ABSTRACT
Two 1-(4-aryl-5-alkyl-pyridin-2-yl)-3-methylurea glucokinase activators were identified with robust in vivo efficacy. These two compounds possessed higher solubilities than the previously identified triaryl compounds (i.e., AM-2394). Structure-activity relationship studies are presented along with relevant pharmacokinetic and in vivo data.
ABSTRACT
Glucokinase (GK) catalyzes the phosphorylation of glucose to glucose-6-phosphate. We present the structure-activity relationships leading to the discovery of AM-2394, a structurally distinct GKA. AM-2394 activates GK with an EC50 of 60 nM, increases the affinity of GK for glucose by approximately 10-fold, exhibits moderate clearance and good oral bioavailability in multiple animal models, and lowers glucose excursion following an oral glucose tolerance test in an ob/ob mouse model of diabetes.
ABSTRACT
Glucokinase (GK) activators represent a class of type 2 diabetes therapeutics actively pursued due to the central role that GK plays in regulating glucose homeostasis. Herein we report a novel C5-alkyl-2-methylurea-substituted pyridine series of GK activators derived from our previously reported thiazolylamino pyridine series. Our efforts in optimizing potency, enzyme kinetic properties, and metabolic stability led to the identification of compound 26 (AM-9514). This analogue showed a favorable combination of in vitro potency, enzyme kinetic properties, acceptable pharmacokinetic profiles in preclinical species, and robust efficacy in a rodent PD model.
ABSTRACT
Retinol-Binding Protein 4 (RBP4) is a plasma protein that transports retinol (vitamin A) from the liver to peripheral tissues. This Letter highlights our efforts in discovering the first, to our knowledge, non-retinoid small molecules that bind to RBP4 at the retinol site and reduce serum RBP4 levels in mice, by disrupting the interaction between RBP4 and transthyretin (TTR), a plasma protein that binds RBP4 and protects it from renal excretion. Potent compounds were discovered and optimized quickly from high-throughput screen (HTS) hits utilizing a structure-based approach. Inhibitor co-crystal X-ray structures revealed unique disruptions of RBP4-TTR interactions by our compounds through induced loop conformational changes instead of steric hindrance exemplified by fenretinide. When administered to mice, A1120, a representative compound in the series, showed concentration-dependent retinol and RBP4 lowering.
Subject(s)
Drug Discovery , Retinol-Binding Proteins, Plasma/antagonists & inhibitors , Small Molecule Libraries/pharmacology , Animals , Crystallography, X-Ray , Dose-Response Relationship, Drug , Humans , Ligands , Male , Mice , Models, Molecular , Molecular Structure , Rats , Retinol-Binding Proteins, Plasma/metabolism , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/chemistry , Structure-Activity Relationship , Vitamin A/bloodABSTRACT
Glucokinase (GK) is a hexokinase isozyme that catalyzes the phosphorylation of glucose to glucose-6-phosphate. Glucokinase activators are being investigated as potential diabetes therapies because of their effects on hepatic glucose output and/or insulin secretion. Here, we have examined the efficacy and mechanisms of action of a novel glucokinase activator, GKA23. In vitro, GKA23 increased the affinity of rat and mouse glucokinase for glucose, and increased glucose uptake in primary rat hepatocytes. In vivo, GKA23 treatment improved glucose homeostasis in rats by enhancing beta cell insulin secretion and suppressing hepatic glucose production. Sub-chronic GKA23 treatment of mice fed a high-fat diet resulted in improved glucose homeostasis and lipid profile.
Subject(s)
Aminopyridines/chemistry , Enzyme Activators/chemistry , Glucokinase/metabolism , Thiadiazoles/chemistry , Animals , Area Under Curve , Blood Glucose/metabolism , Catalysis , Diabetes Mellitus, Experimental/drug therapy , Glucose/metabolism , Glucose Tolerance Test , Hepatocytes/metabolism , Homeostasis , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/cytology , Kinetics , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Obesity/drug therapy , Phosphorylation , Rats , Rats, Sprague-DawleyABSTRACT
We describe the discovery and optimization of 5-(2-((1-(phenylsulfonyl)-1,2,3,4-tetrahydroquinolin-7-yl)oxy)pyridin-4-yl)-1,2,4-oxadiazoles as novel agonists of GPR119. Previously described aniline 2 had suboptimal efficacy in signaling assays using cynomolgus monkey (cyno) GPR119 making evaluation of the target in preclinical models difficult. Replacement of the aniline ring with a tetrahydroquinoline ring constrained the rotation of the aniline C-N bond and gave compounds with increased efficacy on human and cyno receptors. Additional optimization led to the discovery of 10, which possesses higher free fraction in plasma and improved pharmacokinetic properties in rat and cyno compared to 2.
