ID50 of 0.11 mg/kg i.p., and 2.0 mg/kg p.o. SB 242084 (0.1-1 mg/kg i.p.) exhibited an anxiolytic-like profile in the rat social interaction test, increasing time spent in social interaction, but having no effect on locomotion. SB 242084 (0.1-1 mg/kg i.p.) also markedly increased punished responding in a rat Geller-Seifter conflict test of anxiety, but had no consistent effect on unpunished responding. A large acute dose of SB 242084 (30 mg/kg p.o.) had no effect on seizure susceptibility in the rat maximal electroshock seizure threshold test. Also, while SB 242084 (2 and 6 mg/kg p.o. 1 hr pre-test) antagonized the hypophagic response to mCPP, neither acute nor subchronic administration of the drug, for 5 days at 2 or 6 mg/kg p.o. twice daily, affected food intake or weight gain. The results suggest that SB 242084 is the first reported selective potent and brain penetrant 5-HT2C receptor antagonist and has anxiolytic-like activity, but does not possess either proconvulsant or hyperphagic properties which are characteristic of mutant mice lacking the 5-HT2C receptor.
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Affiliation(s)
- G A Kennett
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, Harlow, Essex, U.K
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15
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Forbes IT, Dabbs S, Duckworth DM, Ham P, Jones GE, King FD, Saunders DV, Blaney FE, Naylor CB, Baxter GS, Blackburn TP, Kennett GA, Wood MD. Synthesis, biological activity, and molecular modeling of selective 5-HT(2C/2B) receptor antagonists. J Med Chem 1996; 39:4966-77. [PMID: 8960557 DOI: 10.1021/jm960571v] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [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: 02/03/2023]
Abstract
The synthesis and biological activity are reported for a series of analogues of the previously published indole urea 2 (SB-206553), designed to probe the 5-HT(2C) receptor binding site. Small molecule modeling studies have been used to define a region in space which is allowed at the 5-HT(2C) receptor but disallowed at the 5-HT(2A) receptor. In a complementary approach, docking of 2 into our model of the 5-HT(2C) receptor has allowed us to propose a novel primary binding interaction for this series of diaryl ureas, involving a potential double hydrogen-bonding interaction between the urea carbonyl oxygen of the ligand and two serine residues in the receptor. The difference of two valine residues in the 5-HT(2C) receptor for leucine residues in the 5-HT(2A) receptor is believed to account for the observed 5-HT(2C)/5-HT(2A) selectivity with 2.
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Affiliation(s)
- I T Forbes
- SmithKline Beecham Pharmaceuticals, Discovery Research, Harlow, Essex, England
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16
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Kennett GA, Wood MD, Bright F, Cilia J, Piper DC, Gager T, Thomas D, Baxter GS, Forbes IT, Ham P, Blackburn TP. In vitro and in vivo profile of SB 206553, a potent 5-HT2C/5-HT2B receptor antagonist with anxiolytic-like properties. Br J Pharmacol 1996; 117:427-434. [PMID: 8821530 PMCID: PMC1909304 DOI: 10.1111/j.1476-5381.1996.tb15208.x] [Citation(s) in RCA: 193] [Impact Index Per Article: 6.9] [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: 02/02/2023] Open
Abstract
1. SB 206553 (5-methyl-1-(3-pyridylcarbamoyl)-1,2,3,5-tetrahydropyrrolo[2 ,3-f]indole) displays a high affinity (pK1 7.9) for the cloned human 5-HT2C receptor expressed in HEK 293 cells and the 5-HT2B receptor (pA2 8.9) as measured in the rat stomach fundus preparation. SB 206553 has low affinity for cloned human 5-HT2A receptors expressed in HEK 293 cells (pK1 5.8) and (pK1 < 6) for a wide variety of other neurotransmitter receptors. 2. SB 206553 appears to be a surmountable antagonist of 5-HT-stimulated phosphoinositide hydrolysis in HEK 293 cells expressing the human 5-HT2C receptor (pKB 9.0). 3. The compound potently (ID50 5.5 mg kg-1, p.o., 0.27 mg kg-1, i.v.) inhibited the hypolocomotor response to m-chlorophenylpiperazine (mCPP), a putative model of 5-HT2C/5-HT2B receptor function in vivo. 4. At similar doses (2-20 mg kg-1, p.o.) SB 206553 increased total interaction scores in a rat social interaction test and increased punished responding in a rat Geller-Seifter conflict test. These effects are consistent with the possession of anxiolytic properties. 5. SB 206553 also increased suppressed responding in a marmoset conflict model of anxiety at somewhat higher doses (15 and 20 mg kg-1, p.o.) but also reduced unsuppressed responding. 6. These results suggest that SB 206553 is a potent mixed 5-HT2C/5-HT2B receptor antagonist with selectivity over the 5-HT2A and all other sites studied and possesses anxiolytic-like properties.
