RESUMO
Excess aldosterone production and signaling are primary contributors to numerous cardiovascular disorders including primary aldosteronism and resistant hypertension. Recently, inhibition of aldosterone synthesis via the enzyme aldosterone synthase (CYP11B2) has been pursued to ameliorate the negative effects of elevated aldosterone. Herein, we report the development of aldosterone synthase inhibitors using a pyrimidine-based metal binding group leading to the highly selective CYP11B2 inhibitor 22. Superior selectivity combined with robust pharmacokinetics afforded highly selective in vivo aldosterone suppression in a monkey model of adrenal steroidogenesis, demonstrating the potential for selective aldosterone lowering in humans with pyrimidine 22.
RESUMO
Insulin-like growth factor 1 receptor (IGF-1R) is an attractive target for anti-cancer therapy due to its anti-apoptotic effect on tumor cells, but inhibition of insulin receptor (IR) may have undesired metabolic consequences. The primary sequences of the ATP substrate-binding sites of these receptors are identical and the crystal structures of the activated kinase domains are correspondingly similar. Thus, most small-molecule inhibitors described to date are equally potent against the activated kinase domains of IGF-1R and IR. In contrast, the non-phosphorylated kinase domains of these receptors have several structural features that may accommodate differences in binding affinity for kinase inhibitors. We used a cell-based assay measuring IGF-1R autophosphorylation as an inhibitor screen, and identified a potent purine derivative that is selective compared to IR. Surprisingly, the compound is a weak inhibitor of the activated IGF-1R tyrosine kinase domain. Biochemical and structural studies are presented that indicate the compound preferentially binds to the ATP site of non-phosphorylated IGF-1R compared to phosphorylated IGF-1R. The potential selectivity and potency advantages of this binding mode are discussed.
