Field production of purple coneflower for beneficial phytochemicals

Abstract

ABSTRACT Purple coneflower (Echinacea purpurea Moench [L.]) is widely used as a health supplement and is cultivated for its production of bioactive phytochemicals. However, there is a lack of information on how agronomic planting designs and environment affect the phytochemical content of different coneflower tissues. Experimental plots were established at two locations in Minnesota to evaluate the effect of environment and agronomic planting design on the phytochemical profile of purple coneflower, as well as the relative content of several provisionally identified compounds. Root, stem, leaf, flower, and seed tissues were harvested, and extracts were analysed using liquid chromatography-mass spectrometry. The growing environment affected the levels of several caffeic acid derivatives in leaf, stem, and root tissue, but agronomic design had little to no effect on phytochemical content. Although all tissue types contained phytochemicals of medicinal interest, no single tissue contained the highest amount of all compounds with known bioactive properties, indicating that the most beneficial purple coneflower supplements may be the combination of several tissue types. Additionally, the phytochemical content of purple coneflower seed, which is uncommon in Echinacea supplements, was chemically similar to root tissue. Seed tissue, after additional evaluations, may be a suitable alternative for root in supplement mixtures.