SEPARATION AND STRUCTURE DETERMINATION OF CENTELLASAPONIN A AND ITS ISOMER ASIATICOSIDE FROM CENTELLA ASIATICA TOTAL TRITERPENOID SAPONINS

Abstract

A high performance liquid chromatographic method was developed for the separation and determination of centellasaponin A and asiaticoside isomers in Centella asiatica products. The method comprises separation by reversed phase chromatography on a Synergi 4μ Hydro-RP 80A reversed-phase column using acetonitrile-water (21:79, v/v) as mobile phase. Centellasaponin A and asiaticoside were separated with high resolution by the developed method. The method's linearity, precision, and recovery were validated. The effects of mobile phase composition, temperature, and flow rate on the separation of the two isomers were also investigated. Experimental results indicated that acetonitrile-water as the mobile phase offered enhancing resolution to the polar isomers. Furthermore, it was observed that the sequence of centellasaponin A and asiaticoside was reversed in peak consequence by using methanol-water as the mobile phase compared to acetonitrile-water, which could be used for the separation of other isomeric triterpenoid saponins.

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Keywords:

• asiaticoside
• Centella asiatica
• centellasaponin A
• isomer
• separation
• triterpenoid saponin

ACKNOWLEDGMENTS

The authors gratefully acknowledge the financial support by Zhejiang Provincial Key Science and Technology Program (No. 2006C13009) and National S&T Major Project (No. 2009ZX09313-036).