ABSTRACT
Minor structural modifications-sometimes single atom changes-can have a dramatic impact on the properties of compounds. This is illustrated here on structures related to known mTOR inhibitor Sapanisertib. Subtle changes in the hinge binder lead to strikingly different overall profiles with changes in physical properties, metabolism, and kinase selectivity.
ABSTRACT
The use of an interleukin ß antibody is currently being investigated in the clinic for the treatment of acne, a dermatological disorder affecting 650M persons globally. Inhibiting the protease responsible for the cleavage of inactive pro-IL1ß into active IL-1ß, caspase-1, could be an alternative small molecule approach. This report describes the discovery of uracil 20, a potent (38 nM in THP1 cells assay) caspase-1 inhibitor for the topical treatment of inflammatory acne. The uracil series was designed according to a published caspase-1 pharmacophore model involving a reactive warhead in P1 for covalent reversible inhibition and an aryl moiety in P4 for selectivity against the apoptotic caspases. Reversibility was assessed in an enzymatic dilution assay or by using different substrate concentrations. In addition to classical structure-activity-relationship exploration, topical administration challenges such as phototoxicity, organic and aqueous solubility, chemical stability in solution, and skin metabolic stability are discussed and successfully resolved.
Subject(s)
Acne Vulgaris/drug therapy , Caspase 1/metabolism , Caspase Inhibitors/administration & dosage , Caspase Inhibitors/pharmacology , Drug Design , Acne Vulgaris/enzymology , Administration, Topical , Animals , Caspase 1/chemistry , Caspase Inhibitors/pharmacokinetics , Caspase Inhibitors/therapeutic use , Cell Line , Humans , Mice , Models, Molecular , Protein Conformation , Solvents/chemistry , Tissue DistributionABSTRACT
Virtual fragmentation of a library of 12,000 compounds inspired by natural products led to a dataset of 153,000 fragments that was used as a source to identify effective P2-P3 scaffold replacement solutions for peptidic Caspase-1 inhibitors. Our strategy led to the identification of an original 2-azabicyclo-octane scaffold (2-ABO) that was further elaborated into the potent Caspase-1 inhibitor CD10847 (IC50â¯=â¯17â¯nM). The crystal structure of Caspase-1 in complex with CD10847 was obtained, and its binding mode was shown to be similar to the one predicted by docking and in good agreement with other known inhibitors.
