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Rubio-Ruiz B, Pérez-López AM, Sebastián V, Unciti-Broceta A. A minimally-masked inactive prodrug of panobinostat that is bioorthogonally activated by gold chemistry. Bioorg Med Chem 2021; 41:116217. [PMID: 34022529 DOI: 10.1016/j.bmc.2021.116217] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/04/2021] [Accepted: 05/11/2021] [Indexed: 11/28/2022]
Abstract
The recent incorporation of Au chemistry in the bioorthogonal toolbox has opened up new opportunities to deliver biologically independent reactions in living environments. Herein we report that the O-propargylation of the hydroxamate group of the potent HDAC inhibitor panobinostat leads to a vast reduction of its anticancer properties (>500-fold). We also show that this novel prodrug is converted back into panobinostat in the presence of Au catalysts in vitro and in cell culture.
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Affiliation(s)
- Belén Rubio-Ruiz
- Cancer Research UK Edinburgh Centre, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, UK.
| | - Ana M Pérez-López
- Cancer Research UK Edinburgh Centre, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, UK
| | - Víctor Sebastián
- Department of Chemical Engineering, University of Zaragoza, Campus Río Ebro-Edificio I+D, C/ Poeta Mariano Esquillor S/N, 50018 Zaragoza, Spain; Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain; Networking Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER- BBN), Madrid, Spain
| | - Asier Unciti-Broceta
- Cancer Research UK Edinburgh Centre, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, UK.
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2
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Abstract
Marine natural products (MNPs) containing pyrone rings have been isolated
from numerous marine organisms, and also produced by marine fungi and bacteria, particularly,
actinomycetes. They constitute a versatile structure unit of bioactive natural
products that exhibit various biological activities such as antibiotic, antifungal, cytotoxic,
neurotoxic, phytotoxic and anti-tyrosinase. The two structure isomers of pyrone ring are γ-
pyrone and α-pyrone. In terms of chemical motif, γ-pyrone is the vinologous form of α-
pyrone which possesses a lactone ring. Actinomycete bacteria are responsible for the production
of several α-pyrone compounds such as elijopyrones A-D, salinipyrones and violapyrones
etc. to name a few. A class of pyrone metabolites, polypropionates which have
fascinating carbon skeleton, is primarily produced by marine molluscs. Interestingly, some
of the pyrone polytketides which are found in cone snails are actually synthesized by actinomycete bacteria.
Several pyrone derivatives have been obtained from marine fungi such as Aspergillums flavus, Altenaria sp.,
etc. The γ-pyrone derivative namely, kojic acid obtained from Aspergillus fungus has high commercial demand
and finds various applications. Kojic acid and its derivative displayed inhibition of tyrosinase activity and, it is
also extensively used as a ligand in coordination chemistry. Owing to their commercial and biological significance,
the synthesis of pyrone containing compounds has been given attention over the past years. Few reviews
on the total synthesis of pyrone containing natural products namely, polypropionate metabolites have been reported.
However, these reviews skipped other marine pyrone metabolites and also omitted discussion on isolation
and detailed biological activities. This review presents a brief account of the isolation of marine metabolites
containing a pyrone ring and their reported bio-activities. Further, the review covers the synthesis of marine
pyrone metabolites such as cyercene-A, placidenes, onchitriol-I, onchitriol-II, crispatene, photodeoxytrichidione,
(-) membrenone-C, lihualide-B, macrocyclic enol ethers and auripyrones-A & B.
