Isolation of four high-purity dammarane saponins from extract of Panax notoginseng by centrifugal partition chromatography coupled with evaporative light scattering detection in one operation.

INTRODUCTION

Centrifugal partition chromatography (CPC), as a continuous liquid-liquid partition chromatography with no solid support matrix, combined with evaporative light scattering detection (ELSD) was employed for systematic separation and purification of weak-chromophoric saponins from a highly valued and important traditional Chinese herbal medicine, Panax notoginseng.

OBJECTIVE

To separate and isolate high-purity saponins from extract of Panax notoginseng using CPC-ELSD with a simple and low toxicity solvent system.

METHODOLOGY

Samples were preparaed by extracting the root material with acetone, treated with n-butanol and then freeze-dried. CPC-ELSD was applied in the separation and detection of notoginsenoside and ginsenosides from extract of Panax notoginseng using a solvent system composed of ethyl acetate-n-butanol-water (1:1:2, v/v/v). The saponins were analysed and identified by their retention time with high-performance liquid chromatography (HPLC) coupled with ELSD, as well as electrospray ionisation tandem mass spectrometry (ESI-MS(n) ) in the negative and positive ion modes with the authentic standards.

RESULTS

A total of 9.6 mg of notoginsenoside R₁, 67.8 mg of ginsenoside Rg₁, 2.3 mg of Re and 286.5 mg of Rb₁ were purified from 487.2 mg of n-butanol extract of P. notoginseng. The purities of obtained saponins in a single run were assessed to be over 98% by HPLC-ELSD.

CONCLUSION

CPC-ELSD was proved to be a very fast and efficient tool for separation of high-purity dammarane saponins.