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Rathore M, Das N, Ghosh N, Guha R. Insights on discovery, efficacy, safety and clinical applications of ghrelin receptor agonist capromorelin in veterinary medicine. Vet Res Commun 2024; 48:1-10. [PMID: 37493940 DOI: 10.1007/s11259-023-10184-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/20/2023] [Indexed: 07/27/2023]
Abstract
Growth hormone and insulin like growth factor-1 plays an important role in the regulation of body composition and metabolism. Growth Hormone is released from the pituitary through a specific G-protein coupled receptor (GPCR) called growth hormone secretagogue receptor 1a expressed in the hypothalamus. Ghrelin is a peptide hormone released from the cells in the stomach, which stimulates appetite and food intake in mammals, regulates gut motility, gastric acid secretion, taste sensation, circadian rhythm, learning and memory, oxidative stress, autophagy, glucose metabolism etc. When the release of the endogenous ligand GHSR-1a, i.e., ghrelin is malfunctioned or stopped, external substitutes are administrated to induce the stimulation of growth hormone and appetite. A class of compound known as ghrelin receptor agonists are developed as an external substitute of ghrelin for regulation and stimulation of growth hormone in frailty, for body weight gain, muscle mass gain, prevention of cachexia and for the treatment of chronic fatigue syndromes. Capromorelin [Entyce™ (Aratana Therapeutics, Leawood, KS, USA)] is the only FDA (Food and Drug Administration) approved (May 2016) drug used for stimulating appetite in dogs and was marketed in the fall of 2017. In 2020, USFDA approved Capromorelin [Elura™ (Elanco US Inc.)] for the management of weight loss in chronic kidney disease of cats. This article reviews the discovery of the ghrelin receptor agonist capromorelin, its efficacy, safety, clinical applications and aims to delineate its further scope of use in veterinary practice.
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Affiliation(s)
- Manisha Rathore
- Laboratory Animal Facility, CSIR-Central Drug Research Institute, Lucknow, India
| | - Nabanita Das
- National Institute of Pharmaceutical Education and Research, Raebareli, India
| | - Nayan Ghosh
- Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow, India
| | - Rajdeep Guha
- Laboratory Animal Facility, CSIR-Central Drug Research Institute, Lucknow, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
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Nargund R, Wyvratt M, Lin S, Sebhat I, Greenlee W. Annotated Bibliography of Dr. Arthur A. Patchett. J Med Chem 2023; 66:15567-15575. [PMID: 38032081 DOI: 10.1021/acs.jmedchem.3c02131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
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3
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Worm DJ, Els‐Heindl S, Beck‐Sickinger AG. Targeting of peptide‐binding receptors on cancer cells with peptide‐drug conjugates. Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24171] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Dennis J. Worm
- Faculty of Life Sciences, Institute of BiochemistryLeipzig University Leipzig Germany
| | - Sylvia Els‐Heindl
- Faculty of Life Sciences, Institute of BiochemistryLeipzig University Leipzig Germany
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Blough B, Namjoshi O. Small Molecule Neuropeptide S and Melanocortin 4 Receptor Ligands as Potential Treatments for Substance Use Disorders. Handb Exp Pharmacol 2019; 258:61-87. [PMID: 31628605 DOI: 10.1007/164_2019_313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There is a vital need for novel approaches and biological targets for drug discovery and development. Treatment strategies for substance use disorders (SUDs) to date have been mostly ineffective other than substitution-like therapeutics. Two such targets are the peptide G-protein-coupled receptors neuropeptide S (NPS) and melanocortin 4 (MC4). Preclinical evidence suggests that antagonists, inverse agonists, or negative allosteric modulators of these receptors might be novel therapeutics for SUDs. NPS is a relatively unexplored receptor with high potential for treating SUD. MC4 has a strong link to early-onset obesity, and emerging evidence suggests significant overlap between food-maintained and drug-maintained behaviors making MC4 an intriguing target for SUD. This chapter provides an overview of the literature in relation to the roles of NPS and MC4 in drug-seeking behaviors and then provides a medicinal chemistry-based survey of the small molecule ligands for each receptor.
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Affiliation(s)
- Bruce Blough
- Center for Drug Discovery, RTI International, Research Triangle Park, NC, USA.
| | - Ojas Namjoshi
- Center for Drug Discovery, RTI International, Research Triangle Park, NC, USA
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Fowkes MM, Lalonde T, Yu L, Dhanvantari S, Kovacs MS, Luyt LG. Peptidomimetic growth hormone secretagogue derivatives for positron emission tomography imaging of the ghrelin receptor. Eur J Med Chem 2018; 157:1500-1511. [PMID: 30282322 DOI: 10.1016/j.ejmech.2018.08.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 08/16/2018] [Accepted: 08/22/2018] [Indexed: 02/06/2023]
Abstract
The ghrelin receptor is a seven-transmembrane (7-TM) receptor known to have an increased level of expression in human carcinoma and heart failure. Recent work has focused on the synthesis of positron emission tomography (PET) probes designed to target and image this receptor for disease diagnosis and staging. However, these probes have been restricted to small-molecule quinalizonones and peptide derivatives of the endogenous ligand ghrelin. We describe the design, synthesis and biological evaluation of a series of 4-fluorobenzoylated growth hormone secretagogues (GHSs) derived from peptidic (GHRP-1, GHPR-2 and GHRP-6) and peptidomimetic (G-7039, [1-Nal4]G-7039 and ipamorelin) families in order to test locations for the insertion of fluorine-18 for PET imaging. The peptidomimetic G-7039 was found to be the most suitable for 18F-radiolabelling as its non-radioactive 4-fluorobenzoylated analogue ([1-Nal4,Lys5(4-FB)]G-7039), had both a high binding affinity (IC50 = 69 nM) and promising in vitro efficacy (EC50 = 1.1 nM). Prosthetic group radiolabelling of the precursor compound [1-Nal4]G-7039 using N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB) delivered the PET probe [1-Nal4,Lys5(4-[18F]-FB)]G-7039 in an average decay-corrected radiochemical yield of 48%, a radio-purity ≥ 99% and an average molar activity of >34 GBq/μmol. This compound could be investigated as a PET probe for the detection of diseases that are characterised by overexpression of the ghrelin receptor.
