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Larin EM, Torelli A, Loup J, Lautens M. One-Pot, Three-Step Synthesis of Benzoxazinones via Use of the Bpin Group as a Masked Nucleophile. Org Lett 2021; 23:2720-2725. [PMID: 33689389 DOI: 10.1021/acs.orglett.1c00623] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The utilization of the Bpin group as a pronucleophile to facilitate the assembly of cyclic carbamates has been achieved. This one-pot process involves an initial copper-catalyzed borylation, a subsequent C-B bond oxidation to generate the reactive alcohol intermediate, and a cyclization. We report the use of this efficient, scalable, and simple method toward the synthesis of a wide range of benzoxazinone scaffolds, including enantioselective results. Subsequent transformations into useful scaffolds showcase the utility of this strategy.
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Affiliation(s)
- Egor M Larin
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Alexa Torelli
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Joachim Loup
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Mark Lautens
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
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2
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Sergeeva OA, Chepkova AN, Görg B, Rodrigues Almeida F, Bidmon HJ, Haas HL, Häussinger D. Histamine-induced plasticity and gene expression in corticostriatal pathway under hyperammonemia. CNS Neurosci Ther 2019; 26:355-366. [PMID: 31571389 PMCID: PMC7052803 DOI: 10.1111/cns.13223] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 08/10/2019] [Accepted: 09/04/2019] [Indexed: 01/13/2023] Open
Abstract
Aims Histamine H3 receptor (H3R) antagonists/inverse agonists increase vigilance. We studied brain histaminergic pathways under hyperammonemia and the transcriptome of receptors and their signaling cascades to provide a rationale for wake‐promoting therapies. Methods We analyzed histamine‐induced long‐lasting depression of corticostriatal synaptic transmission (LLDhist). As the expression of dopamine 1 receptors (D1R) is upregulated in LGS‐KO striatum where D1R‐H3R dimers may exist, we investigated actions of H3R and D1R agonists and antagonists. We analyzed transcription of selected genes in cortex and dorsal striatum in a mouse model of inborn hyperammonemia (liver‐specific glutamine synthetase knockout: LGS‐KO) and compared it with human hepatic encephalopathy. Results LGS‐KO mice showed significant reduction of the direct depression (DD) but not the long‐lasting depression (LLD) by histamine. Neither pharmacological activation nor inhibition of D1R significantly affected DDhist and LLDhist in WT striatum, while in LGS‐KO mice D1R activation suppressed LLDhist. Histaminergic signaling was found unchanged at the transcriptional level except for the H2R. A study of cAMP‐regulated genes indicated a significant reduction in the molecular signature of wakefulness in the diseased cortex. Conclusions Our findings provide a rationale for the development of aminergic wake‐promoting therapeutics in hyperammonemic disorders.
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Affiliation(s)
- Olga A Sergeeva
- Molecular Neurophysiology, Medical Faculty, Institute of Neural and Sensory Physiology, Heinrich-Heine University, Duesseldorf, Germany.,Medical Faculty, Institute of Clinical Neurosciences and Medical Psychology, Heinrich-Heine University, Duesseldorf, Germany
| | - Aisa N Chepkova
- Molecular Neurophysiology, Medical Faculty, Institute of Neural and Sensory Physiology, Heinrich-Heine University, Duesseldorf, Germany.,Clinic of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich-Heine University, Duesseldorf, Germany
| | - Boris Görg
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich-Heine University, Duesseldorf, Germany
| | - Filipe Rodrigues Almeida
- Medical Faculty, Institute of Clinical Neurosciences and Medical Psychology, Heinrich-Heine University, Duesseldorf, Germany
| | - Hans-Jürgen Bidmon
- Medical Faculty, C.&O. Vogt Institute for Brain Research, Heinrich-Heine University, Duesseldorf, Germany
| | - Helmut L Haas
- Molecular Neurophysiology, Medical Faculty, Institute of Neural and Sensory Physiology, Heinrich-Heine University, Duesseldorf, Germany
| | - Dieter Häussinger
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich-Heine University, Duesseldorf, Germany
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Prasad AK, Mishra P. Scavenging of superoxide radical anion and hydroxyl radical by urea, thiourea, selenourea and their derivatives without any catalyst: A theoretical study. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.06.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Synthesis, docking study and biological evaluation of some new thiourea derivatives bearing benzenesulfonamide moiety. Chem Cent J 2017; 11:42. [PMID: 29086825 PMCID: PMC5438335 DOI: 10.1186/s13065-017-0271-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/16/2017] [Indexed: 02/01/2023] Open
Abstract
Background A series of novel N-(2, 6-dimethoxypyrimidin-4-yl)-4-(3-(aryl)thioureido) benzenesulfonamides 3a–t was synthesized by the addition of N-(2,6-dimethoxypyrimidin-4-yl)-4-isothiocyanatobenzenesulfonamide 2 to the appropriate aromatic amine. The structures of the synthesized compounds were inspired from the second line antituberculosis pro-drugs. Results Most of the new compounds were screened for their activity against Mycobacterium tuberculosis. The results of the antimycobacterial assay showed that compound 3i exerted the highest activity (MIC = 3.13 µg/mL), followed by compound 3s (MIC = 6.25 µg/mL). Conclusion The structure–activity relationship (SAR) analysis revealed that the introduction of the benzo[1,3]dioxol moiety in 3i and the 4-morpholinyl-4-phenyl moiety in 3s has proven to give the most potent compounds in this study. Docking of the promising compounds inside the active site of M. tuberculosis enoyl reductase InhA was performed in order to emphasize the results. The compounds showed a similar orientation to that of GSK 625 inside the active site of 5JFO and bind to Met 98 in a way similar to that of the co-crystallized ligand.
