101
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Kaufmann I, Hoelzl A, Schliephake F, Hummel T, Chouker A, Łysenko L, Peter K, Thiel M. EFFECTS OF ADENOSINE ON FUNCTIONS OF POLYMORPHONUCLEAR LEUKOCYTES FROM PATIENTS WITH SEPTIC SHOCK. Shock 2007; 27:25-31. [PMID: 17172976 DOI: 10.1097/01.shk.0000238066.00074.90] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Inasmuch as polymorphonuclear leukocytes (PMNs) play a major role in antibacterial defense but can also cause substantial tissue injury, drugs are needed which are able to attenuate tissue-toxic PMN reactions without inhibiting bactericidal mechanisms. Adenosine as a retaliatory metabolite is produced in response to metabolically unfavorable conditions like inflammation. However, it is not known whether adenosine can selectively downregulate adverse PMN reactions in sepsis. In this prospective clinical study, we characterized the effects of adenosine ex vivo on PMN functions in patients with septic shock ([SS] n = 33) and healthy volunteers ([HV] n = 33). The PMNs were primed by tumor necrosis factor-alpha (TNF-alpha) and subsequently stimulated with N-formyl methionyl-leucyl-phenylalanine (fMLP) to test for the formation of hydrogen peroxide (H2O2) in response to soluble inflammatory stimuli. The PMNs were also challenged by opsonized zymosan particles to assess adhesion, phagocytosis, and the associated H2O2 production. As compared with HV, PMNs from SS patients showed strongly enhanced tissue-toxic H2O2 production elicited by TNF-alpha/fMLP. Increasing concentrations of adenosine dose-dependently reduced this tissue-toxic H2O2 production in both groups with a half-maximal inhibitory concentration of 25 nmol/L and 114 nmol/L in HV and SS patients, respectively. This 4.6-fold decrease in the adenosine-mediated inhibition of PMNs from patients with septic shock was compensated by a 3-fold increase in the plasma concentrations of the nucleoside (HV, 42.5 +/- 2.9 nmol/L vs. SS, 125.6 +/- 18.2 nmol/L; mean +/- SEM). When the effects of adenosine were tested at a very high A2A receptor saturating concentration of 10 mol/L, neither adhesion, phagocytosis, nor the associated H2O2 production induced by opsonized zymosan was affected in both groups. These results were confirmed by the highly selective A2A agonist, CGS21680.Thus, adenosine or A2A agonists may be useful to selectively inhibit the potentially tissue-toxic H2O2 production elicited by soluble inflammatory mediators in patients with septic shock.
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Affiliation(s)
- Ines Kaufmann
- Department of Anesthesiology, Klinikum Grosshadern, Munich, Germany
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102
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Conlon PR, Kiesman WF. Synthesis of specifically deuterated adenosine A1 antagonist: BG9928. J Labelled Comp Radiopharm 2007. [DOI: 10.1002/jlcr.1237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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103
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Giorgi I, Bianucci AM, Biagi G, Livi O, Scartoni V, Leonardi M, Pietra D, Coi A, Massarelli I, Nofal FA, Fiamingo FL, Anastasi P, Giannini G. Synthesis, biological activity and molecular modelling of new trisubstituted 8-azaadenines with high affinity for A1 adenosine receptors. Eur J Med Chem 2007; 42:1-9. [DOI: 10.1016/j.ejmech.2006.08.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 07/21/2006] [Accepted: 08/11/2006] [Indexed: 10/24/2022]
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104
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Piersanti G, Giorgi L, Bartoccini F, Tarzia G, Minetti P, Gallo G, Giorgi F, Castorina M, Ghirardi O, Carminati P. Synthesis of benzo[1,2-d;3,4-d′]diimidazole and 1H-pyrazolo[4,3-b]pyridine as putative A2A receptor antagonists. Org Biomol Chem 2007; 5:2567-71. [DOI: 10.1039/b707599e] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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105
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Cosyn L, Palaniappan KK, Kim SK, Duong HT, Gao ZG, Jacobson KA, Van Calenbergh S. 2-triazole-substituted adenosines: a new class of selective A3 adenosine receptor agonists, partial agonists, and antagonists. J Med Chem 2006; 49:7373-83. [PMID: 17149867 PMCID: PMC4968940 DOI: 10.1021/jm0608208] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
"Click chemistry" was explored to synthesize two series of 2-(1,2,3-triazolyl)adenosine derivatives (1-14). Binding affinity at the human A(1), A(2A), and A(3)ARs (adenosine receptors) and relative efficacy at the A(3)AR were determined. Some triazol-1-yl analogues showed A(3)AR affinity in the low nanomolar range, a high ratio of A(3)/A(2A) selectivity, and a moderate-to-high A(3)/A(1) ratio. The 1,2,3-triazol-4-yl regiomers typically showed decreased A(3)AR affinity. Sterically demanding groups at the adenine C2 position tended to reduce relative A(3)AR efficacy. Thus, several 5'-OH derivatives appeared to be selective A(3)AR antagonists, i.e., 10, with 260-fold binding selectivity in comparison to the A(1)AR and displaying a characteristic docking mode in an A(3)AR model. The corresponding 5'-ethyluronamide analogues generally showed increased A(3)AR affinity and behaved as full agonists, i.e., 17, with 910-fold A(3)/A(1) selectivity. Thus, N(6)-substituted 2-(1,2,3-triazolyl)adenosine analogues constitute a novel class of highly potent and selective nucleoside-based A(3)AR antagonists, partial agonists, and agonists.
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Affiliation(s)
| | | | | | | | | | - Kenneth A. Jacobson
- To whom correspondence should be addressed. For K.A.J.: phone, 301-496-9024; fax, 301-480-8422; . For S.V.C.: phone, +32(0)9 264 81 24; fax, +32(0)9 264 81 46;
| | - Serge Van Calenbergh
- To whom correspondence should be addressed. For K.A.J.: phone, 301-496-9024; fax, 301-480-8422; . For S.V.C.: phone, +32(0)9 264 81 24; fax, +32(0)9 264 81 46;
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106
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González MP, Terán C, Teijeira M, Helguera AM. QSAR Studies Using Radial Distribution Function for Predicting A1 Adenosine Receptors Agonists. Bull Math Biol 2006; 69:347-59. [PMID: 17061056 DOI: 10.1007/s11538-006-9127-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 03/29/2006] [Indexed: 10/24/2022]
Abstract
The radial distribution function (RDF) approach has been applied to the study of the A(1) adenosine receptors agonist effect of 32 adenosine analogues. A model able to describe more than 79% of the variance in the experimental activity was developed with the use of the mentioned approach. In contrast, none of the three different approaches, including the use of 2D autocorrelations, BCUT and 3D-MORSE descriptors were able to explain more than 72% of the variance in the mentioned property with the same number of variables in the equation. In addition, we established a comparison with other models reported by us for this receptor subtype using this data set, and the RDF descriptors continue getting the best results.
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Affiliation(s)
- Maykel Pérez González
- Service Unit, Experimental Sugar Cane Station Villa Clara-Cienfuegos, Ranchuelo, C.P. 53100 Villa Clara, Cuba.
