Validation of the oxadiazolone isostere as a carboxylate replacement in caspase inhibitors: approaches involving Strecker-based synthetic methodology development and on-target strategies.

Caspases are intracellular, aspartate selective cysteine proteases. Given their central role in cell death and inflammation, caspases have been studied intensively as drug targets to date. In spite of impressive preclinical results and significant investment in clinical evaluation, no caspase inhibitors have so far been approved as drugs by FDA or EMA. Two important reasons therefore are commonly cited: (1) The large structural homology of caspases that complicates the identification of selective compounds. (2) The limited biopharmaceutical quality of most compounds. Many contain an irreversible covalent warhead function that can potentially induce off-target effects. Most inhibitor families also contain a free carboxylate. Both the ionic character of this group and its potential for toxic metabolite formation, most probably discount critically on the permeability and ADME-Tox properties of inhibitors. Preliminary work at UAMC has identified the oxadiazolone moiety as a useful isosteric replacement for carboxylates in caspase inhibitors. Research in this proposal will validate this finding by introducing an oxadiazolone group in several relevant classes of caspase inhibitors. In addition, synthetic methodology based on the Strecker reaction will be elaborated. The latter will allow efficient access to caspase inhibitors with less reactive warhead types. Finally, drug discovery methodology will be developed that should allow "on-target" synthesis using caspase 1 as a model.

Keywords:CHEMICAL BIOLOGY, MEDICINAL CHEMISTRY

Disciplines:Biomarker discovery and evaluation, Drug discovery and development, Medicinal products, Pharmaceutics, Pharmacognosy and phytochemistry, Pharmacology, Pharmacotherapy, Toxicology and toxinology, Other pharmaceutical sciences

Project type:Collaboration project