TLC screening for eleutherosides B, E, and E1, and isofraxidin in the roots of sixEleutherococcusspecies cultivated in Poland

Because chemical and pharmacological studies of Eleutherococcus species growing in Asia showed their biological activity depends on glycosides known as eleutherosides, we used TLC to search for eleutherosides in ethanol extracts of the roots of E. senticosus, E. setchuensis, E. sesiliflorus, E. henryi, E. gracilistylus, and E. divaricatus cultivated in Poland. Eleutherosides B, E, and E1 were identified in all the roots investigated and isofraxidin was identified in the roots of E. senticosus. Satisfactory separation of the eleutherosides from other components of the extracts was achieved by use of two mobile phases in two-step elution. The identity of the resolved compounds was confirmed by comparing their RF values and UV spectra with those of standards.