Alcoholic extracts of the roots and leaves of three Echinacea species (E. p
urpurea, E. angustifolia and E. pallida) were analysed for the presence of
characteristic chemicals by HPLC directly coupled to ultraviolet absorbance
and electrospray mass spectrometric detectors. The method permitted rapid
characterization and tentative identification of a large number of caffeoyl
conjugates and alkamides in all the samples investigated. The roots of the
three species differed markedly in their contents of characteristic compou
nds. Cichoric acid and verbascoside predominated in extracts of E. purpurea
root whereas cynarine and dodeca-2E,4E,8Z,10Z/E-tetraenoic acid isobutylam
ide were the major chemicals characteristic of E. angustifolia root extract
s. Echinacoside and 6-O-caffeoylechinacoside predominated in extracts of E.
pallida roots. Characteristic alkamides were also examined by electrospray
tandem mass spectrometry (MS/MS) and these compounds provided characterist
ic fragmentation patterns. Extracts of the roots and leaves of all three sp
ecies were found to have antioxidant properties in a free radical scavengin
g assay and in a lipid peroxidation assay.