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Affiliation(s)
- Milan M Fowkes
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada; London Regional Cancer Program, Lawson Health Research Institute, 790 Commissioners Road East, London, Ontario, N6A 4L6, Canada
| | - Tyler Lalonde
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada; London Regional Cancer Program, Lawson Health Research Institute, 790 Commissioners Road East, London, Ontario, N6A 4L6, Canada
| | - Lihai Yu
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada; London Regional Cancer Program, Lawson Health Research Institute, 790 Commissioners Road East, London, Ontario, N6A 4L6, Canada
| | - Savita Dhanvantari
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario, N6A 4V2, Canada
| | - Michael S Kovacs
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario, N6A 4V2, Canada
| | - Leonard G Luyt
- Department of Chemistry, Western University, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada; London Regional Cancer Program, Lawson Health Research Institute, 790 Commissioners Road East, London, Ontario, N6A 4L6, Canada; Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario, N6A 4V2, Canada.
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Curia G, Lucchi C, Vinet J, Gualtieri F, Marinelli C, Torsello A, Costantino L, Biagini G. Pathophysiogenesis of mesial temporal lobe epilepsy: is prevention of damage antiepileptogenic? Curr Med Chem 2014; 21:663-88. [PMID: 24251566 PMCID: PMC4101766 DOI: 10.2174/0929867320666131119152201] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/04/2013] [Accepted: 08/29/2013] [Indexed: 12/26/2022]
Abstract
Temporal lobe epilepsy (TLE) is frequently associated with hippocampal sclerosis, possibly caused by a primary brain injury that occurred a long time before the appearance of neurological symptoms. This type of epilepsy is characterized by refractoriness to drug treatment, so to require surgical resection of mesial temporal regions involved in seizure onset. Even this last therapeutic approach may fail in giving relief to patients. Although prevention of hippocampal damage and epileptogenesis after a primary event could be a key innovative approach to TLE, the lack of clear data on the pathophysiological mechanisms leading to TLE does not allow any rational therapy. Here we address the current knowledge on mechanisms supposed to be involved in epileptogenesis, as well as on the possible innovative treatments that may lead to a preventive approach. Besides loss of principal neurons and of specific interneurons, network rearrangement caused by axonal sprouting and neurogenesis are well known phenomena that are integrated by changes in receptor and channel functioning and modifications in other cellular components. In particular, a growing body of evidence from the study of animal models suggests that disruption of vascular and astrocytic components of the blood-brain barrier takes place in injured brain regions such as the hippocampus and piriform cortex. These events may be counteracted by drugs able to prevent damage to the vascular component, as in the case of the growth hormone secretagogue ghrelin and its analogues. A thoroughly investigation on these new pharmacological tools may lead to design effective preventive therapies.
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Affiliation(s)
| | | | | | | | | | | | | | - G Biagini
- Dipartimento di Scienze Biomediche, Metaboliche e Neuroscienze, Laboratorio di Epilettologia Sperimentale, Universita di Modena e Reggio Emilia, Via Campi, 287, 41125 Modena, Italy.
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7
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Synthesis and pharmacological evaluation of indolinone derivatives as novel ghrelin receptor antagonists. Bioorg Med Chem 2012; 20:5623-36. [DOI: 10.1016/j.bmc.2012.07.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 06/01/2012] [Accepted: 07/11/2012] [Indexed: 02/01/2023]
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9
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Els S, Beck-Sickinger AG, Chollet C. Ghrelin receptor: high constitutive activity and methods for developing inverse agonists. Methods Enzymol 2010; 485:103-21. [PMID: 21050913 DOI: 10.1016/b978-0-12-381296-4.00006-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The ghrelin receptor is a G protein-coupled receptor (GPCR) mainly distributed in the brain, and also expressed in peripheral tissues. Remarkably, the ghrelin receptor possesses a naturally high constitutive activity representing 50% of its maximal activity. Its endogenous ligand ghrelin is the only known orexigenic gastrointestinal peptide and plays a central role in the regulation of appetite, food intake, and energy homeostasis. Reducing the constitutive activity of the ghrelin receptor by inverse agonists is the strategy adopted by our group to develop anti-obesity drugs. Therefore, short peptides were synthesized and showed high inverse agonist potency toward the ghrelin receptor. This review describes the methods used to synthesize the peptides and to evaluate their biological activity. Peptide synthesis was performed on solid phase using a Fmoc/tBu-strategy. Peptide potency was measured with a signal transduction assay, the inositol trisphosphate turnover assay, adapted to a receptor expressing constitutive activity.
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Affiliation(s)
- Sylvia Els
- Institute of Biochemistry, Leipzig University, Brüderstrasse, Leipzig, Germany
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Chollet C, Meyer K, Beck-Sickinger AG. Ghrelin-a novel generation of anti-obesity drug: design, pharmacomodulation and biological activity of ghrelin analogues. J Pept Sci 2009; 15:711-30. [DOI: 10.1002/psc.1177] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Abstract
Background: Ghrelin is a peptide produced predominantly in the stomach and intestines, and is a natural growth hormone (GH) secretagogue-receptor ligand. It is able to stimulate GH release, but it also exhibits an important role in conditions related to processes regulating nutrition, body composition and growth, and heart, liver, thyroid or kidney dysfunction. Drug discovery efforts initially focused on ghrelin-receptor agonists, known as GH secretagogues, to be used as anabolic agents, but none of them reached the market. Discussion: The latest developments in this field are constituted by the discovery of new nonpeptidic compounds endowed with interesting properties: oxindole agonists are able to exert an increase in the fat-free mass, while ghrelin was reported to increase the fat mass gain, and triazole- and 2,4-diaminopyrimidine-based antagonists were shown to be able to reduce food intake, without inhibition of GH secretion stimulated by an agonist to the ghrelin receptor. Other antagonist compounds (quinazolinones) were discovered as antiobesity/antidiabetic agents. Moreover, inverse agonists have been discovered that are able to reduce weight gain. Conclusions: Taking into account the great number of pathological conditions related to ghrelin, and the discovery of several compounds able to modulate the ghrelin receptor, its importance in the field of medicinal chemistry research is set to increase significantly.
