ABSTRACT
The development and optimization of a series of quinolinylpurines as potent and selective PI3Kδ kinase inhibitors with excellent physicochemical properties are described. This medicinal chemistry effort led to the identification of 1 (AMG319), a compound with an IC50 of 16 nM in a human whole blood assay (HWB), excellent selectivity over a large panel of protein kinases, and a high level of in vivo efficacy as measured by two rodent disease models of inflammation.
Subject(s)
Adenosine/pharmacology , Autoimmune Diseases/prevention & control , Class I Phosphatidylinositol 3-Kinases/antagonists & inhibitors , Inflammation/prevention & control , Protein Kinase Inhibitors/pharmacology , Quinolines/pharmacology , Adenosine/chemistry , Adenosine/metabolism , Animals , Cells, Cultured , Class I Phosphatidylinositol 3-Kinases/chemistry , Class I Phosphatidylinositol 3-Kinases/metabolism , Crystallography, X-Ray , Disease Models, Animal , Drug Discovery , Female , Humans , Mice, Inbred BALB C , Mice, Transgenic , Models, Chemical , Models, Molecular , Molecular Structure , Protein Binding , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/metabolism , Protein Structure, Tertiary , Quinolines/chemistry , Quinolines/metabolism , Rats, Inbred Lew , Sf9 Cells , Structure-Activity RelationshipABSTRACT
We report the discovery of a novel series of 2-(3-alkoxy-1-azetidinyl) quinolines as potent and selective PDE10A inhibitors. Structure-activity studies improved the solubility (pH 7.4) and maintained high PDE10A activity compared to initial lead compound 3, with select compounds demonstrating good oral bioavailability. X-ray crystallographic studies revealed two distinct binding modes to the catalytic site of the PDE10A enzyme. An ex vivo receptor occupancy assay in rats demonstrated that this series of compounds covered the target within the striatum.
Subject(s)
Phosphodiesterase Inhibitors/pharmacology , Phosphoric Diester Hydrolases/metabolism , Quinolines/pharmacology , Dose-Response Relationship, Drug , Humans , Models, Molecular , Molecular Structure , Phosphodiesterase Inhibitors/chemical synthesis , Phosphodiesterase Inhibitors/chemistry , Quinolines/chemical synthesis , Quinolines/chemistry , Solubility , Structure-Activity RelationshipABSTRACT
γ-Secretase modulators (GSMs) are potentially disease-modifying treatments for Alzheimer's disease. They selectively lower pathogenic Aß42 levels by shifting the enzyme cleavage sites without inhibiting γ-secretase activity, possibly avoiding known adverse effects observed with complete inhibition of the enzyme complex. A cell-based HTS effort identified the sulfonamide 1 as a GSM lead. Lead optimization studies identified compound 25 with improved cell potency, PKDM properties, and it lowered Aß42 levels in the cerebrospinal fluid (CSF) of Sprague-Dawley rats following oral administration. Further optimization of 25 to improve cellular potency is described.
Subject(s)
Alzheimer Disease/drug therapy , Amides/pharmacology , Amyloid Precursor Protein Secretases/metabolism , Picolines/pharmacology , Alzheimer Disease/enzymology , Amides/chemistry , Animals , HEK293 Cells , Humans , Picolines/chemistry , Rats , Rats, Sprague-DawleyABSTRACT
We report the discovery of a novel series of biaryl ethers as potent and selective PDE10A inhibitors. Structure-activity studies improved the potency and decreased Pgp-mediated efflux found in the initial compound 4. X-ray crystallographic studies revealed two novel binding modes to the catalytic site of the PDE10A enzyme.
Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Drug Discovery , Ethers/metabolism , Ethers/pharmacology , Phosphodiesterase Inhibitors/metabolism , Phosphodiesterase Inhibitors/pharmacology , Phosphoric Diester Hydrolases/metabolism , Crystallography, X-Ray , Dose-Response Relationship, Drug , Ethers/chemical synthesis , Ethers/chemistry , Humans , Models, Molecular , Molecular Structure , Phosphodiesterase Inhibitors/chemical synthesis , Phosphodiesterase Inhibitors/chemistry , Structure-Activity RelationshipABSTRACT
A series of fused 6,6-bicyclic chromenones was investigated for activity against the bradykinin B1 receptor. SAR studies based on a pharmacophore model revealed compounds with high affinity for both human and rabbit B1. These compounds demonstrated favorable pharmacokinetic properties and 5-chlorochromenone 15 was efficacious in a carrageenan-induced mechanical hyperalgesia model for chronic pain.
