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Differential Effects of a Novel Opioid Ligand UTA1003 on Antinociceptive Tolerance and Motor Behaviour. Pharmaceuticals (Basel) 2022; 15:ph15070789. [PMID: 35890089 PMCID: PMC9318816 DOI: 10.3390/ph15070789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/18/2022] [Accepted: 06/21/2022] [Indexed: 02/05/2023] Open
Abstract
Analgesic tolerance is a major problem in the clinic for the maintenance of opioid-induced long-term pain relief. Opioids with mixed activity on multiple opioid receptors promise reduced antinociceptive tolerance in preclinical studies, but these compounds typically show poor bioavailability upon oral, subcutaneous, intraperitoneal, or intravenous administration. We designed UTA1003 as a novel opioid that acts as a mu (MOP) and kappa (KOP) opioid receptor agonist and a partial agonist for delta (DOP) opioid receptor. In the present study, its antinociceptive effects, as well as its effects on antinociceptive tolerance and motor behaviour, were investigated in male rats. Acute antinociception was measured before (basal) and at different time points after subcutaneous injection of UTA1003 or morphine using the tail flick and hot plate assays. Various motor behavioural activities, including horizontal locomotion, rearing, and turning, were automatically measured in an open-field arena. The antinociceptive and behavioural effects of repeated administration of UTA1003 and morphine were determined over eight days. UTA1003 induced mild antinociceptive effects after acute administration but induced no tolerance after repeated treatment. Importantly, UTA1003 co-treatment with morphine prevented antinociceptive tolerance compared to morphine alone. UTA1003 showed less motor suppression than morphine in both acute and sub-chronic treatment regimens, while it did not affect morphine-induced motor suppression or hyper-excitation. Based on these activities, we speculate that UTA1003 crosses the blood-brain barrier after subcutaneous administration and, therefore, could be developed as a lead molecule to avoid opioid-induced antinociceptive tolerance and motor suppression. Further structural modifications to improve its antinociceptive effects, toxicity profile, and ADME parameters are nevertheless required.
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Hirayama S, Fujii H. δ Opioid Receptor Inverse Agonists and their In Vivo Pharmacological Effects. Curr Top Med Chem 2020; 20:2889-2902. [PMID: 32238139 DOI: 10.2174/1568026620666200402115654] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/25/2020] [Accepted: 03/05/2020] [Indexed: 11/22/2022]
Abstract
The discovery of δ opioid receptor inverse agonist activity induced by ICI-174,864, which was previously reported as an δ opioid receptor antagonist, opened the door for the investigation of inverse agonism/constitutive activity of the receptors. Various peptidic or non-peptidic δ opioid receptor inverse agonists have since been developed. Compared with the reports dealing with in vitro inverse agonist activities of novel compounds or known compounds as antagonists, there have been almost no publications describing the in vivo pharmacological effects induced by a δ opioid receptor inverse agonist. After the observation of anorectic effects with the δ opioid receptor antagonism was discussed in the early 2000s, the short-term memory improving effects and antitussive effects have been very recently reported as possible pharmacological effects induced by a δ opioid receptor inverse agonist. In this review, we will survey the developed δ opioid receptor inverse agonists and summarize the possible in vivo pharmacological effects by δ opioid receptor inverse agonists. Moreover, we will discuss important issues involved in the investigation of the in vivo pharmacological effects produced by a δ opioid receptor inverse agonist.
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Affiliation(s)
- Shigeto Hirayama
- Laboratory of Medicinal Chemistry and Medicinal Research Laboratories, School of Pharmacy, Kitasato University, 5- 9-1, Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Hideaki Fujii
- Laboratory of Medicinal Chemistry and Medicinal Research Laboratories, School of Pharmacy, Kitasato University, 5- 9-1, Shirokane, Minato-ku, Tokyo 108-8641, Japan
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3
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Montgomery D, Anand JP, Griggs NW, Fernandez TJ, Hartman JG, Sánchez-Santiago AA, Pogozheva ID, Traynor JR, Mosberg HI. Novel Dimethyltyrosine-Tetrahydroisoquinoline Peptidomimetics with Aromatic Tetrahydroisoquinoline Substitutions Show in Vitro Kappa and Mu Opioid Receptor Agonism. ACS Chem Neurosci 2019; 10:3682-3689. [PMID: 31199621 DOI: 10.1021/acschemneuro.9b00250] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The dimethyltyrosine-tetrahydroisoquinoline (Dmt-Tiq) scaffold was originally developed in the production of selective delta opioid receptor (DOR) antagonists. Installation of a 7-benzyl pendant on the tetrahydroisoquinoline core of this classic opioid scaffold introduced kappa opioid receptor (KOR) agonism. Further modification of this pendant resulted in retention of KOR agonism and the addition of mu opioid receptor (MOR) partial agonism, a bifunctional profile with potential to be used in the treatment of cocaine addiction.
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Affiliation(s)
- Deanna Montgomery
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jessica P. Anand
- Department of Pharmacology, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
- Edward F. Domino Research Center, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Nicholas W. Griggs
- Department of Pharmacology, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Thomas J. Fernandez
- Department of Pharmacology, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Joshua G. Hartman
- Department of Pharmacology, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ashley A. Sánchez-Santiago
- Department of Pharmacology, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Irina D. Pogozheva
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John R. Traynor
- Department of Pharmacology, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
- Edward F. Domino Research Center, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Henry I. Mosberg
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
- Edward F. Domino Research Center, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
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4
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Gendron L, Cahill CM, von Zastrow M, Schiller PW, Pineyro G. Molecular Pharmacology of δ-Opioid Receptors. Pharmacol Rev 2017; 68:631-700. [PMID: 27343248 DOI: 10.1124/pr.114.008979] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Opioids are among the most effective analgesics available and are the first choice in the treatment of acute severe pain. However, partial efficacy, a tendency to produce tolerance, and a host of ill-tolerated side effects make clinically available opioids less effective in the management of chronic pain syndromes. Given that most therapeutic opioids produce their actions via µ-opioid receptors (MOPrs), other targets are constantly being explored, among which δ-opioid receptors (DOPrs) are being increasingly considered as promising alternatives. This review addresses DOPrs from the perspective of cellular and molecular determinants of their pharmacological diversity. Thus, DOPr ligands are examined in terms of structural and functional variety, DOPrs' capacity to engage a multiplicity of canonical and noncanonical G protein-dependent responses is surveyed, and evidence supporting ligand-specific signaling and regulation is analyzed. Pharmacological DOPr subtypes are examined in light of the ability of DOPr to organize into multimeric arrays and to adopt multiple active conformations as well as differences in ligand kinetics. Current knowledge on DOPr targeting to the membrane is examined as a means of understanding how these receptors are especially active in chronic pain management. Insight into cellular and molecular mechanisms of pharmacological diversity should guide the rational design of more effective, longer-lasting, and better-tolerated opioid analgesics for chronic pain management.
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Affiliation(s)
- Louis Gendron
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Catherine M Cahill
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Mark von Zastrow
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Peter W Schiller
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Graciela Pineyro
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
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5
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Huynh AS, Estrella V, Stark VE, Cohen AS, Chen T, Casagni TJ, Josan JS, Lloyd MC, Johnson J, Hruby VJ, Vagner J, Morse DL. Tumor Targeting and Pharmacokinetics of a Near-Infrared Fluorescent-Labeled δ-Opioid Receptor Antagonist Agent, Dmt-Tic-Cy5. Mol Pharm 2016; 13:534-44. [PMID: 26713599 PMCID: PMC4936951 DOI: 10.1021/acs.molpharmaceut.5b00760] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Fluorescence molecular imaging can be employed for the development of novel cancer targeting agents. Herein, we investigated the pharmacokinetics (PK) and cellular uptake of Dmt-Tic-Cy5, a delta-opioid receptor (δOR) antagonist-fluorescent dye conjugate, as a tumor-targeting molecular imaging agent. δOR expression is observed normally in the CNS, and pathologically in some tumors, including lung liver and breast cancers. In vitro, in vivo, and ex vivo experiments were conducted to image and quantify the fluorescence signal associated with Dmt-Tic-Cy5 over time using in vitro and intravital fluorescence microscopy and small animal fluorescence imaging of tumor-bearing mice. We observed specific retention of Dmt-Tic-Cy5 in tumors with maximum uptake in δOR-expressing positive tumors at 3 h and observable persistence for >96 h; clearance from δOR nonexpressing negative tumors by 6 h; and systemic clearance from normal organs by 24 h. Live-cell and intravital fluorescence microscopy demonstrated that Dmt-Tic-Cy5 had sustained cell-surface binding lasting at least 24 h with gradual internalization over the initial 6 h following administration. Dmt-Tic-Cy5 is a δOR-targeted agent that exhibits long-lasting and specific signal in δOR-expressing tumors, is rapidly cleared from systemic circulation, and is not retained in non-δOR-expressing tissues. Hence, Dmt-Tic-Cy5 has potential as a fluorescent tumor imaging agent.
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Affiliation(s)
- Amanda Shanks Huynh
- Department of Cancer Imaging & Metabolism, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612
| | - Veronica Estrella
- Department of Cancer Imaging & Metabolism, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612
| | - Valerie E. Stark
- Department of Cancer Imaging & Metabolism, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612
| | - Allison S. Cohen
- Department of Cancer Imaging & Metabolism, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612
| | - Tingan Chen
- Analytic Microscopy Core, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612
| | - Todd J. Casagni
- Department of Comparative Medicine, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive Tampa, FL 33612
| | - Jatinder S. Josan
- Department of Chemistry, The University of Arizona, 1306 E University Blvd., Tucson, AZ 85719
| | - Mark C. Lloyd
- Analytic Microscopy Core, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612
| | - Joseph Johnson
- Analytic Microscopy Core, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612
| | - Victor J. Hruby
- Department of Chemistry, The University of Arizona, 1306 E University Blvd., Tucson, AZ 85719
| | - Josef Vagner
- The BIO5 Research Institute, University of Arizona, 1657 E Helen Street, Tucson, Arizona 85721
| | - David L. Morse
- Department of Cancer Imaging & Metabolism, H. Lee Moffitt Cancer Center & Research Institute, 12902 Magnolia Drive, Tampa, FL 33612
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Rational Approach to the Design of Bioactive Peptidomimetics: Recent Developments in Opioid Agonist Peptides. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2015. [DOI: 10.1016/b978-0-444-63462-7.00002-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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7
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Vezzi V, Onaran HO, Molinari P, Guerrini R, Balboni G, Calò G, Costa T. Ligands raise the constraint that limits constitutive activation in G protein-coupled opioid receptors. J Biol Chem 2013; 288:23964-78. [PMID: 23836900 DOI: 10.1074/jbc.m113.474452] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Using a cell-free bioluminescence resonance energy transfer strategy we compared the levels of spontaneous and ligand-induced receptor-G protein coupling in δ (DOP) and μ (MOP) opioid receptors. In this assay GDP can suppress spontaneous coupling, thus allowing its quantification. The level of constitutive activity was 4-5 times greater at the DOP than at the MOP receptor. A series of opioid analogues with a common peptidomimetic scaffold displayed remarkable inversions of efficacy in the two receptors. Agonists that enhanced coupling above the low intrinsic level of the MOP receptor were inverse agonists in reducing the greater level of constitutive coupling of the DOP receptor. Yet the intrinsic activities of such ligands are identical when scaled over the GDP base line of both receptors. This pattern is in conflict with the predictions of the ternary complex model and the "two state" extensions. According to this theory, the order of spontaneous and ligand-induced coupling cannot be reversed if a shift of the equilibrium between active and inactive forms raises constitutive activation in one receptor type. We propose that constitutive activation results from a lessened intrinsic barrier that restrains spontaneous coupling. Any ligand, regardless of its efficacy, must enhance this constraint to stabilize the ligand-bound complexed form.