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107
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Drabczyńska A, Müller CE, Lacher SK, Schumacher B, Karolak-Wojciechowska J, Nasal A, Kawczak P, Yuzlenko O, Pekala E, Kieć-Kononowicz K. Synthesis and biological activity of tricyclic aryloimidazo-, pyrimido-, and diazepinopurinediones. Bioorg Med Chem 2006; 14:7258-81. [PMID: 16844379 DOI: 10.1016/j.bmc.2006.06.052] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 06/20/2006] [Accepted: 06/23/2006] [Indexed: 11/24/2022]
Abstract
Syntheses and physicochemical properties of N-aryl-substituted imidazo-, pyrimido-, and 1,3-diazepino[2,1-f]purinediones are described. These derivatives were synthesized by the cyclization of 7-haloalkyl-8-bromo-1,3-dimethyl- or 1,3-dipropyl-xanthine derivatives with corresponding arylamines. The obtained compounds (1-40), which can be envisaged as sterically fixed and configurationally stable analogs of 8-styrylxanthines, were evaluated for their affinity to adenosine A(1) and A(2A) receptors, the receptor subtypes that are predominant in the brain. Selected compounds were additionally investigated for affinity to the A(2B) and A(3) receptor subtypes. Many of the compounds showed adenosine A(2A) receptor affinity at micromolar or submicromolar concentrations and were A(2A)-selective, for example, compound 23 with p-fluoro substituent displayed K(i) value of 0.147 microM at the rat A(2A) receptor and more than 170-fold-A(2A) selectivity, compound 17 with naphthyl substituent had K(i) value of 0.219 microM and a more than 114-fold-A(2A) selectivity. The compounds were somewhat weaker and less selective at the human receptor subtypes. Elongation of the dimethyl substituent to dipropyl in xanthine moiety improved affinity but reduced selectivity. 1,3-Dimethylimidazo-, pyrimido-, and diazepinopurinediones were evaluated in vivo as anticonvulsants in MES, ScMet, TTE tests and examined for neurotoxicity in mice (ip). Substances with pyrimido ring displayed protective activity in ScMet or in MES and ScMet tests, showing also neurotoxicity. The pyrimidine annelated ring is beneficial for both receptor affinity and anticonvulsant activity.
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Affiliation(s)
- Anna Drabczyńska
- Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy, Medical College, Jagiellonian University, Medyczna 9, Pl 30-688 Kraków, Poland
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108
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Invited Lectures : Overviews Purinergic signalling: past, present and future. Purinergic Signal 2006; 2:1-324. [PMID: 18404494 PMCID: PMC2096525 DOI: 10.1007/s11302-006-9006-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2006] [Indexed: 12/11/2022] Open
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109
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Tuccinardi T, Ortore G, Manera C, Saccomanni G, Martinelli A. Adenosine receptor modelling. A1/A2a selectivity. Eur J Med Chem 2006; 41:321-9. [PMID: 16427161 DOI: 10.1016/j.ejmech.2005.09.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 08/24/2005] [Accepted: 09/28/2005] [Indexed: 10/25/2022]
Abstract
Three-dimensional models of the A(1) and A(2a) adenosine receptors (AR) were constructed by means of a homology procedure, using bovine rhodopsin as a template. In order to validate the two models, a docking analysis of selective agonists was carried out. The study shows that A(1)/A(2a) selectivity is mainly influenced by the different ability of the two receptors to give lipophilic interactions, instead of giving different H bonds. The binding site cavity of the A(1)AR is smaller than that of the A(2a)AR, and for this reason, less bulky ligands like CPA are able to give close interactions with the A(1)AR, unlike larger ligands such as CGS-21680. The different dimensions of the binding site cavity could be due to the presence of three residues of proline, which cause a different rearrangement of the TM, thus modifying the side chain disposition inside the inter-helix channel.
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110
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Cosyn L, Gao ZG, Van Rompaey P, Lu C, Jacobson KA, Van Calenbergh S. Synthesis of hypermodified adenosine derivatives as selective adenosine A3 receptor ligands. Bioorg Med Chem 2006; 14:1403-12. [PMID: 16266807 PMCID: PMC8611933 DOI: 10.1016/j.bmc.2005.09.062] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2005] [Revised: 09/21/2005] [Accepted: 09/27/2005] [Indexed: 11/28/2022]
Abstract
We investigated the A(3)AR affinity and selectivity of a series of 2-substituted 3'-azido and 3'-amino adenosine derivatives as well as some 5'-uronamide derivatives thereof. All compounds showed high A(3)AR selectivity. While the 3'-azides appeared to be A(3)AR antagonists with moderate A(3)AR affinity, their 3'-amino congeners exhibit significantly improved A(3)AR affinity and behave as partial agonists. For both the 3'-azides and the 3'-amines, the 5'-methylcarbamoyl modification improved the overall affinity. Introduction of a 2-phenylethynyl substituent provided high affinity for the A(3)AR.
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Affiliation(s)
- Liesbet Cosyn
- Laboratory for Medicinal Chemistry (FFW), UGent, Harelbekestraat 72, B-9000, Belgium
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), DHHS, Bldg. 8A, Rm. B1 A-19, NIH, NIDDK, LBC, Bethesda, MD 20892-0810, USA
| | - Philippe Van Rompaey
- Laboratory for Medicinal Chemistry (FFW), UGent, Harelbekestraat 72, B-9000, Belgium
| | - Changrui Lu
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), DHHS, Bldg. 8A, Rm. B1 A-19, NIH, NIDDK, LBC, Bethesda, MD 20892-0810, USA
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), DHHS, Bldg. 8A, Rm. B1 A-19, NIH, NIDDK, LBC, Bethesda, MD 20892-0810, USA
| | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry (FFW), UGent, Harelbekestraat 72, B-9000, Belgium
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111
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Legraverend M, Grierson DS. The purines: potent and versatile small molecule inhibitors and modulators of key biological targets. Bioorg Med Chem 2006; 14:3987-4006. [PMID: 16503144 DOI: 10.1016/j.bmc.2005.12.060] [Citation(s) in RCA: 258] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 12/29/2005] [Accepted: 12/29/2005] [Indexed: 11/24/2022]
Abstract
The goal of this review is to highlight the wide range of biological activities displayed by purines, with particular emphasis on new purine-based agents which find potential application as chemical-biology tools and/or therapeutic agents. The expanding interest in the biological properties of polyfunctionalized purine derivatives issues, in large part, from the development of rapid high-throughput screening essays for new protein targets, and the corresponding development of efficient synthetic methodology adapted to the construction of highly diverse purine libraries. Purine-based compounds have found new applications as inducers of interferon and lineage-committed cell dedifferentiation, agonists and antagonists of adenosine receptors, ligands of corticotropin-releasing hormone receptors, and as inhibitors of HSP90, Src kinase, p38alpha MAP kinase, sulfotransferases, phosphodiesterases, and Cdks. The scope of application of purines in biology is most certainly far from being exhausted. Testing purine derivatives against the multitude of biological targets for which small molecule probes have not yet been found should thus be a natural reflex.
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Affiliation(s)
- Michel Legraverend
- UMR 176 CNRS-Institut Curie, Laboratoire de Pharmacochimie, Bât. 110, Centre Universitaire, 91405 Orsay, France.
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112
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Karskela T, Lönnberg H. Solid-phase synthesis of 7-substituted 3H-imidazo[2,1-i]purines. Org Biomol Chem 2006; 4:4506-13. [PMID: 17268647 DOI: 10.1039/b612655c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A method for solid-supported synthesis of N,N-disubstituted (3H-imidazo[2,1-i]purin-7-yl)methyl amines has been developed. The key features of this library synthesis are: (i) immobilization of commercially available N6-benzoyl-5'-O-(4,4'-dimethoxytrityl)-2'-deoxyadenosine 3'-(2-cyanoethyl N,N-diisopropylphosphoramidite) by phosphitylation to a hydroxyl-functionalized support, (ii) quantitative conversion of the deprotected adenine base to 3H-imidazo[2,1-i]purine-7-carbaldehyde with bromomalonaldehyde in DMF in the presence of formic acid and 2,6-lutidine, (iii) reductive amination of the formyl group followed by N-alkylation or N-acylation, and (iv) release from the support by acidolytic cleavage of the N-glycosidic bond. Steps (ii) and (iii) have been optimized in some detail by using (adenin-9-yl)acetic acid anchored to a Phe-Wang resin as a model compound.