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Affiliation(s)
- Keisham S. Singh
- Bio-organic Chemistry Laboratory, CSIR-National Institute of Oceanography, Dona Paula-403004, Goa, India
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3
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Verma S, Kumar A, Tripathi T, Kumar A. Muscarinic and nicotinic acetylcholine receptor agonists: current scenario in Alzheimer's disease therapy. J Pharm Pharmacol 2018; 70:985-993. [DOI: 10.1111/jphp.12919] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 03/11/2018] [Indexed: 12/14/2022]
Abstract
Abstract
Objectives
Alzheimer's disease (AD) has become the primary cause of dementia. It shows a progressive cognitive dysfunction with degenerating neurons. Acetylcholine receptors (AChRs) propagate the cognitive ability and it consists of two primary members namely muscarinic (mAChRs) and nicotinic receptors (nAChRs). Where mAChRs is G-protein coupled receptor, (nAChRs) are ligand-gated ion channels. The conventional therapeutic regimen for AD consists of three acetylcholinestearse inhibitors while a single NMDA receptor antagonist. Researchers around the globe are developing new and modifying the existing AChRs agonists to develop lead candidates with lower risk to benefit ratio where benefits clearly outweigh the adverse events.
Key findings
We have searched PubMed, MEDLINE, Google scholar, Science Direct and, Web of Science with keywords “Muscarinic/Nicotinic acetylcholine receptor, agonists and, AD”. The literature search included articles written in English. Scientific relevance for clinical studies, basic science studies is eligibility criteria for articles referred in this paper. M1 is the primary muscarinic subtype while α7 is the primary nAChR subtype that is responsible for cognition and memory and these two have been the major recent experimental targets for mAChR agonist strategy.
Summary
The last cholinergic receptor agonist to enter phase 3 trial was EVP-6124 (Enceniclin) but was withdrawn due to severe gastrointestinal adverse effects. We aim to present an overview of the efforts and achievements in targeting Muscarinic and Nicotinic acetylcholine receptor in the current review for development of better AD therapeutics.
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Affiliation(s)
- Stuti Verma
- Department of Biotechnology, National Institute of Technology Raipur, Raipur, India
| | - Ashwini Kumar
- Department of Biotechnology, National Institute of Technology Raipur, Raipur, India
| | - Timir Tripathi
- Department of Biochemistry, North-Eastern Hill University, Shillong, India
| | - Awanish Kumar
- Department of Biotechnology, National Institute of Technology Raipur, Raipur, India
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4
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Petracca R, Ponzano S, Bertozzi S, Sasso O, Piomelli D, Bandiera T, Bertozzi F. Progress in the development of β-lactams as N-Acylethanolamine Acid Amidase (NAAA) inhibitors: Synthesis and SAR study of new, potent N-O-substituted derivatives. Eur J Med Chem 2017; 126:561-575. [DOI: 10.1016/j.ejmech.2016.11.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 11/18/2016] [Accepted: 11/19/2016] [Indexed: 10/20/2022]
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Pedretti A, Mazzolari A, Ricci C, Vistoli G. Enhancing the Reliability of GPCR Models by Accounting for Flexibility of Their Pro-Containing Helices: the Case of the Human mAChR1 Receptor. Mol Inform 2015; 34:216-27. [PMID: 27490167 DOI: 10.1002/minf.201400159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 12/16/2014] [Indexed: 01/05/2023]
Abstract
To better investigate the GPCR structures, we have recently proposed to explore their flexibility by simulating the bending of their Pro-containing TM helices so generating a set of models (the so-called chimeras) which exhaustively combine the two conformations (bent and straight) of these helices. The primary objective of the study is to investigate whether such an approach can be exploited to enhance the reliability of the GPCR models generated by distant templates. The study was focused on the human mAChR1 receptor for which a presumably reliable model was generated using the congener mAChR3 as the template along with a second less reliable model based on the distant β2-AR template. The second model was then utilized to produce the chimeras by combining the conformations of its Pro-containing helices (i.e., TM4, TM5, TM6 and TM7 with 16 modeled chimeras). The reliability of such chimeras was assessed by virtual screening campaigns as evaluated using a novel skewness metric where they surpassed the predictive power of the more reliable mAChR1 model. Finally, the virtual screening campaigns emphasize the opportunity of synergistically combining the scores of more chimeras using a specially developed tool which generates highly predictive consensus functions by maximizing the corresponding enrichment factors.
