ABSTRACT
A series of trisubstituted hydroxylactams was identified as potent enzymatic and cellular inhibitors of human lactate dehydrogenase A. Utilizing structure-based design and physical property optimization, multiple inhibitors were discovered with <10 µM lactate IC50 in a MiaPaca2 cell line. Optimization of the series led to 29, a potent cell active molecule (MiaPaca2 IC50 = 0.67 µM) that also possessed good exposure when dosed orally to mice.
ABSTRACT
Optimization of 5-(2,6-dichlorophenyl)-3-hydroxy-2-mercaptocyclohex-2-enone using structure-based design strategies resulted in inhibitors with considerable improvement in biochemical potency against human lactate dehydrogenase A (LDHA). These potent inhibitors were typically selective for LDHA over LDHB isoform (410 fold) and other structurally related malate dehydrogenases, MDH1 and MDH2 (>500 fold). An X-ray crystal structure of enzymatically most potent molecule bound to LDHA revealed two additional interactions associated with enhanced biochemical potency.
Subject(s)
Enzyme Inhibitors/chemical synthesis , L-Lactate Dehydrogenase/antagonists & inhibitors , Animals , Crystallography, X-Ray , Dogs , Enzyme Inhibitors/metabolism , Enzyme Inhibitors/pharmacology , Humans , L-Lactate Dehydrogenase/metabolism , Madin Darby Canine Kidney CellsABSTRACT
A novel class of 3-hydroxy-2-mercaptocyclohex-2-enone-containing inhibitors of human lactate dehydrogenase (LDH) was identified through a high-throughput screening approach. Biochemical and surface plasmon resonance experiments performed with a screening hit (LDHA IC50=1.7 µM) indicated that the compound specifically associated with human LDHA in a manner that required simultaneous binding of the NADH co-factor. Structural variation of this screening hit resulted in significant improvements in LDHA biochemical inhibition activity (best IC50=0.18 µM). Two crystal structures of optimized compounds bound to human LDHA were obtained and explained many of the observed structure-activity relationships. In addition, an optimized inhibitor exhibited good pharmacokinetic properties after oral administration to rats (F=45%).
Subject(s)
Cyclohexanones/pharmacology , Enzyme Inhibitors/pharmacology , L-Lactate Dehydrogenase/antagonists & inhibitors , Sulfhydryl Compounds/pharmacology , Administration, Oral , Animals , Cyclohexanones/administration & dosage , Cyclohexanones/chemistry , Dose-Response Relationship, Drug , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/chemistry , High-Throughput Screening Assays , Humans , L-Lactate Dehydrogenase/metabolism , Models, Molecular , Molecular Structure , Rats , Structure-Activity Relationship , Sulfhydryl Compounds/administration & dosage , Sulfhydryl Compounds/chemistryABSTRACT
A novel 2-thio-6-oxo-1,6-dihydropyrimidine-containing inhibitor of human lactate dehydrogenase (LDH) was identified by high-throughput screening (IC50=8.1 µM). Biochemical, surface plasmon resonance, and saturation transfer difference NMR experiments indicated that the compound specifically associated with human LDHA in a manner that required simultaneous binding of the NADH co-factor. Structural variation of the screening hit resulted in significant improvements in LDHA biochemical inhibition activity (best IC50=0.48 µM). A crystal structure of an optimized compound bound to human LDHA was obtained and explained many of the observed structure-activity relationships.