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Affiliation(s)
- Tuomas Karskela
- Department of Chemistry, University of Turku, Turku, FIN-20014, Finland
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113
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Wedekind A, O'Malley MA, Niebauer RT, Robinson AS. Optimization of the Human Adenosine A2a Receptor Yields inSaccharomyces cerevisiae. Biotechnol Prog 2006. [DOI: 10.1002/bp050431r] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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114
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Massip S, Guillon J, Bertarelli D, Bosc JJ, Léger JM, Lacher S, Bontemps C, Dupont T, Müller CE, Jarry C. Synthesis and preliminary evaluation of new 1- and 3-[1-(2-hydroxy-3-phenoxypropyl)]xanthines from 2-amino-2-oxazolines as potential A1 and A2A adenosine receptor antagonists. Bioorg Med Chem 2005; 14:2697-719. [PMID: 16386423 DOI: 10.1016/j.bmc.2005.11.050] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 11/22/2005] [Accepted: 11/28/2005] [Indexed: 11/17/2022]
Abstract
The development of potent and selective adenosine receptor ligands as potential drugs is an active area of research. Xanthines are one of the most important classes of adenosine receptor antagonists and have been widely developed in terms of affinity and selectivity for adenosine receptors. We recently developed new original pathways for the synthesis of xanthine analogues starting from 5-substituted-2-amino-2-oxazoline 5 as a synthon. These procedures allowed us to selectively introduce a large, functionalized and beta-adrenergic 2-hydroxy-3-phenoxypropyl pharmacophore at the 1- and 3-position of the xanthine moiety which allowed further structural modifications. In this study, we present a new synthetic access to racemic xanthine derivatives 1-4 from 5, and their evaluation as adenosine A1, A2A and A3 receptor ligands in radioligand binding studies. The 2-hydroxy-3-phenoxypropyl moiety was well tolerated in the 3-position of the xanthine core, while its introduction in the 1-position of the xanthine moiety led to a large decrease in adenosine receptor affinity. 1,7-Dimethyl-3-[1-(2-chloro-3-phenoxypropyl)]-8-(3,4,5-trimethoxystyryl)xanthine (2n) was the most potent and selective A2A antagonist of the present series (Ki=44 nM, >>200-fold selective vs A1). 1-Propyl-3-[1-(2-hydroxy-3-phenoxypropyl)]-8-noradamantylxanthine (3f) was identified as a potent (KiA1=21 nM) and highly selective (>>350-fold vs A2A and A3 receptor) adenosine A1 receptor antagonist.
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Affiliation(s)
- Stéphane Massip
- EA 2962-Pharmacochimie, UFR des Sciences Pharmaceutiques, Université Victor Segalen Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
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115
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Minetti P, Tinti MO, Carminati P, Castorina M, Di Cesare MA, Di Serio S, Gallo G, Ghirardi O, Giorgi F, Giorgi L, Piersanti G, Bartoccini F, Tarzia G. 2-n-Butyl-9-methyl-8-[1,2,3]triazol-2-yl-9H-purin-6-ylamine and analogues as A2A adenosine receptor antagonists. Design, synthesis, and pharmacological characterization. J Med Chem 2005; 48:6887-96. [PMID: 16250647 DOI: 10.1021/jm058018d] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two types of adenosine receptor ligands were designed, i.e., 9H-purine and 1H-imidazo[4,5-c]pyridines, to obtain selective A(2A) antagonists, and we report here their synthesis and binding affinities for the four adenosine receptor subtypes A(1), A(2A), A(2B) and A(3). The design was carried out on the basis of the molecular modeling of a number of potent adenosine receptor antagonists described in the literature. Three compounds (25b-d) showed an interesting affinity and selectivity for the A(2A) subtype. One of them, i.e., ST1535 (2-n-butyl-9-methyl-8-[1,2,3]triazol-2-yl-9H-purin-6-ylamine, 25b) (K(i) A(2A) = 6.6 nM, K(i) A(1)/A(2A) = 12; K(i) A(2B)/A(2A) = 58; K(i) A(3)/A(2A) > 160), was selected for in vivo study and shown to induce a dose-related increase in locomotor activity, suggestive of an A(2A) antagonist type of activity.
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Affiliation(s)
- Patrizia Minetti
- Istituto di Chimica Farmaceutica, Università degli Studi di Urbino Carlo Bo, Piazza del Rinascimento 6, 61029 Urbino (PU), Italy.
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116
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Belyakov S, Alksnis E, Muravenko V, Turovskis I, Popelis J, Lukevics E. Crystal structure and conformation of 8-(2-hydroxyethylamino) and 8-(pyrrolidin-1-yl) adenosines. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2005; 24:1199-208. [PMID: 16270662 DOI: 10.1081/ncn-200067412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In the course of investigation of 8-alkylamino substituted adenosines, the title compounds were synthesized as potential partial agonists for adenosine receptors. The structure determination of these compounds was carried out with the X-ray crystallography study. Crystals of 8-(2-hydroxyethylamino)adenosine are monoclinic, space group P 2(1); a = 7.0422(2), b = 11.2635(3), c = 8.9215(2) A, beta = 92.261(1) degrees, V = 707.10(3) A3, Z = 2; R-factor is 0.0339. The nucleoside is characterized by the anti conformation; the ribose ring has the C(2')-endo conformation and gauche-gauche form across C(4')-C(5') bond. The molecular structure is stabilized by intramolecular hydrogen bond of N-HO type. Crystals of 8-(pyrrolidin-1-yl)adenosine are monoclinic, space group C 2; a = 19.271(1), b = 7.3572(4), c = 11.0465(7) A, beta = 103.254(2), V = 1524.4(2) degrees A3, Z = 4; R-factor is 0.0498. In this compound, there is syn conformation of the nucleoside; the ribose has the C(2')-endo conformation and gauche -gauche form across C(4')- C(5') bond. The molecular structure is stabilized by intramolecular hydrogen bond of O-HN type. For both compounds, the branching net of intermolecular hydrogen bonds occur in the crystal structures.
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Affiliation(s)
- S Belyakov
- Latvian Institute of Organic Synthesis, Riga, Latvia
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117
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Dowling JE, Vessels JT, Haque S, Chang HX, van Vloten K, Kumaravel G, Engber T, Jin X, Phadke D, Wang J, Ayyub E, Petter RC. Synthesis of [1,2,4]triazolo[1,5-a]pyrazines as adenosine A2A receptor antagonists. Bioorg Med Chem Lett 2005; 15:4809-13. [PMID: 16153830 DOI: 10.1016/j.bmcl.2005.07.052] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Revised: 07/14/2005] [Accepted: 07/14/2005] [Indexed: 10/25/2022]
Abstract
Potent and selective antagonists of the adenosine A2A receptor often contain a nitrogen-rich fused-ring heterocyclic core. Replacement of the core with an isomeric ring system has previously been shown to improve target affinity, selectivity, and in vivo activity. This paper describes the preparation, by a novel route, of A2A receptor antagonists containing the [1,2,4]triazolo[1,5-a]pyrazine nucleus, which is isomeric with the [1,2,4]triazolo[1,5-c]pyrimidine core of a series of known A2A antagonists with in vivo activity in animal models of Parkinson's disease.
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Affiliation(s)
- James E Dowling
- Biogen Idec, Inc., 14 Cambridge Center, Cambridge, MA 02142, USA.