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Affiliation(s)
- Alessandro Pedretti
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli, 25, I-20133 Milano, Italy phone: +39 02 50319349; fax: +39 02 50319359
| | - Angelica Mazzolari
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli, 25, I-20133 Milano, Italy phone: +39 02 50319349; fax: +39 02 50319359
| | - Chiara Ricci
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli, 25, I-20133 Milano, Italy phone: +39 02 50319349; fax: +39 02 50319359
| | - Giulio Vistoli
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli, 25, I-20133 Milano, Italy phone: +39 02 50319349; fax: +39 02 50319359.
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6
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Hoffmeister L, Fukuda T, Pototschnig G, Fürstner A. Total Synthesis of an Exceptional Brominated 4-Pyrone Derivative of Algal Origin: An Exercise in Gold Catalysis and Alkyne Metathesis. Chemistry 2015; 21:4529-33. [DOI: 10.1002/chem.201500437] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Indexed: 02/03/2023]
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7
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Egart B, Lentz D, Czekelius C. Diastereoselective Bromocyclization of O-Allyl-N-tosyl-hydroxylamines. J Org Chem 2013; 78:2490-9. [DOI: 10.1021/jo3026725] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Boris Egart
- Institut
für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195
Berlin, Germany
| | - Dieter Lentz
- Institut
für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195
Berlin, Germany
| | - Constantin Czekelius
- Institut
für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195
Berlin, Germany
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Rezanka T, Nedbalová L, Sigler K. Identification of very-long-chain polyunsaturated fatty acids from Amphidinium carterae by atmospheric pressure chemical ionization liquid chromatography-mass spectroscopy. PHYTOCHEMISTRY 2008; 69:2391-2399. [PMID: 18656907 DOI: 10.1016/j.phytochem.2008.06.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 06/11/2008] [Accepted: 06/11/2008] [Indexed: 05/26/2023]
Abstract
A method is described for the enrichment of very-long-chain polyunsaturated fatty acids (VLCPUFAs) from total fatty acids of Amphidinium carterae and their identification as picolinyl esters by means of microbore liquid chromatography-mass spectrometry with atmospheric pressure chemical ionization (LC-MS/APCI). The combination of argentation TLC and LC-MS/APCI was used to identify unusual VLCPUFAs up to hexatriacontaoctaenoic acid. Two acids, 36:7n-6 and 36:8n-3, were also synthesized to unambiguously confirm their structure. The possibilities of VLCPUFAs biosynthesis are proposed.
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Affiliation(s)
- Tomás Rezanka
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20 Prague, Czech Republic.
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9
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Raddatz R, Schaffhauser H, Marino MJ. Allosteric approaches to the targeting of G-protein-coupled receptors for novel drug discovery: A critical assessment. Biochem Pharmacol 2007; 74:383-91. [PMID: 17572390 DOI: 10.1016/j.bcp.2007.05.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 05/07/2007] [Accepted: 05/08/2007] [Indexed: 10/23/2022]
Abstract
In recent years, the concept of allosteric modulation of G-protein-coupled receptors (GPCRs) has matured and now represents an increasingly viable approach to drug discovery. This is evident in the fact that allosteric modulators have been reported for every class of GPCR, and several are currently in clinical trials with one drug example approved and launched. The allosteric approach has been highlighted for the potential of identifying highly selective compounds with a minimal propensity to produce adverse effect. While much has been written regarding the promises of this approach, important challenges, caveats, and pitfalls exist that are often overlooked. Therefore, a balanced overview of the field that describes both the promises and the challenges of discovering allosteric modulators of GPCRs as novel drugs is presented.
