Robert James Pasteris

Discovery of oxathiapiprolin, a new oomycete fungicide that targets an oxysterol binding protein.

Oxathiapiprolin is the first member of a new class of piperidinyl thiazole isoxazoline fungicides with exceptional activity against plant diseases caused by oomycete pathogens. It acts via inhibition of a novel fungal target-an oxysterol binding protein-resulting in excellent preventative, curative and residual efficacy against key diseases of grapes, potatoes and vegetables. Oxathiapiprolin is being developed globally as DuPont™ Zorvec™ disease control with first registration and sales anticipated in 2015. The discovery, synthesis, optimization and biological efficacy are presented.

Piperidinyl thiazole isoxazolines: A new series of highly potent, slowly reversible FAAH inhibitors with analgesic properties

Fatty acid amide hydrolase (FAAH) is a membrane anchored serine hydrolase that has a principle role in the metabolism of the endogenous cannabinoid anandamide. Docking studies using representative FAAH crystal structures revealed that compounds containing a novel piperidinyl thiazole isoxazoline core fit within the ligand binding domains. New potential FAAH inhibitors were designed and synthesized incorporating urea, carbamate, alkyldione and thiourea reactive centers as potential pharmacophores. A small library of candidate compounds (75) was then screened against human FAAH leading to the identification of new carbamate and urea based inhibitors (Ki=pM and nM, respectively). Representative carbamate and urea based chemotypes displayed slow, time dependent inhibition kinetics leading to enzyme inactivation which was slowly reversible. However, evidence indicated that features of the mechanism of inactivation differ between the two pharmacophore types. Selected compounds were also evaluated for analgesic activity in the mouse-tail flick test.