Acylguanidines as Small-Molecule β-Secretase Inhibitors

Abstract
BACE1 is an aspartyl protease responsible for cleaving amyloid precursor protein to liberate Aβ, which aggregates leading to plaque deposits implicated in Alzheimer's disease. We have identified small-molecule acylguanidine inhibitors of BACE1. Crystallographic studies show that these compounds form unique hydrogen-bonding interactions with the catalytic site aspartic acids and stabilize the protein in a flap-open conformation. Structure-based optimization led to the identification of potent analogs, such as 10d (BACE1 IC50 = 110 nM).