Simultaneous determination of six active compounds in Rhodiola L. by RP-LC

Rhodiola L. has a long history as traditional Chinese medicine (TCM) with a medicinal efficacy similar to Ginseng and Manyprickle Acathopanax roots. There exist three classes of important active constituents, i.e., phenylethanoids (salidroside, p-tyrosol), phenylpropanoides (rosarin, rosavin, rosin), and monoterpene (rosiridin) in this TCM. In this study, by optimizing the extraction, separation and analytical conditions, a sensitive and accurate high performance liquid chromatographic method has been developed for the simultaneous determination of the six active compounds in the different species of Rhodioa L. for the first time. The analysis was performed on a Purospher STAR C18 column at 30 degrees C using 20 mmol L-1 aqueous ammonia acetate/methanol gradient system at a flow rate of 1.0 mL min(-1) and photodiode array detection (DAD ) at wavelengths 276, 250 and 205 nm, respectively. The optimized method provided good linear relation (r(2) > 0.9993 for all the target compounds), satisfactory precision (RSD values less than 1.53%) and good recovery (from 96.3-104.8%). The limits of detection ranged between 0.012 and 0.047 mu g mL(-1) for the different analytes. The developed method has been successfully applied to analysis and quality control of Rhodiola L.