Herein, we report the identification of the HIV protease inhibitor amprenavir as a selective cannabinoid receptor 2 (CB2) agonist and describe structure-activity relationship (SAR) studies toward repurposing this peripherally restricted scaffold for high CB2 potency and CNS exposure. This exercise yielded compounds with exceptional CB2 potency (EC50s 1 receptor, and high predicted permeability/low P-gp efflux activity. Selected compounds were profiled in rat i.v. dosing cassettes; several novel amprenavir analogues displayed good t1/2 (>2 h), moderate plasma clearance, and appreciable brain exposure. Additionally, fully flexible protein-ligand docking studies with molecular dynamics (MD) simulations were used to predict the most likely mode of interaction of highly potent analogue VU6077967 with CB2 and to provide a rationale for the observed selectivity of this series relative to CB1.
Haymer et al. (Thu,) studied this question.