Column chromatography of hydrophilic extracts from Rhodiola rosea and Rodiola quadrifida led to the isolation of cinnamic alcohol, chlorogenic acid, rhodiooctanoside, rosiridin, rosavin and the phenolic compounds salidroside, rhodiolin and a novel compound consisting of viridoside with an attached arabinose unit (mongrhoside). HPLC analysis of plant material from different sources and from different collection periods showed a great variability in the composition and in the amount of pharmacologically active compounds contained.