Alkaloids with acetylcholinesterase inhibitory activity from (Thunb.) Pers.

Two new isoquinoline alkaloids ( and ) along with fourteen known alkaloids (-) were isolated from (Thunb.) Pers. Their structures were elucidated by analyzing spectroscopic and spectrometric data (NMR, UV, IR, and MS) and comparing their spectroscopic, spectrometric and physicochemical data with the values archived in the literature. The absolute configurations of new compounds were determined X-ray crystallographic assay and electronic circular dichroism calculations. Acetylcholinesterase (AChE) inhibitory activity of all compounds was evaluated. Compounds , , , , and exhibited inhibitory activity against AChE with IC values ranged from 10.2 to 63.4 μM.