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Affiliation(s)
- Vanessa Vezzi
- Department of Pharmacology, Istituto Superiore di Sanità, 00161 Rome, Italy
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8
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Abstract
INTRODUCTION Although endomorphins-1 (EM-1; H-Tyr-Pro-Phe-Trp-NH(2)) and -2 (EM-2; H-Tyr-Pro-Phe-Phe-NH(2)) are primarily considered agonists for the μ-opioid receptor (MOR), systematic alterations to specific residues provided antagonists and ligands with mixed μ/δ-opioid properties, suitable for application to health-related topics. While the application of endomorphins as antinociceptive agents and numerous biological endpoints were experimentally delineated in laboratory animals and in vitro, clinical use is currently absent. However, structural alterations provide enhanced stability; formation of MOR antagonists or mixed and dual μ/δ-acting ligands could find considerable therapeutic potential. AREAS COVERED This review attempts to succinctly provide insight on the development and bioactivity of endomorphin analogues during the past decade. Rational design approaches will focus on the engineering of endomorphin agonists, antagonists and mixed ligands for their application as a multi-target ligand. EXPERT OPINION Aside from alleviating pain, EM analogues open new horizons in the treatment of medical syndromes involving neural reward mechanisms and extraneural regulation effects on homeostasis. Highly selective MOR antagonists may be promising to reduce inflammation, attenuate addiction to drugs and excess consumption of high-caloric food, ameliorate alcoholism, affect the immune system and combat opioid bowel dysfunction.
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Affiliation(s)
- Lawrence H Lazarus
- National Institute of Environmental Health Sciences, Laboratory of Toxicology and Pharmacology, 111 South TW Alexander Drive, Research Triangle Park, NC 27709, USA.
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9
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Decreasing the configurational entropy and the hydrophobicity of EBV-derived peptide 11389 increased its antigenicity, immunogenicity and its ability of inducing IL-6. Amino Acids 2011; 42:2165-75. [DOI: 10.1007/s00726-011-0954-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 05/27/2011] [Indexed: 11/28/2022]
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10
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Balboni G, Salvadori S, Marczak ED, Knapp BI, Bidlack JM, Lazarus LH, Peng X, Si YG, Neumeyer JL. Opioid bifunctional ligands from morphine and the opioid pharmacophore Dmt-Tic. Eur J Med Chem 2010; 46:799-803. [PMID: 21216504 DOI: 10.1016/j.ejmech.2010.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 10/28/2010] [Accepted: 12/01/2010] [Indexed: 01/31/2023]
Abstract
Bifunctional ligands containing an ester linkage between morphine and the δ-selective pharmacophore Dmt-Tic were synthesized, and their binding affinity and functional bioactivity at the μ, δ and κ opioid receptors determined. Bifunctional ligands containing or not a spacer of β-alanine between the two pharmacophores lose the μ agonism deriving from morphine becoming partial μ agonists 4 or μ antagonists 5. Partial κ agonism is evidenced only for compound 4. Finally, both compounds showed potent δ antagonism.
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliari, Via Ospedale 72, I-09124 Cagliari, Italy.
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11
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Role of 2',6'-dimethyl-l-tyrosine (Dmt) in some opioid lead compounds. Bioorg Med Chem 2010; 18:6024-30. [PMID: 20637637 DOI: 10.1016/j.bmc.2010.06.073] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 06/16/2010] [Accepted: 06/20/2010] [Indexed: 11/22/2022]
Abstract
Here we evaluated how the interchange of the amino acids 2',6'-dimethyl-L-tyrosine (Dmt), 2',6'-difluoro-L-tyrosine (Dft), and tyrosine in position 1 can affect the pharmacological characterization of some reference opioid peptides and pseudopeptides. Generally, Dft and Tyr provide analogues with a similar pharmacological profile, despite different pK(a) values. Dmt/Tyr(Dft) replacement gives activity changes depending on the reference opioid in which the modification was made. Whereas, H-Dmt-Tic-Asp *-Bid is a potent and selective delta agonist (MVD, IC(50)=0.12nM); H-Dft-Tic-Asp *-Bid and H-Tyr-Tic-Asp *-Bid are potent and selective delta antagonists (pA(2)=8.95 and 8.85, respectively). When these amino acids are employed in the synthesis of deltorphin B and its Dmt(1) and Dft(1) analogues, the three compounds maintain a very similar delta agonism (MVD, IC(50) 0.32-0.53 nM) with a decrease in selectivity relative to the Dmt(1) analogue. In the less selective H-Dmt-Tic-Gly *-Bid the replacement of Dmt with Dft and Tyr retains the delta agonism but with a decrease in potency. Antagonists containing the Dmt-Tic pharmacophore do not support the exchange of Dmt with Dft or Tyr.
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12
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Ballet S, Marczak ED, Feytens D, Salvadori S, Sasaki Y, Abell AD, Lazarus LH, Balboni G, Tourwé D. Novel multiple opioid ligands based on 4-aminobenzazepinone (Aba), azepinoindole (Aia) and tetrahydroisoquinoline (Tic) scaffolds. Bioorg Med Chem Lett 2010; 20:1610-3. [PMID: 20137938 DOI: 10.1016/j.bmcl.2010.01.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 01/12/2010] [Accepted: 01/13/2010] [Indexed: 10/19/2022]
Abstract
The dimerization and trimerization of the Dmt-Tic, Dmt-Aia and Dmt-Aba pharmacophores provided multiple ligands which were evaluated in vitro for opioid receptor binding and functional activity. Whereas the Tic- and Aba multimers proved to be dual and balanced delta/mu antagonists, as determined by the functional [S(35)]GTPgammaS binding assay, the dimerization of potent Aia-based 'parent' ligands unexpectedly resulted in substantial less efficient receptor binding and non-active dimeric compounds.
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Affiliation(s)
- Steven Ballet
- Department of Organic Chemistry, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.
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13
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Balboni G, Trapella C, Sasaki Y, Ambo A, Marczak ED, Lazarus LH, Salvadori S. Influence of the Side Chain Next to C-Terminal Benzimidazole in Opioid Pseudopeptides Containing the Dmt-Tic Pharmacophore. J Med Chem 2009; 52:5556-9. [DOI: 10.1021/jm900686q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliari, I-09124, Cagliari, Italy
| | - Claudio Trapella
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy
| | - Yusuke Sasaki
- Department of Pharmacology, Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome, Aoba-Ku, Sendai 981-8558, Japan
| | - Akihiro Ambo
- Department of Pharmacology, Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome, Aoba-Ku, Sendai 981-8558, Japan
| | - Ewa D. Marczak
- Medicinal Chemistry Group, Laboratory of Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Lawrence H. Lazarus
- Medicinal Chemistry Group, Laboratory of Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Severo Salvadori
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy
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14
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Conformationally constrained opioid ligands: the Dmt-Aba and Dmt-Aia versus Dmt-Tic scaffold. Bioorg Med Chem Lett 2008; 19:433-7. [PMID: 19062273 DOI: 10.1016/j.bmcl.2008.11.051] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 11/13/2008] [Accepted: 11/14/2008] [Indexed: 11/23/2022]
Abstract
Replacement of the constrained phenylalanine analogue 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) in the opioid Dmt-Tic-Gly-NH-Bn scaffold by the 4-amino-1,2,4,5-tetrahydro-indolo[2,3-c]azepin-3-one (Aia) and 4-amino-1,2,4,5-tetrahydro-2-benzazepin-3-one (Aba) scaffolds has led to the discovery of novel potent mu-selective agonists (Structures 5 and 12) as well as potent and selective delta-opioid receptor antagonists (Structures 9 and 15). Both stereochemistry and N-terminal N,N-dimethylation proved to be crucial factors for opioid receptor selectivity and functional bioactivity in the investigated small peptidomimetic templates. In addition to the in vitro pharmacological evaluation, automated docking models of Dmt-Tic and Dmt-Aba analogues were constructed in order to rationalize the observed structure-activity data.
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15
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Balboni G, Fiorini S, Baldisserotto A, Trapella C, Sasaki Y, Ambo A, Marczak ED, Lazarus LH, Salvadori S. Further studies on lead compounds containing the opioid pharmacophore Dmt-Tic. J Med Chem 2008; 51:5109-17. [PMID: 18680274 DOI: 10.1021/jm800587e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Some reference opioids containing the Dmt-Tic pharmacophore, especially the delta agonists H-Dmt-Tic-Gly-NH-Ph (1) and H-Dmt-Tic-NH-(S)CH(CH2-COOH)-Bid (4) (UFP-512) were evaluated for the influence of the substitution of Gly with aspartic acid, its chirality, and the importance of the -NH-Ph and N(1)H-Bid hydrogens in the inductions of delta agonism. The results provide the following conclusions: (i) Asp increases delta selectivity by lowering the mu affinity; (ii) -NH-Ph and N(1)H-Bid nitrogens methylation transforms the delta agonists into delta antagonists; (iii) the substitution of Gly with L-Asp/D-Asp in the delta agonist H-Dmt-Tic-Gly-NH-Ph gave delta antagonists; the same substitution in the delta agonist H-Dmt-Tic-NH-CH2-Bid yielded more selective agonists, H-Dmt-Tic-NH-(S)CH(CH2-COOH)-Bid and H-Dmt-Tic-NH-(R)CH(CH2-COOH)-Bid; (iv) L-Asp seems important only in functional bioactivity, not in receptor affinity; (v) H-Dmt-Tic-NH-(S)CH(CH2-COOH)-Bid(N(1)-Me) (10) evidenced analgesia similar to 4, which was reversed by naltrindole only in the tail flick. 4 and 10 had opposite behaviours in mice; 4 caused agitation, 10 gave sedation and convulsions.
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliari, I-09124 Cagliari, Italy.
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16
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3D Quantitative and Qualitative Structure-Activity Relationships of the δ -Opioid Receptor Antagonists. B KOREAN CHEM SOC 2008. [DOI: 10.5012/bkcs.2008.29.3.656] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Salvadori S, Fiorini S, Trapella C, Porreca F, Davis P, Sasaki^ Y, Ambo A, Ewa DM, Lazarus LH, Balboni G. Role of benzimidazole (Bid) in the delta-opioid agonist pseudopeptide H-Dmt-Tic-NH-CH(2)-Bid (UFP-502). Bioorg Med Chem 2008; 16:3032-8. [PMID: 18178091 PMCID: PMC2390930 DOI: 10.1016/j.bmc.2007.12.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 12/11/2007] [Accepted: 12/18/2007] [Indexed: 10/22/2022]
Abstract
H-Dmt-Tic-NH-CH(2)-Bid (UFP-502) was the first delta-opioid agonist prepared from the Dmt-Tic pharmacophore. It showed interesting pharmacological properties, such as stimulation of mRNA BDNF expression and antidepression. To evaluate the importance of 1H-benzimidazol-2-yl (Bid) in the induction of delta-agonism, it was substituted by similar heterocycles: The substitution of NH(1) by O or S transforms the reference delta-agonist into delta-antagonists. Phenyl ring of benzimidazole is not important for delta-agonism; in fact 1H-imidazole-2-yl retains delta-agonist activity.
