Investigation of the Best Method for Extraction of Phenolic Compounds from Echinaceae purpurea L. (Moench)

Abstract

Background: Echinacea spp. have been used in traditional medicine for many years. Recently, many investigations have been done on this plant and they showed that the plant is an immunostimulant agent. The plant contains different components such as flavonoids, phenolic compounds and isobutylamides. Phenolics are one of the most important agents in immunostimulant effects of the plant therefore, determination of a method for the best extraction of these compounds from the plant is important. Objective: In this research, the effects of solvent, extraction procedure, plant particle size and plant:solvent ratio on extraction of phenolic compounds of Echinacea purpurea (L.) Moench have been investigated. Methods: Different polar and non-polar solvents from hexane to acidic water were used in order to determine the best solvent for phenolics extraction. Moreover, the methods of maceration, sonification, perculation, digestion and continuous extraction (by use of soxhelet apparatus), different particle sizes of the plant powder and various plant:solvent ratios were examined as well. Results: The results showed that the best method for extraction of phenolics is methanol:water 80:20 as solvent, method of digestion (2h, 50 °C), particle size of 300 µm for the plant powder and plant: solvent ratio of 1:200. Conclusion: It can be concluded that in order to efficient extraction of phenolic compounds from Echinacea purpurea aerial parts, special condition should be considered.

Keywords

• echinacea
• phenolic compounds
• extraction
• colorimetry