ABSTRACT
The use of epigenetic bromodomain inhibitors as anticancer therapeutics has transitioned from targeting bromodomain extraterminal domain (BET) proteins into targeting non-BET bromodomains. The two most relevant non-BET bromodomain oncology targets are cyclic AMP response element-binding protein (CBP) and E1A binding protein P300 (EP300). To explore the growing CBP/EP300 interest, we developed a highly efficient two-step synthetic route for dimethylisoxazole-attached imidazo[1,2-a]pyridine scaffold-containing inhibitors. Our efficient two-step reactions enabled high-throughput synthesis of compounds designed by molecular modeling, which together with structure-activity relationship (SAR) studies facilitated an overarching understanding of selective targeting of CBP/EP300 over non-BET bromodomains. This led to the identification of a new potent and selective CBP/EP300 bromodomain inhibitor, UMB298 (compound 23, CBP IC50 72 nM and bromodomain 4, BRD4 IC50 5193 nM). The SAR we established is in good agreement with literature-reported CBP inhibitors, such as CBP30, and demonstrates the advantage of utilizing our two-step approach for inhibitor development of other bromodomains.
Subject(s)
Cyclic AMP Response Element-Binding Protein/antagonists & inhibitors , E1A-Associated p300 Protein/antagonists & inhibitors , Isoxazoles/chemistry , Pyridines/chemistry , Binding Sites , Cell Cycle Proteins/antagonists & inhibitors , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Cell Survival/drug effects , Crystallography, X-Ray , Cyclic AMP Response Element-Binding Protein/metabolism , E1A-Associated p300 Protein/metabolism , Humans , Molecular Docking Simulation , Pyridines/metabolism , Pyridines/pharmacology , Structure-Activity Relationship , Transcription Factors/antagonists & inhibitors , Transcription Factors/metabolismABSTRACT
A reaction sequence involving three-component [3 + 2] cycloaddition of azomethine ylides followed by CuI-catalyzed cascade trifluoromethyl radical addition and cyclization is developed for diastereoselective synthesis of fused-tetrahydrobenzodiazepin-3-ones.
ABSTRACT
The simultaneous inhibition of polo-like kinase 1 (PLK1) and BRD4 bromodomain by a single molecule could lead to the development of an effective therapeutic strategy for a variety of diseases in which PLK1 and BRD4 are implicated. Compound 23 has been found to be a potent dual kinase-bromodomain inhibitor (BRD4-BD1 IC50 = 28 nM, PLK1 IC50 = 40 nM). Compound 6 was found to be the most selective PLK1 inhibitor over BRD4 in our series (BRD4-BD1 IC50 = 2579 nM, PLK1 IC50 = 9.9 nM). Molecular docking studies with 23 and BRD4-BD1/PLK1 as well as with 6 corroborate the biochemical assay results.
Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Drug Design , Leukemia, Myeloid, Acute/drug therapy , Nuclear Proteins/antagonists & inhibitors , Protein Conformation , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , Transcription Factors/antagonists & inhibitors , Humans , Leukemia, Myeloid, Acute/enzymology , Leukemia, Myeloid, Acute/pathology , Models, Molecular , Molecular Docking Simulation , Molecular Structure , Protein Domains , Structure-Activity Relationship , Tumor Cells, Cultured , Polo-Like Kinase 1ABSTRACT
The one-pot [3 + 2] cycloaddition of an azomethine ylide with a maleimide followed by another [3 + 2] cycloaddition of an azide with the second maleimide gives a 1,5-diamino intermediate which is used for a sequential aminomethylation reaction with formaldehyde through [5 + 1] annulation to afford a novel polycyclic scaffold bearing tetrahydroquinazoline, pyrrolidine, pyrrolidinedione, and N-substituted maleimide in stereoselective fashion.
