Echinacea, active principle

Bauer R. Echinacea biological effects and active principles. In Lawson LD, Bauer R, eds. Phytomedicines of Europe. Chemistry and Biological Activity. Washington, D.C. American Chemical Society, 1988 140-157. 

Buuc r. R. Echinacea Biological effects and active principles. In Law son, L. D..and Bauer. R. (eds.). Phytomedicincs of Europe Chemistry and Biological Activity. American Chemical. Society Symposium Series. New Y(Kk. Oxford University Pre.s.s. 1998. p. 140. 

Root extracts of the American coneflower, Echinacea augustifolia DC., also exhibited juvenoid activity [114] ether extracts showed high morphogenic activity on T. molitor pupae but none was observed on fifth instar nymphs of O. fasciatus (500 ig of extract). The active principle in the oil was identified as ( )-10-hydroxy-4,10-dimethy 1-4,11-dodecadien-2-one or echinolone (Fig. (6)) [109]. However, chemically synthesized echinolone was not active in the standard T. molitor pupal bioassay [115]. The authors of this report acknowledge that this may be due to a failure to synthesize the proper compound. However, the spectral data is consistent with that reported. They were also unable to isolate echinolone from the roots of E. augustifolia. The chemical data for echinolone are summarized in Appendix III, Table 12 and the synthesis of racemic echinolone has been reported [115, 116]. 

From pharmacological investigations it is obvious that not a single, but several constituents like the alkamides, cichoric acid, glycoproteins and polysaccharides, contribute to the immunostimulatory activity of Echinacea extracts (for summary see Tab. 1) [152,153]. Therefore the application of extracts is still reasonable and hence the native extract is regarded as the active principle for regulatory purposes by the health authorities [154]. However, standardization of these extracts is a must for a rational therapeutic application of phytopreparations [155, 156], and reproducible quality needs also to be documented from a regulatory point of view [157, 158]. 

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