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(d)-2-tert-Butoxycarbonylamino-5,5-difluoro-5-phenyl-pentanoic acid: Synthesis and incorporation into the growth hormone secretagogues. Bioorg Med Chem Lett 2008; 18:4072-4. [DOI: 10.1016/j.bmcl.2008.05.100] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Revised: 05/22/2008] [Accepted: 05/27/2008] [Indexed: 11/18/2022]
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14
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Li JJ, Wang H, Li J, Qu F, Swartz SG, Hernández AS, Biller SA, Robl JA, Tino JA, Slusarchyk D, Seethala R, Sleph P, Yan M, Grover G, Flynn N, Murphy BJ, Gordon D. Tetrazole based amides as growth hormone secretagogues. Bioorg Med Chem Lett 2008; 18:2536-9. [PMID: 18378446 DOI: 10.1016/j.bmcl.2008.03.059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 03/17/2008] [Accepted: 03/18/2008] [Indexed: 11/18/2022]
Abstract
A novel series of N1 substituted tetrazole amides were prepared and showed to be potent growth hormone (GH) secretagogues. Among them, hydroxyl containing analog 31 displayed excellent in vivo activity by increasing plasma GH 10-fold in an anesthetized IV rat model.
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Affiliation(s)
- James J Li
- Discovery Chemistry, Bristol-Myers Squibb Research and Development, PO Box 5400, Princeton, NJ 08543-5400, USA.
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15
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Webb TR, Venegas RE, Wang J, Deschenes A. Generation of New Synthetic Scaffolds Using Framework Libraries Selected and Refined via Medicinal Chemist Synthetic Expertise. J Chem Inf Model 2008; 48:882-8. [DOI: 10.1021/ci7001928] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas R. Webb
- ChemBridge Research Labs., Inc., ChemBridge Corporation, 16981 Via Tazon, San Diego, California 92127, and Chemical Computing Group, Suite 910-1010 Sherbrooke St. W Montreal, Quebec, Canada H3A 2R7
| | - Ruben E. Venegas
- ChemBridge Research Labs., Inc., ChemBridge Corporation, 16981 Via Tazon, San Diego, California 92127, and Chemical Computing Group, Suite 910-1010 Sherbrooke St. W Montreal, Quebec, Canada H3A 2R7
| | - Jian Wang
- ChemBridge Research Labs., Inc., ChemBridge Corporation, 16981 Via Tazon, San Diego, California 92127, and Chemical Computing Group, Suite 910-1010 Sherbrooke St. W Montreal, Quebec, Canada H3A 2R7
| | - Alain Deschenes
- ChemBridge Research Labs., Inc., ChemBridge Corporation, 16981 Via Tazon, San Diego, California 92127, and Chemical Computing Group, Suite 910-1010 Sherbrooke St. W Montreal, Quebec, Canada H3A 2R7
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Design and synthesis of tetrazole-based growth hormone secretagogue: The SAR studies of the O-benzyl serine side chain. Bioorg Med Chem Lett 2008; 18:1825-9. [DOI: 10.1016/j.bmcl.2008.02.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 02/07/2008] [Accepted: 02/08/2008] [Indexed: 11/17/2022]
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17
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Sebhat IK, Lai Y, Barakat K, Ye Z, Tang R, Kalyani RN, Vongs A, Macneil T, Weinberg DH, Cabello MA, Maroto M, Teran A, Fong TM, Van der Ploeg LHT, Patchett AA, Nargund RP. Melanocortin subtype 4 receptor agonists: Structure–activity relationships about the 4-alkyl piperidine core. Bioorg Med Chem Lett 2007; 17:5720-3. [PMID: 17768046 DOI: 10.1016/j.bmcl.2006.11.084] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 11/28/2006] [Accepted: 11/30/2006] [Indexed: 11/21/2022]
Abstract
SAR about the piperidine core in a series of MC4R agonists is described. A number of alkyl substituents that furnish compounds with good affinity and functional potency are reported.
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Affiliation(s)
- Iyassu K Sebhat
- Department of Medicinal Chemistry, Merck & Co., Inc, PO Box, 2000, Rahway, NJ 07065, USA.
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Blakeney JS, Reid RC, Le GT, Fairlie DP. Nonpeptidic Ligands for Peptide-Activated G Protein-Coupled Receptors. Chem Rev 2007; 107:2960-3041. [PMID: 17622179 DOI: 10.1021/cr050984g] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jade S Blakeney
- Centre for Drug Design and Development, Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
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19
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Lu Z, Tata JR, Cheng K, Wei L, Chan WWS, Butler B, Schleim KD, Jacks TM, Hickey G, Patchett AA. Highly potent growth hormone secretagogues. Bioorg Med Chem Lett 2007; 17:3657-9. [DOI: 10.1016/j.bmcl.2007.04.050] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 04/11/2007] [Accepted: 04/16/2007] [Indexed: 11/17/2022]
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20
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Tamvakopoulos C. Mass spectrometry for the quantification of bioactive peptides in biological fluids. MASS SPECTROMETRY REVIEWS 2007; 26:389-402. [PMID: 17160998 DOI: 10.1002/mas.20120] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The study of pharmacologically active peptides is central to the understanding of disease and development of novel therapies. It would be advantageous to monitor the fate of bioactive peptides in biological fluids and tissues following their in vivo administration (exogenous administration) or the modulation of endogenous factors (e.g., peptide hormones) affected by the administration of a pharmacological agent. Measurement of administered compounds (small molecules) in plasma is a mature field. However, measurement of pharmacologically active peptides presents particular problems for quantitative mass spectrometry, including challenges from selectivity and sensitivity perspectives. Current approaches towards peptide quantification in biological fluids include immunoassays and mass spectrometric techniques. Immunoassays, although sensitive, lack the necessary selectivity for distinction between peptide and metabolites. Modified molecules induced by metabolic transformations (e.g., N- or C-terminal truncation of the peptide) might not be differentiated by the antibody used in the assay, leading to cross-reactivity. However, although it is generally accepted that mass spectrometry is an ideal technique for the quantification of trace levels of analytes in biological fluids, immunological techniques are still characterized by better limits of peptide detection. In this review article, novel mass spectrometric approaches and strategies on peptide quantification will be described. The current capabilities and prospects for advances in this critical area of research will be examined.
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Affiliation(s)
- Constantin Tamvakopoulos
- Foundation for Biomedical Research of the Academy of Athens (IIBEAA), Laboratory of Pharmacology-Pharmacotechnology, Athens, Greece 11527.
