BACE1 and Alzheimer disease: Considering that (2R)-pterosin B displayed a potency to inhibit BACE1 and AChE (IC50 = 29.6 and 16.2 μM, respectively) comparable to quercetin (IC50 = 18.8 μM and 19.8 μM, respectively) and a significant BChE-inhibitory activity (IC50 = 48.1 μM) that quercetin lacks along with an exceptionally high BBB permeability, (2R)-pterosin B was suggested to have a potential to ameliorate AD symptoms.