ABSTRACT
Negative modulators of metabotropic glutamate 2 & 3 receptors demonstrate antidepressant-like activity in animal models and hold promise as novel therapeutic agents for the treatment of major depressive disorder. Herein we describe our efforts to prepare and optimize a series of conformationally constrained 3,4-disubstituted bicyclo[3.1.0]hexane glutamic acid analogs as orthosteric (glutamate site) mGlu2/3 receptor antagonists. This work led to the discovery of a highly potent and efficacious tool compound 18 (hmGlu2 IC50 46±14.2nM, hmGlu3 IC50=46.1±36.2nM). Compound 18 showed activity in the mouse forced swim test with a minimal effective dose (MED) of 1mg/kg ip. While in rat EEG studies it exhibited wake promoting effects at 3 and 10mg/kg ip without any significant effects on locomotor activity. Compound 18 thus represents a novel tool molecule for studying the impact of blocking mGlu2/3 receptors both in vitro and in vivo.
Subject(s)
Antidepressive Agents/chemistry , Antidepressive Agents/pharmacology , Depressive Disorder, Major/drug therapy , Glutamic Acid/analogs & derivatives , Glutamic Acid/pharmacology , Receptors, Metabotropic Glutamate/antagonists & inhibitors , Animals , Antidepressive Agents/pharmacokinetics , Bridged Bicyclo Compounds/chemistry , Bridged Bicyclo Compounds/pharmacokinetics , Bridged Bicyclo Compounds/pharmacology , Cell Line , Depressive Disorder, Major/metabolism , Dogs , Glutamic Acid/pharmacokinetics , Haplorhini , Hexanes/chemistry , Hexanes/pharmacokinetics , Hexanes/pharmacology , Humans , Madin Darby Canine Kidney Cells , Mice , Rats , Receptors, Metabotropic Glutamate/metabolismABSTRACT
Aniline 'headgroups' were synthesized and incorporated into an alkynyl thienopyrimidine series of EGFR and ErbB-2 inhibitors. Potent inhibition of enzyme activity and cellular proliferation was observed. In certain instances, protein binding was reduced and oral exposure was found to be somewhat improved relative to compounds containing the reference aniline.
Subject(s)
Aniline Compounds/chemical synthesis , ErbB Receptors/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Pyrimidines/chemical synthesis , Receptor, ErbB-2/antagonists & inhibitors , Administration, Oral , Aniline Compounds/administration & dosage , Aniline Compounds/pharmacology , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Evaluation, Preclinical/methods , ErbB Receptors/metabolism , Growth Inhibitors/administration & dosage , Growth Inhibitors/chemical synthesis , Growth Inhibitors/pharmacology , Humans , Mice , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , Pyrimidines/administration & dosage , Pyrimidines/pharmacology , Receptor, ErbB-2/metabolismABSTRACT
The optimization of imidazo[1,2-a]pyridine inhibitors as potent and selective inhibitors of IGF-1R is presented. Further optimization of oral exposure in mice is also discussed. Detailed selectivity, in vitro activity, and in vivo PK profiles of an optimized compound is also highlighted.
Subject(s)
Chemistry, Pharmaceutical/methods , Pyridines/chemistry , Receptor, IGF Type 1/antagonists & inhibitors , Receptor, IGF Type 1/chemistry , Administration, Oral , Aniline Compounds/chemistry , Animals , Cell Line, Tumor , Crystallography, X-Ray , Drug Design , Humans , Inhibitory Concentration 50 , Mice , Models, Chemical , Molecular Conformation , Pyridines/chemical synthesis , Pyridines/pharmacology , Receptor, Insulin/metabolismABSTRACT
A novel class of pyrrolidinyl-acetyleneic thieno[3,2-d]pyrimidines has been identified which potently inhibit the EGFR and ErbB-2 receptor tyrosine kinases. Synthetic modifications of the pyrrolidine carbamate moiety result in a range of effects on enzyme and cellular potency. In addition, the impact of the absolute stereochemical configuration on cellular potency and oral mouse pharmacokinetics is described.
Subject(s)
Antineoplastic Agents/chemistry , ErbB Receptors/antagonists & inhibitors , Pyrimidines/pharmacology , Pyrrolidines/pharmacology , Receptor, ErbB-2/antagonists & inhibitors , Administration, Oral , Animals , Mice , Pharmacokinetics , Pyrimidines/chemical synthesis , Pyrrolidines/chemical synthesis , Structure-Activity RelationshipABSTRACT
A series of thiophene PLK1 inhibitors was optimized for increased solubility and reduced protein binding through the appendage of basic amine functionality. Interesting selectivity between PLK1 and PLK3 was also obtained through these modifications.
Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Chemistry, Pharmaceutical/methods , Protein Kinase Inhibitors/chemical synthesis , Protein Serine-Threonine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , Thiophenes/chemistry , Cell Cycle , Cell Cycle Proteins/chemistry , Cell Line, Tumor , Drug Design , Humans , Inhibitory Concentration 50 , Mitosis , Models, Chemical , Molecular Conformation , Protein Binding , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/chemistry , Proto-Oncogene Proteins/chemistry , Solubility , Tumor Suppressor Proteins , Polo-Like Kinase 1ABSTRACT
Metabotropic glutamate 2/3 (mGlu2/3) receptors are of considerable interest owing to their role in modulating glutamate transmission via presynaptic, postsynaptic and glial mechanisms. As part of our ongoing efforts to identify novel ligands for these receptors, we have discovered (1S,2R,3S,4S,5R,6R)-2-amino-3-[(3,4-difluorophenyl)sulfanylmethyl]-4-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid; (LY3020371), a potent and selective orthosteric mGlu2/3 receptor antagonist. In this account, we characterize the effects of LY3020371 in membranes and cells expressing human recombinant mGlu receptor subtypes as well as in native rodent and human brain tissue preparations, providing important translational information for this molecule. In membranes from cells expressing recombinant human mGlu2 and mGlu3 receptor subtypes, LY3020371.HCl competitively displaced binding of the mGlu2/3 agonist ligand [3H]-459477 with high affinity (hmGlu2 Ki = 5.26 nM; hmGlu3 Ki = 2.50 nM). In cells expressing hmGlu2 receptors, LY3020371.HCl potently blocked mGlu2/3 agonist (DCG-IV)-inhibited, forskolin-stimulated cAMP formation (IC50 = 16.2 nM), an effect that was similarly observed in hmGlu3-expressing cells (IC50 = 6.21 nM). Evaluation of LY3020371 in cells expressing the other human mGlu receptor subtypes revealed high mGlu2/3 receptor selectivity. In rat native tissue assays, LY3020371 demonstrated effective displacement of [3H]-459477 from frontal cortical membranes (Ki = 33 nM), and functional antagonist activity in cortical synaptosomes measuring both the reversal of agonist-suppressed second messenger production (IC50 = 29 nM) and agonist-inhibited, K+-evoked glutamate release (IC50 = 86 nM). Antagonism was fully recapitulated in both primary cultured cortical neurons where LY3020371 blocked agonist-suppressed spontaneous Ca2+ oscillations (IC50 = 34 nM) and in an intact hippocampal slice preparation (IC50 = 46 nM). Functional antagonist activity was similarly demonstrated in synaptosomes prepared from epileptic human cortical or hippocampal tissues, suggesting a translation of the mGlu2/3 antagonist pharmacology from rat to human. Intravenous dosing of LY3020371 in rats led to cerebrospinal fluid drug levels that are expected to effectively block mGlu2/3 receptors in vivo. Taken together, these results establish LY3020371 as an important new pharmacological tool for studying mGlu2/3 receptors in vitro and in vivo. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
Subject(s)
Cyclohexanes/pharmacokinetics , Excitatory Amino Acid Antagonists/pharmacokinetics , Receptors, Metabotropic Glutamate/antagonists & inhibitors , Receptors, Metabotropic Glutamate/metabolism , Animals , Cell Line , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Cyclohexanes/chemistry , Dose-Response Relationship, Drug , Excitatory Amino Acid Antagonists/chemistry , Humans , Male , Rats , Rats, Sprague-DawleyABSTRACT
As part of our ongoing efforts to identify novel ligands for the metabotropic glutamate 2 and 3 (mGlu2/3) receptors, we have incorporated substitution at the C3 and C4 positions of the (1S,2R,5R,6R)-2-amino-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid scaffold to generate mGlu2/3 antagonists. Exploration of this structure-activity relationship (SAR) led to the identification of (1S,2R,3S,4S,5R,6R)-2-amino-3-[(3,4-difluorophenyl)sulfanylmethyl]-4-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid hydrochloride (LY3020371·HCl, 19f), a potent, selective, and maximally efficacious mGlu2/3 antagonist. Further characterization of compound 19f binding to the human metabotropic 2 glutamate (hmGlu2) site was established by cocrystallization of this molecule with the amino terminal domain (ATD) of the hmGlu2 receptor protein. The resulting cocrystal structure revealed the specific ligand-protein interactions, which likely explain the high affinity of 19f for this site and support its functional mGlu2 antagonist pharmacology. Further characterization of 19f in vivo demonstrated an antidepressant-like signature in the mouse forced-swim test (mFST) assay when brain levels of this compound exceeded the cellular mGlu2 IC50 value.