Preparation of flavone di-C-glycoside isomers from Jian-Gu injection (Premna fulva Craib.) using recycling counter-current chromatography

Jian-Gu Injection (JGI, Premna fulva Craib) has been demonstrated to be effective in the clinical treatment of bone hyperplasia. However, an effective purification method of the JGI flavone C-glycosides as reference materials is not available. The present work developed a recycling counter-current chromatography approach to prepare these materials in high quality. An optimized biphasic solvent system composed of ethyl acetate/n-butanol/water (1:9:10, v/v/v) was employed to purify the five congeneric flavone C-glycosides, identified as apigenin 6,8-di-C-beta-D-glucopyranoside (vicenin 2), apigenin 6-C-beta-D-xylopyranosyl-8-C-beta-D-glucopyranoside (vicenin 1), apigenin 6-C-beta-n-xylopyranosyl-8-C-beta-D-galactopyranoside, apigenin 6-C-beta-D-glucopyranosyl-8-C-beta-D-xylopyranoside (vicenin 3), and apigenin 6-C-beta-D-galactopyranosyl-8-C-beta-D-xylopyranoside, by means of UHPLC-PDA-ESI-IT-ToF-MSn and NMR spectroscopy. (C) 2019 Elsevier B.V. All rights reserved.