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Webb TR, Jiang L, Sviridov S, Venegas RE, Vlaskina AV, McGrath D, Tucker J, Wang J, Deschenes A, Li R. Application of a novel design paradigm to generate general nonpeptide combinatorial templates mimicking beta-turns: synthesis of ligands for melanocortin receptors. ACTA ACUST UNITED AC 2007; 9:704-10. [PMID: 17429950 DOI: 10.1021/cc0601581] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the further application of a novel approach to template and ligand design by the synthesis of agonists of the melanocortin receptor. This design method uses the conserved structural data from the three-dimensional conformations of beta-turn peptides to design rigid nonpeptide templates that mimic the orientation of the main chain C-alpha atoms in a peptide beta-turn. We report details on a new synthesis of derivatives of template 1 that are useful for the synthesis of exploratory libraries. The utility of this technique is further exemplified by several iterative rounds of high-throughput synthesis and screening, which result in new partially optimized nonpeptide agonists for several melanocortin receptors.
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Affiliation(s)
- Thomas R Webb
- ChemBridge Research Labs, Inc., ChemBridge Corporation, 16981 Via Tazon, San Diego, California 92127, USA.
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22
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Liu J, Jian T, Sebhat I, Nargund R. Preparation of 2,3-dihydro-1H-spiro[isoquinoline-4,4′-piperidine] via an N-sulfonyl Pictet–Spengler reaction. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.05.082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Godden JW, Stahura FL, Bajorath J. Anatomy of fingerprint search calculations on structurally diverse sets of active compounds. J Chem Inf Model 2006; 45:1812-9. [PMID: 16309288 DOI: 10.1021/ci050276w] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Similarity searching using molecular fingerprints is a widely used approach for the identification of novel hits. A fingerprint search involves many pairwise comparisons of bit string representations of known active molecules with those precomputed for database compounds. Bit string overlap, as evaluated by various similarity metrics, is used as a measure of molecular similarity. Results of a number of studies focusing on fingerprints suggest that it is difficult, if not impossible, to develop generally applicable search parameters and strategies, irrespective of the compound classes under investigation. Rather, more or less, each individual search problem requires an adjustment of calculation conditions. Thus, there is a need for diagnostic tools to analyze fingerprint-based similarity searching. We report an analysis of fingerprint search calculations on different sets of structurally diverse active compounds. Calculations on five biological activity classes were carried out with two fingerprints in two compound source databases, and the results were analyzed in histograms. Tanimoto coefficient (Tc) value ranges where active compounds were detected were compared to the distribution of Tc values in the database. The analysis revealed that compound class-specific effects strongly influenced the outcome of these fingerprint calculations. Among the five diverse compound sets studied, very different search results were obtained. The analysis described here can be applied to determine Tc intervals where scaffold hopping occurs. It can also be used to benchmark fingerprint calculations or estimate their probability of success.
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Affiliation(s)
- Jeffrey W Godden
- Department of Life Science Informatics, B-IT, Rheinische Friedrich-Wilhelms-Universität, Görresstrasse 13, D-53113 Bonn, Germany
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Todorovic A, Haskell-Luevano C. A review of melanocortin receptor small molecule ligands. Peptides 2005; 26:2026-36. [PMID: 16051395 DOI: 10.1016/j.peptides.2004.11.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Accepted: 11/18/2004] [Indexed: 11/22/2022]
Abstract
The melanocortin system (MC) is implicated in the regulation of a variety of physiological pathways including pigmentation, steroid function, energy homeostasis, food intake, obesity, cardiovascular, sexual function, and normal gland regulation. The melanocortin system consists of five receptors identified to date (MC1-5R), melanocortin agonists derived from the pro-opiomelanocortin prohormone (POMC) and two naturally existing antagonists. Melanocortin receptor ligand structure-activity studies have been performed since the 1960s, primarily focused on the pigmentation aspect of physiology. During the 1990s, the melanocortin-4 receptor was identified to play a significant physiological role in the regulation of both food intake and obesity. Subsequently, a concerted drug design effort has focused on the design and discovery of melanocortin receptor small molecules. Herein, we present an overview of melanocortin receptor heterocyclic small molecules.
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Affiliation(s)
- Aleksandar Todorovic
- Department of Medicinal Chemistry, University of Florida, P.O. Box 100485, Gainesville, FL 32610, USA
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Abstract
The GH secretagogues (GHS) were developed by reverse pharmacology. The objective was to develop small molecules with pharmacokinetics suitable for once-daily oral administration that would rejuvenate the GH/IGF-I axis. Neither the receptor nor the ligand that controlled pulse amplitude of hormone release was known; therefore, identification of lead structures was based on function. I reasoned that GH pulse amplitude could be increased by four possible mechanisms: 1) increasing GHRH release; 2) amplifying GHRH signaling in somatotrophs of the anterior pituitary gland; 3) reducing somatostatin release; and 4) antagonizing somatostatin receptor signaling. Remarkably, the GHS act through all four mechanisms to reproduce a young adult physiological GH profile in elderly subjects that was accompanied by increased bone mineral density and lean mass, modest improvements in strength, and improved recovery from hip fracture. Furthermore, restoration of thymic function was induced in old mice. The GHS receptor (GHS-R) was subsequently identified by expression cloning and found to be a previously unknown G protein-coupled receptor expressed predominantly in brain, pituitary gland, and pancreas. Reverse pharmacology was completed when the cloned GHS-R was exploited to identify an endogenous agonist (ghrelin) and a partial agonist (adenosine); ghsr-knockout mice studies confirmed that GHS are ghrelin mimetics.
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Affiliation(s)
- Roy G Smith
- Huffington Center on Aging, Baylor College of Medicine, One Baylor Plaza, Room M320, Houston, Texas 77030-3498, USA
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26
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Li JJ, Wang H, Qu F, Musial C, Tino JA, Robl JA, Slusarchyk D, Golla R, Seethala R, Dickinson K, Giupponi L, Grover G, Sleph P, Flynn N, Murphy BJ, Gordon D, Kung M, Stoffel R. Tetrahydroisoquinoline 1-carboxamides as growth hormone secretagogues. Bioorg Med Chem Lett 2005; 15:1799-802. [PMID: 15780609 DOI: 10.1016/j.bmcl.2005.02.040] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Revised: 02/10/2005] [Accepted: 02/14/2005] [Indexed: 11/18/2022]
Abstract
Several novel series of tetrahydroisoquinoline 1-carboxamides were prepared and shown to be potent growth hormone (GH) secretagogues. Among them, carbamate 12a-E2 displays excellent in vivo activity by increasing plasma GH 10-fold in an anesthetized IV rat model.
