Combination of normal-phase medium-pressure liquid chromatography and high-performance counter-current chromatography for preparation of ginsenoside-Ro from panax ginseng with high recovery and efficiency

Ginsenoside-Ro which belongs to the oleanane-type saponins has anti-inflammatory, anti-platelet, anticomplementary and immunomodulatory activities. The present paper described the preparation of ginsenoside-Ro from panax ginseng with high recovery and efficiency by combination of normal-phase medium-pressure liquid chromatography (NP-MPLC) and high-performance counter-current chromatography (HPCCC). The crude sample was preliminarily chromatographed by NP-MPLC to enrich ginsenoside-Ro to the purity of 70.2% with 95.0% recovery. Then, the enriched sample was further purified by HPCCC with a solvent system composed of ethyl acetate–isopropanol–0.1% formic acid (3:1:5, v/v), where 61 mg ginsenoside-Ro was obtained from 100 mg enriched sample with 96.0% purity and 83.4% recovery. The overall recovery of ginsenoside-Ro was 79.2%, whose structure was identified by liquid chromatography–electrospray ionization mass spectrometry (LC–ESI-MS) finally.