ABSTRACT
Pyruvate kinase (PK) is an essential component of cellular metabolism, converting ADP and phosphoenolpyruvate (PEP) to pyruvate in the final step of glycolysis. Of the four unique isoforms of pyruvate kinase, R (PKR) is expressed exclusively in red blood cells and is a tetrameric enzyme that depends on fructose-1,6-bisphosphate (FBP) for activation. PKR deficiency leads to hemolysis of red blood cells resulting in anemia. Activation of PKR in both sickle cell disease and beta-thalassemia patients could lead to improved red blood cell fitness and survival. The discovery of a novel series of substituted urea PKR activators, via the serendipitous identification and diligent characterization of a minor impurity in an High Throughput Screening (HTS) hit will be discussed.
Subject(s)
High-Throughput Screening Assays , Pyruvate Kinase , Pyruvate Kinase/metabolism , Pyruvate Kinase/antagonists & inhibitors , Humans , Drug Discovery , Structure-Activity Relationship , Urea/chemistry , Urea/pharmacology , Enzyme Activators/pharmacology , Enzyme Activators/chemistry , Enzyme Activators/chemical synthesis , Molecular Structure , AnimalsABSTRACT
Utilizing the already described 3,4-bi-aryl pyridine series as a starting point, incorporation of a second ring system with a hydrogen bond donor and additional hydrophobic contacts yielded the azaindole series which exhibited potent, picomolar RSK2 inhibition and the most potent in vitro target modulation seen thus far for a RSK inhibitor. In the context of the more potent core, several changes at the phenol moiety were assessed to potentially find a tool molecule appropriate for in vivo evaluation.
Subject(s)
Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Animals , Chromatography, Liquid , Drug Design , Humans , Mass Spectrometry , Phenols/pharmacology , Protein Kinase Inhibitors/chemistry , Proton Magnetic Resonance Spectroscopy , Structure-Activity RelationshipABSTRACT
The discovery of a novel series of pyrrolopyrazines as JAK inhibitors with comparable enzyme and cellular activity to tofacitinib is described. The series was identified using a scaffold hopping approach aided by structure based drug design using principles of intramolecular hydrogen bonding for conformational restriction and targeting specific pockets for modulating kinase activity.
Subject(s)
Janus Kinase 3/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Pyrazines/chemistry , Pyrroles/chemistry , Drug Design , Humans , Janus Kinase 3/metabolism , Models, Molecular , Molecular Conformation , Molecular Structure , Phosphorylation , Piperidines/pharmacology , Pyrimidines/pharmacology , Pyrroles/pharmacology , Structure-Activity RelationshipABSTRACT
2-Amino-7-substituted benzoxazole analogs were identified by HTS as inhibitors of RSK2. Molecular modeling and medicinal chemistry techniques were employed to explore the SAR for this series with a focus of improving in vitro and target modulation potency and physicochemical properties.
Subject(s)
Benzoxazoles/chemistry , Protein Kinase Inhibitors/chemistry , Ribosomal Protein S6 Kinases, 90-kDa/antagonists & inhibitors , Benzoxazoles/chemical synthesis , Benzoxazoles/metabolism , Binding Sites , Crystallography, X-Ray , Humans , Molecular Dynamics Simulation , Protein Binding , Protein Kinase Inhibitors/chemical synthesis , Protein Structure, Tertiary , Ribosomal Protein S6 Kinases, 90-kDa/metabolism , Structure-Activity RelationshipABSTRACT
The introduction of N-substituted pyrazoles in a new series of CCR5 antagonists was shown to substantially increase antiviral activity.
Subject(s)
Anti-HIV Agents/chemistry , CCR5 Receptor Antagonists , Pyrazoles/chemistry , Anti-HIV Agents/chemical synthesis , Anti-HIV Agents/pharmacology , Humans , Pyrazoles/chemical synthesis , Pyrazoles/pharmacology , Receptors, CCR5/metabolism , Structure-Activity RelationshipABSTRACT
The bicyclic 5-amino-3-azabicyclo[3.3.0]octanes were shown to be effective replacements for the 3-amino-8-azabicyclo[3.2.1]octane found in the CCR5 antagonist maraviroc.
Subject(s)
Anti-HIV Agents/chemistry , Azabicyclo Compounds/chemistry , CCR5 Receptor Antagonists , Cyclohexanes/chemistry , HIV Fusion Inhibitors/chemistry , Triazoles/chemistry , Anti-HIV Agents/chemical synthesis , Anti-HIV Agents/pharmacology , Cell Line, Tumor , Cyclohexanes/chemical synthesis , Cyclohexanes/pharmacology , HIV Fusion Inhibitors/chemical synthesis , HIV Fusion Inhibitors/pharmacology , Humans , Maraviroc , Models, Chemical , Receptors, CCR5/metabolism , Triazoles/chemical synthesis , Triazoles/pharmacologyABSTRACT
Replacement of a secondary amide with an N-acyl or N-sulfonyl gem-disubstituted azacyle in a series of CCR5 antagonists led to the identification of compounds with excellent in vitro HIV antiviral activity and increased intrinsic membrane permeability.