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118
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Manetti F, Schenone S, Bondavalli F, Brullo C, Bruno O, Ranise A, Mosti L, Menozzi G, Fossa P, Trincavelli ML, Martini C, Martinelli A, Tintori C, Botta M. Synthesis and 3D QSAR of New Pyrazolo[3,4-b]pyridines: Potent and Selective Inhibitors of A1 Adenosine Receptors. J Med Chem 2005; 48:7172-85. [PMID: 16279775 DOI: 10.1021/jm050407k] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A number of 4-aminopyrazolo[3,4-b]pyridines 5-carboxylic acid esters (2-8) were synthesized and evaluated for their binding affinity at the A1, A2A, and A3 adenosine receptors (AR), in bovine cortical membranes, as well as for their affinity toward human A1AR (hA1AR). Some of the new compounds were characterized by a high affinity and selectivity toward the A1 receptor subtype, showing a significant improvement in comparison with other pyrazolo-pyridines previously reported in the literature. In particular the methyl ester 2h as well as the isopropyl ester 5h, both of them bearing a p-methoxyphenylethylamino side chain at the position 4, presented Ki values of 6 and 7 nM, respectively. To rationalize the relationships between structure and affinity of the novel compounds, a 3D QSAR model was also generated starting from compounds belonging to different classes of known A1AR antagonists.
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Affiliation(s)
- Fabrizio Manetti
- Dipartimento Farmaco Chimico Tecnologico, Università degli Studi di Siena, Via Aldo Moro, I-53100 Siena, Italy
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Niebauer RT, Wedekind A, Robinson AS. Decreases in yeast expression yields of the human adenosine A2a receptor are a result of translational or post-translational events. Protein Expr Purif 2005; 37:134-43. [PMID: 15294291 DOI: 10.1016/j.pep.2004.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2004] [Revised: 06/01/2004] [Indexed: 11/21/2022]
Abstract
The human adenosine receptor (A2a), a G-protein-coupled receptor (GPCR), was C-terminally tagged with the green fluorescent protein (GFP) and expressed in the yeast Saccharomyces cerevisiae to gain an understanding of the expression limitations of this medically relevant class of membrane proteins. The A2a-GFP protein was able to bind adenosine analogs indicating that the GFP tag did not alter the ligand binding activity of the receptor. A screen based on whole cell fluorescence was developed and a library of clones with various gene copy numbers was screened via flow cytometry to isolate clones with the highest protein expression levels. All clones studied exhibited a decrease in the net A2a-GFP protein production rate over time as determined by whole cell fluorescence, Western blotting, confocal microscopy, and ligand binding. Quantitative PCR showed that A2a-GFP mRNA levels remained relatively high even as the protein production rate decreased. A cycloheximide chase experiment showed that the mature protein was stable over time and was not significantly degraded. Taken together, these results suggest that heterologous expression of GPCRs is limited by a translational or post-translational bottleneck that is unique from expression limitations seen for soluble proteins.
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Affiliation(s)
- Ronald T Niebauer
- Department of Chemical Engineering, University of Delaware, Newark, DE 19716, USA
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120
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Baraldi PG, Tabrizi MA, Preti D, Bovero A, Fruttarolo F, Romagnoli R, Zaid NA, Moorman AR, Varani K, Borea PA. New 2-arylpyrazolo[4,3-c]quinoline derivatives as potent and selective human A3 adenosine receptor antagonists. J Med Chem 2005; 48:5001-8. [PMID: 16033279 DOI: 10.1021/jm050125k] [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] [Indexed: 11/29/2022]
Abstract
In this paper we report the synthesis and biological evaluation of a new class of 2-phenyl-2,5-dihydro-pyrazolo[4,3-c]quinolin-4-ones as A(3) adenosine receptor antagonists. We designed a new route based on the Kira-Vilsmeier reaction for the synthesis of this class of compounds. Some of the synthesized compounds showed A(3) adenosine receptor affinity in the nanomolar range and good selectivity as evaluated in radioligand binding assays at human (h) A(1), A(2A), A(2B), and A(3) adenosine receptor subtypes. We introduced several substituents on the 2-phenyl ring. In particular substitution at the 4-position by methyl, methoxy, and chlorine gave optimal activity and selectivity 6c (K(i)hA(1), A(2A)>1000 nM, EC(50)hA(2B)>1000 nM, K(i)hA(3) = 9 nM), 6d (K(i)hA(1), A(2A)>1000 nM, EC(50)hA(2B)>1000 nM, K(i)hA(3) = 16 nM), 6b (K(i)hA(1), A(2A) >1000 nM, EC(50)hA(2B)>1000 nM, K(i)hA(3) = 19 nM). In conclusion, the 2-phenyl-2,5-dihydro-pyrazolo[4,3-c]quinolin-4-one derivatives described herein represent a new family of in vitro selective antagonists for the adenosine A(3) receptor.
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Affiliation(s)
- Pier Giovanni Baraldi
- Dipartimento di Scienze Farmaceutiche, Dipartimento di Medicina Clinica e Sperimentale-Sezione di Farmacologia, Università di Ferrara, 44100 Ferrara, Italy.
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121
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Catarzi D, Colotta V, Varano F, Calabri FR, Lenzi O, Filacchioni G, Trincavelli L, Martini C, Tralli A, Montopoli C, Moro S. 2-aryl-8-chloro-1,2,4-triazolo[1,5-a]quinoxalin-4-amines as highly potent A1 and A3 adenosine receptor antagonists. Bioorg Med Chem 2005; 13:705-15. [PMID: 15653338 DOI: 10.1016/j.bmc.2004.10.050] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Revised: 10/20/2004] [Accepted: 10/25/2004] [Indexed: 11/27/2022]
Abstract
Some 2-aryl-8-chloro-1,2,4-triazolo[1,5-a]quinoxaline derivatives 2-18, obtained by introducing different substituents on either the 4-amino moiety (acyl or carbamoyl groups) or the 2-phenyl ring (4-OCH3) of previously reported 8-chloro-2-phenyl-1,2,4-triazolo[1,5-a]quinoxalin-4-amine (1), have been synthesized and tested in radioligand binding assays at bovine A1 and A(2A) and at cloned human A1 and A3 adenosine receptors. The rationally designed 8-chloro-2-(4-methoxy-phenyl)-1,2,4-triazolo[1,5-a]quinoxalin-4-acetylamine (14) can be considered one of the most potent and hA3 versus hA1 selective AR antagonists reported till now. The structure-activity relationships of compounds 2-18 are in agreement with those of previously reported 2-aryl-1,2,4-triazolo[4,3-a]quinoxalines (series A) and 2-arylpyrazolo[3,4-c]quinolines (series B), thus suggesting a similar AR binding mode. In fact, the importance for the A3 receptor-ligand interaction of both a strong acidic NH proton donor and a C=O proton acceptor at position-4, able to engage hydrogen-bonding interactions with specific sites on the A3 AR, has been confirmed. Using our recently published hA3 receptor model, to better elucidate our experimental results, we decided to theoretically depict the putative TM binding motif of the herein reported 1,2,4-triazolo[1,5-a]quinoxaline derivatives on human A3 receptor. Structure-activity relationships have been explained analyzing the three-dimensional structure of the antagonist-receptor models obtained by molecular docking simulation.
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Affiliation(s)
- Daniela Catarzi
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Firenze, Polo Scientifico, Via U. Schiff, 6, 50019 Sesto Fiorentino (Firenze), Italy.
