Echinacea Species Cultivated in Bulgaria as a Source of Chicoric and Caftaric Acids

Abstract

The trend towards alternative medicine and naturopathy increases the interest in the use of natural products. This requires larger quantities of qualitative raw material of medicinal plants, including the well-known genus Echinacea. The purpose of this study was to evaluate the quality of E. purpurea and pallida cultivated in Kazanlak, Bulgaria. We developed and validated a rapid, reliable, and inexpensive HPLC method for the quantitative determination of chicoric, caftaric, and caffeic acids, and of cynarin, echinacoside, quercetin, and apigenin. The amount of chicoric and caftaric acids was monitored in different phases of plant development in aerial parts and roots. Maximal concentrations of chicoric acid (3.4%) were reported in roots in the seed-formation phase, and a concentration of 2.8% was reported in aerial parts in the vegetative phase. Caftaric acid was 0.9% in aerial parts in the vegetative and flowering phases and 0.5% in roots in the vegetative and seeding phases. Their amounts significantly exceed the requirements of the European Pharmacopoeia 8.0. Therefore, Kazanlak-grown E. purpurea could be a reliable raw material for the formulation of phytopreparations. In addition, the proposed method was applied to the detection and determination of the above-described substances in phytopreparations containing Echinacea from commercial sources. The amounts of the tested substances were found to vary widely.