Separation and Determination of Sesquiterpene Lactones in Roots of Sasuurea lappa by LC-MSD-TOF

The Chinese medicinal herb Radix Saussureae (Mu Xiang), the dried root of Saussurea lappa Clarke (Asteraceae), has been traditionally used for alleviating pain in abdominal distention, indigestion with anorexia, dysentery, nausea, and vomiting [1]. The root contains up to 3% essential oil, and the principal sesquiterpene lactones isolated include dehydrocostuslactone and costunolide. More recently, dehydrocostuslactone and costunolide are of particular interest since they were reported to have various immunomodulating activities [1]. A simple and specific analytical method for the quantitative determination of sesquiterpene lactones in the roots of S. lappa was developed using LC-MSD-TOF. By LC-MS, the separation was achieved by reversed-phase chromatography on a C18 column with water and methanol (both containing 0.1% formic acid) as the mobile phase. The limits of detection by LC-MS were found to be 5, 10, and 25 ng/mL for costunolide, β-cyclocostunolide and dihydrocostunolide respectively. LC-MS coupled with electrospray ionization (ESI) interface method is described for the identification and quantification of sesquiterpene lactones in roots of S. lappa. This method involved the use of the [M+H]⁺ ions of sesquiterpene lactones in the positive ion mode with extractive ion monitoring (EIM). Acknowledgements: This research is funded in part by “Science Based Authentication of Dietary Supplements“ Funded by the Food and Drug Administration grant number 2 U01 FD 002071-07 and the United States Department of Agriculture, Agricultural Research Service Specific Cooperative Agreement Number 58-6408-06-067. Also this research is supported jointly by CSIR and M/S Zandu pharmaceuticals and NCNPR. The CSIR budget code for this project is “Fellowship abroad p-80104”. References: [1] Pandey MM, et al. (2007) Journal of Ethnopharmacology 110: 379–390.

Fig. 1 Selected ion chromatograms and mass spectra of costunolide, β-cyclocostunolide and dihydrocostunolide extracted from roots of Sasuurea lappa