Preparative Separation of Four Alkaloids from Gelsemium elegans by High-speed Counter-current Chromatography

Objective To develop an efficient preparative method for the separation of Gelsemium alkaloids from Gelsemium elegans. Methods High-speed counter-current chromatography(HSCCC) with several two-phase solvent systems was investigated for the separation of Gelsemium alkaloids. The purity and structure identification of the purified compounds were performed with HPLC and NMR spectra, respectively. Results In a single operation, 206.6 mg of crude alkaloid sample was separated to yield 28.7 mg of koumine, 24.9 mg of gelsemine, 26.9 mg of humantenine, and 7.2 mg of gelsevirine, with the purities of 97.8%, 95.4%, 97.4%, and 93.5%, respectively. Conclusion A preparative HSCCC method is successfully established for the separation of four Gelsemium alkaloids from G. elegans with a modified two-phase solvent system composed of n-hexane-ethyl acetate-ethanol-0.5% triethylamine-H2O(3:5:3:4).