Abstract: An anlytical method for the separation and quantitative determination of three phytoecdysteroids in Rhaponticum uniflorum by high performance liquid chromatography has been developed. Three phytoecdysteroids, ecdysterone (I), rhapontisterone (II) and turkesterone (III) were separated and determined quantitatively by using the solvent system MeOH-H2O (40:60) at 242 nm with flow rate of 1.5 ml/min, the operation can be completed in 10 minutes. Using the external standard method, the content of three phytoecdysteroids in the roots and aerial parts of Rhaponticum uniflorum obtained from different localities was determined. It is proved that this method is sensitive and accurate, and with good reproducibility.

Key words: Rhaponticum uniflorum, HPLC, Ecdysterone, Rhapontisterone, Turkesterone