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Affiliation(s)
- Rita Raddatz
- World Wide Discovery Research, Cephalon, Inc., United States
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10
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Disterhoft JF, Oh MM. Pharmacological and molecular enhancement of learning in aging and Alzheimer's disease. ACTA ACUST UNITED AC 2006; 99:180-92. [PMID: 16458491 DOI: 10.1016/j.jphysparis.2005.12.079] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
When animals learn hippocampus-dependent associative and spatial tasks such as trace eyeblink conditioning and the water maze, CA1 hippocampal neurons become more excitable as a result of reductions in the post-burst, slow afterhyperpolarization. The calcium-activated potassium current that mediates this afterhyperpolarization is activated by the calcium influx that occurs when a series of action potentials fire and serves as a modulator of neuronal firing frequency. As a result, spike frequency accommodation is also reduced after learning. Neuronal calcium buffering processes change and/or voltage-dependent calcium currents increase during aging; leading to enhancements in the slow afterhyperpolarization, increased spike frequency accommodation and age-associated impairments in learning. We describe a series of studies done to characterize this learning-specific enhancement in intrinsic neuronal excitability and its converse in aging brain. We have also combined behavioral pharmacology and biophysics in experiments demonstrating that compounds that increase neuronal excitability in CA1 pyramidal neurons also enhance learning rate of hippocampus-dependent tasks, especially in aging animals. The studies reviewed here include those using nimodipine, an L-type calcium current blocker that tends to cross the blood-brain barrier; metrifonate, a cholinesterase inhibitor; CI1017, a muscarinic cholinergic agonist; and galantamine, a combined cholinesterase inhibitor and nicotinic agonist. Since aging is the chief risk factor for Alzheimer's disease, a disease that targets the hippocampus and associated brain regions and markedly impairs hippocampus-dependent learning, these compounds have potential use as treatments for this disease. Galantamine has been approved by the USDA for this purpose. Finally, we have extended our studies to the TG2576 transgenic mouse model of Alzheimer's disease (AD), that overproduces amyloid precursor protein (APP) and increases levels of toxic beta-amyloid in the brain. Not only do these mice show deficits in hippocampus-dependent learning as they age, but their hippocampal neurons show a reduced capacity to increase their levels of intrinsic excitability with reductions in the slow afterhyperpolarization after application of the muscarinic agonist carbachol. These TG2576 APP overproducing mice were crossed with BACE1 knockout mice, that do not produce beta-amyloid because cleavage of APP by the beta-site APP cleaving enzyme 1 (BACE1) is a critical step in its formation. Not only was hippocampus-dependent learning rescued in the bigenic TG2576-BACE1 mice, but the capacity of hippocampal neurons to show normal enhancements of intrinsic excitability was restored. The series of studies reviewed here support our hypothesis that enhancement in intrinsic excitability by reductions in calcium-activated potassium currents in hippocampal neurons is an important cellular mechanism for hippocampus-dependent learning.
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Affiliation(s)
- John F Disterhoft
- Department of Physiology and Institute for Neuroscience, Feinberg School of Medicine, Northwestern University, 303 E Chicago Avenue, Chicago, IL 60611-3008, USA.
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11
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Kim MG, Bodor ET, Harden TK, Kohn H. C(8)-substituted 1-azabicyclo[3.3.1]non-3-enes: a novel scaffold for muscarinic receptor ligands. Bioorg Med Chem 2004; 12:2357-67. [PMID: 15080933 DOI: 10.1016/j.bmc.2004.02.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2003] [Accepted: 02/04/2004] [Indexed: 11/29/2022]
Abstract
The [3.3.1]-bicyclic amine, exo-8-benzyloxymethyl-3-ethoxycarbonyl-4-hydroxy-1-azabicyclo[3.3.1]non-3-ene (1), has been shown to be a potent competitive antagonist against the hM(1)-hM(5) muscarinic receptors. This heterocyclic system has not been extensively evaluated despite the notable activities reported for other bicyclic amines. Synthetic strategies permitted the selective alteration of five structural sites in 1. Pharmacological evaluation demonstrated that modification of either the C(3) alkoxycarbonyl or the C(4) enol units in 1 gave compounds with high affinity for the hM(1)-hM(5) muscarinic receptors with selectivity for the hM(2) receptor.