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Okuniewski A, Rosiak D, Chojnacki J, Becker B. Coordination polymers and molecular structures among complexes of mercury(II) halides with selected 1-benzoylthioureas. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.01.035] [Citation(s) in RCA: 294] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Synthesis Antimicrobial and Anticancer Evaluation of 1-Aryl-5-(o-methoxyphenyl)-2-S-benzyl Isothiobiurets. INTERNATIONAL JOURNAL OF MEDICINAL CHEMISTRY 2014; 2014:352626. [PMID: 25505990 PMCID: PMC4258328 DOI: 10.1155/2014/352626] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/15/2014] [Accepted: 11/05/2014] [Indexed: 11/17/2022]
Abstract
A series of S-benzyl aryl thiourea were condensed with o-Methoxy phenyl isocyanate to yield respective isothiobiuret derivatives. The newly synthesized compounds were characterized by 1H-NMR, IR, and Mass Spectral studies and tested for biological activities.
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N-Alkenyl and cycloalkyl carbamates as dual acting histamine H3 and H4 receptor ligands. Bioorg Med Chem 2011; 19:2850-8. [DOI: 10.1016/j.bmc.2011.03.046] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 03/10/2011] [Accepted: 03/18/2011] [Indexed: 11/19/2022]
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8
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Receptor-specific functional efficacies of alkyl imidazoles as dual histamine H3/H4 receptor ligands. Eur J Pharmacol 2011; 654:200-8. [DOI: 10.1016/j.ejphar.2010.12.033] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 11/18/2010] [Accepted: 12/15/2010] [Indexed: 11/23/2022]
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9
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Synthesis and antiviral bioactivities of novel chiral bis-thiourea-type derivatives containing α-aminophosphonate moiety. Sci China Chem 2011. [DOI: 10.1007/s11426-010-4179-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Maddani MR, Prabhu KR. A concise synthesis of substituted thiourea derivatives in aqueous medium. J Org Chem 2010; 75:2327-32. [PMID: 20201494 DOI: 10.1021/jo1001593] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient method for the synthesis of symmetrical and unsymmetrical substituted thiourea derivatives by means of simple condensation between available building blocks such as amines and carbon disulfide in aqueous medium is presented. This protocol works smoothly with aliphatic primary amines to afford various di- and trisubstituted thiourea derivatives. The present method is also useful in synthesizing various substituted 2-mercapto imidazole heterocycles. This method proceeds through a xanthate (amino dithiol deivative) intermediate, unlike isothiocyanate as in an earlier known method.
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Affiliation(s)
- Mahagundappa R Maddani
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, Karnataka, India
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Thanh ND, Mai NTT. Synthesis of N-tetra-O-acetyl-β-d-glucopyranosyl-N′-(4′,6′-diarylpyrimidin-2′-yl)thioureas. Carbohydr Res 2009; 344:2399-405. [DOI: 10.1016/j.carres.2009.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2009] [Revised: 08/30/2009] [Accepted: 09/01/2009] [Indexed: 10/20/2022]
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12
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Ananthan S, Faaleolea ER, Goldman RC, Hobrath JV, Kwong CD, Laughon BE, Maddry JA, Mehta A, Rasmussen L, Reynolds RC, Secrist JA, Shindo N, Showe DN, Sosa MI, Suling WJ, White EL. High-throughput screening for inhibitors of Mycobacterium tuberculosis H37Rv. Tuberculosis (Edinb) 2009; 89:334-53. [PMID: 19758845 DOI: 10.1016/j.tube.2009.05.008] [Citation(s) in RCA: 221] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 05/20/2009] [Accepted: 05/27/2009] [Indexed: 10/20/2022]
Abstract
There is an urgent need for the discovery and development of new antitubercular agents that target new biochemical pathways and treat drug resistant forms of the disease. One approach to addressing this need is through high-throughput screening of medicinally relevant libraries against the whole bacterium in order to discover a variety of new, active scaffolds that will stimulate new biological research and drug discovery. Through the Tuberculosis Antimicrobial Acquisition and Coordinating Facility (www.taacf.org), a large, medicinally relevant chemical library was screened against M. tuberculosis strain H37Rv. The screening methods and a medicinal chemistry analysis of the results are reported herein.
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Affiliation(s)
- Subramaniam Ananthan
- Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205, USA.
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YAN Z, CAI X, YANG X, SONG B, CHEN Z, BHADURY SP, HU D, JIN L, XUE W, LU P. Synthesis and Antiviral Activities of Chiral Thiourea Derivatives. CHINESE J CHEM 2009. [DOI: 10.1002/cjoc.200990097] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Synthesis and Stability in Biological Media of 1H-Imidazole-1-carboxylates of ROS203, an Antagonist of the Histamine H3 Receptor. Chem Biodivers 2008; 5:140-52. [DOI: 10.1002/cbdv.200890004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Vaccaro HA, Zhao Z, Clader JW, Song L, Terracina G, Zhang L, Pissarnitski DA. Solution-phase parallel synthesis of carbamates as gamma-secretase inhibitors. ACTA ACUST UNITED AC 2007; 10:56-62. [PMID: 17988101 DOI: 10.1021/cc700100r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A novel methodology for parallel liquid-phase synthesis of carbamates suitable for the preparation of sterically hindered molecules is disclosed. The alcohols are converted to 4-nitrophenylcarbonates, followed by the reaction with amines. Side product 4-nitrophenol and the unreacted excess amines are scavenged by appropriately chosen cleanup resins, selected among Amberlyst A26 (hydroxide form) and macroporous sulfonic acid (MP-TsOH) or polystyrene isocyanate (PS-NCO) and polystyrene benzaldehyde (PS-PhCHO) resins. As a part of a medicinal chemistry program directed toward finding gamma-secretase inhibitors as prospective drug candidates for Alzheimer's disease, a 6 x 24 library of carbamates was prepared. Out of 144 library members, 133 had a purity for the targeted compound of 80% or better. The prepared compounds were assessed in the gamma-secretase inhibition assay and demonstrated activity with IC 50 values in the range from 1 microM to 5 nM, with the activity of 7 compounds being better than 10 nM.
