HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY DETERMINED ALKAMIDE LEVELS IN AUSTRALIAN-GROWN ECHINACEA SPP

Extracts of Echinacea spp. are widely used as therapeutic immunostimul ants with such activity being attributed in part to the alkamide fract ions of these plants. Using high performance liquid chromatography, th e levels of 8 alkamides, including 2 tetraene alkamides (dodeca-2E, 4E , 8Z, 10E/Z-tetraenoic acid isobutylamide), were quantitatively determ ined in 2 Australian-grown Echinacea spp. Overall, the levels of alkam ides in Australian-grown E. angustifolia were found to be comparable w ith levels obtained in this study and other studies for USA and Europe an Echinacea spp. However, results obtained for one sample of E. angus tifolia suggested that it may have been mislabelled and that it was mo st likely a sample of E. pallida. Levels of tetraene alkamides in Aust ralian-grown E. purpurea were also similar to, if not higher, than lev els which have been reported for the same species grown in Germany and the USA. Preliminary studies on the stability of alkamide compounds i n E. angustifolia indicated that they are susceptible to degradation, with a 13% loss of alkamide level over 2 months. Overall, results indi cate that there is considerable potential to develop Echinacea as a vi able crop in Australia.