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Affiliation(s)
- Myoung Goo Kim
- Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7360, USA
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12
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Kim MG, Bodor ET, Wang C, Harden TK, Kohn H. C(8) substituted 1-azabicyclo[3.3.1]non-3-enes and C(8) substituted 1-azabicyclo[3.3.1]nonan-4-ones: novel muscarinic receptor antagonists. J Med Chem 2003; 46:2216-26. [PMID: 12747793 DOI: 10.1021/jm020572p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Expedient syntheses of C(8) substituted 1-azabicyclo[3.3.1]non-3-enes and C(8) substituted 1-azabicyclo[3.3.1]nonan-4-ones are reported to begin with 2,5-disubstituted pyridines. Catalytic reduction of the pyridine to the piperidine followed by treatment with ethyl acrylate and Dieckmann cyclization gave diastereomeric mixtures of C(8) substituted 3-ethoxycarbonyl-4-hydroxy-1-azabicyclo[3.3.1]non-3-enes, which were separable by chromatography. We found that the catalytic reduction (PtO2, H2) procedure provided the cis-substituted piperidine but that pyridine reduction was accompanied by competitive cleavage of the C(2) pyridyl substituent. Accordingly, an alternative route was devised that afforded a diastereomeric mixture of the cis- and trans-2,5-disubstituted piperidine. Treatment of the substituted pyridine with m-CPBA gave the pyridine N-oxide, which was reduced to the piperidine by sequential reduction with ammonium formate in the presence of Pd-C followed by NaBH3CN. Addition of ethyl acrylate completed the synthesis of the substituted piperidine. The overall four-step reaction gave higher yields (57%) than the two-step procedure (13%) with little cleavage of the C(2) pyridyl substituent. Acid decarboxylation of the bicyclo[3.3.1]non-3-enes provided the C(8) substituted 1-azabicyclo[3.3.1]nonan-4-ones. Structural studies revealed diagnostic 13C NMR signals that permit assignment of the orientation of the C(8) substituent. Pharmacological investigations documented that 3-ethoxycarbonyl-4-hydroxy-1-azabicyclo[3.3.1]non-3-enes efficiently bind to the human M1-M5 muscarinic receptors and function as antagonists. We observed that exo-8-benzyloxymethyl-3-ethoxycarbonyl-4-hydroxy-1-azabicyclo[3.3.1]non-3-ene (3) displayed the highest affinity, exhibiting Ki values at all five muscarinic receptors that were approximately 10-50 times lower than carbachol and approximately 30-230 times lower than arecoline. Receptor selectivity was observed for 3. Compound 3 contained two different pharmacophores found in many muscarinic receptor ligands, and preliminary findings indicated the importance of both structural elements for maximal activity. Compound 3 serves as a novel lead compound for further drug development.
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Affiliation(s)
- Myoung Goo Kim
- Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7360, USA
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13
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Rodríguez-Franco MI, Dorronsoro I, Castro A, Martínez A, Badía A, Baños JE. Synthesis and muscarinic activities of O-[(benzyl- or benzoyl-pyrazolyl)propynyl]-oximes of N-methylpiperidinone, 3-tropinone, and 3-quinuclidinone. Bioorg Med Chem 2003; 11:2263-8. [PMID: 12713836 DOI: 10.1016/s0968-0896(03)00111-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The synthesis of O-propynyloximes of N-methylpiperidinone, 3-tropinone, and 3-quinuclidinone, containing several pyrazole frameworks is described, together with their muscarinic receptor affinities. Compounds derived from N-methylpiperidinone or 3-tropinone and N-(4-methoxybenzyl)- or N-(2,4,6-trimethylbenzoyl)pyrazole showed moderate activity for muscarinic receptors in the rat central nervous system. A semi-empirical AM1 calculation has shown that the O-[(benzoyl-pyrazolyl)propynyl]-oximes of tropinone fit a previously described muscarinic pharmacophoric model, revealing structural features useful for the development of new muscarinic agents.