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Affiliation(s)
- Henry A Vaccaro
- Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, USA
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Schlegel B, Laggner C, Meier R, Langer T, Schnell D, Seifert R, Stark H, Höltje HD, Sippl W. Generation of a homology model of the human histamine H3 receptor for ligand docking and pharmacophore-based screening. J Comput Aided Mol Des 2007; 21:437-53. [PMID: 17668276 DOI: 10.1007/s10822-007-9127-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Accepted: 06/29/2007] [Indexed: 10/23/2022]
Abstract
The human histamine H(3) receptor (hH(3)R) is a G-protein coupled receptor (GPCR), which modulates the release of various neurotransmitters in the central and peripheral nervous system and therefore is a potential target in the therapy of numerous diseases. Although ligands addressing this receptor are already known, the discovery of alternative lead structures represents an important goal in drug design. The goal of this work was to study the hH(3)R and its antagonists by means of molecular modelling tools. For this purpose, a strategy was pursued in which a homology model of the hH(3)R based on the crystal structure of bovine rhodopsin was generated and refined by molecular dynamics simulations in a dipalmitoylphosphatidylcholine (DPPC)/water membrane mimic before the resulting binding pocket was used for high-throughput docking using the program GOLD. Alternatively, a pharmacophore-based procedure was carried out where the alleged bioactive conformations of three different potent hH(3)R antagonists were used as templates for the generation of pharmacophore models. A pharmacophore-based screening was then carried out using the program Catalyst. Based upon a database of 418 validated hH(3)R antagonists both strategies could be validated in respect of their performance. Seven hits obtained during this screening procedure were commercially purchased, and experimentally tested in a [(3)H]N(alpha)-methylhistamine binding assay. The compounds tested showed affinities at hH(3)R with K ( i ) values ranging from 0.079 to 6.3 muM.
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Affiliation(s)
- Birgit Schlegel
- Institute of Pharmaceutical Chemistry, Heinrich-Heine-Universität Düsseldorf, Universitätsstr 1, 40197, Dusseldorf, Germany
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Katritzky AR, Witek RM, Rodriguez-Garcia V, Mohapatra PP, Rogers JW, Cusido J, Abdel-Fattah AAA, Steel PJ. Benzotriazole-assisted thioacylation. J Org Chem 2006; 70:7866-81. [PMID: 16277306 DOI: 10.1021/jo050670t] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[Chemical reaction: See text] Benzotriazole reagents for thioacylation (RCSBt), thiocarbamoylation (RR'NCSBt), aryl/alkoxythioacylation (ROCSBt), and aryl/alkylthiothioacylation (RSCSBt) are synthesized, and their utility is assessed by syntheses of representative heteroaryl thioureas 3a-g, thioamides 15a-s, thionoesters 16a-h, thiocarbamates 17a-e, dithiocarbamates 18a-d, thiocarbonates 19a-c, and dithiocarbonates 20a-c.
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Affiliation(s)
- Alan R Katritzky
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
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Breuzard JAJ, Christ-Tommasino ML, Lemaire M. Chiral Ureas and Thiroureas in Asymmetric Catalysis. TOP ORGANOMETAL CHEM 2005. [DOI: 10.1007/b136352] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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Walczyński K, Zuiderveld OP, Timmerman H. Non-imidazole histamine H3 ligands. Part III. New 4-n-propylpiperazines as non-imidazole histamine H3-antagonists. Eur J Med Chem 2005; 40:15-23. [PMID: 15642406 DOI: 10.1016/j.ejmech.2004.09.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Revised: 09/01/2004] [Accepted: 09/06/2004] [Indexed: 11/25/2022]
Abstract
In search for a new lead of non-imidazole histamine H3-receptor antagonists, a series of 1[(2-thiazolopyridine)-4-n-propyl]piperazines, the analogous 1-[(2-oxazolopyridine)-4-npropyl]piperazines, 1-[(2-benzothiazole)-4-n-propyl]piperazine and 1-[(2-benzooxazole)4-n-propyl]piperazine were prepared and in vitro tested as H3-receptor antagonists (the electrically evoked contraction of the guinea-pig jejunum). It appeared that by comparison of homologous pairs the thiazolo derivatives have slightly higher activity than their oxazolo analogues. The most potent compound of these series is the 1-(2-thiazolo[4,5-c]pyridine)-4-n-propylpiperazine (3c) with pA2 = 7.25 (its oxazole analogue (4g) showed pA2 = 6.9). The structure-activity relationships for compounds with various positions of the nitrogen in the benzene ring for the thiazoles compared with oxazoles are discussed.
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Affiliation(s)
- Krzysztof Walczyński
- Department of Synthesis and Technology of Drugs, Medical University Muszyńskiego, Muszyńskiego Street 1, 90-145 Łódź, Poland.
