ABSTRACT
Polo-like kinase-2 (Plk-2) is a potential therapeutic target for Parkinson's disease and this Letter describes the SAR of a series of dihydropteridinone based Plk-2 inhibitors. By optimizing both the N-8 substituent and the biaryl region of the inhibitors we obtained single digit nanomolar compounds such as 37 with excellent selectivity for Plk-2 over Plk-1. When dosed orally in rats, compound 37 demonstrated a 41-45% reduction of pS129-α-synuclein levels in the cerebral cortex.
Subject(s)
Drug Design , Protein Kinase Inhibitors/chemical synthesis , Protein Serine-Threonine Kinases/antagonists & inhibitors , Administration, Oral , Animals , Brain/metabolism , Cell Cycle Proteins/antagonists & inhibitors , Cell Cycle Proteins/metabolism , HEK293 Cells , Half-Life , Humans , Mice , Microsomes, Liver/metabolism , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins/antagonists & inhibitors , Proto-Oncogene Proteins/metabolism , Pteridines/chemical synthesis , Pteridines/chemistry , Pteridines/pharmacokinetics , Rats , Structure-Activity Relationship , Polo-Like Kinase 1ABSTRACT
The SAR of a series of brain penetrant, trisubstituted thiophene based JNK inhibitors with improved pharmacokinetic properties is described. These compounds were designed based on information derived from metabolite identification studies which led to compounds such as 42 with lower clearance, greater brain exposure and longer half life compared to earlier analogs.
Subject(s)
Brain/metabolism , Drug Design , Nerve Degeneration/prevention & control , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Thiophenes/pharmacology , Thiophenes/pharmacokinetics , Animals , Chemistry Techniques, Synthetic , Crystallography, X-Ray , Dose-Response Relationship, Drug , Half-Life , JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors , JNK Mitogen-Activated Protein Kinases/metabolism , Mice , Models, Molecular , Molecular Structure , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Stereoisomerism , Structure-Activity Relationship , Thiophenes/chemical synthesis , Thiophenes/chemistryABSTRACT
In this Letter, we describe the discovery of selective JNK2 and JNK3 inhibitors, such as 10, that routinely exhibit >10-fold selectivity over JNK1 and >1000-fold selectivity over related MAPKs, p38α and ERK2. Substitution of the naphthalene ring affords an isoform selective JNK3 inhibitor, 30, with approximately 10-fold selectivity over both JNK1 and JNK2. A naphthalene ring penetrates deep into the selectivity pocket accounting for the differentiation amongst the kinases. Interestingly, the gatekeeper Met146 sulfide interacts with the naphthalene ring in a sulfur-π stacking interaction. Compound 38 ameliorates neurotoxicity induced by amyloid-ß in human cortical neurons. Lastly, we demonstrate how to install propitious in vitro CNS-like properties into these selective inhibitors.
Subject(s)
Aminopyridines/chemistry , Mitogen-Activated Protein Kinase 10/antagonists & inhibitors , Mitogen-Activated Protein Kinase 9/antagonists & inhibitors , Neurodegenerative Diseases/drug therapy , Neuroprotective Agents/chemistry , Protein Kinase Inhibitors/chemistry , Triazines/chemistry , Aminopyridines/pharmacokinetics , Aminopyridines/therapeutic use , Animals , Binding Sites , Central Nervous System/metabolism , Computer Simulation , Humans , Mice , Microsomes, Liver/metabolism , Mitogen-Activated Protein Kinase 10/metabolism , Mitogen-Activated Protein Kinase 9/metabolism , Neuroprotective Agents/pharmacokinetics , Neuroprotective Agents/therapeutic use , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/therapeutic use , Structure-Activity Relationship , Triazines/pharmacokinetics , Triazines/therapeutic useABSTRACT
From high throughput screening, we discovered compound 1, the prototype for a series of disubstituted thiophene inhibitors of JNK which is selective towards closely related MAP kinases p38 and Erk2. Herein we describe the evolution of these compounds to a novel class of thiophene and thiazole JNK inhibitors that retain favorable solubility, permeability, and P-gp properties for development as CNS agents for treatment of neurodegeneration. Compound 61 demonstrated JNK3 IC(50)=77 nM and retained the excellent broad kinase selectivity observed for the series.
