Preparative separation of quaternary ammonium alkaloids from Corydalis yanhusuo W. T. Wang by pH-zone-refining counter-current chromatography.

The optimal extraction condition for extracting quaternary ammonium alkaloid dehydrocorydaline from Corydalis yanhusuo W. T. Wang was investigated using orthogonal experimental design. pH-zone-refining counter-current chromatography (CCC) with normal phase elution was successfully applied to preparative separation of alkaloids from the crude extract of Corydalis yanhusuo. The separation was performed with a biphasic solvent system composed of chloroform (CHCl(3))-methanol (MeOH)-water (2:1:1, v/v), in which the lower organic phase containing 10 mM of triethylamine was used as the mobile phase, while the upper aqueous phase containing 10 mM of hydrochloric acid was used as the stationary phase. The separation mechanism of quaternary ammonium alkaloids using pH-zone-refining CCC was discussed in comparison with standard high-speed CCC. In the present study, the separation of 1.200 g of crude sample yielded 129 mg of dehydrocorydaline and 12 mg of palmatine at a high purity of 94 and 92%, respectively. Recovery for dehydrocorydaline and palmatine was 85 and 86%, respectively.