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Vacondio F, Mor M, Silva C, Zuliani V, Rivara M, Rivara S, Bordi F, Plazzi PV, Magnanini F, Bertoni S, Ballabeni V, Barocelli E, Carrupt PA, Testa B. Imidazole H3-antagonists: relationship between structure and ex vivo binding to rat brain H3-receptors. Eur J Pharm Sci 2004; 23:89-98. [PMID: 15324926 DOI: 10.1016/j.ejps.2004.06.003] [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] [Received: 02/09/2004] [Revised: 05/24/2004] [Accepted: 06/07/2004] [Indexed: 01/16/2023]
Abstract
H3-antagonists possess promising pharmacological effects on awakening, learning and memory, but few data on their access to the central nervous system (CNS) have been reported so far. The purpose of this work was to investigate the relationships between structure and brain penetration of a series of H3-antagonists, using ex vivo binding experiments in rats. H3-antagonists belonging to different chemical classes but all having an imidazole ring, an alkyl spacer, a polar fragment and a lipophilic ending group, were selected among the numerous H3-antagonists recently described by us. Ex vivo binding studies were performed by inhibiting specific [3H]-(R)-alpha-methylhistamine ([3H]-RAMHA) binding to rat cerebral cortical membranes following H3-antagonist peripheral administration. Ionization constants and partition coefficients in n-octanol/water and 1,2-dichloroethane/water were determined by the potentiometric pH-metric method and were compared to the ex vivo binding potencies to analyse structure-property relationships (SPR). In the ex vivo assay, the H3-antagonists showed different potencies (pED50) not correlated to their in vitro H3-receptor binding affinities (pKi). Compound 4a, having a benzothiazol-2-yl-thioethyl chain, showed high ex vivo potency (ED50=1.35 mg kg(-1) i.p.) and a fast brain penetration, eliciting maximal displacement of [3H]-RAMHA already 5 min after i.v. or i.p. administration. Ex vivo binding assays of three compounds, following i.v. and i.p. administration, showed that the observed i.p. ex vivo potencies were not significantly affected by biotransformation. Within the set of compounds, those having a better ability to reach the CNS had a logDoct(7.4) in the range 2-3.5, and a DeltalogPoct-dce < 2. The combined use of two easily measurable physicochemical descriptors, namely logDoct(7.4) (apparent lipophilicity at pH 7.4) and DeltalogPoct-dce (a descriptor of H-bond donor capacity) allowed to model brain permeation of the majority of the compounds examined.
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Affiliation(s)
- Federica Vacondio
- Dipartimento Farmaceutico, Università degli Studi di Parma, Parco Area delle Scienze 27a, I-43100 Parma, Italy.
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Katritzky AR, Ledoux S, Witek RM, Nair SK. 1-(Alkyl/arylthiocarbamoyl)benzotriazoles as stable isothiocyanate equivalents: synthesis of Di- and trisubstituted thioureas. J Org Chem 2004; 69:2976-82. [PMID: 15104434 DOI: 10.1021/jo035680d] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1-(Alkyl/arylthiocarbamoyl)benzotriazoles 4a-i were synthesized in yields of 91-99% from bis(benzotriazolyl)methanethione (3). Reagents 4a-g were then used as isothiocyanate equivalents for the efficient synthesis of 10 secondary and 14 tertiary thioureas in high-yielding, convenient processes.
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Affiliation(s)
- Alan R Katritzky
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
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Zuliani V, Bordi F, Rivara M, Silva C, Vacondio F, Morini G, Rivara S, Barocelli E, Ballabeni V, Bertoni S, Magnanini F, Plazzi PV. The role of HB-donor groups in the heterocyclic polar fragment of H3-antagonists. ACTA ACUST UNITED AC 2003; 58:891-9. [PMID: 13679184 DOI: 10.1016/s0014-827x(03)00147-2] [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: 11/26/2022]
Abstract
It has been recently reported that compounds composed of an imidazole connected through an alkyl spacer to a 2-aminobenzimidazole showed high affinity towards the H(3)-receptor. The guanidine fragment of the 2-aminobenzimidazole is probably involved in hydrogen bond interactions at the binding site, and is referred to as the 'polar fragment'. In the present work, starting from 2-aminobenzimidazole derivatives with a di-methylene spacer 1 (pK(i)=7.25) or a tri-methylene one 2 (pK(i)=8.90), we investigated the importance of the hydrogen bond (HB) donor groups at the polar fragment in the interaction with the H(3)-receptor. The replacement of 2-aminobenzimidazoles with different moieties [2-aminobenzothiazole, 3, 4; 2-thiobenzimidazole, 5, 6; 2-thiobenzothiazole, 7, 8; 2-thio-4-phenyl- or 2-thio-5-phenyl-N-methylimidazoles, 9-12] highlighted the effect of the polar group basicity on the optimal length of the alkyl chain: longer spacers were preferred with polar groups of moderate basicity whereas, in the presence of neutral polar groups, the best affinity values were obtained with di-methylene chains. Moreover, N-methylation at the 2-aminobenzimidazole moiety 13-16 revealed different behaviour for compounds having different spacer lengths. In fact, methylation of the exocyclic NH group maintained high affinity for the tri-methylene 2-aminobenzimidazole derivative, while a drop in affinity was observed for the annular N-methylation. An opposite trend characterised di-methylene derivatives. These observed SAR suggest that, within this class of compounds, the number of HB-donor groups can be lowered while maintaining high receptor affinity. Since the presence of HB-donor groups strongly affects brain access, this observation could be useful to design and prepare new H(3)-antagonists.
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Affiliation(s)
- Valentina Zuliani
- Dipartimento Farmaceutico, Università degli Studi di Parma, Parco Area delle Scienze 27/A, I-43100 Parma, Italy
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Katritzky AR, Cai X, Rogovoy BV. Solid phase synthesis and application of trisubstituted thioureas. JOURNAL OF COMBINATORIAL CHEMISTRY 2003; 5:392-9. [PMID: 12857107 DOI: 10.1021/cc020109y] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Resin-bound amines 1a-e condense with isothiocyanates to give thiourea resins 2a-i. Resins 2a-g subsequently react with iodomethane followed by cleavage affording S-methyl isothioureas 4a-g, and resins 2a-b,h-i react with acyl chlorides to afford N-acylated thioureas 6a-d. N-Acylthioureas 8a-f (R(2) = H) were prepared directly from resin-bound amines 1a-d with acyl isothiocyanates. N-Acylthioureas 8a-d,f(R(2) = H) were used for the preparation of S-methyl-N-acylisothioureas 10a-e. Alkylation was performed using methyl iodide. Resin-bound S-methyl-N-acylisothioureas 10a,b,d are converted by an action of hydrazines into 3-amino-1,2,4-triazoles 13a-d. Condensation of resins 8a-e (R(2) = H) with 2-bromoacetophenones in the presence of TEA affords thiazoles 15 a-e. All transformations proceeded in high yields and gave products of good purities.