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Pellegrino D, Tota B, Randall DJ. Adenosine/nitric oxide crosstalk in the branchial circulation of Squalus acanthias and Anguilla anguilla. Comp Biochem Physiol A Mol Integr Physiol 2005; 142:198-204. [PMID: 15979367 DOI: 10.1016/j.cbpb.2005.05.047] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2005] [Revised: 05/18/2005] [Accepted: 05/19/2005] [Indexed: 11/30/2022]
Abstract
The potent vasomodulator adenosine (AD), thanks to the interaction with by A(1) and A(2) receptors, dilates systemic, coronary and cerebral vasculatures but exert a constrictor action in several vessels of respiratory organs. Recent investigations suggest that nitric oxide (NO) contributes to AD effects. In fish, both NO and AD induce atypical effects compared to mammals. Since there is very little information on the role of NO and its involvement in mediating the actions of AD in fish, we have analysed this question in the branchial vasculature of the elasmobranch Squalus acanthias and the teleost Anguilla anguilla using an isolated perfused head and a branchial basket preparation, respectively. In both dogfish and eel, AD dose-response curves showed a biphasic effect: vasoconstriction (pico to nanomolar range) and vasodilation (micromolar range). Both effects were abolished by the classic xanthine inhibitor theophylline (Theo) and also by specific antagonists of A(1) and A(2) receptor subtypes. To analyse the involvement of the NO/cGMP system in the AD responses, we tested a NOS inhibitor, l-NIO, and a specific soluble guanylate cyclase (sGC) blocker, ODQ. In both dogfish and eel preparations l-NIO abrogated all vasomotor effects of AD, whereas ODQ blocked the AD-mediated vasoconstriction without affecting the vasorelaxant response. This indicates that only AD-induced vasoconstriction is mediated by a NO-cGMP-dependent mechanism. By using the NO donor SIN-1, we showed a dose-dependent vasoconstrictory effect which was completely blocked by ODQ. These results provide compelling evidence that the vasoactive role of AD in the branchial circulation of S. acanthias and A. anguilla involves a NO signalling.
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Affiliation(s)
- D Pellegrino
- Department of Pharmaco-Biology, University of Calabria, 87030 Arcavacata di Rende, CS, Italy.
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123
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Ishiwata K, Mizuno M, Kimura Y, Kawamura K, Oda K, Sasaki T, Nakamura Y, Muraoka I, Ishii K. Potential of [11C]TMSX for the evaluation of adenosine A2A receptors in the skeletal muscle by positron emission tomography. Nucl Med Biol 2005; 31:949-56. [PMID: 15464397 DOI: 10.1016/j.nucmedbio.2004.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2004] [Revised: 05/10/2004] [Accepted: 05/14/2004] [Indexed: 11/20/2022]
Abstract
We examined the potential of [7-methyl-11C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthine ([11C]TMSX) for the assessment of adenosine A2A receptors in muscle. In rodents, specific binding of [11C]TMSX was observed in muscle and heart by blockade with A2A-selective CSC and non-selective theophylline, but not with A1-selective DPCPX. Swimming exercise fluctuated radioligand-receptor binding in these tissues. In a PET study of two subjects, theophylline-infusion slightly deceased the distribution volume of [11C]TMSX in the heart (20% reduction) and muscle (10% reduction), which suggested the specific binding.
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Affiliation(s)
- Kiichi Ishiwata
- Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, 1-1 Naka-cho, Itabashi-ku, Tokyo 173-0022, Japan.
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124
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Bioorganic & medicinal chemistry reviews and perspectives. Bioorg Med Chem 2005. [DOI: 10.1016/j.bmc.2005.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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125
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Volpini R, Costanzi S, Lambertucci C, Vittori S, Martini C, Trincavelli ML, Klotz KN, Cristalli G. 2- and 8-alkynyl-9-ethyladenines: Synthesis and biological activity at human and rat adenosine receptors. Purinergic Signal 2005; 1:173-81. [PMID: 18404502 PMCID: PMC2096531 DOI: 10.1007/s11302-005-6216-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Revised: 10/21/2004] [Indexed: 12/05/2022] Open
Abstract
The synthesis of a series of 9-ethyladenine derivatives bearing alkynyl chains in 2- or 8-position was undertaken, based on the observation that replacement of the sugar moiety in adenosine derivatives with alkyl groups led to adenosine receptor antagonists. All the synthesized compounds were tested for their affinity at human and rat A1, A2A, and A3 adenosine receptors in binding assays; the activity at the human A2B receptor was determined in adenylyl cyclase experiments. Biological data showed that the 2-alkynyl derivatives possess good affinity and are slightly selective for the human A2A receptor. The same compounds tested on the rat A1 and A2A subtypes showed in general lower affinity for both receptors. On the other hand, the affinity of the 8-alkynyl derivatives at the human A1, A2A, and A2B receptors proved to be lower than that of the corresponding 2-alkynyl derivatives. On the contrary, the affinity of the same compounds for the human A3 receptor was improved, resulting in A3 selectivity. As in the case of the 2-alkynyl-substituted compounds, the 8-alkynyl derivatives showed decreased affinity for rat receptors. However, it is worthwhile to note that the 8-phenylethynyl-9-ethyladenine was the most active compound of the two series (Ki in the nanomolar range) at both the human and rat A3 subtype. Docking experiments of the 2- and 8-phenylethynyl-9-ethyladenines, at a rhodopsin-based homology model, gave a rational explanation of the preference of the human A3 receptor for the 8-substituted compound.
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Affiliation(s)
- Rosaria Volpini
- Dipartimento di Scienze Chimiche, Università di Camerino, Camerino, Italy
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126
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Yan L, Burbiel JC, Maass A, Müller CE. Adenosine receptor agonists: from basic medicinal chemistry to clinical development. Expert Opin Emerg Drugs 2005; 8:537-76. [PMID: 14662005 DOI: 10.1517/14728214.8.2.537] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Adenosine is a physiological nucleoside which acts as an autocoid and activates G protein-coupled membrane receptors, designated A(1), A(2A), A(2B) and A(3). Adenosine plays an important role in many (patho)physiological conditions in the CNS as well as in peripheral organs and tissues. Adenosine receptors are present on virtually every cell. However, receptor subtype distribution and densities vary greatly. Adenosine itself is used as a therapeutic agent for the treatment of supraventricular paroxysmal tachycardia and arrhythmias and as a vasodilatatory agent in cardiac imaging. During the past 20 years, a number of selective agonists for A(1), A(2A) and A(3) adenosine receptors have been developed, all of them structurally derived from adenosine. Several such compounds are currently undergoing clinical trials for the treatment of cardiovascular diseases (A(1)and A(2A)), pain (A(1)), wound healing (A(2A)), diabetic foot ulcers (A(2A)), colorectal cancer (A(3)) and rheumatoid arthritis (A(3)). Clinical evaluation of some A(1) and A(2A) adenosine receptor agonists has been discontinued. Major problems include side effects due to the wide distribution of adenosine receptors; low brain penetration, which is important for the targeting of CNS diseases; short half-lifes of compounds; or a lack of effects, in some cases perhaps due to receptor desensitisation or to low receptor density in the targeted tissue. Partial agonists, inhibitors of adenosine metabolism (adenosine kinase and deaminase inhibitors) or allosteric activators of adenosine receptors may be advantageous for certain indications, as they may exhibit fewer side effects.
