Caffeoyl phenols and alkamides of cultivated Echinacea purpurea and Echinacea atrorubens var. paradoxa

Echinacea is an herbaceous perennial of Asteraceae family that grows throughout the eastern and central United States and southern Canada. Three species of Echinacea are valued as medicinal herb: E. purpurea (L.) Moench, E. pallida (Nutt.) Nutt., and E. angustifolia DC (Mistríková & Vaverková, 2007). All three species show pharmacological activity, which appears to result from the combined effects of caffeoyl phenols, alkamides, and polysaccharides (Binns et al., 2002; Randolph et al., 2003; Raduner et al., 2006; Pillai et al., 2007). However, E. purpurea is the most cultivated and widely used of the three species, due to ease of cultivation and total use of the whole plant (Wills & Stuart, 1999; Seidler-Lozykowska & Dabrowska, 2003; Kreft, 2005). Extracts and compounds are commercially produced from the various parts of E. purpurea for the prevention of common cold, flu, respiratory infections and inflammations, and the stimulation of immunomodulation (Mahady et al., 2001; Goel et al., 2005; Vimalanthan et al., 2005; Hinz et al., 2007). The seeds of Echinacea purpurea cv. Magnus and White Swan were purchased from Park Seed, Greenwood, SC. The seeds of E. atrorubens var. paradoxa were obtained from Seeds of Change, Santa Fe, NM. The seed population CLS-P2 of Echinacea purpurea selected from a consecutive mass selection program was obtained from National Chung Hsing University. The phytochemical traits of medicinal plants, depending on growing sites, climate conditions, and