Subject(s)
Benzopyrans/chemical synthesis , Bradykinin B1 Receptor Antagonists , Animals , Benzopyrans/pharmacology , Carrageenan/pharmacology , Chemistry, Pharmaceutical/methods , Chronic Pain/drug therapy , Drug Design , Humans , Hyperalgesia/drug therapy , Inhibitory Concentration 50 , Kinetics , Models, Chemical , Rabbits , Structure-Activity Relationship , Tumor Necrosis Factor-alpha/metabolismABSTRACT
An efficient and convenient method for the synthesis of [1,2,4]triazolo[4,3-a]pyridines was exemplified by the synthesis of 20 analogues bearing a variety of substituents at the 3-position. The methodology involves a palladium-catalyzed addition of hydrazides to 2-chloropyridine, which occurs chemoselectively at the terminal nitrogen atom of the hydrazide, followed by dehydration in acetic acid under microwave irradiation.
Subject(s)
Combinatorial Chemistry Techniques , Hydrazines/chemistry , Palladium/chemistry , Pyridines/chemistry , Pyridines/chemical synthesis , Triazoles/chemical synthesis , Acetic Acid/chemistry , Catalysis , Cyclization , Microwaves , Molecular Structure , Triazoles/chemistryABSTRACT
Cyclin-dependent kinase 5 (CDK5) is a serine-threonine protein kinase that plays a significant role in neuronal development. In association with p25, CDK5 abnormally phosphorylates a number of cellular targets involved in neurodegenerative disorders. Using active site homology and previous structure-activity relationships, a new series of potent CDK5 inhibitors was designed. This report describes the optimization of 6-oxo-1,6-dihydropyridines as CDK5 inhibitors.
Subject(s)
Cyclin-Dependent Kinase 5/antagonists & inhibitors , Drug Design , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Pyridones/chemical synthesis , Pyridones/pharmacology , Molecular Structure , Protein Kinase Inhibitors/chemistry , Pyridones/chemistry , Stereoisomerism , Structure-Activity RelationshipABSTRACT
The p38 mitogen-activated protein kinase (MAPK) is a central signaling molecule in many proinflammatory pathways, regulating the cellular response to a multitude of external stimuli including heat, ultraviolet radiation, osmotic shock, and a variety of cytokines especially interleukin-1beta and tumor necrosis factor alpha. Thus, inhibitors of this enzyme are postulated to have significant therapeutic potential for the treatment of rheumatoid arthritis, inflammatory bowel disease, osteoporosis, and many other diseases where aberrant cytokine signaling is the driver of disease. Herein, we describe a novel class of 3-amino-7-phthalazinylbenzoisoxazole-based inhibitors. With relatively low molecular weight, these compounds are highly potent in enzyme and cell-based assays, with minimal protein shift in 50% human whole blood. Compound 3c was efficacious (ED 50 = 0.05 mg/kg) in the rat collagen induced arthritis (CIA) model.
Subject(s)
Amines/chemistry , Benzene/chemistry , Isoxazoles/administration & dosage , Isoxazoles/pharmacology , Mitogen-Activated Protein Kinase 14/antagonists & inhibitors , Phthalazines/chemistry , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , Administration, Oral , Animals , Arthritis/chemically induced , Arthritis/drug therapy , Arthritis/enzymology , Crystallography, X-Ray , Disease Models, Animal , Humans , Isoxazoles/chemistry , Isoxazoles/therapeutic use , Mitogen-Activated Protein Kinase 14/chemistry , Mitogen-Activated Protein Kinase 14/metabolism , Models, Molecular , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Rats , Structure-Activity RelationshipABSTRACT
Investigations into the structure-activity relationships (SAR) of a series of phthalazine-based inhibitors of p38 are described. These efforts originated from quinazoline 1 and through rational design led to the development of a series of orally bioavailable, potent, and selective inhibitors. Kinase selectivity was achieved by exploiting a collection of interactions with p38alpha including close contact to Ala157, occupation of the hydrophobic gatekeeper pocket, and a residue flip with Gly110. Substitutions on the phthalazine influenced the pharmacokinetic properties, of which compound 16 displayed the most desirable profile. Oral dosing (0.03 mg/kg) of 16 in rats 1 h prior to LPS challenge gave a >50% decrease in TNFalpha production.
