ABSTRACT
Sodium-hydrogen exchanger isoform 1 (NHE1) is a ubiquitously expressed transmembrane ion channel responsible for intracellular pH regulation. During myocardial ischemia, low pH activates NHE1 and causes increased intracellular calcium levels and aberrant cellular processes, leading to myocardial stunning, arrhythmias, and ultimately cell damage and death. The role of NHE1 in cardiac injury has prompted interest in the development of NHE1 inhibitors for the treatment of heart failure. This report outlines our efforts to identify a compound suitable for once daily, oral administration with low drug-drug interaction potential starting from NHE1 inhibitor sabiporide. Substitution of a piperidine for the piperazine of sabiporide followed by replacement of the pyrrole moiety and subsequent optimization to improve potency and eliminate off-target activities resulted in the identification of N-[4-(1-acetyl-piperidin-4-yl)-3-trifluoromethyl-benzoyl]-guanidine (60). Pharmacological evaluation of 60 revealed a remarkable ability to prevent ischemic damage in an ex vivo model of ischemia reperfusion injury in isolated rat hearts.
Subject(s)
Benzamides/chemical synthesis , Guanidines/chemical synthesis , Myocardial Infarction/drug therapy , Myocardial Reperfusion Injury/prevention & control , Sodium-Hydrogen Exchangers/antagonists & inhibitors , Animals , Benzamides/chemistry , Benzamides/pharmacology , Biological Availability , Blood Platelets/cytology , Blood Platelets/drug effects , Cell Line , Cell Membrane Permeability , Cell Size , Cytochrome P-450 Enzyme Inhibitors , Dogs , ERG1 Potassium Channel , Ether-A-Go-Go Potassium Channels/antagonists & inhibitors , Guanidines/chemistry , Guanidines/pharmacology , Humans , Male , Membranes, Artificial , Microsomes, Liver/metabolism , Models, Molecular , Permeability , Protein Isoforms/antagonists & inhibitors , Rats , Rats, Sprague-Dawley , Sodium-Hydrogen Exchanger 1 , Structure-Activity RelationshipABSTRACT
A high throughput screening campaign identified aryl 1,4-diazepane compounds as potent and selective cannabinoid receptor 2 agonists as compared to cannabinoid receptor 1. This class of compounds suffered from poor drug-like parameters as well as low microsomal stability and poor solubility. Structure-activity relationships are described with a focus on improving the drug-like parameters resulting in compounds with improved solubility and permeability.
Subject(s)
Azepines/chemistry , Receptor, Cannabinoid, CB2/agonists , Azepines/pharmacology , Caco-2 Cells , Cell Membrane Permeability , High-Throughput Screening Assays , Humans , Microsomes, Liver/metabolism , Receptor, Cannabinoid, CB1/agonists , Receptor, Cannabinoid, CB1/metabolism , Receptor, Cannabinoid, CB2/metabolism , Solubility , Structure-Activity RelationshipABSTRACT
Two closely related scaffolds were identified through an uHTS campaign as desirable starting points for the development of Rho-Kinase (ROCK) inhibitors. Here, we describe our hit-to-lead evaluation process which culminated in the rapid discovery of potent leads such as 22 which successfully demonstrated an early in vivo proof of concept for anti-hypertensive activity.
Subject(s)
Isoquinolines/pharmacology , Protein Kinase Inhibitors/pharmacology , rho-Associated Kinases/antagonists & inhibitors , Animals , Antihypertensive Agents/chemistry , Antihypertensive Agents/pharmacology , Blood Pressure/drug effects , Crystallography, X-Ray , Drug Discovery , Isoquinolines/chemistry , Models, Molecular , Protein Kinase Inhibitors/chemistry , RatsABSTRACT
A highly selective series of bisbenzamide inhibitors of Rho-associated coiled-coil forming protein kinase (ROCK) and a related ureidobenzamide series, both identified by high throughput screening (HTS), are described. Details of the hit validation and lead generation process, including structure-activity relationship (SAR) studies, a selectivity assessment, target-independent profiling (TIP) results, and an analysis of functional activity using a rat aortic ring assay are discussed.
Subject(s)
Bisbenzimidazole/chemistry , Protein Kinase Inhibitors/chemistry , rho-Associated Kinases/antagonists & inhibitors , Animals , Aorta/enzymology , Bisbenzimidazole/pharmacology , Drug Discovery , Drug Evaluation, Preclinical/methods , Inhibitory Concentration 50 , Protein Kinase Inhibitors/pharmacology , Rats , Structure-Activity Relationship , Urea/chemistryABSTRACT
A series of novel 5-aminomethyl-1H-benzimidazole based inhibitors of Itk were prepared. Structure-activity relationships, selectivity and cell activity are reported for this series. Compound 2, a potent and selective antagonist of Itk, inhibited anti-CD3 antibody induced IL-2 production in vivo in mice.