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Affiliation(s)
- James J Li
- Discovery Chemistry, Bristol-Myers Squibb Pharmaceutical Research Institute, PO Box 5400, Princeton, NJ 08543, USA
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27
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Abstract
Aging is associated with a progressive decline in physical and cognitive functions. The impact of age-dependent endocrine changes regulated by the central nervous system on the dynamics of neuronal behavior, neurodegeneration, cognition, biological rhythms, sexual behavior, and metabolism are reviewed. We also briefly review how functional deficits associated with increases in glucocorticoids and cytokines and declining production of sex steroids, GH, and IGF are likely exacerbated by age-dependent molecular misreading and alterations in components of signal transduction pathways and transcription factors.
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Affiliation(s)
- Roy G Smith
- Huffington Center on Aging, Baylor College of Medicine, One Baylor Plaza, M320, Houston, TX 77030, USA.
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28
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Xie QF, Wu CX, Meng QY, Li N. Ghrelin and truncated ghrelin variant plasmid vectors administration into skeletal muscle augments long-term growth in rats. Domest Anim Endocrinol 2004; 27:155-64. [PMID: 15219934 DOI: 10.1016/j.domaniend.2004.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2004] [Accepted: 03/21/2004] [Indexed: 10/26/2022]
Abstract
Ghrelin is an acylated peptide recently identified as an endogenous ligand for the growth hormone (GH) secretagogues (GHSs) receptor (GHS-R) and is involved in a novel system for regulating GH release. To study the biological activities of ghrelin using plasmid vector administration, we constructed myogenic expression vectors containing the full length cDNA of swine ghrelin-28 (pGEM-wt-sGhln) and truncated variant (pGEM-tmt-sGhln) consisting of the first seven residues of ghrelin (including Ser3 substituted with Trp3) with addition of a basic amino acid, Lys (K) at the C-terminus. After intramuscular injection of pGEM-wt-sGhln and pGEM-tmt-sGhln, RT-PCR analysis demonstrated that the ectopic expressions of ghrelin and its variant were observed 30 days post-injection. The level of GH increased in rat serum, and was significantly higher than that of the control group 20 days post-injection with pGEM-tmt-sGhln (P < 0.05). Administration of 150 microg of pGEM-wt-sGhln and pGEM-tmt-sGhln enhanced growth in rats over 30 days and great stimulatory responses were observed at day 10 and 20 post-injection respectively, whose body weight gains were on average 15% (P < 0.05) and 21% P < 0.033 significantly heavier than controls. These results suggested that skeletal muscle might have the potential to perform post-translational acylation for ghrelin, and short ghrelin variant might have the biological effects as wild type ghrelin.
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Affiliation(s)
- Q F Xie
- State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100094 [corrected]
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29
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Dyck B, Parker J, Phillips T, Carter L, Murphy B, Summers R, Hermann J, Baker T, Cismowski M, Saunders J, Goodfellow V. Aryl piperazine melanocortin MC4 receptor agonists. Bioorg Med Chem Lett 2004; 13:3793-6. [PMID: 14552781 DOI: 10.1016/s0960-894x(03)00796-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Incorporation of substituted phenyl piperazine privileged structures into a known MC4 specific dipeptoid consensus sequence resulted in a series of potent (EC(50)=24 nM) and selective MC4-R agonists. We report the SAR of this series of compounds using in vitro cAMP functional assays in cells transfected with the MC4 or other melancortin receptors.
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Affiliation(s)
- Brian Dyck
- Department of Medicinal Chemistry, Neurocrine Biosciences Inc., 10555 Science Center Drive, San Diego, CA 92121, USA
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30
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van der Lely AJ, Tschöp M, Heiman ML, Ghigo E. Biological, physiological, pathophysiological, and pharmacological aspects of ghrelin. Endocr Rev 2004; 25:426-57. [PMID: 15180951 DOI: 10.1210/er.2002-0029] [Citation(s) in RCA: 802] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ghrelin is a peptide predominantly produced by the stomach. Ghrelin displays strong GH-releasing activity. This activity is mediated by the activation of the so-called GH secretagogue receptor type 1a. This receptor had been shown to be specific for a family of synthetic, peptidyl and nonpeptidyl GH secretagogues. Apart from a potent GH-releasing action, ghrelin has other activities including stimulation of lactotroph and corticotroph function, influence on the pituitary gonadal axis, stimulation of appetite, control of energy balance, influence on sleep and behavior, control of gastric motility and acid secretion, and influence on pancreatic exocrine and endocrine function as well as on glucose metabolism. Cardiovascular actions and modulation of proliferation of neoplastic cells, as well as of the immune system, are other actions of ghrelin. Therefore, we consider ghrelin a gastrointestinal peptide contributing to the regulation of diverse functions of the gut-brain axis. So, there is indeed a possibility that ghrelin analogs, acting as either agonists or antagonists, might have clinical impact.
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Affiliation(s)
- Aart J van der Lely
- Department of Internal Medicine, Erasmus Medical Center, 3015 GD Rotterdam, The Netherlands.
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31
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Richardson TI, Ornstein PL, Briner K, Fisher MJ, Backer RT, Biggers CK, Clay MP, Emmerson PJ, Hertel LW, Hsiung HM, Husain S, Kahl SD, Lee JA, Lindstrom TD, Martinelli MJ, Mayer JP, Mullaney JT, O'Brien TP, Pawlak JM, Revell KD, Shah J, Zgombick JM, Herr RJ, Melekhov A, Sampson PB, King CHR. Synthesis and structure-activity relationships of novel arylpiperazines as potent and selective agonists of the melanocortin subtype-4 receptor. J Med Chem 2004; 47:744-55. [PMID: 14736255 DOI: 10.1021/jm0304109] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The melanocortin receptors have been implicated as potential targets for a number of important therapeutic indications, including inflammation, sexual dysfunction, and obesity. We identified compound 1, an arylpiperazine attached to the dipeptide H-d-Tic-d-p-Cl-Phe-OH, as a novel melanocortin subtype-4 receptor (MC4R) agonist through iterative directed screening of nonpeptidyl G-protein-coupled receptor biased libraries. Structure-activity relationship (SAR) studies demonstrated that substitutions at the ortho position of the aryl ring improved binding and functional potency. For example, the o-isopropyl-substituted compound 29 (K(i) = 720 nM) possessed 9-fold better binding affinity compared to the unsubstituted aryl ring (K(i) = 6600 nM). Sulfonamide 39 (K(i) = 220 nM) fills this space with a polar substituent, resulting in a further 2-fold improvement in binding affinity. The most potent compounds such as the diethylamine 44 (K(i) = 60 nM) contain a basic group at this position. Basic heterocycles such as the imidazole 50 (K(i) = 110 nM) were similarly effective. We also demonstrated good oral bioavailability for sulfonamide 39.