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14
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Böhme TM, Augelli-Szafran CE, Hallak H, Pugsley T, Serpa K, Schwarz RD. Synthesis and pharmacology of benzoxazines as highly selective antagonists at M(4) muscarinic receptors. J Med Chem 2002; 45:3094-102. [PMID: 12086495 DOI: 10.1021/jm011116o] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Previously, we reported on PD 102807 (41) as being the most selective synthetic M(4) muscarinic antagonist identified to date. Synthesized analogues of 41 showed no improvement in affinity and selectivity at that time. However, several newly synthesized compounds exhibit a 7-fold higher affinity at M(4) receptors and demonstrate a selectivity of at least 100-fold over all other muscarinic receptor subtypes. For example, compound 28 showed an affinity of pK(i) = 9.00 at M(4) receptors and a selectivity of M(1)/M(4) = 13 183-fold, M(2)/M(4) = 339-fold, M(3)/M(4) = 151-fold, and M(5)/M(4) = 11 220-fold. This high selectivity along with high affinity has not been reported for any synthetic muscarinic antagonist, nor for natural occurring M(4) antagonists such as the M(4) selective Eastern Green Mamba venom MT3 (M(4) pK(b) = 8.7, M(1)/M(4) = 40-fold, M(2)/M(4) > or = 500-fold, M(3)/M(4) > or = 500-fold, and M(5)/M(4) > or = 500-fold). Derivative 24, a compound with a high selectivity pattern as well, has been tested for in vivo efficacy. It was able to block the L-3,4-dihydroxyphenylalanine accumulation produced by CI-1017, an M(1)/M(4) selective muscarinic agonist, in the mesolimbic region and striatum, which suggests that 24 is capable of crossing the blood-brain barrier and confirms the pharmacokinetic data obtained on this compound. This is evidence that suggests that agonist-induced increase in catecholamine synthesis observed in these regions is mediated by M(4) receptors.
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Affiliation(s)
- Thomas M Böhme
- Department of Medicinal Chemistry, Pfizer Global Research and Development, Ann Arbor Laboratories, 2800 Plymouth Road, Ann Arbor, MI 48105, USA.
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15
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Spalding TA, Trotter C, Skjaerbaek N, Messier TL, Currier EA, Burstein ES, Li D, Hacksell U, Brann MR. Discovery of an ectopic activation site on the M(1) muscarinic receptor. Mol Pharmacol 2002; 61:1297-302. [PMID: 12021390 DOI: 10.1124/mol.61.6.1297] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Receptors have well-conserved regions that are recognized and activated by hormones and neurotransmitters. Most drugs bind to these sites and mimic or block the action of the native ligands. Using a high-throughput functional screen, we identified a potent and selective M(1) muscarinic receptor agonist from a novel structural class. Using a series of chimeric receptors, we demonstrated that this ligand activates the receptor through a region that is not conserved among receptor subtypes, explaining its unprecedented selectivity. This region of the receptor is distinct from the conserved region that is recognized by traditional ligands. The finding that receptors for small-molecule transmitters can have multiple, structurally distinct activation sites has broad implications for the study of receptor structure/function and the potential for the discovery of novel ligands with high selectivity.
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16
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Somanadhan B, Loke WK, Sim MK, Go ML. Quinuclidinone O-Alkynyloximes with muscarinic agonist activity. Bioorg Med Chem 2002; 10:207-13. [PMID: 11738623 DOI: 10.1016/s0968-0896(01)00267-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A series of quinuclidinone O-alkynyloximes (14-19) were synthesized and evaluated in radioligand displacement assays for binding affinities to M1-M3 muscarinic receptors. Radioligand displacement assays were carried out using [3H] oxotremorine-M and [3H] pirenzepine on rat cortical tissue and [3H] N-methylscopolamine on rat heart and submandibulary glands. Two alkynyloximes 15 and 18 had pirenzepine/oxotremorine M ratios which were indicative of muscarinic agonist and partial agonist activity, respectively. They were tested for their mnemonic effects in mice using the swimming escape task and found to attenuate scopolamine induced impairment of the task in mice at 2mg/kg. The results show that the O-alkynyloxime moiety linked to azacycles of appropriate size and rigidity (for example quinuclidine and tropane) is a potentially useful muscarinic pharmacophore that can be exploited for the design of muscarinic agonists.