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Affiliation(s)
- Severo Salvadori
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy
| | - Stella Fiorini
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy
| | - Claudio Trapella
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy
| | - Frank Porreca
- Department of Pharmacology, University of Arizona, Tucson, Arizona 85721, USA
| | - Peg Davis
- Department of Pharmacology, University of Arizona, Tucson, Arizona 85721, USA
| | - Yusuke Sasaki^
- Tohoku Pharmaceutical University, 4-1, Komatsushima 4-chome, Aoba-Ku, Sendai 981-8558, Japan
| | - Akihiro Ambo
- Tohoku Pharmaceutical University, 4-1, Komatsushima 4-chome, Aoba-Ku, Sendai 981-8558, Japan
| | - D Marczak Ewa
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Lawrence H. Lazarus
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Gianfranco Balboni
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy
- Department of Toxicology, University of Cagliari, I-09124, Cagliari, Italy
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18
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Li T, Shiotani K, Miyazaki A, Tsuda Y, Ambo A, Sasaki Y, Jinsmaa Y, Marczak E, Bryant SD, Lazarus LH, Okada Y. Bifunctional [2',6'-dimethyl-L-tyrosine1]endomorphin-2 analogues substituted at position 3 with alkylated phenylalanine derivatives yield potent mixed mu-agonist/delta-antagonist and dual mu-agonist/delta-agonist opioid ligands. J Med Chem 2007; 50:2753-66. [PMID: 17497839 PMCID: PMC2669435 DOI: 10.1021/jm061238m] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Endomorphin-2 (H-Tyr-Pro-Phe-Phe-NH2) and [Dmt1]EM-2 (Dmt = 2',6'-dimethyl-l-tyrosine) analogues, containing alkylated Phe3 derivatives, 2'-monomethyl (2, 2'), 3',5'- and 2',6'-dimethyl (3, 3', and 4', respectively), 2',4',6'-trimethyl (6, 6'), 2'-ethyl-6'-methyl (7, 7'), and 2'-isopropyl-6'-methyl (8, 8') groups or Dmt (5, 5'), had the following characteristics: (i) [Xaa3]EM-2 analogues exhibited improved mu- and delta-opioid receptor affinities. The latter, however, were inconsequential (Kidelta = 491-3451 nM). (ii) [Dmt1,Xaa3]EM-2 analogues enhanced mu- and delta-opioid receptor affinities (Kimu = 0.069-0.32 nM; Kidelta = 1.83-99.8 nM) without kappa-opioid receptor interaction. (iii) There were elevated mu-bioactivity (IC50 = 0.12-14.4 nM) and abolished delta-agonism (IC50 > 10 muM in 2', 3', 4', 5', 6'), although 4' and 6' demonstrated a potent mixed mu-agonism/delta-antagonism (for 4', IC50mu = 0.12 and pA2 = 8.15; for 6', IC50mu = 0.21 nM and pA2 = 9.05) and 7' was a dual mu-agonist/delta-agonist (IC50mu = 0.17 nM; IC50delta = 0.51 nM).
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MESH Headings
- Animals
- Binding, Competitive
- Brain/metabolism
- Guinea Pigs
- In Vitro Techniques
- Ligands
- Male
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/innervation
- Muscle, Smooth/physiology
- Myenteric Plexus/physiology
- Neuromuscular Junction/drug effects
- Neuromuscular Junction/physiology
- Oligopeptides/chemical synthesis
- Oligopeptides/pharmacology
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, mu/agonists
- Structure-Activity Relationship
- Synaptosomes/metabolism
- Tyrosine/analogs & derivatives
- Tyrosine/chemical synthesis
- Tyrosine/pharmacology
- Vas Deferens/drug effects
- Vas Deferens/physiology
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Affiliation(s)
- Tingyou Li
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Kimitaka Shiotani
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Anna Miyazaki
- Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Yuko Tsuda
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
- Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
| | - Akihiro Ambo
- Department of Biochemistry, Tohoku Pharmaceutical University, Aoba-ku, Sendai 981-8558, Japan
| | - Yusuke Sasaki
- Department of Biochemistry, Tohoku Pharmaceutical University, Aoba-ku, Sendai 981-8558, Japan
| | - Yunden Jinsmaa
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, U.S.A
| | - Ewa Marczak
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, U.S.A
| | - Sharon D. Bryant
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, U.S.A
| | - Lawrence H. Lazarus
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, U.S.A
- Corresponding authors: Y. Okada: Tel: +81-78-974-1551, fax: +81-78-974-5689., E-mail: . L. H. Lazarus: Tel: +1-919-541-3238, fax: + 1-919-541-5737. E-mail:
| | - Yoshio Okada
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
- Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
- Corresponding authors: Y. Okada: Tel: +81-78-974-1551, fax: +81-78-974-5689., E-mail: . L. H. Lazarus: Tel: +1-919-541-3238, fax: + 1-919-541-5737. E-mail:
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19
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Further studies on the effect of lysine at the C-terminus of the Dmt-Tic opioid pharmacophore. Bioorg Med Chem 2007; 15:3143-51. [PMID: 17339114 DOI: 10.1016/j.bmc.2007.02.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 02/13/2007] [Accepted: 02/20/2007] [Indexed: 10/23/2022]
Abstract
A wide range of activities are induced by Lys when introduced at C-terminus of the delta-opioid Dmt-Tic pharmacophore through the alpha-amine group, including: improved delta-antagonism, mu-agonism and mu-antagonism. Here we report the synthesis of a new series of compounds with the general formula H-Dmt-Tic-NH-(CH(2))(4)-CH(R)-R' (R=-NH(2), -NH-Ac, -NH-Z; R'=CO-NH-Ph, -CO-NH-CH(2)-Ph, -Bid) in which Lys is linked to Dmt-Tic through its side-chain amine group. All new compounds (1-9) displayed potent and selective delta-antagonism (MVD, pA(2)=7.81-8.27), which was independent of the functionalized alpha-amine and carboxylic groups of C-terminal Lys. This behaviour suggests a direct application as a prototype intermediate, such as Boc-Dmt-Tic-epsilon-Lys(Z)-OMe, which could be successfully applied in the synthesis (after Z or methyl ester removal) of unique designed multiple ligands containing the pharmacophore of the quintessential delta-antagonist Dmt-Tic and another opioid or biologically active non-opioid ligand.
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20
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Vergura R, Valenti E, Hebbes CP, Gavioli EC, Spagnolo B, McDonald J, Lambert DG, Balboni G, Salvadori S, Regoli D, Calo' G. Dmt-Tic-NH-CH2-Bid (UFP-502), a potent DOP receptor agonist: in vitro and in vivo studies. Peptides 2006; 27:3322-30. [PMID: 16963157 DOI: 10.1016/j.peptides.2006.07.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 07/24/2006] [Accepted: 07/24/2006] [Indexed: 11/16/2022]
Abstract
Knockout and pharmacological studies demonstrated that the activation of delta opioid peptide (DOP) receptors produces antidepressant-like effects in rodents. Here we report the results obtained with the novel DOP ligand H-Dmt-Tic-NH-CH(2)-Bid (UFP-502). UFP-502 bound with high affinity (pK(i) 9.43) to recombinant DOP receptors displaying moderate selectivity over MOP and KOP. In CHO(hDOP) [(35)S]GTPgammaS binding and mouse vas deferens experiments, UFP-502 behaved as a potent (pEC(50) 10.09 and 10.70, respectively) full agonist. In these preparations, naloxone, naltrindole and N,N(CH(3))(2)Dmt-Tic-OH showed similar pA(2) values against UFP-502 and DPDPE and the same rank order of potency. In vivo in mice, UFP-502 mimicked DPDPE actions, producing a significant reduction of immobility time after intracerebroventricular administration in the forced swimming test and a clear antinociceptive effect after intrathecal injection in the tail withdrawal assay. However, while the effects of DPDPE were fully prevented by naltrindole those evoked by UFP-502 were unaffected (tail withdrawal assay) or only partially reversed (forced swimming test). In conclusion, UFP-502 represents a novel and useful chemical template for the design of selective agonists for the DOP receptor.
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Affiliation(s)
- Raffaella Vergura
- Department of Experimental and Clinical Medicine, Section of Pharmacology, and Neuroscience Centre, University of Ferrara, via Fossato di Mortara 19, 44100 Ferrara, Italy
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21
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Neumeyer JL, Peng X, Knapp BI, Bidlack JM, Lazarus LH, Salvadori S, Trapella C, Balboni G. New opioid designed multiple ligand from Dmt-Tic and morphinan pharmacophores. J Med Chem 2006; 49:5640-3. [PMID: 16942040 PMCID: PMC2435260 DOI: 10.1021/jm0605785] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Here, we report the synthesis of a designed multi-pharmacophore ligand derived from the linkage of a delta selective peptide antagonist (Dmt-Tic) and a mu/kappa morphinan agonist butorphan (MCL 101) through a two methylene spacer. The new compound MCL 450 maintains the same characteristics as those the two reference compounds. MCL 450 represents a useful starting point for the synthesis of other multiple opioid ligands endowed with analgesic properties with low tolerance and dependence.
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Affiliation(s)
- John L Neumeyer
- Alcohol and Drug Abuse Research Center, McLean Hospital, Harvard Medical School, 115 Mill Street, Belmont, Massachusetts 02478, USA
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22
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Balboni G, Onnis V, Congiu C, Zotti M, Sasaki Y, Ambo A, Bryant SD, Jinsmaa Y, Lazarus LH, Trapella C, Salvadori S. Effect of lysine at C-terminus of the Dmt-Tic opioid pharmacophore. J Med Chem 2006; 49:5610-7. [PMID: 16942034 PMCID: PMC2533050 DOI: 10.1021/jm060741w] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Substitution of Gly with side-chain-protected or unprotected Lys in lead compounds containing the opioid pharmacophore Dmt-Tic [H-Dmt-Tic-Gly-NH-CH(2)-Ph, mu agonist/delta antagonist; H-Dmt-Tic-Gly-NH-Ph, mu agonist/delta agonist; and H-Dmt-Tic-NH-CH(2)-Bid, delta agonist (Bid = 1H-benzimidazole-2-yl)] yielded a new series of compounds endowed with distinct pharmacological activities. Compounds (1-10) included high delta- (Ki(delta) = 0.068-0.64 nM) and mu-opioid affinities (Ki(mu) = 0.13-5.50 nM), with a bioactivity that ranged from mu-opioid agonism {10, H-Dmt-Tic-NH-CH[(CH2)4-NH2]-Bid (IC50 GPI = 39.7 nM)} to a selective mu-opioid antagonist [3, H-Dmt-Tic-Lys-NH-CH2-Ph (pA2(mu) = 7.96)] and a selective delta-opioid antagonist [5, H-Dmt-Tic-Lys(Ac)-NH-Ph (pA2(delta) = 12.0)]. The presence of a Lys linker provides new lead compounds in the formation of opioid peptidomimetics containing the Dmt-Tic pharmacophore with distinct agonist and/or antagonist properties.