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Affiliation(s)
- Timothy I Richardson
- Lilly Research Laboratories, A Division of Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana 46285, USA.
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32
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Chianelli D, Kim YC, Lvovskiy D, Webb TR. Application of a novel design paradigm to generate general nonpeptide combinatorial scaffolds mimicking beta turns: synthesis of ligands for somatostatin receptors. Bioorg Med Chem 2003; 11:5059-68. [PMID: 14604669 DOI: 10.1016/j.bmc.2003.08.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Nonpeptide compounds that mimic bioactive peptides are desirable for a number of clinical indications. We report a new practical method for the design of scaffolds exhibiting drug-like properties that are suitable for the display of peptide pharmacophores. The synthesis of various synthons of 7'-hydroxy-2',3'-dihydro-1'H,2H,5H-spiro[imidazolidine-4,4'-quinoline]-2,5-dione (1) and methods for the introduction of several mimics of amino acid side-chains are described. This method is exemplified by derivatives that show agonist activity for the somatostatin type 2 receptor.
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Affiliation(s)
- Dona Chianelli
- ChemBridge Research Labs., LLC, 16981 Via Tazon, San Diego, CA 92127, USA
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33
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Schmidt B, Schieffer B. Angiotensin II AT1 receptor antagonists. Clinical implications of active metabolites. J Med Chem 2003; 46:2261-70. [PMID: 12773029 DOI: 10.1021/jm0204237] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Boris Schmidt
- Clemens Schöpf Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Petersenstrasse 22, Germany.
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34
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Lu Z, Tata JR, Cheng K, Wei L, Chan WWS, Butler B, Schleim KD, Jacks TM, Hickey G, Patchett AA. Substituted bridged phenyl piperidines: orally active growth hormone secretagogues. Bioorg Med Chem Lett 2003; 13:1817-20. [PMID: 12729672 DOI: 10.1016/s0960-894x(03)00261-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A new series of growth hormone secretagogues have been discovered. The best compound, 26j, shows excellent ability to release growth hormone both in vitro and in vivo. The synthesis and biological activity of these compounds are discussed.
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Affiliation(s)
- Zhijian Lu
- Department of Medicinal Chemistry, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA.
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35
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Ankersen M. Growth hormone secretagogues: discovery of small orally active molecules by peptidomimetic strategies. PROGRESS IN MEDICINAL CHEMISTRY 2003; 39:173-214. [PMID: 12536673 DOI: 10.1016/s0079-6468(08)70071-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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36
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Carpino PA, Lefker BA, Toler SM, Pan LC, Hadcock JR, Cook ER, DiBrino JN, Campeta AM, DeNinno SL, Chidsey-Frink KL, Hada WA, Inthavongsay J, Mangano FM, Mullins MA, Nickerson DF, Ng O, Pirie CM, Ragan JA, Rose CR, Tess DA, Wright AS, Yu L, Zawistoski MP, DaSilva-Jardine PA, Wilson TC, Thompson DD. Pyrazolinone-piperidine dipeptide growth hormone secretagogues (GHSs). Discovery of capromorelin. Bioorg Med Chem 2003; 11:581-90. [PMID: 12538023 DOI: 10.1016/s0968-0896(02)00433-9] [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: 10/27/2022]
Abstract
Novel pyrazolinone-piperidine dipeptide derivatives were synthesized and evaluated as growth hormone secretagogues (GHSs). Two analogues, capromorelin (5, CP-424391-18, hGHS-R1a K(i)=7 nM, rat pituicyte EC(50)=3 nM) and the des-methyl analogue 5c (hGHS-R1a K(i)=17 nM, rat pituicyte EC(50)=3 nM), increased plasma GH levels in an anesthesized rat model, with ED(50) values less than 0.05 mg/kg iv. Capromorelin showed enhanced intestinal absorption in rodent models and exhibited superior pharmacokinetic properties, including high bioavailabilities in two animal species [F(rat)=65%, F(dog)=44%]. This short-duration GHS was orally active in canine models and was selected as a development candidate for the treatment of musculoskeletal frailty in elderly adults.
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Affiliation(s)
- Philip A Carpino
- Pfizer Global Research and Development, Groton Labs, MS8220-3004, Eastern Point Rd, CT 06340, Groton, USA.
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37
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Patchett AA. 2002 Alfred Burger Award Address in Medicinal Chemistry. Natural products and design: interrelated approaches in drug discovery. J Med Chem 2002; 45:5609-16. [PMID: 12477342 DOI: 10.1021/jm020424z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Arthur A Patchett
- Department of Medicinal Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
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38
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Sebhat IK, Martin WJ, Ye Z, Barakat K, Mosley RT, Johnston DBR, Bakshi R, Palucki B, Weinberg DH, MacNeil T, Kalyani RN, Tang R, Stearns RA, Miller RR, Tamvakopoulos C, Strack AM, McGowan E, Cashen DE, Drisko JE, Hom GJ, Howard AD, MacIntyre DE, van der Ploeg LHT, Patchett AA, Nargund RP. Design and pharmacology of N-[(3R)-1,2,3,4-tetrahydroisoquinolinium- 3-ylcarbonyl]-(1R)-1-(4-chlorobenzyl)- 2-[4-cyclohexyl-4-(1H-1,2,4-triazol- 1-ylmethyl)piperidin-1-yl]-2-oxoethylamine (1), a potent, selective, melanocortin subtype-4 receptor agonist. J Med Chem 2002; 45:4589-93. [PMID: 12361385 DOI: 10.1021/jm025539h] [Citation(s) in RCA: 159] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Synthetic and natural peptides that act as nonselective melanocortin receptor agonists have been found to be anorexigenic and to stimulate erectile activity. We report the design and development of 1, a potent, selective (1184-fold vs MC3R, 350-fold vs MC5R), small-molecule agonist of the MC4 receptor. Pharmacological testing confirms the food intake lowering effects of MC4R agonism and suggests another role for the receptor in the stimulation of erectile activity.