Subject(s)
Amides/chemistry , Anti-HIV Agents/chemistry , Aza Compounds/chemistry , CCR5 Receptor Antagonists , HIV Fusion Inhibitors/chemistry , Anti-HIV Agents/chemical synthesis , Anti-HIV Agents/pharmacology , Aza Compounds/chemical synthesis , Aza Compounds/pharmacology , Cell Line, Tumor , Cell Membrane Permeability/drug effects , HIV Fusion Inhibitors/chemical synthesis , HIV Fusion Inhibitors/pharmacology , Humans , Receptors, CCR5/metabolismABSTRACT
The bicyclic 5-amino-3-azabicyclo[3.3.0]octanes were shown to be effective replacements for the conformationally restricted 4-aminopiperidine ring found in several series of CCR5 antagonists.
Subject(s)
CCR5 Receptor Antagonists , Drug Evaluation, Preclinical , Piperidines/chemistry , Models, MolecularABSTRACT
Starting with a high-throughput screening lead, a novel series of CCR5 antagonists was developed utilizing an information-based approach. Improvement of pharmacokinetic properties for the series was pursued by SAR exploration of the lead template. The synthesis, SAR and biological profiles of the series are described.
Subject(s)
Anti-HIV Agents/chemistry , Benzamides/chemistry , CCR5 Receptor Antagonists , HIV Fusion Inhibitors/chemistry , Pyrroles/chemistry , Animals , Anti-HIV Agents/chemical synthesis , Anti-HIV Agents/pharmacokinetics , Benzamides/chemical synthesis , Benzamides/pharmacology , HIV Fusion Inhibitors/chemical synthesis , HIV Fusion Inhibitors/pharmacokinetics , Humans , Microsomes, Liver/metabolism , Pyrroles/chemical synthesis , Pyrroles/pharmacokinetics , Rats , Receptors, CCR5/metabolism , Structure-Activity RelationshipABSTRACT
Direct pharmacological inhibition of RAS has remained elusive, and efforts to target CRAF have been challenging due to the complex nature of RAF signaling, downstream of activated RAS, and the poor overall kinase selectivity of putative RAF inhibitors. Herein, we describe 15 (LXH254, Aversa, R.; et al. Int. Patent WO2014151616A1, 2014), a selective B/C RAF inhibitor, which was developed by focusing on drug-like properties and selectivity. Our previous tool compound, 3 (RAF709; Nishiguchi, G. A.; et al. J. Med. Chem. 2017, 60, 4969), was potent, selective, efficacious, and well tolerated in preclinical models, but the high human intrinsic clearance precluded further development and prompted further investigation of close analogues. A structure-based approach led to a pyridine series with an alcohol side chain that could interact with the DFG loop and significantly improved cell potency. Further mitigation of human intrinsic clearance and time-dependent inhibition led to the discovery of 15. Due to its excellent properties, it was progressed through toxicology studies and is being tested in phase 1 clinical trials.
Subject(s)
Antineoplastic Agents/chemistry , Drug Discovery/methods , Mutation/genetics , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Animals , Antineoplastic Agents/pharmacology , Drug Design , Drug Discovery/trends , Humans , Molecular Docking Simulation/methods , Molecular Docking Simulation/trends , Mutation/drug effects , Protein Kinase Inhibitors/pharmacology , Xenograft Model Antitumor Assays/methodsABSTRACT
A novel series of CCR5 antagonists has been identified, utilizing leads from high-throughput screening which were further modified based on insights from competitor molecules. Lead optimization was pursued by balancing opposing trends of metabolic stability and potency. Selective and potent analogs with good pharmacokinetic properties were successfully developed.
Subject(s)
CCR5 Receptor Antagonists , Piperidines/chemistry , Piperidines/pharmacology , Receptors, CCR5/metabolism , Animals , Caco-2 Cells , Dogs , Haplorhini , Humans , Piperidines/pharmacokinetics , Rats , Spiro Compounds/chemistry , Spiro Compounds/pharmacokinetics , Spiro Compounds/pharmacology , Structure-Activity RelationshipABSTRACT
RAS oncogenes have been implicated in >30% of human cancers, all representing high unmet medical need. The exquisite dependency on CRAF kinase in KRAS mutant tumors has been established in genetically engineered mouse models and human tumor cells. To date, many small molecule approaches are under investigation to target CRAF, yet kinase-selective and cellular potent inhibitors remain challenging to identify. Herein, we describe 14 (RAF709) [ Aversa , Biaryl amide compounds as kinase inhibitors and their preparation . WO 2014151616, 2014 ], a selective B/C RAF inhibitor, which was developed through a hypothesis-driven approach focusing on drug-like properties. A key challenge encountered in the medicinal chemistry campaign was maintaining a balance between good solubility and potent cellular activity (suppression of pMEK and proliferation) in KRAS mutant tumor cell lines. We investigated the small molecule crystal structure of lead molecule 7 and hypothesized that disruption of the crystal packing would improve solubility, which led to a change from N-methylpyridone to a tetrahydropyranyl oxy-pyridine derivative. 14 proved to be soluble, kinase selective, and efficacious in a KRAS mutant xenograft model.