Subject(s)
Drug Discovery , Oxadiazoles/pharmacology , Quinolines/pharmacology , Receptors, G-Protein-Coupled/agonists , Animals , Dose-Response Relationship, Drug , Humans , Macaca fascicularis , Molecular Structure , Oxadiazoles/chemical synthesis , Oxadiazoles/chemistry , Quinolines/chemical synthesis , Quinolines/chemistry , Rats , Structure-Activity RelationshipABSTRACT
The discovery and optimization of novel N-(3-(1,3-dioxo-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-4-yloxy)phenyl)benzenesulfonamide GPR119 agonists is described. Modification of the pyridylphthalimide motif of the molecule with R(1)=-Me and R(2)=-(i)Pr substituents, incorporated with a 6-fluoro substitution on the central phenyl ring offered a potent and metabolically stable tool compound 22.
Subject(s)
Drug Discovery , Pyridines/pharmacology , Receptors, G-Protein-Coupled/agonists , Sulfonamides/pharmacology , Animals , Dose-Response Relationship, Drug , Humans , Microsomes, Liver/chemistry , Microsomes, Liver/metabolism , Molecular Structure , Pyridines/chemistry , Pyridines/metabolism , Rats , Structure-Activity Relationship , Sulfonamides/chemistry , Sulfonamides/metabolismABSTRACT
We describe the discovery of a series of arylsulfonyl 3-(pyridin-2-yloxy)anilines as GPR119 agonists derived from compound 1. Replacement of the three methyl groups in 1 with metabolically stable moieties led to the identification of compound 34, a potent and efficacious GPR119 agonist with improved pharmacokinetic (PK) properties.
Subject(s)
Aniline Compounds/chemistry , Aniline Compounds/pharmacology , Receptors, G-Protein-Coupled/agonists , Aniline Compounds/chemical synthesis , Animals , Diabetes Mellitus, Type 2/drug therapy , Drug Discovery , Humans , Mice , Models, Molecular , Receptors, G-Protein-Coupled/chemistry , Structure-Activity RelationshipABSTRACT
The present report describes our efforts to convert an existing LXR agonist into an LXR antagonist using a structure-based approach. A series of benzenesulfonamides was synthesized based on structural modification of a known LXR agonist and was determined to be potent dual liver X receptor (LXR α/ß) ligands. Herein we report the identification of compound 54 as the first reported LXR antagonist that is suitable for pharmacological in vivo evaluation in rodents.
Subject(s)
Drug Discovery , Orphan Nuclear Receptors/antagonists & inhibitors , Sulfonamides/pharmacology , Animals , Dose-Response Relationship, Drug , HEK293 Cells , Hep G2 Cells , Humans , Ligands , Liver X Receptors , Male , Mice , Molecular Structure , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship , Sulfonamides/chemical synthesis , Sulfonamides/chemistry , BenzenesulfonamidesABSTRACT
Structural modification of a series of dual LXRα/ß agonists led to the identification of a new class of LXRß partial agonists. An X-ray co-crystal structure shows that a representative member of this series, pyrrole 5, binds to LXRß with a reversed orientation compared to 1.
Subject(s)
Orphan Nuclear Receptors/agonists , Protein Isoforms/agonists , Pyrroles/chemical synthesis , Binding Sites , Caco-2 Cells , Crystallography, X-Ray , Genes, Reporter , HEK293 Cells , Humans , Liver X Receptors , Orphan Nuclear Receptors/chemistry , Protein Binding , Protein Isoforms/chemistry , Pyrroles/pharmacology , Structure-Activity Relationship , TransfectionABSTRACT
The discovery and parallel synthesis of potent, small molecule antagonists of Neuromedin B receptor based on the ary-hexahydro-dibenzodiazepin-1-one core is described.
Subject(s)
Benzodiazepinones/chemical synthesis , Chemistry, Pharmaceutical/methods , Receptors, Bombesin/antagonists & inhibitors , Animals , Benzodiazepinones/pharmacology , Dose-Response Relationship, Drug , Drug Design , Electrons , Gastrin-Releasing Peptide/chemistry , HeLa Cells , Humans , Inhibitory Concentration 50 , Ligands , Models, Chemical , Peptides/chemistry , Structure-Activity RelationshipABSTRACT
The discovery and optimization of a series of potent PPARdelta full agonists with partial agonistic activity against PPARgamma is described.
