β‐secretase inhibitory effects of furanocoumarins from the root of Angelica dahurica

In the course of screening antidementia agents from natural products, five β‐secretase (BACE1) inhibitors were isolated from the root extract of Angelica dahurica (Umbelliferae). They were identified as furanocoumarins, isoimperatorin (1), imperatorin (2), (+)‐oxypeucedanin (3), (+)‐byakangelicol (4) and (+)‐byakangelicin (5). Among them, compounds 2 and 4 showed significant inhibitory activity against β‐secretase (BACE1) with IC₅₀ values of 91.8 ± 7.5 and 104.9 ± 2.4 μM , respectively. Compounds 1‐5 inhibited BACE1 activity in a dose‐dependent manner. Copyright © 2009 John Wiley & Sons, Ltd.