ABSTRACT
6,7-Dihydro-5H-2,1-benzisoxazol-4-one analogs are potent inhibitors of aldosterone synthase (CYP11B2) with selectivity over the highly homologous enzyme cortisol synthase (CYP11B1). These compounds are unique among inhibitors of CYP11B2 in their lack of a strong-heme binding group such as a pyridine or imidazole. Poor metabolic stability in hepatocyte incubations was found to proceed via a reduction of the isoxazole ring. While the enzyme responsible for the reductive metabolism remains unknown, the rate of metabolism could be attenuated by the addition of polar functionality. The in vitro CYP11B2 potency and selectivity were confirmed in vivo in a cynomolgus monkey model by the inhibition of ACTH stimulated aldosterone production without impacting plasma cortisol concentrations.
Subject(s)
Cytochrome P-450 CYP11B2/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Isoxazoles/pharmacology , Cytochrome P-450 CYP11B2/metabolism , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Isoxazoles/chemical synthesis , Isoxazoles/chemistry , Molecular Structure , Structure-Activity RelationshipABSTRACT
Chemistry has been developed to specifically functionalize two structurally similar classes of indole-based MK2 inhibitors at positions prompted by a combination of X-ray crystallographic and computer assisted drug design. A gain in molecular potency was obtained by introducing aminomethyl groups to the lactam rings of 6-arylcarbamoyl-tetrahydro-beta-carbolinone and 6-arylcarbamoyl-dihydropyrazino[1,2-a]indolone MK2 inhibitors. In addition, improvements in molecular potency were achieved by expansion of the lactam from a 6- to 7-membered ring leading to 7-arylcarbamoyl-tetrahydro-[1,4]diazepino[1,2-a]indolones.
Subject(s)
Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Indoles/chemical synthesis , Indoles/pharmacology , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein Serine-Threonine Kinases/antagonists & inhibitors , Animals , Crystallography, X-Ray , Drug Design , Indoles/chemistry , Intracellular Signaling Peptides and Proteins/metabolism , Mice , Models, Molecular , Molecular Structure , Protein Serine-Threonine Kinases/metabolism , Structure-Activity RelationshipABSTRACT
An uHTS campaign was performed to identify selective inhibitors of PKC-theta. Initial triaging of the hit set based on selectivity and historical analysis led to the identification of 2,4-diamino-5-nitropyrimidines as potent and selective PKC-theta inhibitors. A homology model and initial SAR is presented demonstrating that a 2-arylalkylamino substituent in conjunction with suitable 4-diamino substituent are essential for achieving selectivity over many kinases. Additional hit to lead profiling is presented on selected compounds.