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MESH Headings
- Animals
- Dipeptides/chemical synthesis
- Dipeptides/chemistry
- Dipeptides/pharmacology
- Electric Stimulation
- Guinea Pigs
- Ileum/drug effects
- Ileum/physiology
- In Vitro Techniques
- Ligands
- Male
- Mice
- Muscle, Smooth/drug effects
- Muscle, Smooth/physiology
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Structure-Activity Relationship
- Tetrahydroisoquinolines/chemical synthesis
- Tetrahydroisoquinolines/chemistry
- Tetrahydroisoquinolines/pharmacology
- Vas Deferens/drug effects
- Vas Deferens/physiology
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliari, I-09124, Cagliari, Italy.
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23
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Tourwé D, Salvadori S, Bryant SD, Jinsmaa Y, Lazarus LH, Negri L, Giannini E, Lattanzi R, Balboni G. New 2',6'-dimethyl-L-tyrosine (Dmt) opioid peptidomimetics based on the Aba-Gly scaffold. Development of unique mu-opioid receptor ligands. J Med Chem 2006; 49:3990-3. [PMID: 16789756 PMCID: PMC2983084 DOI: 10.1021/jm0603264] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Aba-Gly scaffold, incorporated into Dmt-Tic ligands (H-Dmt-Tic-Gly-NH-CH2-Ph, H-Dmt-Tic-Gly-NH-Ph, H-Dmt-Tic-NH-CH2-Bid), exhibited mixed micro/delta or delta opioid receptor activities with micro agonism. Substitution of Tic by Aba-Gly coupled to -NH-CH2-Ph (1), -NH-Ph (2), or -Bid (Bid=1H-benzimidazole-2-yl) (3) shifted affinity (Ki(micro)=0.46, 1.48, and 19.9 nM, respectively), selectivity, and bioactivity to micro-opioid receptors. These compounds represent templates for a new class of lead opioid agonists that are easily synthesized and suitable for therapeutic pain relief.
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MESH Headings
- Analgesics, Opioid/chemical synthesis
- Analgesics, Opioid/chemistry
- Analgesics, Opioid/pharmacology
- Animals
- Benzazepines/chemical synthesis
- Benzazepines/pharmacology
- Glycine/analogs & derivatives
- Glycine/chemical synthesis
- Glycine/pharmacology
- Guinea Pigs
- In Vitro Techniques
- Ligands
- Molecular Mimicry
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/innervation
- Muscle, Smooth/physiology
- Myenteric Plexus/physiology
- Peptides/chemistry
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/agonists
- Structure-Activity Relationship
- Synaptosomes/drug effects
- Synaptosomes/metabolism
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Affiliation(s)
- Dirk Tourwé
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Severo Salvadori
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy
| | - Sharon D. Bryant
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Yunden Jinsmaa
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Lawrence H. Lazarus
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Lucia Negri
- Department of Human Physiology and Pharmacology “Vittorio Erspamer,” University La Sapienza, I-00185 Rome, Italy
| | - Elisa Giannini
- Department of Human Physiology and Pharmacology “Vittorio Erspamer,” University La Sapienza, I-00185 Rome, Italy
| | - Roberta Lattanzi
- Department of Human Physiology and Pharmacology “Vittorio Erspamer,” University La Sapienza, I-00185 Rome, Italy
| | - Gianfranco Balboni
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy
- Department of Toxicology, University of Cagliari, I-09124, Cagliari, Italy
- To whom Correspondence should be addressed. Tel.: +39-532-291-275; Fax: +39-532-291-296; E-mail: ;
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24
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Jinsmaa Y, Marczak E, Fujita Y, Shiotani K, Miyazaki A, Li T, Tsuda Y, Ambo A, Sasaki Y, Bryant SD, Okada Y, Lazarus LH. Potent in vivo antinociception and opioid receptor preference of the novel analogue [Dmt1]endomorphin-1. Pharmacol Biochem Behav 2006; 84:252-8. [PMID: 16782179 DOI: 10.1016/j.pbb.2006.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Revised: 05/09/2006] [Accepted: 05/11/2006] [Indexed: 10/24/2022]
Abstract
[Dmt1]Endomorphin-1 is a novel analogue of the potent mu-opioid agonist endomorphin-1. Given the physiological role of endomorphin-1 in vivo, this compound was investigated to determine if the antinociception occurred through systemic, supraspinal or in a combination of both neuronal pathways. This compound exhibited a potent dose-dependent effect intracerebroventricularly in both spinal and supraspinal regions, and was blocked by opioid antagonist naloxone, which verified the involvement of opioid receptors. Specific opioid antagonists characterized the apparent receptor type: beta-funaltrexamine (mu1/mu2-irreversible antagonist) equally inhibited spinal- and central-mediated antinociception; on the other hand, naloxonazine (mu1-subtype) was ineffective in both neural pathways and naltrindole (delta-selective antagonist) partially (26%), though not significantly, blocked only the spinal-mediated antinociception. Therefore, spinal antinociception was primarily triggered by mu2-subtypes without involvement of mu1-opioid receptors; however, although a slight enhancement of antinociception by delta-receptors cannot be completely ruled out since functional bioactivity indicated mixed mu-agonism/delta-antagonism. In terms of the CNS action, [Dmt1]endomorphin-1 appears to act through mu2-opioid receptor subtypes.
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Affiliation(s)
- Yunden Jinsmaa
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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25
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Li T, Fujita Y, Shiotani K, Miyazaki A, Tsuda Y, Ambo A, Sasaki Y, Jinsmaa Y, Marczak E, Bryant SD, Salvadori S, Lazarus LH, Okada Y. Potent Dmt-Tic Pharmacophoric δ- and μ-Opioid Receptor Antagonists. J Med Chem 2005; 48:8035-44. [PMID: 16335927 DOI: 10.1021/jm050377l] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of dimeric Dmt-Tic (2',6'-dimethyl-L-tyrosyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) analogues (8-14, 18-22) were covalently linked through diaminoalkane and symmetric or asymmetric 3,6-diaminoalkyl-2(1H)-pyrazinone moieties. All the compounds exhibited high affinity for both delta-opioid receptors [Ki(delta) = 0.06-1.53 nM] and mu-opioid receptors [Ki(mu) = 1.37-5.72 nM], resulting in moderate delta-receptor selectivity [Ki(mu)/Ki(delta) = 3-46]. Regardless of the type of linker between the Dmt-Tic pharmacophores, delta-opioid-mediated antagonism was extraordinarily high in all analogues (pA2 = 10.42-11.28), while in vitro agonism (MVD and GPI bioassays) was essentially absent (ca. 3 to >10 microM). While an unmodified N-terminus (9, 13, 18) revealed weak mu-opioid antagonism (pA2 = 6.78-6.99), N,N'-dimethylation (21, 22), which negatively impacts on mu-opioid-associated agonism (Balboni et al., Bioorg. Med. Chem. 2003, 11, 5435-5441), markedly enhanced mu-opioid antagonism (pA2 = 8.34 and 7.71 for 21 and 22, respectively) without affecting delta-opioid activity. These data are the first evidence that a single dimeric opioid ligand containing the Dmt-Tic pharmacophore exhibits highly potent delta- and mu-opioid antagonist activities.
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MESH Headings
- Animals
- Binding, Competitive
- Brain/metabolism
- Diamines/chemical synthesis
- Diamines/chemistry
- Diamines/pharmacology
- Dipeptides/chemical synthesis
- Dipeptides/chemistry
- Dipeptides/pharmacology
- Guinea Pigs
- Ileum/drug effects
- Ileum/physiology
- In Vitro Techniques
- Ligands
- Male
- Mice
- Muscle, Smooth/drug effects
- Muscle, Smooth/physiology
- Peptides/chemical synthesis
- Peptides/chemistry
- Peptides/pharmacology
- Pyrazines/chemical synthesis
- Pyrazines/chemistry
- Pyrazines/pharmacology
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Structure-Activity Relationship
- Tetrahydroisoquinolines/chemical synthesis
- Tetrahydroisoquinolines/chemistry
- Tetrahydroisoquinolines/pharmacology
- Vas Deferens/drug effects
- Vas Deferens/physiology
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Affiliation(s)
- Tingyou Li
- The Graduate School of Food and Medicinal Sciences and Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
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Balboni G, Cocco MT, Salvadori S, Romagnoli R, Sasaki Y, Okada Y, Bryant SD, Jinsmaa Y, Lazarus LH. From the potent and selective mu opioid receptor agonist H-Dmt-d-Arg-Phe-Lys-NH(2) to the potent delta antagonist H-Dmt-Tic-Phe-Lys(Z)-OH. J Med Chem 2005; 48:5608-11. [PMID: 16107162 DOI: 10.1021/jm0504959] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
H-Dmt-d-Arg-Phe-Lys-NH(2) ([Dmt(1)]DALDA) binds with high affinity and selectivity to the mu opioid receptor and is a potent and long-acting analgesic. Substitution of d-Arg in position 2 with Tic and masking of the lysine amine side chain by Z protection and of the C-terminal carboxylic function instead of the amide function transform a potent and selective mu agonist into a potent and selective delta antagonist H-Dmt-Tic-Phe-Lys(Z)-OH. Such a delta antagonist could be used as a pharmacological tool.
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliari, I-09124, Cagliari, Italy.
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Li T, Shiotani K, Miyazaki A, Fujita Y, Tsuda Y, Ambo A, Sasaki Y, Jinsmaa Y, Marczak E, Bryant SD, Lazarus LH, Okada Y. New series of potent delta-opioid antagonists containing the H-Dmt-Tic-NH-hexyl-NH-R motif. Bioorg Med Chem Lett 2005; 15:5517-20. [PMID: 16183273 DOI: 10.1016/j.bmcl.2005.08.073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 08/20/2005] [Accepted: 08/26/2005] [Indexed: 11/20/2022]
Abstract
Heterodimeric compounds H-Dmt-Tic-NH-hexyl-NH-R (R=Dmt, Tic, and Phe) exhibited high affinity to delta- (K(i)delta=0.13-0.89nM) and mu-opioid receptors (K(i)mu=0.38-2.81nM) with extraordinary potent delta antagonism (pA(2)=10.2-10.4). These compounds represent the prototype for a new class of structural homologues lacking mu-opioid receptor-associated agonism (IC(50)=1.6-5.8muM) based on the framework of bis-[H-Dmt-NH]-alkyl (Okada, Y.; Tsuda, Y.; Fujita, Y.; Yokoi, T.; Sasaki, Y.; Ambo, A.; Konishi, R.; Nagata, M.; Salvadori, S.; Jinsmaa, Y.; Bryant, S. D.; Lazarus, L. H. J. Med. Chem.2003, 46, 3201), which exhibited both high mu affinity and bioactivity.
