Abstract
The roots of Echinacea pallida are characterized by TLC and HPLC fingerprints of the polyacetylenes, polyenes, and the caffeic acid derivatives. The fingerprints can also be used for the differentiation between E. pallida and E. angustifolia root extracts. The main constituents of E. pallida roots are tetradeca-8Z-ene-11,13-diyn-2-one (2), pentadeca-8Z-ene-11,13-diyn-2-one (3), pentadeca-8Z,13Z-dien-11-yn-2-one (4), pentadeca-8Z,11Z,13E-trien-2-one (5), pentadeca-8Z,11E,13Z-trien-2-one (6), pentadeca-8Z,11Z-dien-2-one (7), and echinacoside (13). E. angustifolia is usually void of these polyacetylenes and polyenes and is characterized by isobutylamides, echinacoside, and cynarine. The polyacetylenes of E. pallida are very susceptible to autoxidation to the 8-hydroxy-9-ene derivatives. Thus, the chemical composition of the roots depends on the storage conditions.