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Affiliation(s)
- Luo Yan
- University of Bonn, Pharmaceutical Institute Poppelsdorf, Kreuzbergweg 26, D-53115 Bonn, Germany
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127
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Baraldi PG, Cacciari B, Romagnoli R, Spalluto G. A1 and A3 adenosine receptor agonists: an overview. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.9.5.515] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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128
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129
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130
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Clark KL, Merkel L. Potential of adenosine receptor agonists for the prevention and treatment of coronary artery disease and acute myocardial infarction. ACTA ACUST UNITED AC 2005. [DOI: 10.1517/14728214.5.1.89] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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131
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Gessi S, Cattabriga E, Avitabile A, Gafa' R, Lanza G, Cavazzini L, Bianchi N, Gambari R, Feo C, Liboni A, Gullini S, Leung E, Mac-Lennan S, Borea PA. Elevated expression of A3 adenosine receptors in human colorectal cancer is reflected in peripheral blood cells. Clin Cancer Res 2005; 10:5895-901. [PMID: 15355922 DOI: 10.1158/1078-0432.ccr-1134-03] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE Adenosine is a ubiquitous nucleoside that accumulates at high levels in hypoxic regions of solid tumors, and A(3) adenosine receptors have been recently demonstrated to play a pivotal role in the adenosine-mediated inhibition of tumor cell proliferation. In the present work, we addressed the question of the putative relevance of A(3) subtypes in colorectal adenocarcinomas. EXPERIMENTAL DESIGN Seventy-three paired samples of tumor and surrounding peritumoral normal mucosa at a distance of 2 and 10 cm from the tumor and blood samples obtained from a cohort of 30 patients with colorectal cancer were investigated to determine the presence of A(3) receptors by means of binding, immunocytochemistry, and real-time reverse transcription-polymerase chain reaction studies. RESULTS As measured by receptor binding assays, the density of A(3) receptor was higher in colon carcinomas as compared with normal mucosa originating from the same individuals (P < 0.05). Overexpression of A(3) receptors at the protein level was confirmed by immunohistochemical studies, whereas no changes in A(3) mRNA accumulation in tumors as compared with the corresponding normal tissue were revealed. The overexpression of A(3) receptors in tumors was reflected in peripheral blood cells, where the density was approximately 3-fold higher compared with healthy subjects (P < 0.01). In a cohort of 10 patients studied longitudinally, expression of A(3) receptors in circulating blood cells returned to normal after surgical resection for colorectal cancer. CONCLUSIONS This study provides the first evidence that A(3) receptor plays a role in colon tumorigenesis and, more importantly, can potentially be used as a diagnostic marker or a therapeutic target for colon cancer.
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Affiliation(s)
- Stefania Gessi
- Department of Clinical and Experimental Medicine, Pharmacology Unit, Interdisciplinary Center for the Study of Inflammation, St. Anna Hospital, University of Ferrara, Ferrara, Italy
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132
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Wong CH. Bioorganic & medicinal chemistry reviews and perspectives. Bioorg Med Chem 2005. [DOI: 10.1016/j.bmc.2005.01.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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133
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Wong CH. Bioorganic & medicinal chemistry reviews and perspectives. Bioorg Med Chem 2005. [DOI: 10.1016/j.bmc.2004.12.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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134
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González MP, Terán C, Fall Y, Teijeira M, Besada P. A radial distribution function approach to predict A2B agonist effect of adenosine analogues. Bioorg Med Chem 2005; 13:601-8. [PMID: 15653328 DOI: 10.1016/j.bmc.2004.10.063] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Revised: 10/27/2004] [Accepted: 10/30/2004] [Indexed: 10/26/2022]
Abstract
The radial distribution function (RDF) approach has been applied to the study of the A(2B) agonist effect of a set of 89 adenosine analogues reported with this activity. A model able to describe more than 70% of the variance in the experimental activity was developed with the use of the mentioned approach. In contrast, none of the eleven different approaches including the use of Constitutional, Topological, Molecular walk count, BCUT, Galvez topological charge indices, 2D autocorrelations, Randić molecular profiles, Geometrical, 3D Morse, WHIM and GETAWAY descriptors was able to explain more than 47% of the variance in the mentioned property with the same number of descriptors.
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Affiliation(s)
- Maykel Pérez González
- Unit of Services, Department of Drug Design, Experimental Sugar Cane Station Villa Clara-Cienfuegos, Ranchuelo, Cuba.
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135
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Bioorganic & medicinal chemistry reviews and perspectives. Bioorg Med Chem 2005. [DOI: 10.1016/j.bmc.2004.11.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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136
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Chang LCW, Brussee J, Ijzerman AP. Non-Xanthine Antagonists for the Adenosine A1 Receptor. Chem Biodivers 2004; 1:1591-626. [PMID: 17191804 DOI: 10.1002/cbdv.200490122] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Lisa C W Chang
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, P.O. Box 9502, NL-2300 RA Leiden
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137
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Vittori S, Costanzi S, Lambertucci C, Portino FR, Taffi S, Volpini R, Klotz KN, Cristalli G. A2B adenosine receptor agonists: synthesis and biological evaluation of 2-phenylhydroxypropynyl adenosine and NECA derivatives. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2004; 23:471-81. [PMID: 15043167 DOI: 10.1081/ncn-120028340] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In the search for agonists for the elusive A2B adenosine receptor subtypes, 2-phenylhydroxypropynyl-5'-N-methylcarboxamido adenosine (PHPMECA, 14), 2-phenylhydroxypropynyl-5'-N-propylcarboxamido adenosine (PHPPECA, 15), and N6-ethyl-2-phenylhydroxypropynyl-5'-N-ethylcarboxamidoadenosine (19) were synthesized on the basis that introduction of alkynyl chains in 2-position of adenosine derivatives resulted in reasonably good A2B potency compared to NECA [see N6-ethyl-2-phenylhydroxypropynyl adenosine (5) EC50 = 1,700 nM and 2-phenylhydroxypropynyl-5'-N-ethylcarboxamido adenosine (PHPNECA, 8) EC50 = 1,100 nM, respectively]. Radioligand binding studies and adenylyl cyclase assays, performed with recently cloned human A1, A2A, A2B, and A3 adenosine receptors, showed that these modifications produced a decrease in potency at A2B receptor, as well as a general reduction in affinity at the other receptor subtypes. On the other hand, the contemporary presence of an ethyl substituent in N6-position and of a 4'-ethylcarboxamido group in the same compounds led to (R,S)-N6-ethyl-2-phenylhydroxypropynyl-5'-N-ethylcarboxamidoadenosine and (S)-N6-ethyl-2-phenylhydroxypropynyl-5'-N-ethylcarboxamidoadenosine, which did not show the expected increase in potency at A2B subtype. Hence, (S)-2-phenylhydroxypropynyl-5'-N-ethylcarboxamidoadenosine [(S)-PHPNECA] with EC50 A2B = 220 nM remains the most potent agonist at A2B receptor reported so far.
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Affiliation(s)
- S Vittori
- Dipartimento di Scienze Chimiche, Università di Camerino, Camerino (MC), Italy
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138
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Elzein E, Palle V, Wu Y, Maa T, Zeng D, Zablocki J. 2-Pyrazolyl-N(6)-substituted adenosine derivatives as high affinity and selective adenosine A(3) receptor agonists. J Med Chem 2004; 47:4766-73. [PMID: 15341491 DOI: 10.1021/jm049682h] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe the synthesis of new high affinity and selective A(3)-adenosine receptor (A(3)-AdoR) agonists. Introduction of a methyl group at the N(6)-position of the A(2A)-AdoR selective 2-pyrazolyl-adenosine analogues (Figure 2) brought about a substantial increase in the A(3)-AdoR binding affinity and selectivity. While the N(6)-desmethyl analogues 3a and 4 were inactive at the A(3)-AdoR (K(i) > 10 microM), the corresponding N(6)-methyl analogues 5 and 22 showed good binding affinity at the A(3)-AdoR (K(i) = 73 and 97 nM, respectively). Replacement of the carboxamide group in 5 with different heteroaryl groups resulted in analogues with high affinities and selectivity for the A(3)-AdoR. (2R,3S,4R)-tetrahydro-2-(hydroxymethyl)-5-(6-(methylamino)-2-(4-(pyridin-2-yl)-1H-pyrazol-1-yl)-9H-purin-9-yl)furan-3,4-diol (15, K(i) = 2 nM) displayed high selectivity for the A(3)-AdoR versus A(1)- and A(2A)-AdoRs (selectivity ratios of 1900 and >2000, respectively).
