Isolation and Purification of Alkaloids from the Fruits of Macleaya cordata by Ionic-Liquid-Modified High Speed Counter-Current Chromatography.

Macleaya cordata (Willd) R. Br. is a medicinal plant. The most important bioactive compounds of M. cordata are alkaloids that have many biological activities including anti-fungal, anti-inflammatory, and anti-tumor. In this study, an ionic-liquid-modified high speed counter-current chromatography method was established to obtain alkaloids from the fruits of M. cordata. The conditions of ionic-liquid-modified high speed counter-current chromatography, including solvent systems, the content of an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [C₄ mim][BF₄ ]), and the post-treatment of the ionic liquid, were investigated. Five alkaloids protopine, allocryptopine, sanguinarine, 8-O-demethylchelerythrine, and chelerythrine were separated from the extract of the fruits using a high speed counter-current chromatography with two-phase solvent system composed of dichloromethane/methanol/0.3 mol/L hydrochloric acid aqueous solution/[C₄ mim][BF₄ ] (4:2:2:0.015, v/v). Their purities were 96.33%, 95.56%, 97.94%, 96.22%, and 97.90%, respectively. The results indicated that a small amount of ionic liquids as modifier of the two-phase solvent system could shorten the separation time and improve the separation efficiency of the alkaloids from the fruits. The ionic-liquid-modified high speed counter-current chromatography would provide a feasible way for highly effective separation of alkaloids from natural products. This article is protected by copyright. All rights reserved.