8-hydroxydihydrochelerythrine and 8-hydroxydihydrosanguinarine with a potent acetylcholinesterase inhibitory activity from Chelidonium majus L.

Ethanol extract of the aerial portion of Chelidonium majus L. inhibited acetylcholinesterase (ACNE) activity without a significant inhibition of butyrylcholinesterase (BuChE). Using mass spectrometry and NMR studies, three active constituents were isolated and identified: 8-hydroxydihydrochelerythrine (1), 8-hydroxydihydrosan-guinarine (2), and berberine (3). Compounds 1-3 showed potent inhibitory activity against ACNE, with IC50 (mu m) values of 0.61-1.85. Compound 1 exhibited competitive and selective inhibition for AChE.