Inhibition of cholinesterase and amyloid-beta aggregation by resveratrol oligomers from Vitis amurensis.

In the course of screening for acetylcholinesterase and butyrylcholinesterase inhibitors from natural products by an in vitro Ellman method, the extract of the roots of Vitis amurensis Rupr. (Vitaceae) showed significant cholinesterase inhibitory activity. Employing a bioassay-linked HPLC method, followed by a semi-preparative HPLC method, two compounds of interest were isolated and characterized as vitisin A and heyneanol A. They inhibited effectively both acetylcholinesterase and butyrylcholinesterase in a dose-dependent manner and exhibited higher activity against butyrylcholinesterase compared with that of galantamine, a positive control. Furthermore, the aggregation of beta-amyloid was evaluated in vitro based on a thioflavine T fluorescence assay to expand their activity profile, with the result that both compounds showed the ability to block beta-amyloid aggregation. (c) 2008 John Wiley & Sons, Ltd.