PREPARATIVE ISOLATION OF STEROIDAL SAPONINS FROM GARLIC (ALLIUM SATIVUM L.) USING HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY COUPLED WITH EVAPORATIVE LIGHT SCATTERING DETECTION

Abstract

High-speed counter-current chromatography (HSCCC) coupled with evaporative light scattering detection (ELSD) was successfully applied for preparative separation and purification of four steroidal saponins (compounds 1–4) from crude extracts of garlic (Allium sativum L.) by one-step separation, using n-butanol-acetic acid-6 mM aqueous ammonium acetate (4:1:5, v/v/v) as a solvent system. The quantities of compounds 1–4 isolated from 300 mg of the crude sample were 23.5 mg, 14.7 mg, 18.2 mg, and 7.0 mg, respectively. Their purities were found to be over 93.0% by HPLC-ELSD analysis. Their chemical structures were confirmed by ESI-MS, ¹H- and ¹³C- NMR. This is the first time steroidal saponins have been separated using HSCCC-ELSD.

Keywords:

• Allium sativum L.
• buffer salt
• emulsification
• garlic
• HSCCC
• steroidal saponins

ACKNOWLEDGMENTS

This research work was financially supported by the Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of China (707033) and the National Key Scientific and Technological Special Projects (2009ZX09502-011).