Development of an Efficient Protocol for Cimifugin Isolation from Peucedanum schottii and Evaluation of Enzyme Inhibitory Activity

Abstract

The dichloromethane (DCM) extract of the fruits of Peucedanum schottii Besser ex DC. (Apiaceae) was subjected to high-performance counter-current chromatography (HPCCC) for the efficient and fast separation (30 min) and isolation of cimifugin using an ethyl acetate: water (1:1 v/v, K = 1.01) system. The analytical scale-optimized separation was easily scaled to semi-preparative conditions. Cimifugin (11.25% yield, 96.5% purity) was isolated for the first time from P. schottii and characterized by NMR spectroscopy. Cimifugin and the crude DCM extract were evaluated using ELISA microtiter assays for their inhibitory potential against the cholinesterases (acetylcholinesterase - AChE and butyrylcholinesterase - BChE), and tyrosinase (TYR), which are key enzymes for the treatment of some neurodegenerative diseases, i.e. Alzheimer's and Parkinson's. The crude extract exhibited a weak inhibitory activity against AChE, BChE, and TYR (4.2, 35.5, and 0% at 100 μg mL⁻¹ and 10.3, 40.0, and 12.2% at 200 μg mL⁻¹, respectively), while cimifugin displayed low to moderate inhibition towards AChE and BChE (3.1 and 21.6%, respectively) at 200 μg mL⁻¹.