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Affiliation(s)
- Elfatih Elzein
- Department of Bioorganic Chemistry, CV Therapeutics Inc., 3172 Porter Drive, Palo Alto, California 94304, USA.
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139
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Liu CH, Wang B, Li WZ, Yun LH, Liu Y, Su RB, Li J, Liu H. Design, synthesis, and biological evaluation of novel 4-alkylamino-1-hydroxymethylimidazo[1,2-a]quinoxalines as adenosine A1 receptor antagonists. Bioorg Med Chem 2004; 12:4701-7. [PMID: 15358296 DOI: 10.1016/j.bmc.2004.06.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2004] [Revised: 06/20/2004] [Accepted: 06/21/2004] [Indexed: 11/20/2022]
Abstract
A series of 4-alkylamino-1-hydroxymethylimidazo[1,2-a]quinoxalines have been synthesized and evaluated for their adenosine A(1) receptor inhibitory activity in the radioligand binding assays. The compounds were tested for the inhibition percent (IP) and the affinity toward A(1)AR (K(i)) that IP were more than 90% in the nanomolar range. 4-Cyclopentylamino-7,8-dichloro-1-hydroxymethylimidazo[1,2-a]quinoxaline 18 is the most potent compound in this series, having K(i)=7nM, which is remarkably higher than that of IRFI-165 (K(i)=48). 1-Hydroxymethyl groups of the tricyclic heteroarmatic compounds displayed the potent affinities toward A(1)AR.
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Affiliation(s)
- Chun-He Liu
- No. 7 Department, Beijing Institute of Pharmacology and Toxicology Academy, 27 Taiping Road, Beijing 100850, PR China.
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140
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Noji T, Karasawa A, Kusaka H. Adenosine uptake inhibitors. Eur J Pharmacol 2004; 495:1-16. [PMID: 15219815 DOI: 10.1016/j.ejphar.2004.05.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2004] [Revised: 04/30/2004] [Accepted: 05/10/2004] [Indexed: 12/23/2022]
Abstract
Adenosine is a purine nucleoside and modulates a variety of physiological functions by interacting with cell-surface adenosine receptors. Under several adverse conditions, including ischemia, trauma, stress, seizures and inflammation, extracellular levels of adenosine are increased due to increased energy demands and ATP metabolism. Increased adenosine could protect against excessive cellular damage and organ dysfunction. Indeed, several protective effects of adenosine have been widely reported (e.g., amelioration of ischemic heart and brain injury, seizures and inflammation). However, the effects of adenosine itself are insufficient because extracellular adenosine is rapidly taken up into adjacent cells and subsequently metabolized. Adenosine uptake inhibitors (nucleoside transport inhibitors) could retard the disappearance of adenosine from the extracellular space by blocking adenosine uptake into cells. Therefore, it is expected that adenosine uptake inhibitors will have protective effects in various diseases, by elevating extracellular adenosine levels. Protective or ameliorating effects of adenosine uptake inhibitors in ischemic cardiac and cerebral injury, organ transplantation, seizures, thrombosis, insomnia, pain, and inflammatory diseases have been reported. Preclinical and clinical results indicate the possibility of therapeutic application of adenosine uptake inhibitors.
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Affiliation(s)
- Tohru Noji
- Pharmaceutical Research Institute, Kyowa Hakko Kogyo Co., Ltd., 1188 Shimotogari, Nagaizumi, Sunto, Shizuoka 411-8731, Japan.
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141
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Gutiérrez-de-Terán H, Pastor M, Centeno NB, Aqvist J, Sanz F. Comparative Analysis of Putative Agonist-Binding Modes in the Human A1 Adenosine Receptor. Chembiochem 2004; 5:841-9. [PMID: 15174168 DOI: 10.1002/cbic.200300817] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A recent study reported a model of the human A(1) adenosine receptor and its agonist binding site, proposing two putative binding modes in the same binding site for the natural agonist, adenosine. The present work investigates the flexibility of this binding site by exhaustive exploration with the natural agonist and with three other adenosine derivatives: N6-cyclopentyladenosine (CPA), 2-chloro-N6-cyclopentyladenosine (CCPA), and 5'-N-ethylcarboxamidoadenosine (NECA). Our aim was to find a common binding mode for agonists that would explain the role in the binding process of the different substitutions allowed at the 2, N6, and 5' positions of adenosine. This problem was addressed through docking simulations, molecular dynamics studies, and estimations of the ligand-binding free energy with both the AUTODOCK scoring function and the linear interaction energy (LIE) approach. The results point to a single receptor-binding position that explains the effects of the different chemical modifications on the adenosine derivatives considered here.
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Affiliation(s)
- Hugo Gutiérrez-de-Terán
- Research Group on Biomedical Informatics (GRIB), Institut Municipal d'Investigació Mèdica, Universitat Pompeu Fabra, Carrer Dr. Aiguader 80, 08003 Barcelona, Spain
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142
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Fishman P, Bar-Yehuda S, Ohana G, Barer F, Ochaion A, Erlanger A, Madi L. An agonist to the A3 adenosine receptor inhibits colon carcinoma growth in mice via modulation of GSK-3 beta and NF-kappa B. Oncogene 2004; 23:2465-71. [PMID: 14691449 DOI: 10.1038/sj.onc.1207355] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A(3) adenosine receptor (A(3)AR) activation with the specific agonist CF101 has been shown to inhibit the development of colon carcinoma growth in syngeneic and xenograft murine models. In the present study, we looked into the effect of CF101 on the molecular mechanisms involved in the inhibition of HCT-116 colon carcinoma in mice. In tumor lesions derived from CF101-treated mice, a decrease in the expression level of protein kinase A (PKA) and an increase in glycogen synthase kinase-3 beta (GSK-3 beta) was observed. This gave rise to downregulation of beta-catenin and its transcriptional gene products cyclin D1 and c-Myc. Further mechanistic studies in vitro revealed that these responses were counteracted by the selective A(3)AR antagonist MRS 1523 and by the GSK-3 beta inhibitors lithium and SB216763, confirming that the observed effects were A(3)AR and GSK-3 beta mediated. CF101 downregulated PKB/Akt expression level, resulting in a decrease in the level and DNA-binding capacity of NF-kappa B, both in vivo and in vitro. Furthermore, the PKA and PKB/Akt inhibitors H89 and Worthmannin mimicked the effect of CF101, supporting their involvement in mediating the response to the agonist. This is the first demonstration that A(3)AR activation induces colon carcinoma growth inhibition via the modulation of the key proteins GSK-3 beta and NF-kappa B.
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Affiliation(s)
- Pnina Fishman
- Can-Fite Biopharma Ltd, Kiryat-Matalon, Petach-Tikva 49170, Israel.
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143
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Fontaine F, Pastor M, Sanz F. Incorporating Molecular Shape into the Alignment-free GRid-INdependent Descriptors. J Med Chem 2004; 47:2805-15. [PMID: 15139758 DOI: 10.1021/jm0311240] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The recently introduced GRid-INdependent Descriptors (GRIND) were designed to provide a suitable description of a series of ligands for 3D-QSAR studies not requiring the spatial superimposition of their structures. Despite the proven usefulness of the method, it was recognized that the original GRIND failed to describe appropriately the shape of the ligand molecules, which in some cases plays a major role in ligand-receptor binding. For this reason, the original descriptors have been enhanced with the addition of a molecular shape description based on the local curvature of the molecular surface. The integration of this description into the GRIND allows the generation of 3D-QSAR models able to identify both favorable and unfavorable shape complementarity in a simple and alignment-independent way. The usefulness of the new GRIND-shape description in 3D-QSAR is illustrated using two structure-activity studies: one performed on a set of xanthine-like antagonists of the A(1) adenosine receptor; another performed on a series of Plasmodium falciparum plasmepsin II inhibitors.