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Affiliation(s)
- Alan R Katritzky
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
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26
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Grassmann S, Apelt J, Sippl W, Ligneau X, Pertz HH, Zhao YH, Arrang JM, Ganellin CR, Schwartz JC, Schunack W, Stark H. Imidazole derivatives as a novel class of hybrid compounds with inhibitory histamine N-methyltransferase potencies and histamine hH3 receptor affinities. Bioorg Med Chem 2003; 11:2163-74. [PMID: 12713826 DOI: 10.1016/s0968-0896(03)00120-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, a novel series of imidazole-containing compounds with dual properties, that is, inhibitory potency at the enzyme histamine N(tau)-methyltransferase (HMT) and antagonist potency at histamine H(3) receptors was designed and synthesized. Pharmacologically, these new hybrid drugs were evaluated in functional assays for their inhibitory potencies at rat kidney HMT and for their antagonist activities on synaptosomes of rat cerebral cortex. For selected compounds, binding affinities at recombinant human histamine H(3) receptors were determined. The first compounds (1-10) of the series proved to be H(3) receptor ligands of high potency at rat synaptosomes or of high binding affinity at human H(3) receptors, respectively, but of only moderate activity as inhibitors of rat kidney HMT. In contrast, aminoquinoline- or tetrahydroacridine-containing derivatives 11-17 also displayed HMT inhibitory potency in the nanomolar concentration range. Preliminary data from molecular modeling investigations showed that the imidazole derivative 15 and the HMT inhibitor quinacrine possess identical binding areas. The most interesting compound (14) is simultaneously a highly potent H(3) receptor ligand (K(i)=4.1nM) and a highly potent HMT inhibitor (IC(50)=24nM), which makes this derivative a valuable pharmacological tool for further development.
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Affiliation(s)
- Sven Grassmann
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Strasse 2+4, 14195 Berlin, Germany
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27
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Bachurin SO. Medicinal chemistry approaches for the treatment and prevention of Alzheimer's disease. Med Res Rev 2003; 23:48-88. [PMID: 12424753 DOI: 10.1002/med.10026] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia, which is characterised by progressive deterioration of memory and higher cortical functions that ultimately result in total degradation of intellectual and mental activities. Modern strategies in the search of new therapeutic approaches are based on the morphological and biochemical characteristics of AD, and focused on following directions: agents that compensate the hypofunction of cholinergic system, agents that interfere with the metabolism of beta-amyloid peptide, agents that protect nerve cells from toxic metabolites formed in neurodegenerative processes, agents that activate other neurotransmitter systems that indirectly compensate for the deficit of cholinergic functions, agents that affect the process of the formation of neurofibrillary tangles, anti-inflammatory agents that prevent the negative response of nerve cells to the pathological process. The goal of the present review is the validation and an analysis from the point of view of medicinal chemistry of the principles of the directed search of drugs for the treatment and prevention of AD and related neurodegenerative disorders. It is based on systematization of the data on biochemical and structural similarities in the interaction between physiologically active compounds and their biological targets related to the development of such pathologies. The main emphasis is on cholinomimetic, anti-amyloid and anti-metabolic agents, using the data that were published during the last 3 to 4 years, as well as the results of clinical trials presented on corresponding websites.
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Affiliation(s)
- S O Bachurin
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, 142432 Chernogolovka, Moscow region, Russia.
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28
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Grassmann S, Sadek B, Ligneau X, Elz S, Ganellin CR, Arrang JM, Schwartz JC, Stark H, Schunack W. Progress in the proxifan class: heterocyclic congeners as novel potent and selective histamine H(3)-receptor antagonists. Eur J Pharm Sci 2002; 15:367-78. [PMID: 11988398 DOI: 10.1016/s0928-0987(02)00024-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Histamine H(3) receptors are critically involved in the pathophysiology of several disorders of the central nervous system (CNS). Among other families of H(3)-receptor ligands, the proxifan class has recently been described to contain numerous potent histamine H(3)-receptor antagonists, e.g. ciproxifan or imoproxifan. In the present study, we report on the design of novel heterocyclic proxifan analogues and their antagonist potencies at histamine H(3) receptors. The new compounds were tested for in vitro and in vivo H(3)-receptor antagonist potencies in different species as well as for H(3)-receptor selectivity vs. H(1) and H(2) receptors. In vitro, all compounds investigated proved to be potent H(3)-receptor antagonists in the rat as well as in the guinea-pig. In addition, they showed good to high oral CNS potency in vivo in mice. Especially, oxadiazole derivatives 24-26 displayed nanomolar antagonist activity in vitro and high potency in vivo (ED(50)=0.47-0.57 mg/kg). The results show that the additional heteroaromatic moieties might act as bioisosteres of the ketone or oxime moieties of ciproxifan or imoproxifan, respectively, and might cause divergent pharmacokinetic properties. Thus, these novel H(3)-receptor antagonists are interesting leads for further development.
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Affiliation(s)
- Sven Grassmann
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Strasse 2+4, 14195, Germany.
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29
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Tozer MJ, Buck IM, Cooke T, Kalindjian SB, Pether MJ, Steel KIM. omega-(Imidazol-4-yl)alkane-1-sulfonamides: a new series of potent histamine H(3) receptor antagonists. Bioorg Med Chem 2002; 10:425-32. [PMID: 11741790 DOI: 10.1016/s0968-0896(01)00295-4] [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: 11/26/2022]
Abstract
omega-(1H-Imidazol-4-yl)alkane-1-sulfonamides were prepared and found to be potent histamine H(3) receptor antagonists. High receptor affinity and a low difference in the data between the bioassays were achieved with 5-(1H-imidazol-4-yl)pentane-1-sulfonic acid 4-chlorobenzylamide (16). Good in vitro profiles were also obtained for 2-hydroxysulfonamide and vinylsulfonamide analogues. This complements and completes the existing set of imidazole-based sulfonamides and sulfamides.