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Affiliation(s)
- Brinda Somanadhan
- Department of Pharmacy, National University of Singapore, Republic of Singapore
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17
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Rajeswaran WG, Cao Y, Huang XP, Wroblewski ME, Colclough T, Lee S, Liu F, Nagy PI, Ellis J, Levine BA, Nocka KH, Messer WS. Design, synthesis, and biological characterization of bivalent 1-methyl-1,2,5,6-tetrahydropyridyl-1,2,5-thiadiazole derivatives as selective muscarinic agonists. J Med Chem 2001; 44:4563-76. [PMID: 11741475 DOI: 10.1021/jm0102405] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Selective muscarinic agonists could be useful in the treatment of neurological disorders such as Alzheimer's disease, schizophrenia, and chronic pain. Many muscarinic agonists have been developed, yet most exhibit at best limited functional selectivity for a given receptor subtype perhaps because of the high degree of sequence homology within the putative binding site, which appears to be buried within the transmembrane domains. Bivalent compounds containing essentially two agonist pharmacophores within the same molecule were synthesized and tested for receptor binding affinity and muscarinic agonist activity. A series of bis-1,2,5-thiadiazole derivatives of 1,2,5,6-tetrahydropyridine linked by an alkyloxy moiety exhibited very high affinity (K(i) < 1 nM) and strong agonist activity. The degree of activity depended on the length of the linking alkyl group, which could be replaced by a poly(ethylene glycol) moiety, resulting in improved water solubility, binding affinity, and agonist potency.
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Affiliation(s)
- W G Rajeswaran
- Department of Medicinal and Biological Chemistry, Center for Drug Design and Development, College of Pharmacy, The University of Toledo, Ohio 43606, USA
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Felder CC, Bymaster FP, Ward J, DeLapp N. Therapeutic opportunities for muscarinic receptors in the central nervous system. J Med Chem 2000; 43:4333-53. [PMID: 11087557 DOI: 10.1021/jm990607u] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- C C Felder
- Eli Lilly Research Laboratories, Indianapolis, Indiana 46285, USA.
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Ros E, Aleu J, Marsal J, Solsona C. Effects of CI-1002 and CI-1017 on spontaneous synaptic activity and on the nicotinic acetylcholine receptor of Torpedo electric organ. Eur J Pharmacol 2000; 390:7-13. [PMID: 10708701 DOI: 10.1016/s0014-2999(99)00911-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effect of azepino[2,1-b]quinazoline 1,3-dichloro-6,7,8,9,10, 12-hexahydro-, mono-hydrochloride (CI-1002), a tacrine derivative, and 1-azabicyclo[2.2.1]heptan-3-one, O-[3-(methoxyphenyl)-2-propynyl]oxime [R-(Z)]-2-butenedioate (CI-1017), a muscarinic M(1) receptor agonist, on spontaneous synaptic activity was investigated by measuring amplitude, rise time, velocity of rising, half-width, and electrical charge of miniature endplate potentials (m.e.p.p.) recorded extracellularly in Torpedo electric organ fragments. The effect of CI-1002 and CI-1017 on the nicotinic acetylcholine receptor was investigated by measuring the current induced by acetylcholine in Xenopus laevis oocytes transplanted with membranes from Torpedo electric organ. CI-1002, at a concentration of 1 microM, altered the m.e.p.p. by increasing the amplitude (from 1.08+/-0.01 to 2.76+/-0.03 mV), rise time (from 0. 700+/-0.006 to 1.02+/-0.01 ms), rising rate (from 1.79+/-0.02 to 3. 