Effects of different drying methods on caffeic acid derivatives content of Echinacea purpurea cultivated in Turkey

Echinacea sp. are promoted primarily in oral dosage forms as an immune stimulant that helps increase resistance to colds, influenza and other infections; topical products for wounds and inflammatory skin conditions are also avaible (1,2). E. purpurea (L.) Moench aerial parts contain at least 4 major groups of compounds generally considered to be a medicinal interest: alkamides, caffeic acid derivatives (phenylpropanoids), polyacetylenes, and polysaccharides (3). In this work, E. purpurea aerial parts and radix were dried under different drying conditions; sun-drying, shade-drying and oven-drying. Aerial parts and radix were dried under the sun for 48h at average 28 ^oC, under the shade for 96h at average 26 ^oC, in the oven for 72h at 40 ^oC. When the amount of moisture in the plant reduced below 14%, drying process was ended. Agilent 1100 Series HPLC system was used for analysis of caffeic acid derivatives (caftaric acid, cichoric acid), and Zorbax ODS (250×4,6mm, 5um) column was used with gradient elution. According to HPLC results; oven drying was found to be the best method compared with the others. The highest levels of caftaric and cichoric acids in E. purpurea aerial parts were 0,5019±0,0088% and 1,3742±0,0354%; respectively. And the content of caftaric and cichoric acids in the radix were found as 0,1872±0,0285% and 1,4768±0,1567%; respectively. As a result, oven drying is the best appropriate method for E. purpurea drying process.

References: 1. Ebadi M (2002) Pharmacodynamic Basis of Herbal Medicine. CRC Press. USA.

2. Stuart DL, Wills RBH (2003)J Agric Food Chem 51: 1608–1610.

3. Upton et al. (2007) American Herbal Pharmacopoeia and Therapeutic Compendium. American Herbal Pharmacopoeia. USA.