Development of a succinyl CoA:3-ketoacid CoA transferase inhibitor selective for peripheral tissues that improves glycemia in obesity.

Many individuals with type 2 diabetes (T2D) cannot take current therapies due to their adverse effects. Thus, new glucose-lowering agents targeting unique mechanisms are needed. Studies have demonstrated that decreasing ketone oxidation, secondary to muscle-specific deletion of succinyl-CoA:3-ketoacid-CoA transferase (SCOT), protects mice against obesity-related hyperglycemia. In silico studies identified that the antipsychotic diphenylbutylpiperidines can inhibit SCOT and alleviate obesity-related hyperglycemia. Because ketones are a major brain fuel, whereas the diphenylbutylpiperidines have central nervous system-related adverse effects, we aimed to develop a peripheral selective SCOT inhibitor (PSSI). Using a pharmacophore derived from the diphenylbutylpiperidine-SCOT interaction, we synthesized PSSI-51, which inhibited SCOT activity in peripheral but not brain tissue, while decreasing myocardial ketone oxidation. Importantly, PSSI-51 treatment improved glycemia in obese mice and demonstrated reduced brain accumulation compared to the diphenylbutylpiperidine pimozide. We propose that PSSI-51 can lay the foundation for optimizing a new class of brain-impermeable SCOT inhibitors for treating T2D.