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Affiliation(s)
- G A Kennett
- Department of Psychiatry, SmithKline Beecham Pharmaceuticals, Essex
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Forbes IT, Ham P, Booth DH, Martin RT, Thompson M, Baxter GS, Blackburn TP, Glen A, Kennett GA, Wood MD. 5-Methyl-1-(3-pyridylcarbamoyl)-1,2,3,5-tetrahydropyrrolo[2,3-f]indole: a novel 5-HT2C/5-HT2B receptor antagonist with improved affinity, selectivity, and oral activity. J Med Chem 1995; 38:2524-30. [PMID: 7629791 DOI: 10.1021/jm00014a004] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [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: 01/26/2023]
Abstract
The preparation of a series of conformationally restricted analogues of indolylurea 1, namely tetrahydropyrroloindoles and tetrahydropyrroloquinolines, is described. The binding affinities of these compounds at 5-HT2A, 5-HT2B, and 5-HT2C receptors were determined. Of these compounds, the 1,2,3,5-tetrahydropyrrolo[2,3-f]indole derivative, compound 11, was found to have high affinity for the 5-HT2C (pKI 8.0) and 5-HT2B receptors (pA2 8.5), with excellent selectivity over the 5-HT2A and various other receptors (pKI < 6). 11 is also considerably more active than 1 in both an in vitro functional model, 5-HT-stimulated phosphoinositol hydrolysis (pKB 8.8), and an in vivo functional model, mCPP-induced hypolocomotion (ID50 5.5 mg/kg po). 11 should therefore be of significant utility as a pharmacological tool to delineate the functional significance of blockade of 5-HT2B and 5-HT2C receptors.
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Affiliation(s)
- I T Forbes
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, Harlow, Essex, England
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Forbes IT, Jones GE, Murphy OE, Holland V, Baxter GS. N-(1-methyl-5-indolyl)-N'-(3-methyl-5-isothiazolyl)urea: a novel, high-affinity 5-HT2B receptor antagonist. J Med Chem 1995; 38:855-7. [PMID: 7699699 DOI: 10.1021/jm00006a001] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- I T Forbes
- SmithKline Beecham Pharmaceuticals, Discovery Research, Harlow, Essex, England
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Forbes IT, Kennett GA, Gadre A, Ham P, Hayward CJ, Martin RT, Thompson M, Wood MD, Baxter GS, Glen A. N-(1-methyl-5-indolyl)-N'-(3-pyridyl)urea hydrochloride: the first selective 5-HT1C receptor antagonist. J Med Chem 1993; 36:1104-7. [PMID: 8478907 DOI: 10.1021/jm00060a019] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- I T Forbes
- Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, Harlow, Essex, England
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Forbes IT, Johnson CN, Jones GE, Loudon J, Nicholass JM, Thompson M, Upton N. Synthesis and evaluation of a series of aryl[e]fused pyrazolo[4,3-c]pyridines with potential anxiolytic activity. J Med Chem 1990; 33:2640-5. [PMID: 1975276 DOI: 10.1021/jm00171a046] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A series of pyrazolo[4,3-c]pyridines has been synthesized and evaluated as potential anxiolytic agents. Selected compounds from this series show a pharmacological profile of action different from that of diazepam. A number of the compounds possess higher affinity for central benzodiazepine receptors than diazepam, yet show less anticonvulsant activity and are less sedative. The structure-activity relationships of these potential anxiolytic agents are discussed.
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Affiliation(s)
- I T Forbes
- Beecham Pharmaceuticals, Medicinal Research Centre, Harlow, Essex, England
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