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Affiliation(s)
- Fabien Fontaine
- Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, C/Dr. Aiguader, 80, E-08003 Barcelona, Spain
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144
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Bioorganic & Medicinal Chemistry Reviews. Bioorg Med Chem 2004. [DOI: 10.1016/j.bmc.2004.02.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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145
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Bioorganic & Medicinal Chemistry Reviews. Bioorg Med Chem 2004. [DOI: 10.1016/j.bmc.2004.01.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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146
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Fry CH, Ikeda Y, Harvey R, Wu C, Sui GP. Control of bladder function by peripheral nerves: avenues for novel drug targets. Urology 2004; 63:24-31. [PMID: 15013649 DOI: 10.1016/j.urology.2003.10.031] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The micturition reflex involves afferent nerve activation when the bladder is sufficiently full and subsequent controlled firing of parasympathetic efferent nerves to contract the detrusor muscle as part of the voiding mechanism. Alteration of the sensitivity of afferent activation or loss of control over transmitter release could lead to sensory- or motor-activated incontinence, respectively. The control mechanisms that regulate these 2 activities remain poorly understood. Current opinion is that the sensation of bladder fullness is relayed by afferent nerves in the mucosal layer, which are activated by the release of chemical mediators, such as adenosine triphosphate (ATP), from the urothelium when it is stretched as the bladder fills. This hypothesis supports the concept that other chemical signals that affect bladder sensation (eg, changes in urine composition and agents such as capsaicin) can modulate the sensitivity of the basic system. It has also been proposed that a layer of myofibroblasts immediately below the basal lamina of the urothelium acts as a variable gain regulator of the sensory process between ATP release and afferent excitation. These myofibroblasts are functionally connected to form an electrical syncytium, make close contact with nerves, and respond by generating electrical responses and transient increases in intracellular Ca2+ when exposed to ATP. On the efferent side, using a guinea pig detrusor model, possible modulators of transmitter release have been investigated, including adenosine (the breakdown product of the neurotransmitter ATP). Adenosine reduces the force of nerve-mediated contractions by acting predominantly at presynaptic sites at the nerve-muscle junction via a subtype of an adenosine receptor-the A1 receptor. An additional effect, possibly via A2 receptors, is also present on the detrusor muscle itself. These actions of adenosine are less evident in human detrusor muscle but remain a potential modulatory target. In summary, the cellular and molecular regulation of bladder fullness sensation and efferent transmitter release are becoming better understood and represent potential drug targets for the management of detrusor overactivity.
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147
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Schenone S, Bruno O, Bondavalli F, Ranise A, Mosti L, Menozzi G, Fossa P, Manetti F, Morbidelli L, Trincavelli L, Martini C, Lucacchini A. Synthesis of 1-(2-chloro-2-phenylethyl)-6-methylthio-1H-pyrazolo[3,4-d]pyrimidines 4-amino substituted and their biological evaluation. Eur J Med Chem 2004; 39:153-60. [PMID: 14987824 DOI: 10.1016/j.ejmech.2003.11.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2003] [Revised: 11/19/2003] [Accepted: 11/19/2003] [Indexed: 11/23/2022]
Abstract
A new series of 4-amino-6-methylthio-1H-pyrazolo[3,4-d]pyrimidines (2a-m) bearing the 2-chloro-2-phenylethyl chain at the N1 position, has been synthesized. The affinity of these compounds for A1 adenosine receptor (A1AR) was measured. The compounds showed poor affinity. A more interesting result was obtained by 2a, 2d, 2g, which demonstrated inhibitory activity on cell proliferation of the A-431 cell line stimulated by epithelial growth factor (EGF) and on EGF receptor tyrosine kinase (EGFR-TK) phosphorylation.
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Affiliation(s)
- Silvia Schenone
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Genova, viale Benedetto XV, 16132 Genoa, Italy.
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148
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Catarzi D, Colotta V, Varano F, Filacchioni G, Martini C, Trincavelli L, Lucacchini A. 1,2,4-Triazolo[1,5-a]quinoxaline derivatives: synthesis and biological evaluation as adenosine receptor antagonists. ACTA ACUST UNITED AC 2004; 59:71-81. [PMID: 14871498 DOI: 10.1016/j.farmac.2003.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2003] [Accepted: 09/05/2003] [Indexed: 11/24/2022]
Abstract
Since most of the reported adenosine receptor antagonists are 2-(hetero)aryl-substituted tricyclic heteroaromatic derivatives, in the present study we report the synthesis and the biological evaluation of a new set of 4-amino-1,2,4-triazolo[1,5-a]quinoxalines containing at position-2 an ethyl carboxylate group or a hydrogen atom. The structure-activity relationships on these compounds were in accordance with those of a previously reported series of analogous size and shape, thus suggesting a similar A(1)-binding mode. In particular, the binding data indicate that alkylation of the 4-amino group of these derivatives lead to potent A(1)-receptor antagonists. Moreover, as new results, this study has pointed out that the ethyl 2-carboxylate group can advantageously replace the 2-(hetero)aryl ring of previously reported triazoloquinoxaline derivatives, affording an ameliorated interaction with the A(1)-receptor subtype.
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Affiliation(s)
- Daniela Catarzi
- Dipartimento di Scienze Farmaceutiche, Polo Scientifico, Università degli Studi di Firenze, Via U. Schiff, 6, Sesto Fiorentino (FZ), 50019, Italy.
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149
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Gutiérrez-de-Terán H, Centeno NB, Pastor M, Sanz F. Novel approaches for modeling of the A1adenosine receptor and its agonist binding site. Proteins 2004; 54:705-15. [PMID: 14997566 DOI: 10.1002/prot.10617] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The present work describes the building of a human A(1) adenosine receptor (hA(1)AR) model, based on the X-ray crystal structure of bovine rhodopsin, and its use as a basis for the investigation of some important structural characteristics of the receptor. One of the issues investigated was the protonation position of two histidine residues known to influence ligand binding, with protonation of His251 (6.52) in epsilon position and His278 (7.43) in delta position showing the best agreement with experimental evidence. The model was also used to study the position and structural role of water molecules present in the helical bundle. Finally, the binding site location and the ligand docking were investigated using an objective strategy. A suitable site for the binding of the ribose moiety of adenosine was first postulated and further confirmed by means of a novel chemometric strategy based on GRIND descriptors. Using this position as an anchor point, the binding of adenosine was studied by docking and molecular dynamics simulations obtaining two putative binding positions in good agreement with experimental data.
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Affiliation(s)
- Hugo Gutiérrez-de-Terán
- Research Group on Biomedical Informatics (GRIB), Institut Municipal d'Investigació Mèdica, Universitat Pompeu Fabra, Barcelona, Spain
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150
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Da Settimo F, Primofiore G, Taliani S, La Motta C, Novellino E, Greco G, Lavecchia A, Cosimelli B, Iadanza M, Klotz KN, Tuscano D, Trincavelli ML, Martini C. A1 adenosine receptor antagonists, 3-aryl[1,2,4]triazino[4,3-a]benzimidazol-4-(10H)-ones (ATBIs) andN-alkyl andN-acyl-(7-substituted-2-phenylimidazo[1,2-a][1,3,5]triazin-4-yl)amines (ITAs): Different recognition of bovine and human binding sites. Drug Dev Res 2004. [DOI: 10.1002/ddr.10366] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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