Liquid chromatographic method for the quantification of salidroside and cinnamyl alcohol glycosides for quality control of golden root (Rhodiola rosea L.)

Rhodiola rosea L. (golden root, arctic root) is a medicinal plant encountered in traditional herbal medicinal products in Europe and in many food/dietary supplements. Salidroside and the cinnamyl alcohol glycosides, i.e. rosin, rosarin and rosavin, are characteristic constituents used as analytical markers in the quality control of the herbal material. There is a need for a validated HPLC method to be used for quality control of Rhodiola rosea products. The objective of the study was to develop and validate an HPLC-method for quantification of salidroside and the sum of rosin, rosarin and rosavin in Rhodiola rosea and closely related species. Samples of dried powered plant material were prepared by extraction with 75% methanol. An HPLC method using a CSH Fluoro-phenyl column showed to be suitable for the analysis. The content of salidroside and the sum of rosin, rosarin and rosavin, were determined. Validation showed that the chromatographic method has good selectivity with no interfering peaks. Selectivity, linearity, precision, repeatability, and accuracy were shown to be adequate. In the analyses of 27 batches of Rhodiola rosea, the average content of salidroside was 0.6% (0.3–1.5%), and for the sum of rosin, rosavin and rosarin, expressed as rosin, it was 1.4% (0.6–2.6%). As a quality standard, a minimum limit of 0.3% of salidroside and 0.6% of the sum of rosin, rosarin and rosavin could be considered for plant material of Rhodiola rosea. The method was also shown to be appropriate for quantitative determination of salidroside and the sum of rosin, rosarin and rosavin, in two other Rhodiola spp.