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Affiliation(s)
- Matthew J Tozer
- The James Black Foundation, 68 Half Moon Lane, Dulwich, SE24 9JE, London, UK.
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30
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Stark H, Arrang JM, Ligneau X, Garbarg M, Ganellin CR, Schwartz JC, Schunack W. The histamine H3 receptor and its ligands. PROGRESS IN MEDICINAL CHEMISTRY 2002; 38:279-308. [PMID: 11774797 DOI: 10.1016/s0079-6468(08)70096-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- H Stark
- Freie Universität Berlin, Institut für Pharmazie, Königin-Luise-Strasse 2 + 4, 14195 Berlin, Germany
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31
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Meier G, Apelt J, Reichert U, Grassmann S, Ligneau X, Elz S, Leurquin F, Ganellin CR, Schwartz JC, Schunack W, Stark H. Influence of imidazole replacement in different structural classes of histamine H(3)-receptor antagonists. Eur J Pharm Sci 2001; 13:249-59. [PMID: 11384847 DOI: 10.1016/s0928-0987(01)00106-3] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reference compounds for histamine H(3)-receptor antagonists carry as a common feature an imidazole moiety substituted in the 4-position. Very recently novel ligands lacking an imidazole ring have been described possessing a N-containing non-aromatic heterocycle instead. In this study we investigated whether imidazole replacement, favourably by a piperidine moiety, is generally applicable to different structural classes of reference compounds, e.g., thioperamide, carboperamide, clobenpropit, FUB 181, ciproxifan, etc. While replacement led to a loss of affinity for many of the compounds, it was successfully applied to some ether derivatives. The piperidine analogues of FUB 181 and ciproxifan, 3-(4-chlorophenyl)propyl 3-piperidinopropyl ether hydrogen oxalate (6) and cyclopropyl 4-(3-piperidinopropyloxy)phenyl methanone hydrogen maleate (7), almost maintained in vitro affinities, pK(i) values of 7.8 and 8.4, respectively, and showed high potency in vivo after p.o. administration (ED(50) values of 1.6 and 0.18 mg/kg, respectively).
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Affiliation(s)
- G Meier
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Strasse 2+4, 14195, Berlin, Germany
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32
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Stark H, Sippl W, Ligneau X, Arrang JM, Ganellin CR, Schwartz JC, Schunack W. Different antagonist binding properties of human and rat histamine H3 receptors. Bioorg Med Chem Lett 2001; 11:951-4. [PMID: 11294398 DOI: 10.1016/s0960-894x(01)00090-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Different histamine H3-receptor antagonists have been tested in displacement studies at human and rat H3 receptors in stably transfected cells. Based on an actual rhodopsin structure, models for receptor antagonist interaction were developed for receptors of both species. Similarities and discrepancies in binding profiles can be explained, but not quantified by hydrophilic interactions with Asp114 and an important lipophilic binding pocket modified by two nearby amino acids.
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Affiliation(s)
- H Stark
- Freie Universität Berlin, Institut für Pharmazie, Berlin, Germany.
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33
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Sasse A, Schunack W, Stark H. Separation of chiral 4-substituted imidazole derivatives by cyclodextrin-modified capillary electrophoresis. Biomed Chromatogr 2001; 15:25-30. [PMID: 11180297 DOI: 10.1002/bmc.22] [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: 11/06/2022]
Abstract
Enantiomeric separations by cyclodextrin-modified capillary electrophoresis of chiral carbamates containing a 4-substituted imidazole heterocycle, pharmacologically acting as histamine H3-receptor antagonists, were carried out. Various cyclodextrins (alpha-, beta- and substituted beta-cyclodextrins) were investigated. Baseline resolution was achieved with six out of 11 compounds. Heptakis-2,3,6-trimethyl-beta-cyclodextrin modified buffers seemed to be most efficient in separating most of the investigated compounds. The optical purity of one pair of enantiomers was determined.
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Affiliation(s)
- A Sasse
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Strasse 2 + 4, 14195 Berlin, Germany
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34
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Sasse A, Ligneau X, Sadek B, Elz S, Pertz HH, Ganellin CR, Arrang JM, Schwartz JC, Schunack W, Stark H. Benzophenone derivatives and related compounds as potent histamine H3-receptor antagonists and potential PET/SPECT ligands. Arch Pharm (Weinheim) 2001; 334:45-52. [PMID: 11268774 DOI: 10.1002/1521-4184(200102)334:2<45::aid-ardp45>3.0.co;2-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Para-substituted aromatic ethers with benzophenone or related structural elements and a 3-(1H-imidazol-4-yl)propyloxy moiety were prepared by Mitsunobu-type ether synthesis or SNAr reaction. Most of the title compounds possess high antagonist potency in histamine H3-receptor assays in vitro as well as in vivo in mouse CNS following oral administration. After defining 4-(3-(1H-imidazol-4-yl)propyloxy)phenyl phenyl methanone as a new lead, structure-activity relationships were investigated for this new class of compounds. Substitution of the meta'-position of the benzophenone moiety with halogen atoms (e.g., iodine, fluorine) led to compounds with high antagonist potency in vitro as well as in vivo (Ki = 9.3 and 4.3 nM, ED50 = 0.7 and 0.47 mg/kg p.o., 18 and 12, respectively). A receptor profile of several functional in vitro assays for several biogenic amine receptors for the meta'-iodinated derivative demonstrated high selectivity toward the histamine H3 receptor.
