Extraction and in vitro screening of potential acetylcholinesterase inhibitors from the leaves of Panax japonicus

•UFLC–MS is an effective method for screening AChE inhibitors from the leaves of Panax japonicus.•Five saponins with potential anti-Alzheimer's disease activity were identified and isolated.•Continuous MAE-CPC was developed for scaled up production of pure AChE inhibitors.•The MAE-CPC parameters were optimized using a multi-exponential function model. Ultrafiltration liquid chromatography-mass spectrometry (UFLC–MS) is an efficient method that can be applied to rapidly screen and identify ligands for acetylcholinesterase (AChE) from the leaves of Panax japonicus. Using this method, we identified 5 major compounds, chikusetsusaponins V, Ib, IV, IVa, and IVa ethyl ester, as potent AChE inhibitors, which were assessed for anti-Alzheimer disease activity using the PC12 cell model. A continuous online method, which consisted of microwave-assisted extraction, a solvent concentration tank, and centrifugal partition chromatography (MAE-SCT-CPC), was newly developed for scaled up production of these compounds with high purity and efficiency. The bioactivities of the compounds separated were assessed by the PC12 cell model. This novel approach of using UFLC–MS coupled with MAE-SCT-CPC and a PC12 cell model could be applied to efficiently screen, extract, and separate AChE inhibitors from complex samples, and could serve as an important platform for the large-scale production of functional food and nutraceutical ingredients.