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Affiliation(s)
- Tingyou Li
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
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28
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Fujita Y, Tsuda Y, Motoyama T, Li T, Miyazaki A, Yokoi T, Sasaki Y, Ambo A, Niizuma H, Jinsmaa Y, Bryant SD, Lazarus LH, Okada Y. Studies on the structure–activity relationship of 2′,6′-dimethyl-l-tyrosine (Dmt) derivatives: bioactivity profile of H–Dmt–NH–CH3. Bioorg Med Chem Lett 2005; 15:599-602. [PMID: 15664820 DOI: 10.1016/j.bmcl.2004.11.040] [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] [Received: 10/11/2004] [Revised: 11/16/2004] [Accepted: 11/17/2004] [Indexed: 10/26/2022]
Abstract
The 2',6'-dimethyl-l-tyrosine (Dmt) enhances receptor affinity, functional bioactivity and in vivo analgesia of opioid peptides. To further investigate its direct influence on these opioid parameters, we developed a series of compounds (H-Dmt-NH-X). Among them, H-Dmt-NH-CH(3) showed the highest affinity (K(i)mu=7.45 nM) equal to that of morphine, partial mu-opioid agonism (E(max)=66.6%) in vitro and a moderate antinociception in mice.
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Affiliation(s)
- Yoshio Fujita
- The Graduate School of Food and Medicinal Sciences, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
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29
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Jinsmaa Y, Fujita Y, Shiotani K, Miyazaki A, Li T, Tsuda Y, Okada Y, Ambo A, Sasaki Y, Bryant SD, Lazarus LH. Differentiation of opioid receptor preference by [Dmt1]endomorphin-2-mediated antinociception in the mouse. Eur J Pharmacol 2005; 509:37-42. [PMID: 15713427 DOI: 10.1016/j.ejphar.2004.12.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 12/07/2004] [Accepted: 12/09/2004] [Indexed: 10/25/2022]
Abstract
The potent opioid [Dmt1]endomorphin-2 (Dmt-Pro-Phe-Phe-NH2) differentiated between the opioid receptor subtypes responsible for the antinociception elicited by endomorphin-2 in mice. Antinociception, induced by the intracerebroventricular administration of [Dmt1]endomorphin-2 and inhibited by various opioid receptor antagonists [naloxone, naltrindole, beta-funaltrexamine, naloxonazine], was determined by the tail-flick (spinal effect) and hot-plate (supraspinal effect) tests. The opioid receptor subtypes involved in [Dmt1]endomorphin-2-induced antinociception differed between these in vivo model paradigms: naloxone (non-specific opioid receptor antagonist) and beta-funaltrexamine (irreversible mu1/mu2-opioid receptor antagonist) blocked antinociception in both tests, although stronger inhibition occurred in the hot-plate than the tail-flick test suggesting involvement of other opioid receptors. Consequently, we applied naloxonazine (mu1-opioid receptor antagonist) that significantly blocked the effect in the hot-plate test and naltrindole (delta-opioid receptor antagonist), which was only effective in the tail-flick test. The data indicated that [Dmt1]endomorphin-2-induced spinal antinociception was primarily mediated by both mu2- and delta-opioid receptors, while a supraspinal mechanism involved only mu1/mu2-subtypes.
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MESH Headings
- Analgesia
- Animals
- Dose-Response Relationship, Drug
- Drug Evaluation, Preclinical/methods
- Hot Temperature/adverse effects
- Injections, Intraventricular
- Injections, Subcutaneous
- Male
- Mice
- Naloxone/administration & dosage
- Naloxone/analogs & derivatives
- Naloxone/antagonists & inhibitors
- Naloxone/pharmacokinetics
- Naltrexone/administration & dosage
- Naltrexone/analogs & derivatives
- Naltrexone/antagonists & inhibitors
- Naltrexone/pharmacokinetics
- Nociceptors/drug effects
- Oligopeptides/antagonists & inhibitors
- Oligopeptides/chemical synthesis
- Oligopeptides/pharmacology
- Pain
- Pain Measurement/drug effects
- Pain Measurement/methods
- Receptors, Opioid, delta/chemistry
- Receptors, Opioid, delta/drug effects
- Receptors, Opioid, delta/physiology
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/physiology
- Tail
- Time Factors
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Affiliation(s)
- Yunden Jinsmaa
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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Li T, Fujita Y, Tsuda Y, Miyazaki A, Ambo A, Sasaki Y, Jinsmaa Y, Bryant SD, Lazarus LH, Okada Y. Development of Potent μ-Opioid Receptor Ligands Using Unique Tyrosine Analogues of Endomorphin-2. J Med Chem 2005; 48:586-92. [PMID: 15658871 DOI: 10.1021/jm049384k] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Six analogues of tyrosine, which contained alkyl groups at positions 2', 3', and 6', either singly or in combination on the tyramine ring, were investigated for their effect on the opioid activity of [Xaa(1)]endomorphin-2 (EM-2). The opioid analogues displayed the following characteristics: (i) high mu-opioid receptor affinity [K(i)(mu) = 0.063-2.29 nM] with selectivity [K(i)(delta)/K(i)(mu)] ranging from 46 to 5347; (ii) potent functional mu-opioid agonism [GPI assay (IC(50) = 0.623-0.924 nM)] and with a correlation between delta-opioid receptor affinities and functional bioactivity using MVD; (iii) intracerebroventricular administration of [Dmt(1)]- (14) and [Det(1)]EM-2 (10) produced a dose-response antinociception in mice, with the former analogue more active than the latter; and (iv) a marked shift occurred from the trans-orientation at the Tyr(1)-Pro(2) bond to a cis-conformer compared to that observed previously with [Dmt(1)]EM-2 (14) (Okada et al. Bioorg. Med. Chem. 2003, 11, 1983-1984) except [Mmt(1)]EM-2 (7). The active profile of the [Xaa(1)]EM-2 analogues indicated that significant modifications on the tyramine ring are possible while high biological activity is maintained.
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MESH Headings
- Analgesics, Opioid/chemical synthesis
- Analgesics, Opioid/chemistry
- Analgesics, Opioid/pharmacology
- Animals
- Binding, Competitive
- Brain/metabolism
- Guinea Pigs
- Ileum/drug effects
- Ileum/innervation
- Ileum/physiology
- In Vitro Techniques
- Ligands
- Male
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/innervation
- Muscle, Smooth/physiology
- Oligopeptides/chemical synthesis
- Oligopeptides/chemistry
- Oligopeptides/pharmacology
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, mu/agonists
- Stereoisomerism
- Structure-Activity Relationship
- Tyrosine/analogs & derivatives
- Tyrosine/chemical synthesis
- Tyrosine/chemistry
- Tyrosine/pharmacology
- Vas Deferens/drug effects
- Vas Deferens/physiology
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Affiliation(s)
- Tingyou Li
- The Graduate School of Food and Medicinal Sciences, Faculty of Pharmaceutical Sciences, and High Technology Research Center, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
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Balboni G, Salvadori S, Guerrini R, Negri L, Giannini E, Bryant SD, Jinsmaa Y, Lazarus LH. Direct influence of C-terminally substituted amino acids in the Dmt-Tic pharmacophore on delta-opioid receptor selectivity and antagonism. J Med Chem 2004; 47:4066-71. [PMID: 15267245 DOI: 10.1021/jm040033f] [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] [Indexed: 11/29/2022]
Abstract
A series of 17 analogues were developed on the basis of the general formula H-Dmt-Tic-NH-CH(R)-R' (denotes chirality; R = charged, neutral, or aromatic functional group; R' = -OH or -NH(2)). These compounds were designed to test the following hypothesis: the physicochemical properties of third-residue substitutions C-terminal to Tic in the Dmt-Tic pharmacophore modify delta-opioid receptor selectivity and delta-opioid receptor antagonism through enhanced interactions with the mu-opioid receptor. The data substantiate the following conclusions: (i) all compounds had high receptor affinity [K(i)(delta) = 0.034-1.1 nM], while that for the mu-opioid receptor fluctuated by orders of magnitude [K(i)(mu) = 15.1-3966 nM]; (ii) delta-opioid receptor selectivity [K(i)(mu)/K(i)(delta)] declined 1000-fold from 22,600 to 21; (iii) a C-terminal carboxyl group enhanced selectivity but only as a consequence of the specific residue; (iv) amidated, positive charged residues [Lys-NH(2) (6), Arg-NH(2) (7)], and a negatively charged aromatic residue [Trp-OH (11)] enhanced mu-opioid affinity [K(i)(mu) = 17.0, 15.1, and 15.7 nM, respectively], while Gly-NH(2) (8), Ser-NH(2) (10), and His-OH (12) were nearly one-tenth as active; and (v) D-isomers exhibited mixed effects on mu-opioid receptor affinity (2' << 3' < 4' < 1' < 5') and decreased delta-selectivity in D-Asp-NH(2) (1') and D-Lys(Ac)-OH (5'). The analogues exhibited delta-opioid receptor antagonism (pA(2) = 6.9-10.07) and weak mu-opioid receptor agonism (IC(50) > 1 microM) except H-Dmt-Tic-Glu-NH(2) (3), which was a partial delta-opioid receptor agonist (IC(50) = 2.5 nM). Thus, these C-terminally extended analogues indicated that an amino acid residue containing a single charge, amino or guanidino functionality, or aromatic group substantially altered the delta-opioid receptor activity profile (selectivity and antagonism) of the Dmt-Tic pharmacophore, which suggests that the C-terminal constituent plays a major role in determining opioid receptor activity as an "address domain".
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MESH Headings
- Amino Acid Substitution
- Animals
- Binding, Competitive
- Brain/metabolism
- Brain/ultrastructure
- Dipeptides/chemical synthesis
- Dipeptides/chemistry
- Dipeptides/pharmacology
- Electric Stimulation
- Guinea Pigs
- In Vitro Techniques
- Male
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/physiology
- Radioligand Assay
- Rats
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/metabolism
- Stereoisomerism
- Structure-Activity Relationship
- Synaptosomes/metabolism
- Tetrahydroisoquinolines/chemical synthesis
- Tetrahydroisoquinolines/chemistry
- Tetrahydroisoquinolines/pharmacology
- Vas Deferens/drug effects
- Vas Deferens/physiology
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliary, I-09126 Cagliary, Italy
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Balboni G, Salvadori S, Guerrini R, Negri L, Giannini E, Bryant SD, Jinsmaa Y, Lazarus LH. Synthesis and opioid activity of N,N-dimethyl-Dmt-Tic-NH-CH(R)-R' analogues: acquisition of potent delta antagonism. Bioorg Med Chem 2004; 11:5435-41. [PMID: 14642588 DOI: 10.1016/j.bmc.2003.09.039] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
N,N-Dimethylation of the H-Dmt-Tic-NH-CH(R)-R' series of compounds produced no significant affect on the high delta-opioid receptor affinity (K(i)=0.035-0.454 nM), but dramatically decreased that for the micro-opioid receptor. The effect of N-methylation was independent of the length of the linker (R); however, the bioactivities were affected by the chemical composition of the third aromatic group (R'): phenyl (Ph) (5'-8') elicited a greater reduction in micro-affinity (40-70-fold) compared to analogues containing 1H-benzimidazole-2-yl (Bid) (9-fold). The major consequences of N,N-dimethylation on in vitro bioactivity were: (i). a loss of delta-agonism coupled with the appearance of potent delta antagonism (4'-7') (pA(2)=8.14-9.47), while 1 exhibited only a 160-fold decreased delta agonism (1') and the delta antagonism of 8 enhanced >10-fold (pA(2)=10.62, 8'); and (ii). a consistent loss of micro-affinity resulted in enhanced delta-opioid receptor selectivity. With the exception of compound 1', the change in the hydrophobic environment at the N-terminus and formation of a tertiary amine by N,N-dimethylation in analogues of the Dmt-Tic pharmacophore produced potent delta-selective antagonists.