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Affiliation(s)
- A Sasse
- Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Strasse 2 + 4, 14195 Berlin, Germany
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35
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Mills JE, de Esch IJ, Perkins TD, Dean PM. SLATE: a method for the superposition of flexible ligands. J Comput Aided Mol Des 2001; 15:81-96. [PMID: 11217921 DOI: 10.1023/a:1011102129244] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A novel program for the superposition of flexible molecules, SLATE, is presented. It uses simulated annealing to minimise the difference between the distance matrices calculated from the hydrogen-bonding and aromaticring properties of two ligands. A method for generating a molecular stack using multiple pairwise matches is illustrated. These stacks are used by the program DOH to predict the relative positions of receptor atoms that could form hydrogen bonds to two or more ligands in the dataset. The methodology has been applied to ligands binding to dihydrofolate reductase, thermolysin. H3 histamine receptors, alpha2 adrenoceptors and 5-HT1D receptors. When there are sufficient numbers and diversity of molecules in the dataset, the prediction of receptor-atom positions is applicable to compound design.
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Affiliation(s)
- J E Mills
- Department of Pharmacology, University of Cambridge, UK
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36
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Stark H, Krause M, Rouleau A, Garbarg M, Schwartz JC, Schunack W. Enzyme-catalyzed prodrug approaches for the histamine H3-receptor agonist (R)-alpha-methylhistamine. Bioorg Med Chem 2001; 9:191-8. [PMID: 11197341 DOI: 10.1016/s0968-0896(00)00237-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Five novel prodrug types of the potent and selective histamine H3-receptor agonist (R)-alpha-methylhistamine (1) were prepared and pharmacologically tested in vitro as well as in vivo. In particular, an amide of fatty acid, mono- and dicarbamates, an (acyloxy)alkylcarbamate, and a diphthalidyl derivative were synthesized, all of which require initial prodrug activation through an enzyme-catalyzed reaction in contrast to formerly developed azomethine prodrugs which are cleaved by chemical hydrolysis only. Further drug liberation may ensue spontaneously in a cascade to give 1. Since they have diverse stabilities the prodrugs were investigated for drug liberation in vitro under neutral, acidic, and basic conditions at different temperatures as well as with liver homogenates. In vivo investigation of prodrugs after oral administration to mice proved that the fatty amide 2, the Nalpha-methylcarbamate 4a, and the Nalpha-(1-(acetyloxy)ethylcarbamate) 5 showed moderate to high plasma levels of 1. Compound 5 displayed even more than 2.5 times the AUC for 1 than that of the reference azomethine prodrug BP2.94 in the periphery and also displayed a detectable drug level in the central nervous system. It was shown that prodrug approaches based on an initial enzyme-catalyzed liberation step are successfully applicable to different pro-moieties for improved bioavailability and prolonged half-live. These approaches may also be used for other aminergic compounds of this class to optimize pharmacokinetic behavior.
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Affiliation(s)
- H Stark
- lnstitut für Pharmazie, Freie Universität Berlin, Germany.
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37
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Silva C, Plazzi PV, Bordi F, Rivara S, Vacondio F, Zuliani V, Caretta A, Mor M. Structure-property relationships on histamine H3-antagonists: binding of phenyl-substituted alkylthioimidazole derivatives to rat plasma proteins. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2000; 55:239-45. [PMID: 10966153 DOI: 10.1016/s0014-827x(00)00026-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The binding of a series of H3-antagonists to rat plasma proteins was investigated by dialysis experiments, with RP-HPLC measurement of the free ligand. The series was composed of 4(5)-phenyl-2-[[2-[4(5)-imidazolyl]ethyl]thio]imidazoles having, on the phenyl ring, meta- and para-substituents, with different physico-chemical characteristics. As high protein binding had been proposed as being one of the features limiting brain access for the reference H3-antagonist thioperamide, the title series was employed to test the possibility of achieving lower protein binding by modulation of lipophilicity, while maintaining good receptor affinity. The compounds tested showed quotas of bound drug ranging from 60 to 97.5%, while for thioperamide a 78% bound drug quota was observed at high total concentrations, with a steep increase in bound percentage at lower concentrations. Two of the tested compounds, having a carboxamide substituent, showed lower protein binding compared to thioperamide over a wide range of total concentration, without a significant loss in affinity with respect to the parent compound. A strict dependence of protein binding on lipophilicity was observed, and a QSPR model was derived which could also account for the protein binding observed for thioperamide, while receptor affinity had been reported to be quite insensitive to phenyl ring substitution. It is therefore possible to modulate protein binding of these H3-antagonists, through lipophilicity adjustment, without losing receptor affinity; this finding could help in the design of new compounds with improved brain access.
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Affiliation(s)
- C Silva
- Dipartimento Farmaceutico, Università degli Studi di Parma, Viale delle Scienze, Italy
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38
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Walczyński K, Guryn R, Zuiderveld OP, Timmerman H. Non-imidazole histamine H3 ligands. Part I. Synthesis of 2-(1-piperazinyl)- and 2-(hexahydro-1H-1,4-diazepin-1-yl)benzothiazole derivatives as H3-antagonists with H1 blocking activities. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 1999; 54:684-94. [PMID: 10575738 DOI: 10.1016/s0014-827x(99)00081-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
New 2-(1-Piperazinyl)- and 2-(hexahydro-1H-1,4-diazepin-1-yl)benzothiazoles were prepared and tested as H1- and H3-receptor antagonists. A number of compounds showed weak H1-antagonistic activity, with pA2 values ranging from 5.5 to 6.1. The simple alkyl substituted, 2-[1-(4-methyl and 4-ethyl)piperazinyl] analogues show increasing, moderate H3-antagonistic activity (pA2 = 6.0, and pA2 = 7.0). The compounds with 4-phenylalkyl substitution, for both the piperazinyl and the hexahydro-1H-1,4-diazepin-1-yl homologues series, regardless of the different physicochemical properties of the para substituents at the phenyl ring, showed weak H3-antagonistic activity with pA2 values ranging from 4.4 to 5.6.
