Preparative Separation of Chelerythrine and Sanguinarine from Macleaya cordata by pH-Zone-Refining Counter-current Chromatography

Chelerythrine and sanguinarine are the representative and major active constituents of Macleaya cordata. Few reports regarding the preparative separation of these two alkaloids from this Chinese herbal medicine were found. In the present study, an efficient method was established to separate chelerythrine and sanguinarine from Macleaya cordata by pH-zone-refining counter-current chromatography. The crude sample was separated into two fractions, which corresponded to chelerythrine (a) and sanguinarine (b) with the two-phase solvent system chloroform-ethyl acetate-methanol-water (3:1:3:2, v/v/v/v) where 10mM HCl was added in the upper phase and 10mM trithylamine in the lower phase. From 2.0g of crude extract, chelerythrine (600mg) and sanguinarine (750mg) were obtained in a single run with the purity of both over 95.0% as determined by HPLC. The chemical structures were confirmed by electrospray ionization-mass spectrometry, H-1 NMR and C-13 NMR.