Echinacoside, echinacea component

The three most widely used species of Echinacea are Echinacea purpurea, E pallida, and E angustifolia. The chemical constituents include flavonoids, lipophilic constituents (eg, alkamides, polyacetylenes), water-soluble polysaccharides, and water-soluble caffeoyl conjugates (eg, echinacoside, chicoric acid, caffeic acid). Within any marketed echinacea formulation, the relative amounts of these components are dependent upon the species used, the method of manufacture, and the plant parts used. Epurpurea has been the most widely studied in clinical trials. Although the active constituents of echinacea are not completely known, chicoric acid from E purpurea and echinacoside from E pallida and E angustifolia, as well as alkamides and polysaccharides, are most often noted as having immune-modulating properties. Most commercial formulations, however, are not standardized for any particular constituent. 

The standardization of Echinacea products based on cichoric acid and alkamides has been proposed (Bauer 1999a,b Perry et al 2000, 2001). The CADs are also commonly used as marker compounds and labeled as phenolics on many dietary supplements. The main reason for standardization is that the level of the active components varies based on plant material, age of the Echinacea, and method of preparation. However, the specific compounds responsible for the immune-enhancing activity of Echinacea are not fully understood. Echinacoside has been used to standardize many preparations, but the lack of immune-enhancing activity of this component... 

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