Preparative separation of alkaloids from Nelumbo nucifera leaves by conventional and pH-zone-refining counter-current chromatography

Two modes of high-speed counter-current chromatography (HSCCC) were successfully applied to the separation of alkaloids from crude extract of Nelumbo nucifera leaves. The conventional HSCCC separations were performed with a two-phase solvent system composed of tetrachloromethane-CHCl3-methanol-0 1 M HCl at a volume ratio of 1.3.3 2 (v/v/v/v), and 120 mg crude extract could be successfully separated. pH-Zone-refining CCC was performed with a two-phase solvent system composed of petroleum at her (60-90 degrees C)-ethyl acetate-methanol-water (5 5 2 8, v/v/v/v) where trimethylamine (10 mM) was added to the upper organic stationary phase as a retainer and hydrochloric acid (5 mM) to the aqueous mobile phase as an eluent From 4 0 g of the crude extract, 120 mg N-nornuciferine. 1020 mg nuciferine and 96 mg roemerine were obtained in a single run each with a purity of over 98% as determined by HPLC The structures of the isolated compounds wet e identified by ESI-MS, H-1 NMR and C-13 NMR. (C) 2010 Elsevier B V All rights reserved