45+/-0.05 mV/ms), half-width (from 0.990+/-0.008 to 2.40+/-0.02 ms), and electrical charge (from 304+/-4 to 784+/-11 mV s). CI-1017, at a concentration of 1 microM, altered the m.e.p.p. by decreasing the amplitude (from 1.08+/-0.01 to 0.650+/-0.007 mV), rise time (from 0. 700+/-0.006 to 0.530+/-0.007 ms), rising rate (from 1.79+/-0.02 to 1. 53+/-0.02 mV/ms), half-width (from 0.990+/-0.008 to 0.670+/-0.007 ms), and electrical charge (from 304+/-4 to 75+/-1 mV s). CI-1002 inhibited the acetylcholine-induced current of nicotinic acetylcholine receptors with an IC(50) of 3.4+/-0.3 microM. CI-1017 inhibited the acetylcholine-induced current of nicotinic acetylcholine receptors with an IC(50) of 0.8+/-0.1 microM. These results indicate that, although both drugs interacted negatively with nicotinic acetylcholine receptors, CI-1002 overcame this inhibition by recruiting more acetylcholine to build a quantum.
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Affiliation(s)
- E Ros
- Laboratori de Neurobiologia Cellular i Molecular, Departament de Biologia Cellular i Anatomia Patològica, Hospital de Bellvitge, Universitat de Barcelona, Campus de Bellvitge, Pavelló de Govern, Feixa Llarga s/n E-08907, L'Hospitalet de Llobregat, SpainE
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The M1 muscarinic agonist CI-1017 facilitates trace eyeblink conditioning in aging rabbits and increases the excitability of CA1 pyramidal neurons. J Neurosci 2000. [PMID: 10632607 DOI: 10.1523/jneurosci.20-02-00783.2000] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The M1 muscarinic agonist CI-1017 was administered intravenously to aging rabbits on a daily basis before and during hippocampally dependent trace eyeblink conditioning sessions. Circulating levels of CI-1017 were significantly related to the drug dose. The drug was found to significantly increase the rate and amount of learning in a dose-dependent manner with no significant effects on the amplitude, area, or latency of conditioned responses. There was no evidence of pseudoconditioning at the highest drug concentration, and the minimally effective dose produced only mild and temporary hypersalivation as a side effect. CI-1017 (10 microM) was also found to increase the excitability of CA1 pyramidal neurons recorded from hippocampal slices from young and aging naive rabbits as measured by changes in spike-frequency adaptation and the postburst afterhyperpolarization. These biophysical changes were reversed with either atropine (1 microM) or pirenzepine (1 microM). These results suggest that M1 agonists ameliorate age-related learning and memory impairments at least in part by reducing the afterhyperpolarization and spike-frequency adaptation of hippocampal pyramidal neurons and that M1 agonists may be an effective therapy for reducing the cognitive deficits that accompany normal aging and/or Alzheimer's disease.
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Choi KI, Cha JH, Cho YS, Pae AN, Jin C, Yook J, Cheon HG, Jeong D, Kong JY, Koh HY. Binding affinities of 3-(3-phenylisoxazol-5-yl)methylidene-1-azabicycles to acetylcholine receptors. Bioorg Med Chem Lett 1999; 9:2795-800. [PMID: 10522693 DOI: 10.1016/s0960-894x(99)00477-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of 3-(3-phenylisoxazol-5-yl)methylidene-1-azabicycles synthesized showed different binding characteristics to acetylcholine receptors depending on the substituents on the phenyl ring. Small polar substituents gave preferential binding affinity to nicotinic receptors, and large hydrophobic substituents to muscarinic receptors.
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Affiliation(s)
- K I Choi
- Life Sciences Division, Korea Institute of Science and Technology, Seoul
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