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Affiliation(s)
- Iyassu K Sebhat
- Department of Chemistry, Merck & Co., Inc., P.O. Box 2000, Rahway, New Jersey 07065-0900, USA.
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39
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A concise and regioselective synthesis of 6-iodo-4-trifluoromethylisatin, an intermediate in the synthesis of the novel, non-peptidyl growth hormone secretagogue SM-130686. Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)00300-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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40
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Abstract
Peptide recognition by G-protein coupled receptors (GPCRs) is reviewed with an emphasis on the indirect approach used to determine the receptor-bound conformation of peptide ligands. This approach was developed in response to the lack of detailed structural information available for these receptors. Recent advances in the structural determination of rhodopsin (the GPCR of the visual system) by crystallography have provided a scaffold for homology modeling of the inactive state of a wide variety of GPCRs that interact with peptide messages. Additionally, the ability to mutate GPCRs and assay compounds of similar chemical structure to test a common binding site on the receptor provides a firm experimental basis for structure-activity studies. Recognition motifs, common in other well-studied systems such as proteolytic enzymes and major histocompatibility class receptors (MHC) are reviewed briefly to provide a basis of comparison. Finally, the development of true peptidomimetics is contrasted with nonpeptide ligands, discovered through combinatorial chemistry. In many systems, the evidence suggests that the peptide ligands bind at the interface between the transmembrane segments and the extracellular loops, while nonpeptide antagonists bind within the transmembrane segments. Plausible models of GPCRs and the mechanism by which they activate G-proteins on binding peptides are beginning to emerge.
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Affiliation(s)
- G R Marshall
- Center for Computational Biology, 700 S. Euclid Avenue, Washington University, St. Louis, MO 63110, USA.
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41
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Matsumoto M, Hosoda H, Kitajima Y, Morozumi N, Minamitake Y, Tanaka S, Matsuo H, Kojima M, Hayashi Y, Kangawa K. Structure-activity relationship of ghrelin: pharmacological study of ghrelin peptides. Biochem Biophys Res Commun 2001; 287:142-6. [PMID: 11549267 DOI: 10.1006/bbrc.2001.5553] [Citation(s) in RCA: 193] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ghrelin, a novel peptide purified from the stomach, is the endogenous ligand of the growth hormone secretagogue receptor. The Ser(3) residue of ghrelin is modified with a lipid n-octanoic acid, a modification necessary for hormonal activity. To clarify the role of acyl modification and to identify the active core of ghrelin, we examined the activities of partially digested ghrelin and synthetic ghrelin derivatives. The activities confirmed that the N-terminal portion is the active core. Moreover, synthetic ghrelin derivatives demonstrated that octanoic acid is not the only modification of the Ser(3) side chain to sustain the activity of ghrelin; other acyl acid modifications maintained activity. Amino acid replacement of Ser(3) indicated that an L-configuration of the third residue is critical for ghrelin activity. In addition, more stable ether or thioether bonds are capable of replacing the octanoyl ester bond in ghrelin, advantageous for the generation of pharmaceuticals with longer stability.
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Affiliation(s)
- M Matsumoto
- Suntory Institute for Medicinal Research & Development, Kurakake 2716-1, Akaiwa, Chiyoda-machi, Ohra-gun, Gunma 370-0503, Japan
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42
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Palucki BL, Feighner SD, Pong S, McKee KK, Hreniuk DL, Tan C, Howard AD, Van der Ploeg LH, Patchett AA, Nargund RP. Spiro(indoline-3,4'-piperidine) growth hormone secretagogues as ghrelin mimetics. Bioorg Med Chem Lett 2001; 11:1955-7. [PMID: 11459669 DOI: 10.1016/s0960-894x(01)00324-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A series of small molecules derived from MK-0677, a potent synthetic GHS, mimicking the N-terminal Gly-Ser-O-(n-octanoyl)-L-Ser-Phe segment of ghrelin was synthesized and tested in a binding and in a functional assay measuring intracellular calcium elevation in HEK-293 cells expressing hGHSR1a. Replacement of Phe in this tetrapeptide with a spiro(indoline-3,4'-piperidine) group, Gly-Ser with 2-aminoisobutyric acid, and O-(n-octanoyl)-L-Ser with O-benzyl-D-Ser provided synthetic GHS agonists with similar functional potency as ghrelin.
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Affiliation(s)
- B L Palucki
- Department of Medicinal Chemistry, Merck Research Laboratories, 07065, Rahway, NJ, USA.
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43
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Matsumoto M, Kitajima Y, Iwanami T, Hayashi Y, Tanaka S, Minamitake Y, Hosoda H, Kojima M, Matsuo H, Kangawa K. Structural similarity of ghrelin derivatives to peptidyl growth hormone secretagogues. Biochem Biophys Res Commun 2001; 284:655-9. [PMID: 11396951 DOI: 10.1006/bbrc.2001.5014] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ghrelin is a 28-amino acid residue endogenous growth hormone secretagogue. Intensive investigations revealed that the N-terminus tetrapeptide, having octanoyl group at Ser(3), is the minimum active core. In this study, we further explored the structure-function relationships of the active N-terminus portion of ghrelin using a Ca(2+) mobilization assay. The smallest and most potent ghrelin derivative we have found so far is 5-aminopentanoyl-Ser(Octyl)-Phe-Leu-aminoethylamide, showing comparable activity to the natural molecule. In the process of modifying the active core, the ghrelin-derived short analogues emerged structurally close to peptidyl growth hormone secretagogues. The N-terminus modification suggested that Gly(1)-Ser(2) unit works as a spacer, forming adequate distance between N(alpha)-amino group and n-octanoyl group. Replacement of 3rd and 4th amino acid residues to D-isomer suggested that the N-terminal dipeptide contributes to shape the biologically active geometry by effecting conformation of residues in positions 3 and 4.