Subject(s)
PPAR delta/agonists , PPAR gamma/agonists , Thiazoles/chemistry , Animals , Computer Simulation , Crystallography, X-Ray , PPAR delta/metabolism , PPAR gamma/metabolism , Rats , Rats, Sprague-Dawley , Thiazoles/chemical synthesis , Thiazoles/pharmacologyABSTRACT
Retinol-binding protein 4 (RBP4) transports retinol from the liver to extrahepatic tissues, and RBP4 lowering is reported to improve insulin sensitivity in mice. We have identified A1120, a high affinity (K(i) = 8.3 nm) non-retinoid ligand for RBP4, which disrupts the interaction between RBP4 and its binding partner transthyretin. Analysis of the RBP4-A1120 co-crystal structure reveals that A1120 induces critical conformational changes at the RBP4-transthyretin interface. Administration of A1120 to mice lowers serum RBP4 and retinol levels but, unexpectedly, does not improve insulin sensitivity. In addition, we show that Rpb4(-/-) mice display normal insulin sensitivity and are not protected from high fat diet-induced insulin resistance. We conclude that lowering RBP4 levels does not improve insulin sensitivity in mice. Therefore, RBP4 lowering may not be an effective strategy for treating diabetes.
Subject(s)
Heterocyclic Compounds, 3-Ring/chemistry , Heterocyclic Compounds, 3-Ring/pharmacology , Piperidines/chemistry , Retinol-Binding Proteins, Plasma , Vitamin A/blood , Animals , Crystallography, X-Ray , Diabetes Mellitus/blood , Diabetes Mellitus/drug therapy , Dietary Fats/adverse effects , Humans , Insulin/metabolism , Insulin Resistance , Ligands , Mice , Mice, Knockout , Piperidines/pharmacology , Protein Structure, Tertiary , Retinol-Binding Proteins, Plasma/agonists , Retinol-Binding Proteins, Plasma/chemistry , Retinol-Binding Proteins, Plasma/metabolismABSTRACT
Retinol binding protein 4 (RBP4) is a serum protein that serves as the major transport protein for retinol (vitamin A). Recent reports suggest that elevated levels of RBP4 are associated with insulin resistance and that insulin sensitivity may be improved by reducing serum RBP4 levels. This can be accomplished by administration of small molecules, such as fenretinide, that compete with retinol for binding to RBP4 and disrupt the protein-protein interaction between RBP4 and transthyretin (TTR), another serum protein that protects RBP4 from renal clearance. We developed a fluorescence resonance energy transfer (FRET) assay that measures the interaction between RBP4 and TTR and can be used to determine the binding affinities of RBP4 ligands. We present an allosteric model that describes the pharmacology of interaction among RBP4, TTR, retinol, and fenretinide, and we show data that support the model. We show that retinol increases the affinity of RBP4 for TTR by a factor of 4 and determine the affinity constants of fenretinide and retinyl acetate. The assay may be useful for characterizing small molecule ligands that bind to RBP4 and disrupt its interaction with TTR. In addition, such a model could be used to describe other protein-protein interactions that are modulated by small molecules.
Subject(s)
Fenretinide/metabolism , Prealbumin/metabolism , Retinol-Binding Proteins, Plasma/metabolism , Binding Sites , Diterpenes , Fenretinide/chemistry , Fluorescence Resonance Energy Transfer/methods , Humans , Kinetics , Ligands , Models, Biological , Prealbumin/chemistry , Retinol-Binding Proteins, Plasma/chemistry , Retinyl Esters , Structure-Activity Relationship , Vitamin A/analogs & derivatives , Vitamin A/chemistry , Vitamin A/metabolismABSTRACT
The objective of this study was to demonstrate the efficacy of a novel peroxisome proliferator-activated receptor (PPAR) agonist and known PPARalpha and PPARdelta agonists to increase HDL-cholesterol (HDL-C) in the St. Kitts vervet, a nonhuman primate model of atherosclerosis. Four groups (n = 6) were studied and each group was assigned one of the following "treatments": a) vehicle only (vehicle); b) the PPARdelta selective agonist GW501516 (GW); c) the PPARalpha/delta agonist T913659 (T659); and d) the PPARalpha agonist TriCor (fenofibrate). No statistically significant changes were seen in body weight, total plasma cholesterol, plasma triglycerides, VLDL-C, LDL-C, or apolipoprotein B (apoB) concentrations. Each of the PPARalpha and PPARdelta agonists investigated in this study increased plasma HDL-C, apoA-I, and apoA-II concentrations and increased HDL particle size in St. Kitts vervets. The maximum percentage increase in HDL-C from baseline for each group was as follows: vehicle, 5%; GW, 43%; T659, 43%; and fenofibrate, 20%. Treatment with GW and T659 resulted in an increase in medium-sized HDL particles, whereas fenofibrate showed increases in large HDL particles. These data provide additional evidence that PPARalpha and PPARdelta agonists (both mixed and selective) have beneficial effects on HDL-C in these experimental primates.
Subject(s)
Cholesterol, HDL/blood , PPAR alpha/agonists , PPAR gamma/agonists , Animals , Chlorocebus aethiops , Male , Particle Size , Thiazoles/pharmacologyABSTRACT
The design and parallel synthesis of potent, small molecule partial agonists of Neuromedin B receptor based on the 3-amino-2,3,4,9-tetrahydro-1H-carbazole-3-carboxylic acid amide core is described.