Subject(s)
2,2'-Dipyridyl/analogs & derivatives , Antineoplastic Agents/pharmacology , Benzamides/pharmacology , raf Kinases/antagonists & inhibitors , ras Proteins/genetics , 2,2'-Dipyridyl/chemistry , 2,2'-Dipyridyl/pharmacology , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Benzamides/chemistry , Crystallography, X-Ray , Dogs , Drug Design , Drug Discovery , Drug Stability , Humans , Inhibitory Concentration 50 , Mice , Molecular Targeted Therapy , Neoplasms/drug therapy , Neoplasms/genetics , Proto-Oncogene Proteins B-raf/chemistry , Proto-Oncogene Proteins p21(ras)/genetics , Rats , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
While the p90 ribosomal S6 kinase (RSK) family has been implicated in multiple tumor cell functions, the full understanding of this kinase family has been restricted by the lack of highly selective inhibitors. A bis-phenol pyrazole was identified from high-throughput screening as an inhibitor of the N-terminal kinase of RSK2. Structure-based drug design using crystallography, conformational analysis, and scaffold morphing resulted in highly optimized difluorophenol pyridine inhibitors of the RSK kinase family as demonstrated cellularly by the inhibition of YB1 phosphorylation. These compounds provide for the first time in vitro tools with an improved selectivity and potency profile to examine the importance of RSK signaling in cancer cells and to fully evaluate RSK as a therapeutic target.
Subject(s)
Pyrazoles/chemistry , Pyridines/chemistry , Pyrimidines/chemistry , Ribosomal Protein S6 Kinases, 90-kDa/antagonists & inhibitors , Animals , Cell Line , Crystallography, X-Ray , Humans , Male , Mice , Models, Molecular , Phosphorylation , Protein Conformation , Pyrazoles/chemical synthesis , Pyrazoles/pharmacology , Pyridines/chemical synthesis , Pyridines/pharmacology , Pyrimidines/chemical synthesis , Pyrimidines/pharmacology , Rats, Sprague-Dawley , Signal Transduction , Structure-Activity Relationship , Y-Box-Binding Protein 1/metabolismABSTRACT
Compound 13 was discovered through morphing of the ATR biochemical HTS hit 1. The ABI series was potent and selective for ATR. Incorporation of a 6-azaindole afforded a marked increase in cellular potency but was associated with poor PK and hERG ion channel inhibition. DMPK experiments established that CYP P450 and AO metabolism in conjunction with Pgp and BCRP efflux were major causative mechanisms for the observed PK. The series also harbored the CYP3A4 TDI liability driven by the presence of both a morpholine and an indole moiety. Incorporation of an adjacent fluorine or nitrogen into the 6-azaindole addressed many of the various medicinal chemistry issues encountered.
ABSTRACT
A novel series of orally active pyrimido[5,4-3][1,2,4]triazine-5,7-diamine-based hypoglycemic agents have been identified. These compounds show non-selective inhibitory properties against a panel of protein tyrosine phosphatases including PTP1B. Compounds 12 and 13 display oral glucose lowering effects in ob/ob mice.
Subject(s)
Diamines/pharmacology , Enzyme Inhibitors/pharmacology , Hypoglycemic Agents/pharmacology , Protein Tyrosine Phosphatases/antagonists & inhibitors , Triazines/pharmacology , Administration, Oral , Animals , Biological Availability , Blood Glucose/drug effects , Diamines/chemical synthesis , Diamines/pharmacokinetics , Disease Models, Animal , Dithiothreitol/chemistry , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/pharmacokinetics , Inhibitory Concentration 50 , Injections, Intravenous , Male , Mice , Mice, Inbred C57BL , Mice, Obese , Structure-Activity Relationship , Triazines/chemistry , Triazines/pharmacokineticsABSTRACT
A series of 7-[(5R)-substituted 2-oxo-1-pyrrolidinyl]-heptanoic acids were prepared, their isomeric purity determined, and pharmacologically evaluated. Lactams with affinity for the EP(4) receptor displayed agonist behavior. The lower side-chain of the lactam template could be substituted to afford ligands (e.g., 17, 24, 30, 31, and 33) of high potency and greater than 1000-fold affinity for EP(4) versus the other EP prostanoid receptors.