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliary, I-09126, Cagliary, Italy
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Gibson SE, Jones JO, Kalindjian S, Knight JD, Mainolfi N, Rudd M, Steed JW, Tozer MJ, Wright PT. Synthesis of meta- and paracyclophanes containing unsaturated amino acid residues. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.05.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
A model for the human delta opioid receptor has been generated via sequence alignment, structure building using the crystal structure of bovine rhodopsin as a template, and refinement by molecular dynamics simulation. The model building suggested that, in addition to the previously postulated interaction between D128 and Y308, an internal salt bridge also exists between residues D128 and R192, both of which are conserved in all the opioid receptors. The model and salt bridge were then shown to be stable during a 20-nsec simulation in a lipid bilayer. It is therefore proposed that both of these interactions play a role in stabilizing the inactive state of the receptor. The model is also used in an effort to rationalize many of the mutational studies performed on delta opioid receptors, and to suggest a plausible explanation for the differences between known delta opioid agonists and antagonists.
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Affiliation(s)
- Mahalaxmi Aburi
- Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506-3701, USA
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Bryant SD, Jinsmaa Y, Salvadori S, Okada Y, Lazarus LH. Dmt and opioid peptides: a potent alliance. Biopolymers 2004; 71:86-102. [PMID: 12767112 DOI: 10.1002/bip.10399] [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: 11/09/2022]
Abstract
The introduction of the Dmt (2',6'-dimethyl-L-tyrosine)-Tic pharmacophore into the design of opioid ligands produced an extraordinary family of potent delta-opioid receptor antagonists and heralded a new phase in opioid research. First reviewed extensively in 1998, the incorporation of Dmt into a diverse group of opioid molecules stimulated the opioid field leading to the development of unique analogues with remarkable properties. This overview will document the crucial role played by this residue in the proliferation of opioid peptides with high receptor affinity (K(i) equal to or less than 1 nM) and potent bioactivity. The discussion will include the metamorphosis between delta-opioid receptor antagonists to delta-agonists based solely on subtle structural changes at the C-terminal region of the Dmt-Tic pharmacophore as well as their behavior in vivo. Dmt may be considered promiscuous due to the acquisition of potent mu-agonism by dermorphin and endomorphin derivatives as well as by a unique class of opioidmimetics containing two Dmt residues separated by alkyl or pyrazinone linkers. Structural studies on the Dmt-Tic compounds were enhanced tremendously by x-ray diffraction data for three potent and biologically diverse Dmt-Tic opioidmimetics that led to the development of pharmacophores for both delta-opioid receptor agonists and antagonists. Molecular modeling studies of other unique Dmt opioid analogues illuminated structural differences between delta- and mu-receptor ligand interactions. The future of these compounds as therapeutic applications for various medical syndromes including the control of cancer-associated pain is only a matter of time and perseverance.
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Affiliation(s)
- Sharon D Bryant
- Peptide Neurochemistry, LCBRA, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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36
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Middleton RJ, Mellor SL, Chhabra SR, Bycroft BW, Chan WC. Expedient synthesis of a novel class of pseudoaromatic amino acids: tetrahydroindazol-3-yl- and tetrahydrobenzisoxazol-3-ylalanine derivatives. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2003.11.133] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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37
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Erchegyi J, Penke B, Simon L, Michaelson S, Wenger S, Waser B, Cescato R, Schaer JC, Reubi JC, Rivier J. Novel sst(4)-selective somatostatin (SRIF) agonists. 2. Analogues with beta-methyl-3-(2-naphthyl)alanine substitutions at position 8. J Med Chem 2004; 46:5587-96. [PMID: 14667213 DOI: 10.1021/jm0302445] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We present a family of human sst(4)-selective, high-affinity (IC(50) = 2-4 nM) cyclic somatostatin (SRIF) octapeptides. These peptides result from the substitution of dTrp(8) in H-c[Cys(3)-Phe(6)-Phe(7)-DTrp(8)-Lys(9)-Thr(10)-Phe(11)-Cys(14)]-OH (SRIF numbering) (ODT-8) by one of the four conformationally biased stereoisomers of beta-methyl-3-(2-naphthyl)alanine (beta-Me2Nal). Whereas H-c[Cys-Phe-Phe-DNal-Lys-Thr-Phe-Cys]-OH (ODN-8, 2) has high affinity and marginal selectivity for human sst(3) (Reubi et al., Proc. Natl. Acad. Sci. U.S.A. 2000, 97, 13973-13978), H-c[Cys-Phe-Tyr-D-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH (5) has high affinity for all sst's except for sst(1); H-c[Cys-Phe-Tyr-L-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH (6) has high affinity for sst(4) (IC(50) = 2.1 nM), with more than 50-fold selectivity toward the other receptors. Analogues 7 and 8, containing d- and l-erythro-beta-Me2Nal instead of the corresponding threo derivatives at position 8, are essentially inactive at all receptors. Substitution of Tyr(7) in 5 and 6 by Aph(7) resulted in 9 and 10 with similar affinity patterns overall yet lowered affinity. The substitution of DCys(3) for Cys(3) in 5 and 6 yielded H-c[DCys-Phe-Tyr-D-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH (11) and H-c[DCys-Phe-Tyr-L-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH (12), with biological profiles almost identical to those of their parents 5 and 6 (i.e., high affinity for sst(2-5) for 11 and high affinity and selectivity for sst(4) for 12). Analogue 12, with high sst(4) affinity combined with the highest sst(4) selectivity among all tested compounds, is an agonist in the cAMP accumulation assay (EC(50) = 1.29 nM). Cold monoiodination of 12 yielded 14, with loss of sst(4) selectivity and loss of high affinity (IC(50) = 21 nM). Introduction of Tyr(2) in 9 and 10 and substitution of Cys(3) by dCys(3), to yield 15 and 16 (IC(50) = 9.8 and 61 nM, respectively, for sst(4) and limited selectivity), failed to generate a high-affinity (125)iodinatable sst(4)-selective ligand. Substitution of Phe by Tyr at position 11 in H-c[DCys-Phe-Phe-L-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH yielded 18 (IC(50) = 11.8 nM at sst(4)), with limited sst(4) selectivity (30-fold or greater at the other receptors) yet only slightly improved affinity over that of 14. Cold monoiodination of 18 yielded 20 (IC(50) = 30 nM at sst(4) and high selectivity). Whereas we were able, in this study, to identify a new family of sst(4)-selective, high-affinity compounds, our additional goal, to identify highly potent and sst(4)-selective ligands amenable to (125)iodination, could not be achieved satisfactorily. On the other hand, some of the diastereomers identified in this study, such as 5, 11, 17, and 19, are very potent ligands at all receptors but sst(1).
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Affiliation(s)
- Judit Erchegyi
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
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Jinsmaa Y, Okada Y, Tsuda Y, Shiotani K, Sasaki Y, Ambo A, Bryant SD, Lazarus LH. Novel 2′,6′-Dimethyl-l-Tyrosine-Containing Pyrazinone Opioid Mimetic μ-Agonists with Potent Antinociceptive Activity in Mice. J Pharmacol Exp Ther 2004; 309:432-8. [PMID: 14718580 DOI: 10.1124/jpet.103.060061] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Novel bioactive opioid mimetic agonists containing 2',6'-dimethyl-l-tyrosine (Dmt) and a pyrazinone ring interact with mu- and delta-opioid receptors. Compound 1 [3-(4' -Dmt-aminobutyl)-6-(3'-Dmt-aminopropyl)-5-methyl-2(1H)pyrazinone] exhibited high mu-opioid receptor affinity and selectivity (K(i)mu = 0.021 nM and K(i)delta/K(i)mu = 1,519, respectively), and agonist activity on guinea pig ileum (IC(50) = 1.7 nM) with weaker delta-bioactivity on mouse vas deferens (IC(50) = 25.8 nM). Other compounds (2-4) had mu-opioid receptor affinities and selectivities 2- to 5-fold and 4- to 7-fold less than 1, respectively. Intracerebroventricular administration of 1 in mice exhibited potent naloxone reversible antinociception (65 to 71 times greater than morphine) in both tail-flick (TF) and hot-plate (HP) tests. Distinct opioid antagonists had differential effects on antinociception: naltrindole (delta-antagonist) partially blocked antinociception in the TF, but it was ineffective in the HP test, whereas beta-funaltrexamine (irreversible antagonist, mu(1)/mu(2)-subtypes) but not naloxonazine (mu(1)-subtype) inhibited TF test antinociception, yet both blocked antinociception in the HP test. Our data indicated that 1 acted through mu- and delta-opioid receptors to produce spinal antinociception, although primarily through the mu(2)-receptor subtype; however, the mu(1)-receptor subtype dominates supraspinally. Subcutaneous and oral administration indicated that 1 crossed gastrointestinal and blood-brain barriers to produce central nervous system-mediated antinociception. Furthermore, daily s.c. dosing of mice with 1 for 1 week developed tolerance in a similar manner to that of morphine in TF and HP tests, implicating that 1 also acts through a similar mechanism analogous to morphine at mu-opioid receptors.
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Affiliation(s)
- Yunden Jinsmaa
- Medicinal Chemistry Group, Laboratory of Computational Biology and Risk Analysis, National Institute of Environmental Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709, USA.
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Sasaki Y, Sasaki A, Ariizumi T, Igari Y, Sato K, Kohara H, Niizuma H, Ambo A. 2',6'-Dimethylphenylalanine (Dmp) Can Mimic the N-Terminal Tyr in Opioid Peptides. Biol Pharm Bull 2004; 27:244-7. [PMID: 14758045 DOI: 10.1248/bpb.27.244] [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: 11/22/2022]
Abstract
Substitution of 2',6'-dimethyltyrosine (Dmt) for the N-terminal Tyr in opioid peptides has recently been shown to be a promising tool for improving opioid receptor affinity and biological activity. We have also demonstrated that another unnatural amino acid, 2',6'-dimethylphenylalanine (Dmp), is not only an excellent substitute for Phe at position 3 but also can mimic the aromatic N-terminal Tyr residue in a micro opioid receptor-selective dermorphin analogue (YRFB: Tyr-D-Arg-Phe-betaAla-NH(2)). To further evaluate the value of Dmp in opioid peptides, we investigated Dmp(1)-substituted analogues of the delta receptor ligands, deltorphin II (DLT: Tyr-D-Ala-Phe-Glu-Val-Val-Gly-NH(2)) and enkephalin (ENK: Tyr-Gly-Gly-Phe-Leu). In the receptor binding assay, both [Dmp(1)]DLT and [Dmp(1)]ENK bound to the delta-receptor with high affinity and selectivity, and were nearly as effective as the parent peptides. The potency of the Dmp(1)-peptides on the MVD and GPI assays correlated well with the receptor binding affinity data. These results are in contrast to the tendency of corresponding Dmt(1)-analogues to have poor receptor selectivity. Taken together with the results with YRFB, we conclude that the Dmp(1)-peptide is superior to the corresponding Dmt(1)-peptide in its receptor selectivity. [Dmp(1)]DLT and [Dmp(1)]YRFB may serve as pharmacological tools for the studies of ligand recognition and opioid receptor signal transduction.