Subject(s)
Benzimidazoles/administration & dosage , Benzimidazoles/chemistry , Benzimidazoles/chemical synthesis , Chemistry, Pharmaceutical/methods , Protein-Tyrosine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/chemistry , Administration, Oral , Animals , Benzimidazoles/pharmacology , CD3 Complex/biosynthesis , Drug Design , Humans , Inhibitory Concentration 50 , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Models, Chemical , Structure-Activity Relationship , T-Lymphocytes/cytologyABSTRACT
We have identified two novel MEK5 inhibitors, BIX02188 and BIX02189, which inhibited catalytic function of purified, MEK5 enzyme. The MEK5 inhibitors blocked phosphorylation of ERK5, without affecting phosphorylation of ERK1/2 in sorbitol-stimulated HeLa cells. The compounds also inhibited transcriptional activation of MEF2C, a downstream substrate of the MEK5/ERK5 signaling cascade, in a cellular trans-reporter assay system. These inhibitors offer novel pharmacological tools to better characterize the role of the MEK5/ERK5 pathway in various biological systems.
Subject(s)
Aniline Compounds/pharmacology , Indoles/pharmacology , MAP Kinase Kinase 5/antagonists & inhibitors , Mitogen-Activated Protein Kinase 7/antagonists & inhibitors , Protein Kinase Inhibitors/pharmacology , Aniline Compounds/isolation & purification , HeLa Cells , Humans , Indoles/isolation & purification , MADS Domain Proteins/antagonists & inhibitors , MADS Domain Proteins/genetics , MAP Kinase Kinase 5/metabolism , MEF2 Transcription Factors , Mitogen-Activated Protein Kinase 7/metabolism , Myogenic Regulatory Factors/antagonists & inhibitors , Myogenic Regulatory Factors/genetics , Phosphorylation/drug effects , Protein Kinase Inhibitors/isolation & purification , Sorbitol/pharmacology , Transcriptional Activation/drug effectsABSTRACT
Previously, we reported a series of novel benzimidazole based Itk inhibitors that exhibited excellent enzymatic potency and selectivity but low microsomal stability. Employing a structure based approach a new series of inhibitors with comparable potency and selectivity to the original series and with a potential for improved microsome stability was identified.
Subject(s)
Benzimidazoles/chemistry , Benzimidazoles/chemical synthesis , Chemistry, Pharmaceutical/methods , Enzyme Inhibitors/chemical synthesis , Microsomes, Liver/metabolism , Protein-Tyrosine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/chemistry , Adenosine Triphosphate/chemistry , Administration, Oral , Binding Sites , CD3 Complex/chemistry , Crystallography, X-Ray/methods , Drug Design , Enzyme Inhibitors/chemistry , Humans , Inhibitory Concentration 50 , Microsomes, Liver/chemistry , Structure-Activity Relationship , T-Lymphocytes/metabolismABSTRACT
We have recently reported the discovery of a novel class of glucocorticoid receptor (GR) antagonists, exemplified by 3, containing a 1,2-dihydroquinoline molecular scaffold. Further SAR studies of these antagonists uncovered chemical modifications conveying agonist functional activity to this series. These agonists exhibit good GR binding affinity and are selective against other nuclear hormone receptors.
Subject(s)
Quinolines/chemistry , Quinolines/pharmacology , Receptors, Glucocorticoid/agonists , Quinolines/metabolism , Receptors, Glucocorticoid/metabolism , Structure-Activity RelationshipABSTRACT
An uHTS campaign was performed to identify selective inhibitors of PKC-theta. Initial triaging of the hit set based on selectivity and historical analysis led to the identification of 2,4-diamino-5-nitropyrimidines as potent and selective PKC-theta inhibitors. A homology model and initial SAR is presented demonstrating that a 2-arylalkylamino substituent in conjunction with suitable 4-diamino substituent are essential for achieving selectivity over many kinases. Additional hit to lead profiling is presented on selected compounds.
Subject(s)
Isoenzymes/antagonists & inhibitors , Protein Kinase C/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Pyrimidines/chemistry , Pyrimidines/pharmacology , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/enzymology , CD4-Positive T-Lymphocytes/immunology , Humans , Interleukin-2/metabolism , Models, Molecular , Molecular Structure , Protein Conformation , Protein Kinase C-theta , Structure-Activity RelationshipABSTRACT
High-throughput screening is routinely employed as a method for the identification of novel hit structures. Large numbers of active compounds are typically procured in this way and must undergo a rigorous validation process. This process is described in detail for a collection of screening hits identified as inhibitors of IkappaB kinase-beta (IKKbeta), a key regulatory enzyme in the nuclear factor-kappaB (NF-kappaB) pathway. From these studies, a promising hit series was selected. Subsequent lead generation activities included the development of a pharmacophore hypothesis and structure-activity relationship (SAR) for the hit series. This led to the exploration of related scaffolds offering additional opportunities, and the various structural classes were comparatively evaluated for enzyme inhibition, selectivity, and drug-like properties. A novel lead series of thienopyridines was thereby established, and this series advanced into lead optimization for further development.
