Acetylcholinesterase inhibitors from the twigs of Vaccinium oldhami Miquel.

In the course of finding Korean natural products with acetylcholinesterase (AChE) inhibitory activity, we found that a methanolic extract of the twigs of Vaccinium oldhami significantly inhibited AChE. Bioassay-guided fractionation of the methanolic extract resulted in the isolation of two compounds, taraxerol (1) and scopoletin (2), as active constituents. These compounds inhibited AChE activity in a dose-dependent manner, and the IC50 values of compounds 1 and 2 were 33.6 (79 microM) and 10.0 (52 microM) microg/mL, respectively.