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Affiliation(s)
- Yusuke Sasaki
- Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
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40
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Ingman K, Salvadori S, Lazarus L, Korpi ER, Honkanen A. Selective delta-opioid receptor antagonist N,N(CH3)2-Dmt-Tic-OH does not reduce ethanol intake in alcohol-preferring AA rats. Addict Biol 2003; 8:173-9. [PMID: 12850776 DOI: 10.1080/1355621031000117400] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We studied the effect of a novel delta-opioid receptor antagonist N,N(CH(3))(2)Dmt-Tic-OH (Me(2)-Dmt-Tic-OH) on voluntary ethanol intake in an alcohol-preferring AA (Alko, Alcohol) rat line using a 4-hour limited access paradigm. Acute injections of Me(2)-Dmt-Tic-OH (10 and 30 mg/kg, i.p.) did not reduce 1-hour or 4-hour ethanol intake. Subtype non-selective opioid receptor antagonist naltrexone [0.1 and 0.3 mg/kg, subcutaneously (s.c.)] significantly reduced 1-hour ethanol drinking but had no effect on 4-hour ethanol consumption. Locomotor stimulation induced by the delta-opioid receptor agonist Tyr-D-Pen-Gly-Phe-D-Pen (DPDPE; 15 microg, intracerebroventricularly) was significantly attenuated by Me(2)-Dmt-Tic-OH (10 and 30 mg/kg, i.p.), which confirmed its efficacy as a delta-opioid receptor antagonist in rat brain. Our results support the idea that delta-opioid receptors do not mediate alcohol reward in AA rats.
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Affiliation(s)
- Kimmo Ingman
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Finland.
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41
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Pagé D, Nguyen N, Bernard S, Coupal M, Gosselin M, Lepage J, Adam L, Brown W. New scaffolds in the development of mu opioid-receptor ligands. Bioorg Med Chem Lett 2003; 13:1585-9. [PMID: 12699761 DOI: 10.1016/s0960-894x(03)00194-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A new class of mu selective receptor antagonists has been developed using a combinatorial approach based on previously reported Dmt-Tic dipeptide ligands. Modified tetrahydroisoquinoline (Tiq) residues were reacted with different electrophiles in order to create novel molecules that would mimic the original dipeptide. A specific class of thioureas bearing basic pyrrolidine residues were shown to give good binding affinities. Further alkylation of the pyrrolidine ring with benzyl derivatives also proved to increase the mu binding affinity. In addition, it was demonstrated that mu binding was enhanced by the presence of polar groups around the benzyl ring having hydrogen-bonding character (donor/acceptor). This new class of ligands represents a novel scaffold in the development of opioid analogues.
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Affiliation(s)
- Daniel Pagé
- Department of Chemistry, AstraZeneca R&D Montreal, 7171 Frederick-Banting, Saint-Laurent, Quebec, Canada H4S 1Z9.
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42
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Ambo A, Niizuma H, Sasaki A, Kohara H, Sasaki Y. Dermorphin tetrapeptide analogues with 2',6'-dimethylphenylalanine (Dmp) substituted for aromatic amino acids have high mu opioid receptor binding and biological activities. Bioorg Med Chem Lett 2003; 13:1269-72. [PMID: 12657261 DOI: 10.1016/s0960-894x(03)00110-0] [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: 10/27/2022]
Abstract
To investigate the value of the 2',6'-dimethylphenylalanine (Dmp) residue as an aromatic amino acid substitution, we prepared analogues of the mu opioid receptor-selective dermorphin tetrapeptide Tyr-D-Arg-Phe-betaAla-NH(2) (YRFB) in which Dmp or its D-isomer replaced Tyr(1) or Phe(3). Replacing Phe(3) with Dmp essentially tripled mu receptor affinity and the receptor's in vitro biological activities as determined with the guinea pig ileum (GPI) assay but did not change delta receptor affinity. Despite an inversion of the D configuration at this position, mu receptor affinity and selectivity remained comparable with those of the L-isomer. Replacing the N-terminal Tyr residue with Dmp produced a slightly improved mu receptor affinity and a potent GPI activity, even though the substituted compound lacks the side chain phenolic hydroxyl group at the N-terminal residue. Dual substitution of Dmp for Tyr(1) and Phe(3) produced significantly improved mu receptor affinity and selectivity compared with the singly substituted analogues. Subcutaneous injection of the two analogues, [Dmp(3)]YRFB and [Dmp(1)]YRFB, in mice produced potent analgesic activities that were greater than morphine in the formalin test. These lines of evidence suggest that the Dmp residue would be an effective aromatic amino acid surrogate for both Tyr and Phe in the design and development of novel opioid mimetics.
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MESH Headings
- Amino Acids, Aromatic/chemistry
- Analgesics, Opioid/chemical synthesis
- Analgesics, Opioid/metabolism
- Analgesics, Opioid/pharmacology
- Animals
- Dose-Response Relationship, Drug
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/metabolism
- Guinea Pigs
- Ileum/drug effects
- In Vitro Techniques
- Indicators and Reagents
- Kinetics
- Male
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Oligopeptides/chemical synthesis
- Oligopeptides/metabolism
- Oligopeptides/pharmacology
- Opioid Peptides
- Pain Measurement/drug effects
- Phenylalanine/analogs & derivatives
- Phenylalanine/chemistry
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/metabolism
- Vas Deferens/drug effects
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43
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Abstract
Advances in x-ray crystallographic data collection, structure solution, and refinement/validation have reduced the time required and expanded the range of samples amenable to x-ray crystallographic studies. Consequently, we can now collect complete atomic resolution data sets on physically smaller crystals and solve larger problems by direct methods beyond what could have been accomplished even five years ago. Applying these improved methods to the study of opioid ligands has enhanced our knowledge of the opioid pharmacophore. Despite considerable progress, it is still difficult to define the pharmacophoric parameters required for highly selective and potent opioid peptides. In part this is due to the conformational flexibility remaining even in conformationally constrained peptides.
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Affiliation(s)
- Jeffrey R Deschamps
- Laboratory for the Structure of Matter, Naval Research Laboratory Washington, DC 20375, USA.
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44
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Sasaki Y, Sasaki A, Niizuma H, Goto H, Ambo A. Endomorphin 2 analogues containing Dmp residue as an aromatic amino acid surrogate with high mu-opioid receptor affinity and selectivity. Bioorg Med Chem 2003; 11:675-8. [PMID: 12537996 DOI: 10.1016/s0968-0896(02)00601-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To investigate the effectiveness of a 2',6'-dimethylphenylalanine (Dmp) residue as an aromatic amino acid surrogate, endomorphin 2 (EM(2): Tyr-Pro-Phe-Phe-NH(2)) analogues were prepared, in which the constitutive aromatic amino acids (Tyr(1), Phe(3), or Phe(4)) were replaced by Dmp or its isomer, D-Dmp. Replacement of Phe(3) by Dmp increased the affinity over 10-fold for both mu- and delta-opioid receptors, without affecting receptor selectivity. In contrast, replacement of Phe(4) considerably reduced the mu-receptor affinity and selectivity. These data indicated that the Dmp-substitution of Phe(3), but not Phe(4), in EM(2) is favorable for improving mu-receptor specificity. Inversion of the chirality of the substituted Dmp residue resulted in marked decrease in the mu-receptor affinity. Replacement of Tyr(1) by Dmp yielded an analogue that exhibited only a limited decrease in mu-receptor affinity and GPI potency, despite the lack of a phenolic hydroxyl group at the N-terminal residue. In contrast, D-Dmp(1)- or Phe(1)-substitution of Tyr(1) resulted in a significant decrease in mu-receptor affinity and GPI potency. These results suggested that the Dmp residue can mimic Tyr(1), which is one of the critical structural elements of opioid peptides.
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Affiliation(s)
- Yusuke Sasaki
- Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome, Aoba-ku, Sendai 981-8558, Japan.
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45
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Hosohata K, Varga EV, Alfaro-Lopez J, Tang X, Vanderah TW, Porreca F, Hruby VJ, Roeske WR, Yamamura HI. (2S,3R) beta-methyl-2',6'-dimethyltyrosine-L-tetrahydroisoquinoline-3-carboxylic acid [(2S,3R)TMT-L-Tic-OH] is a potent, selective delta-opioid receptor antagonist in mouse brain. J Pharmacol Exp Ther 2003; 304:683-8. [PMID: 12538822 DOI: 10.1124/jpet.102.042929] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The constrained opioid peptide (2S,3R)beta-methyl-2',6'-dimethyltyrosine-L-tetrahydroisoquinoline-3-carboxylic acid [(2S,3R)TMT-L-Tic-OH] exhibits high affinity and selectivity for the delta-opioid receptors (). In the present study, we examined the pharmacological properties of (2S,3R)TMT-L-Tic-OH in mouse brain. A 5'-O-(3-[(35)S]thiotriphosphate) ([(35)S]GTP gamma S) binding assay was used to determine the effect of (2S,3R)TMT-L-Tic-OH on G protein activity in vitro, in mouse brain membranes. delta- (SNC80; (+)-4-[(alpha R)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxy-benzyl]-N,N-diethyl-benzamide) or mu- (DAMGO; [D-Ala(2), Me-Phe(4),Gly(ol)(5)]enkephalin) selective opioid full agonists stimulated [(35)S]GTP gamma S binding in mouse brain membranes 150 +/- 4.5% and 152 +/- 5.7% over the basal level, respectively. (2S,3R)TMT-L-Tic-OH did not influence basal [(35)S]GTP gamma S binding in mouse brain membranes but dose dependently shifted the dose-response curve of SNC80 to the right, with a K(e) value of 3.6 +/- 0.7 nM. In contrast, (2S,3R)TMT-L-Tic-OH had no effect on the dose-response curve of the mu-selective opioid agonist, DAMGO. Warm water (55 degrees C) tail-flick and radiant heat paw-withdrawal tests were used to determine the in vivo nociceptive properties of (2S,3R)TMT-L-Tic-OH in the mouse. Intracerebroventricular injection of (2S,3R)TMT-L-Tic-OH had no significant effect on withdrawal latencies in either nociceptive tests. (2S,3R)TMT-L-Tic-OH (30 nmol/mouse) attenuated deltorphin II- but not DAMGO-mediated antinociception (40 +/- 13 and 100% of maximal possible effect, respectively) when administered intracerebroventricularly 10 min before the agonist. Taken together these results suggest that (2S,3R)TMT-L-Tic-OH is a potent highly selective neutral delta-opioid antagonist in mouse brain.