Subject(s)
Mitogen-Activated Protein Kinase 14/antagonists & inhibitors , Phthalazines/chemistry , Phthalazines/pharmacology , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Animals , Cells, Cultured , Crystallography, X-Ray , Drug Evaluation, Preclinical , Humans , Mitogen-Activated Protein Kinase 14/chemistry , Mitogen-Activated Protein Kinase 14/metabolism , Models, Molecular , Molecular Structure , Phthalazines/chemical synthesis , Protein Kinase Inhibitors/chemical synthesis , Quinolines/chemical synthesis , Quinolines/chemistry , Quinolines/pharmacology , Rats , Sensitivity and Specificity , Structure-Activity RelationshipABSTRACT
Natural products continue to demonstrate their utility both as therapeutics and as molecular probes for the discovery and mechanistic deconvolution of various cellular processes. However, this utility is dampened by the inherent difficulties involved in isolating and characterizing new bioactive natural products, in obtaining sufficient quantities of purified compound for further biological studies, and in developing bioactive probes. Key to characterizing the biological activity of natural products is the identification of the molecular target(s) within the cell. The marine sponge-derived natural product Pateamine A (PatA) has been found to be an inhibitor of eukaryotic translation initiation. Herein, we describe the methods utilized for identification of the eukaryotic translation initiation factor 4A (eIF4A) as one of the primary protein targets of PatA. We begin by describing the synthesis of an active biotin conjugate of PatA (B-PatA), made possible by total synthesis, followed by its use for affinity purification of PatA binding proteins from cellular lysates. We have attempted to present the methodology as a general technique for the identification of protein targets for small molecules including natural products.
Subject(s)
Epoxy Compounds/isolation & purification , Epoxy Compounds/pharmacology , Eukaryotic Initiation Factor-4A/antagonists & inhibitors , Macrolides/isolation & purification , Macrolides/pharmacology , Thiazoles/isolation & purification , Thiazoles/pharmacology , Animals , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Biotin/chemistry , Biotin/metabolism , Chromatography, Affinity , Cyclohexylamines/chemistry , Drug Design , Epoxy Compounds/chemistry , Epoxy Compounds/metabolism , Eukaryotic Initiation Factor-4A/isolation & purification , Humans , Macrolides/chemical synthesis , Macrolides/chemistry , Macrolides/metabolism , Models, Biological , Protein Binding , Sepharose/analogs & derivatives , Sepharose/chemistry , Sepharose/metabolism , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/metabolismABSTRACT
Cyclin-dependent kinase 5 (CDK5) is a serine/threonine kinase that plays a critical role in the early development of the nervous system. Deregulation of CDK5 is believed to contribute to the abnormal phosphorylation of various cellular substrates associated with neurodegenerative disorders such as Alzheimer's disease, amyotrophic lateral sclerosis, and ischemic stroke. Acyclic urea 3 was identified as a potent CDK5 inhibitor and co-crystallographic data of urea 3/CDK2 enzyme were used to design a novel series of 3,4-dihydroquinazolin-2(1H)-ones as CDK5 inhibitors. In this investigation we present our synthetic studies toward this series of compounds and discuss their biological relevance as CDK5 inhibitors.
Subject(s)
Cyclin-Dependent Kinase 5/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Quinazolinones/chemistry , Quinazolinones/pharmacology , Benzimidazoles/chemical synthesis , Benzimidazoles/chemistry , Benzimidazoles/pharmacology , Benzyl Compounds/chemical synthesis , Benzyl Compounds/chemistry , Benzylamines/chemical synthesis , Benzylamines/chemistry , Binding Sites , Crystallography, X-Ray , Cyclin-Dependent Kinase 5/metabolism , Hydrogen/chemistry , Inhibitory Concentration 50 , Isomerism , Models, Molecular , Molecular Structure , Oxadiazoles/chemical synthesis , Oxadiazoles/chemistry , Protein Kinase Inhibitors/chemistry , Quinazolinones/chemical synthesis , Structure-Activity Relationship , Thiadiazoles/chemical synthesis , Thiadiazoles/chemistry , Thiazoles/chemical synthesis , Thiazoles/chemistryABSTRACT
Cyclin-dependent kinase 5 (CDK5) is a serine/threonine protein kinase and its deregulation is implicated in a number of neurodegenerative disorders such as Alzheimer's disease, amyotrophic lateral sclerosis, and ischemic stroke. Using active site homology modeling between CDK5 and CDK2, we explored several different chemical series of potent CDK5 inhibitors. In this report, we describe the design, synthesis, and CDK5 inhibitory activities of quinolin-2(1H)-one derivatives.
