ABSTRACT
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.
Subject(s)
Antidepressive Agents/pharmacology , Behavior, Animal/drug effects , Drug Discovery , Receptors, Metabotropic Glutamate/antagonists & inhibitors , Animals , Antidepressive Agents/chemical synthesis , Antidepressive Agents/chemistry , Brain/drug effects , Cyclohexanes/chemical synthesis , Cyclohexanes/chemistry , Cyclohexanes/pharmacology , Dose-Response Relationship, Drug , Humans , Male , Mice , Mice, Inbred Strains , Models, Molecular , Molecular Structure , Motor Activity/drug effects , Receptors, Metabotropic Glutamate/chemistry , Receptors, Metabotropic Glutamate/isolation & purification , Structure-Activity Relationship , SwimmingABSTRACT
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
A highly regioselective Pd-catalyzed arylation of N-methylpyrazoles with aryl bromides is described. This transformation was studied extensively via automated reaction screening. A Design of Experiments (DoE) approach for optimizing the critical parameters was applied, resulting in excellent conditions for preparing selectively 5-arylpyrazoles in moderate to excellent yields under mild conditions.
Subject(s)
Chlorine Compounds/chemistry , Palladium/chemistry , Pyrazoles/chemistry , Catalysis , Molecular Structure , StereoisomerismABSTRACT
An automated liquid-liquid extraction workstation has been developed. This module processes up to 96 samples in an automated and parallel mode avoiding the time-consuming and intensive sample manipulation during the workup process. To validate the workstation, a highly automated and chromatography-free synthesis of differentially substituted quinazolin-4(3H)-ones with two diversity points has been carried out using isatoic anhydride as starting material.