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MESH Headings
- Analgesics, Opioid/metabolism
- Analgesics, Opioid/pharmacology
- Animals
- Brain/drug effects
- Brain/metabolism
- Dose-Response Relationship, Drug
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/metabolism
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology
- Isoquinolines/metabolism
- Isoquinolines/pharmacology
- Male
- Mice
- Mice, Inbred ICR
- Narcotic Antagonists/metabolism
- Narcotic Antagonists/pharmacology
- Pain Measurement/drug effects
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Tetrahydroisoquinolines
- Tyrosine/analogs & derivatives
- Tyrosine/metabolism
- Tyrosine/pharmacology
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Affiliation(s)
- Keiko Hosohata
- Department of Pharmacology, University of Arizona, Tucson, Arizona 85724, USA
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46
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Balboni G, Salvadori S, Guerrini R, Negri L, Giannini E, Jinsmaa Y, Bryant SD, Lazarus LH. Potent delta-opioid receptor agonists containing the Dmt-Tic pharmacophore. J Med Chem 2002; 45:5556-63. [PMID: 12459023 DOI: 10.1021/jm020336e] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Conversion of delta-opioid receptor antagonists containing the 2',6'-dimethyl-L-tyrosine (Dmt)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) pharmacophore into potent delta-agonists required a third heteroaromatic nucleus, such as 1H-benzimidazole-2-yl (Bid) and a linker of specified length both located C-terminally to Tic in the general formula H-Dmt-Tic-NH-CH(R)-R'. The distance between Tic and Bid is a determining factor responsible for the acquisition of delta agonism (2, 2', 3, 4, 6) or delta antagonism (8). Compounds containing a C-terminal Ala (1, 1'), Asp (5), or Asn (7) with an amide (1, 1', 5) or free acid group (7) served as delta-antagonist controls lacking the third heteroaromatic ring. A change in chirality of the spacer (2, 2') or inclusion of a negative charge via derivatives of Asp (4, 6) resulted in potent delta agonism and moderate mu agonism, although delta-receptor affinity decreased about 10-fold for 4 while mu affinity fell by over 2 orders of magnitude. Repositioning of the negative charge in the linker altered activity: H-Dmt-Tic-NH-CH(CH(2)-Bid)COOH (6) maintained high delta affinity (K(i) = 0.042 nM) and delta agonism (IC(50) = 0.015 nM), but attachment of the free acid group to Bid [H-Dmt-Tic-NH-CH(2)-Bid(CH(2)-COOH) (9)] reconstituted delta antagonism (K(e) = 0.27 nM). The data demonstrate that a linker separating the Dmt-Tic pharmacophore and Bid, regardless of the presence of a negative charge, is important in the acquisition of opioids exhibiting potent delta agonism and weak mu agonism from a parent delta antagonist.
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MESH Headings
- Animals
- Benzimidazoles/chemical synthesis
- Benzimidazoles/chemistry
- Benzimidazoles/pharmacology
- Binding, Competitive
- Brain/metabolism
- Dipeptides/chemical synthesis
- Dipeptides/chemistry
- Dipeptides/pharmacology
- Electric Stimulation
- Guinea Pigs
- In Vitro Techniques
- Intestine, Small/innervation
- Models, Molecular
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/innervation
- Myenteric Plexus/drug effects
- Neuromuscular Junction/drug effects
- Neuromuscular Junction/physiology
- Radioligand Assay
- Rats
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/metabolism
- Structure-Activity Relationship
- Tetrahydroisoquinolines
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliari, I-09126 Cagliari, Italy
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47
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Bryant SD, George C, Flippen-Anderson JL, Deschamps JR, Salvadori S, Balboni G, Guerrini R, Lazarus LH. Crystal structures of dipeptides containing the Dmt-Tic pharmacophore. J Med Chem 2002; 45:5506-13. [PMID: 12459018 DOI: 10.1021/jm020330p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The crystal structures of three analogues of the potent delta-opioid receptor antagonist H-Dmt-Tic-OH (2',6'-dimethyl-L-tyrosine-L-1,2,3,4-tetrahydroisoquinoline-3-carboxylate), N,N (CH(3))(2)-Dmt-Tic-OH (1), H-Dmt-Tic-NH-1-adamantane (2), and N,N(CH(3))(2)-Dmt-Tic-NH-1-adamantane (3) were determined by X-ray single-crystal analysis. Crystals of 1 were grown by slow evaporation, while those of 2 and 3 were grown by vapor diffusion. Compounds 1 and 3 crystallized in the monoclinic space group P2(1), and 2 crystallized in the tetragonal space group P4(3). Common backbone atom superimpositions of structures derived from X-ray diffraction studies resulted in root-mean-square (rms) deviations of 0.2-0.5 A, while all-atom superimpositions gave higher rms deviations from 0.8 to 1.2 A. Intramolecular distances between the aromatic ring centers of Dmt and Tic were 5.1 A in 1, 6.3 A in 2, and 6.5 A in 3. The orientation of the C-terminal substituent 1-adamantane in 2 and 3 was affected by differences in the psi torsion angles and strong hydrogen bonds with adjacent molecules. Despite the high delta-opioid receptor affinity exhibited by each analogue (K(i) < 0.3 nM), high mu receptor affinity (K(i) < 1 nM) was manifested only with the bulky C-terminal 1-adamantane analogues 2 and 3. Furthermore, the bioactivity of both 2 and 3 exhibited mu-agonism, while 3 also had potent delta-antagonist activity. Those data demonstrated that a C-terminal hydrophobic group was an important determinant for eliciting mu-agonism, whereas N-methylation maintained delta-antagonism. Furthermore, the structural results support the hypothesis that expanded dimensions between aromatic nuclei is important for acquiring mu-agonism.
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Affiliation(s)
- Sharon D Bryant
- Peptide Neurochemistry, LCBRA, National Institute of Environmental Health Sciences, P.O. Box 12233, Mail Drop C3-04, Research Triangle Park, North Carolina 27709, USA.
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48
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Gibson SE, Guillo N, Jones JO, Buck IM, Kalindjian SB, Roberts S, Tozer MJ. CCK(2) receptor antagonists containing the conformationally constrained phenylalanine derivatives, including the new amino acid Xic. Eur J Med Chem 2002; 37:379-89. [PMID: 12008052 DOI: 10.1016/s0223-5234(02)01351-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The conformationally constrained analogues of phenylalanine, tetrahydroisoquinoline-3-carboxylic acid (Tic), Sic, Hic and Nic, and the new amino acid Xic have been incorporated into a potent and highly selective cholecystokinin-2 (CCK(2)) receptor antagonist (2) in place of the phenylalanine residue, producing compounds 15a-e. High selectivities for CCK(2) over CCK(1) were observed for compounds 15a-e. The in vitro profile of the analogue containing the Nic residue (15d) was identical to that of compound 2, whereas the alternative conformational constraints resulted in a significant loss of affinity. The apparent advantage of Nic in the context of these CCK(2) ligands was subsequently demonstrated to be statistically significant.
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Affiliation(s)
- Susan E Gibson
- Department of Chemistry, King's College London, Strand, UK
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49
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Ambo A, Murase H, Niizuma H, Ouchi H, Yamamoto Y, Sasaki Y. Dermorphin and deltorphin heptapeptide analogues: replacement of Phe residue by Dmp greatly improves opioid receptor affinity and selectivity. Bioorg Med Chem Lett 2002; 12:879-81. [PMID: 11958984 DOI: 10.1016/s0960-894x(02)00035-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The usefulness of 2,6-dimethylphenylalanine (Dmp) as a Phe surrogate in two opioid peptides, dermorphin (DM) and deltorphin II (DT), was investigated. Compared to DM, [L-Dmp(3)]DM (1) showed a 170-fold increase in mu affinity and only a 4-fold increase in delta affinity, resulting in a 40-fold improvement in mu receptor selectivity. Compared to DT, [L-Dmp(3)]DT (3) showed a 22-fold increase in delta affinity and somewhat of a loss in mu affinity, and consequently a marked (75-fold) improvement in delta receptor selectivity. The D-Dmp replacement, however, resulted in a great loss in receptor selectivity in each of the peptides. The specific receptor interactions of 1 and 3 were confirmed by in vitro bioassays. Analogues 1 and 3 seem to be useful as pharmacological tools for the study of opioid systems.
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Affiliation(s)
- Akihiro Ambo
- Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome, Aoba-ku, 981-8558, Sendai, Japan
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50
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Balboni G, Guerrini R, Salvadori S, Bianchi C, Rizzi D, Bryant SD, Lazarus LH. Evaluation of the Dmt-Tic pharmacophore: conversion of a potent delta-opioid receptor antagonist into a potent delta agonist and ligands with mixed properties. J Med Chem 2002; 45:713-20. [PMID: 11806723 DOI: 10.1021/jm010449i] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Analogues of the 2',6'-dimethyl-L-tyrosine (Dmt)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) pharmacophore were prepared to test the hypothesis that a "spacer" and a third aromatic center in opioid peptides are required to convert a delta-antagonist into ligands with delta-agonist or with mixed delta-antagonist/mu-agonist properties. Potent delta-agonists and bifunctional compounds with high delta- and mu-opioid receptor affinities were obtained by varying the spacer length [none, NH-CH(2), NH-CH(2)-CH(2), Gly-NH-CH(2)] and C-terminal aromatic nucleus [1H-benzimidazole-2-yl, phenyl (Ph) and benzyl groups]. C-terminal modification primarily affected mu-opioid receptor affinities, which increased maximally 1700-fold relative to the prototype delta-antagonist H-Dmt-Tic-NH(2) and differentially modified bioactivity. In the absence of a spacer (1), the analogue exhibited dual delta-agonism (pEC(50), 7.28) and delta-antagonism (pA(2), 7.90). H-Dmt-Tic-NH-CH(2)-1H-benzimidazole-2-yl (Bid) (2) became a highly potent delta-agonist (pEC(50), 9.90), slightly greater than deltorphin C (pEC(50), 9.56), with mu-agonism (pE(50), 7.57), while H-Dmt-Tic-Gly-NH-CH(2)-Bid (4) retained potent delta-antagonism (pA(2), 9.0) but with an order of magnitude less mu-agonism. Similarly, H-Dmt-Tic-Gly-NH-Ph (5) had nearly equivalent high delta-agonism (pEC(50), 8.52) and mu-agonism (pEC(50), 8.59), while H-Dmt-Tic-Gly-NH-CH(2)-Ph (6) whose spacer was longer by a single methylene group exhibited potent delta-antagonism (pA(2), 9.25) and very high mu-agonism (pEC(50), 8.57). These data confirm that the distance between the Dmt-Tic pharmacophore and a third aromatic nucleus is an important criterion in converting Dmt-Tic from a highly potent delta-antagonist into a potent delta-agonist or into ligands with mixed delta- and mu-opioid properties.
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliary, I09126 Cagliary, Italy
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