Subject(s)
JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Quinolines/chemical synthesis , Thiazoles/chemistry , Thiophenes/chemistry , Animals , Drug Design , Humans , JNK Mitogen-Activated Protein Kinases/metabolism , Mice , Microsomes, Liver/metabolism , Mitogen-Activated Protein Kinase 10/antagonists & inhibitors , Mitogen-Activated Protein Kinase 10/metabolism , Mitogen-Activated Protein Kinase 8/antagonists & inhibitors , Mitogen-Activated Protein Kinase 8/metabolism , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Quinolines/chemistry , Quinolines/pharmacology , Structure-Activity Relationship , Thiazoles/chemical synthesis , Thiazoles/pharmacology , Thiophenes/chemical synthesis , Thiophenes/pharmacologyABSTRACT
In this Letter, we describe our efforts to design HEA BACE-1 inhibitors that are highly permeable coupled with negligible levels of permeability-glycoprotein activity. These efforts culminate in producing 16 which lowers Αß by 28% and 32% in the cortex and CSF, respectively, in the preclinical wild type Hartley guinea pig animal model when dosed orally at 30mpk BID for 2.5days.
Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Ethylamines/chemical synthesis , Ethylamines/pharmacology , Protease Inhibitors/chemical synthesis , Protease Inhibitors/pharmacology , Alkylation , Alzheimer Disease , Animals , Brain/metabolism , Cell Line , Dogs , Drug Design , Guinea Pigs , Humans , Indicators and Reagents , Protease Inhibitors/pharmacokinetics , Protein Binding , Structure-Activity RelationshipABSTRACT
The structure-activity relationship of the prime region of hydroxyethylamine BACE inhibitors is described. Variation in the aryl linker region with 5- and 6-membered heterocycles provided compounds such as 33 with improved permeability and reduced P-gp liability compared to benzyl amine analog 1.
Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid Precursor Protein Secretases/metabolism , Aspartic Acid Endopeptidases/antagonists & inhibitors , Aspartic Acid Endopeptidases/metabolism , Ethylamines/chemistry , Ethylamines/pharmacology , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Alzheimer Disease/drug therapy , Amyloid Precursor Protein Secretases/chemistry , Aspartic Acid Endopeptidases/chemistry , Crystallography, X-Ray , Ethylamines/chemical synthesis , Humans , Models, Molecular , Protease Inhibitors/chemical synthesis , Protein Binding , Structure-Activity RelationshipABSTRACT
Herein we describe further evolution of hydroxyethylamine inhibitors of BACE-1 with enhanced permeability characteristics necessary for CNS penetration. Variation at the P2' position of the inhibitor with more polar substituents led to compounds 19 and 32, which retained the potency of more lipophilic analog 1 but with much higher observed passive permeability in MDCK cellular assay.
Subject(s)
Acetamides/chemistry , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Butanols/chemistry , Cyclohexylamines/chemistry , Protease Inhibitors/chemistry , Acetamides/chemical synthesis , Acetamides/pharmacokinetics , Amyloid Precursor Protein Secretases/metabolism , Aspartic Acid Endopeptidases/metabolism , Binding Sites , Butanols/chemical synthesis , Butanols/pharmacokinetics , Cell Membrane Permeability/drug effects , Crystallography, X-Ray , Cyclohexylamines/chemical synthesis , Cyclohexylamines/pharmacokinetics , Humans , Protease Inhibitors/chemical synthesis , Protease Inhibitors/pharmacokinetics , Structure-Activity RelationshipABSTRACT
Using structure-guided design, hydroxyethylamine BACE-1 inhibitors were optimized to nanomolar Abeta cellular inhibition with selectivity against cathepsin-D. X-ray crystallography illuminated the S1' residues critical to this effort, which culminated in compounds 56 and 57 that exhibited potency and selectivity but poor permeability and high P-gp efflux.
Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/chemistry , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Drug Design , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Amyloid Precursor Protein Secretases/chemistry , Amyloid Precursor Protein Secretases/genetics , Aspartic Acid Endopeptidases/chemistry , Aspartic Acid Endopeptidases/genetics , Humans , Models, Molecular , Molecular Structure , Structure-Activity Relationship , Substrate SpecificityABSTRACT
The role of HMPA as a ligand for SmI2 and the stoichiometry and energetics of formation for the SmI2-HMPA complex in THF were investigated employing UV-vis spectroscopy, isothermal titration calorimetry (ITC), and vapor pressure osmometry (VPO). The aggregation number for SmI2 in THF was found to be 0.98 ± 0.09 over the entire concentration range studied (6.71-84.0 mM), indicating that SmI2 is monomeric. The UV-vis data suggest that four HMPA ligands coordinate to SmI2, and this was supported by ITC experiments. The combined results are consistent with [SmI2(HMPA)4] being the reductant responsible for the unique reactivity exhibited by SmI2-HMPA cosolvent combinations.