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Affiliation(s)
- M Matsumoto
- Suntory Institute for Medicinal Research & Development, 2716-1 Kurakake, Akaiwa, Chiyoda-machi, Ohra-gun, Gunma 370-0503, Japan
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44
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Koo GC, Huang C, Camacho R, Trainor C, Blake JT, Sirotina-Meisher A, Schleim KD, Wu TJ, Cheng K, Nargund R, McKissick G. Immune enhancing effect of a growth hormone secretagogue. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:4195-201. [PMID: 11238671 DOI: 10.4049/jimmunol.166.6.4195] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Growth hormone (GH) has been known to enhance immune responses, whether directly or through the insulin like growth factor-1, induced by GH. Recently a nonpeptidyl small m.w. compound, a GH secretagogue (GHS), was found to induce the production of GH by the pituitary gland. In this study, we examined the effect of GHS in immunological functions of 5- to 6-wk-old and 16- to 24-month-old mice. In young mice, we observed a significant increase in PBLs, but T and B cell-proliferative responses were not consistently enhanced. The old mice, treated with GHS for 3 wk, did not show increases in peripheral lymphocytes, but they exhibited a statistically significant increase in thymic cellularity and differentiation. When inoculated with a transplantable lymphoma cell line, EL4, the treated old mice showed statistically significant resistance to the initiation of tumors and the subsequent metastases. Generation of CTL to EL4 cells was also enhanced in the treated mice, suggesting that GHS has a considerable immune enhancing effect, particularly in the old mice. We have also found that GHS promoted better thymic engraftment in bone marrow transplant of SCID mice. We found more cycling cells in the spleens of treated mice, suggesting that GHS may exert its immune enhancing effect by promoting cell division in lymphoid cells. These observations ascribe to GHS a novel therapy possible for aging, AIDS, and transplant individuals, whose immune functions are compromised.
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Affiliation(s)
- G C Koo
- Department of Immunology Research, Merck Research Laboratories, Rahway, NJ 07065, USA.
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45
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Proceedings of the 10th hGH Symposium. Seville, April 23-24, 1999. HORMONE RESEARCH 2001; 51 Suppl 3:1-179. [PMID: 10766565 DOI: 10.1159/000044375] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A series of structurally diverse growth hormone (GH) releasing substances have been synthesized that are distinct from the naturally occurring GH releasing hormone (GHRH). These synthetic molecules range from the family of GH releasing peptides and mimetics such as MK-0677. The physiological importance of these molecules and their receptor is exemplified by studies in the elderly. For example, when MK-0677 was administered chronically to 70- to 90-year-old subjects, once daily, the age-related reduced amplitude of GH pulses was reversed to that of the physiological profile typical of young adults. In 1996, the synthesis of <sup>35</sup>S-MK-0677 was reported and used as a ligand to characterize a common receptor (GH secretagogue receptor [GHS-R]) for the GH releasing substances. The GHS-R is distinct from the GHRH receptor. Subsequently, the GHS-R gene was cloned and shown to encode a unique G-protein coupled receptor with a deduced protein sequence that was 96% identical in human and rat. Because of the physiological importance of the GHS-R, a search for family members (FMs) was initiated and its molecular evolution investigated. Three FMs GPR38, GPR39 and FM3 were isolated from human genomic libraries. To accelerate the identification of other FMs, a vertebrate organism with a compact genome distant in evolutionary terms from humans was exploited. The pufferfish (Spheroides nephelus) genome provides an ideal model for the discovery of human genes. Three distinct full-length clones encoding proteins of significant sequence identity to the human GHS-R were cloned from the pufferfish. Remarkably, the pufferfish gene with highest sequence homology to the human receptor was activated by the hexapeptide and non-peptide ligands. These intriguing results show that the structure and function of the ligand binding pocket of the human GHS-R has been highly conserved in evolution (<sim>400 million years) and strongly suggests that an endogenous natural ligand has been conserved. This new information is consistent with a natural ligand for the GHS-R playing a fundamentally important and conserved role in physiology.
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46
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Belen’kii L, Kruchkovskaya N, Gramenitskaya V. The Literature of Heterocyclic Chemistry, Part VII: 1997–1999. ADVANCES IN HETEROCYCLIC CHEMISTRY 2001. [DOI: 10.1016/s0065-2725(01)79024-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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47
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48
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Ankersen M, Kramer Nielsen K, Kruse Hansen T, Raun K, Sehested Hansen B. Growth hormone secretagogues derived from NN703 with hydrazidesas c-terminal. Eur J Med Chem 2000; 35:487-97. [PMID: 10889328 DOI: 10.1016/s0223-5234(00)00146-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of GH secretagogues based on modifications in the C-terminal of NN703 is reported. The C-terminal N-methyl amide of NN703 has been replaced with alkylated hydrazides in order to decrease the volume of distribution and identify GH secretagogues with shorter duration of action. Most of the prepared compounds show high potency in a rat pituitary assay. Subsequent to an initial in vivo screening in dogs, four compounds were selected for further pharmacological and pharmacokinetic evaluation. The four compounds showed oral bioavailability around 35% and equipotency in vitro compared to NN703. The relationship between lipophilicity and volume of distribution is discussed and it is speculated whether the lower volume of distribution is attributed to the observed higher in vivo potency and shorter plasma elimination half-life.
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Affiliation(s)
- M Ankersen
- Health Care Chemistry, Novo Nordisk A/S, Novo Nordisk Park, DK-2760, Mâløv, Denmark.
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Ye Z, Gao Y, Bakshi RK, Chen MH, Rohrer SP, Feighner SD, Pong SS, Howard AD, Blake A, Birzin ET, Locco L, Parmar RM, Chan WW, Schaeffer JM, Smith RG, Patchett AA, Nargund RP. Modeling directed design and biological evaluation of quinazolinones as non-peptidic growth hormone secretagogues. Bioorg Med Chem Lett 2000; 10:5-8. [PMID: 10636230 DOI: 10.1016/s0960-894x(99)00584-3] [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: 10/18/2022]
Abstract
Quinazolinone derivatives were synthesized and evaluated as non-peptidic growth hormone secretagogues. Modeling guided design of quinazolinone compound 21 led to a potency enhancement of greater than 200-fold compared to human growth hormone secretagogue affinity of a screening lead 4.
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Affiliation(s)
- Z Ye
- Department of Medicinal Chemistry, Merck Research Laboratories, Rahway, NJ 07065, USA
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