Influence of Seed Source on Chemical Composition of Echinacea purpurea and Echinacea angustifolia Grown as Medicinal Herbs in Two Environments

Three year field trials were initiated in 2012 in the southern mountains (Mills River) and upper piedmont (Reidsville) regions of North Carolina to evaluate the effect of seed source, plant age, and environment on the phytochemical profile of Echinacea purpurea (EP) and Echinacea angustifolia (EA). The tops and roots of these plants are used in a wide variety of commercially available natural botanical products. At each location there are two studies, one for each species. Within each species six seed sources are being compared and plants are being harvested after one, two, and three years of growth. The aerial parts and roots of EP, and the roots of EA are dehydrated and extracted for phytochemical analysis. After one year of growth, significant differences among EP sources for caftaric acid, cichoric acid, and total polyphenols in the aerial tops were found in both locations. EP and EA sources were significantly different for total polyphenols in the roots in both locations. Significant differences for total alkamides were found in the roots among EA sources, but not among EP sources in both locations. EP and EA sources were significantly different for caftaric acid and chlorogenic acid, respectively, in the roots from Reidsville, but not from Mills River. One EA source had significantly higher amounts of echinacoside and total alkamides in the roots than the other sources at both locations. The location differences are most likely due to variations in climate, soil type, and fertility which will be examined as these studies continue as will the influence of plant age on the chemical profiles. The results indicate that there may be potential for some Echinacea sources to provide specific commercial characteristics and fulfill certain market needs.