Subject(s)
Cyclin-Dependent Kinase 5/antagonists & inhibitors , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Quinolines/chemical synthesis , Quinolines/pharmacology , Binding Sites , Cyclin-Dependent Kinase 2/chemistry , Cyclin-Dependent Kinase 5/chemistry , Drug Design , Indicators and Reagents , Models, Molecular , Protein Binding , Structure-Activity RelationshipABSTRACT
The vanilloid receptor-1 (VR1 or TRPV1) is a member of the transient receptor potential (TRP) family of ion channels and plays a role as an integrator of multiple pain-producing stimuli. From a high-throughput screening assay, measuring calcium uptake in TRPV1-expressing cells, we identified an N-aryl trans-cinnamide (AMG9810, compound 9) that acts as a potent TRPV1 antagonist. We have demonstrated the antihyperalgesic properties of 9 in vivo and have also reported the discovery of novel, orally bioavailable cinnamides derived from this lead. Herein, we expand our investigations and describe the synthesis and biological evaluation of a series of conformationally constrained analogues of the s-cis conformer of compound 9. These investigations resulted in the identification of 4-amino- and 4-oxopyrimidine cores as suitable isosteric replacements for the trans-acrylamide moiety. The best examples from this series, pyrimidines 79 and 74, were orally bioavailable and exhibited potent antagonism of both rat (IC50 = 4.5 and 0.6 nM, respectively) and human TRPV1 (IC50 = 7.4 and 3.7 nM, respectively). In addition, compound 74 was shown to be efficacious at blocking a TRPV1-mediated physiological response in vivo in the capsaicin-induced hypothermia model in rats; however, it was ineffective at preventing thermal hyperalgesia induced by complete Freund's adjuvant in rats.
Subject(s)
Aminoquinolines/chemical synthesis , Analgesics/chemical synthesis , Pyrimidines/chemical synthesis , Quinolines/chemical synthesis , TRPV Cation Channels/antagonists & inhibitors , Administration, Oral , Aminoquinolines/chemistry , Aminoquinolines/pharmacology , Analgesics/chemistry , Analgesics/pharmacology , Animals , Biological Availability , Body Temperature/drug effects , CHO Cells , Cricetinae , Cricetulus , Humans , Hyperalgesia/prevention & control , Injections, Intravenous , Male , Models, Molecular , Molecular Conformation , Pyrimidines/chemistry , Pyrimidines/pharmacology , Quinolines/chemistry , Quinolines/pharmacology , Rats , Rats, Sprague-Dawley , Stereoisomerism , Structure-Activity Relationship , ThermodynamicsABSTRACT
A series of novel 4-oxopyrimidine TRPV1 antagonists was evaluated in assays measuring the blockade of capsaicin or acid-induced influx of calcium into CHO cells expressing TRPV1. The investigation of the structure-activity relationships in the heterocyclic A-region revealed the optimum pharmacophoric elements required for activity in this series and resulted in the identification of subnanomolar TRPV1 antagonists. The most potent of these antagonists were thoroughly profiled in pharmacokinetic assays. Optimization of the heterocyclic A-region led to the design and synthesis of 23, a compound that potently blocked multiple modes of TRPV1 activation. Compound 23 was shown to be effective in a rodent "on-target" biochemical challenge model (capsaicin-induced flinch, ED50 = 0.33 mg/kg p.o.) and was antihyperalgesic in a model of inflammatory pain (CFA-induced thermal hyperalgesia, MED = 0.83 mg/kg, p.o.). Based on its in vivo efficacy and pharmacokinetic profile, compound 23 (N-{4-[6-(4-trifluoromethyl-phenyl)-pyrimidin-4-yloxy]-benzothiazol-2-yl}-acetamide; AMG 517) was selected for further evaluation in human clinical trials.