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Affiliation(s)
- K Walczyński
- Department of Synthesis and Technology of Drugs, Medical Academy, Lódź, Poland
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39
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Morini G, Grandi D, Bertaccini G, Leschke C, Schunack W. Stereoselective inhibition of ethanol-induced gastric lesions in the rat by the H(3)-receptor agonist (R)-alpha-methylhistamine and its (S)-configured isomer. Pharmacology 1999; 59:192-200. [PMID: 10474079 DOI: 10.1159/000028320] [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: 11/19/2022]
Abstract
The histamine H(3) receptor shows high degree of stereoselectivity for histamine analogues branched in the side chain. The hypothesis that gastroprotection by (R)-alpha-methylhistamine could be H(3) receptor-mediated was tested by comparing the effect of (R)-alpha-methylhistamine and of (S)-alpha-methylhistamine on ethanol-induced histologic lesions in the rat gastric mucosa. Extensive damage was caused by 60 min exposure to absolute ethanol, 91% of the mucosa examined being damaged. Conversely only 23% of the mucosa was damaged after pretreatment with (R)-alpha-methylhistamine (100 mg/kg i.g.). In the groups pretreated with (S)-alpha-methylhistamine (55.44 and 166.3 mg/kg i.g.) total damage ranged from 77 to 79%, though it was confined to the upper portion of the mucosa. Morphometric analysis of stained intraepithelial mucosubstances revealed that (R)-alpha-methylhistamine pretreatment resulted in an increase in number and volume of surface mucous cells, not evident after (S)-alpha-methylhistamine pretreatment. Scanning electron microscopy confirmed light microscopy evaluations. The two isomers of alpha-methylhistamine differently affect the response of rat gastric mucosa to absolute ethanol and they appear to differ in their influence on surface mucous cells. A basis for interpreting the effects of the two isomers of alpha-methylhistamine rests on the high degree of stereoselectivity of H(3) receptors and on the different affinities of the two isomers for these receptors.
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Affiliation(s)
- G Morini
- Institute of Pharmacology, University of Parma, Italy
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40
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Ram VJ, Goel A. Present status of hepatoprotectants. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 1999; 52:53-101. [PMID: 10396126 DOI: 10.1007/978-3-0348-8730-4_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Perpetual exposure of liver to xenobiotics and therapeutic agents leads to toxic manifestations of a complex and diverse nature. Not a single curative therapeutic agent has been found so far which could provide lasting remedy to patients suffering from hepatic disorders. In fact, the remedies available in the modern system of medicine provide only symptomatic relief without any significant changes on the disease process. Moreover, their use is associated with severe side effects and chances of relapses. Except some natural products claimed to be effective, no safe synthetic product is yet available for the management of hepatic disorders. Lack of effective, least toxic and curative hepatoprotectants made the task difficult to discover newer drugs. This review is an attempt to provide an overall view of the development of synthetic and natural products as hepatoprotective agents.
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Affiliation(s)
- V J Ram
- Medicinal Chemistry Division, Central Drug Research Institute, Lucknow, India
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41
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Stark H, Ligneau X, Arrang JM, Schwartz JC, Schunack W. General construction pattern of histamine H3-receptor antagonists: change of a paradigm. Bioorg Med Chem Lett 1998; 8:2011-6. [PMID: 9873477 DOI: 10.1016/s0960-894x(98)00342-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Novel omega-phenyl substituted and unsubstituted alkyl and alkenyl imidazole derivatives were prepared and tested for their antagonist activity in vitro and in vivo at histamine H3-receptors. Some compounds showed high in vitro and in vivo H3-receptor activity despite their structure bearing no polar moiety in the centre of the molecule which is a common structural feature of all other antagonists known. Quite probably there are further in vivo effects for some compounds resulting from other receptor interactions.
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Affiliation(s)
- H Stark
- Institut für Pharmazie I, Freie Universität Berlin, Germany.
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42
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Recent Advances in Histamine H3 Receptor Agents. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1998. [DOI: 10.1016/s0065-7743(08)61069-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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43
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Hüls A, Purand K, Stark H, Reidemeister S, Ligneau X, Arrang JM, Schwartz JC, Schunack W. Novel histamine H3-receptor antagonists with benzyl ether structure or related moieties: synthesis and structure-activity relationships. Arch Pharm (Weinheim) 1996; 329:379-85. [PMID: 8915097 DOI: 10.1002/ardp.19963290802] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In search of new histamine H3-receptor ligands sixteen ether derivatives of 3-(1H-imidazol-4-yl)propanol with benzylic partial structure or related moieties were prepared and investigated as H3-receptor antagonists. The new compounds belong to a general construction pattern developed by other histamine H3-receptor antagonists. Structural modifications were introduced in an attempt to optimize in vitro as well as in vivo activity. Structure-activity relationships of the new histamine H3-receptor antagonists are discussed. All ether derivatives showed in vitro activities in the nanomolar concentration range, but only compounds with bulky lipophilic residues were also active under in vivo conditions. The most active compound within this series was 3-(1H-imidazol-4-yl)propyl 1-naphthylmethyl ether (4n) presenting an ED50 of 3.2 +/- 1.9 mg/kg regarding enhancement of endogenous histamine in brain after p.o. administration to mice. Furthermore, comparison of the H3-receptor activities measured on synaptosomes of rat cerebral cortex and on guinea pig ileum gave a good correlation indicating homogeneity of central and peripheral H3-receptor test models. The most interesting compounds were also evaluated in functional in vitro assays with regard to their activities at histamine H1-, H2-, and muscarinic M3-receptors. The tested compounds showed very weak activities at these receptor subtypes demonstrating their H3-receptor selectivity.
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Affiliation(s)
- A Hüls
- Institut für Pharmazie Freie Universität Berlin, Germany
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Hüls A, Purand K, Stark H, Ligneau X, Arrang JM, Schwartz JC, Schunack W. Diphenylmethyl ethers: synthesis and histamine H3-receptor antagonist in vitro and in vivo activity. Bioorg Med Chem Lett 1996. [DOI: 10.1016/0960-894x(96)00361-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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