Echinacea

Echinacea is a genus of herbaceous flowering plants (family Asteraceae) native to North America, most commonly cultivated as Echinacea purpurata, E. angustifolia and E. pallida. The roots, aerial parts, and sometimes the whole plant are used in dietary supplements primarily to modulate immune function and to support the body’s response to acute respiratory infections.

• Alkylamides: e.g., N‑(2‑methylbutyl)‑2‑(3‑hydroxy‑4‑methoxyphenyl)‑prop‑2‑enamide (C₁₈H₂₅NO₃, MW 295.4 g mol⁻¹) with a characteristic amide‑linked unsaturated carbon chain.
• Caffeic‑acid derivatives: cichoric acid (C₁₈H₁₆O₉, MW 354.31 g mol⁻¹) with a central quinic acid core esterified to two caffeic acid moieties, providing multiple phenolic hydroxyl groups.
• Polysaccharides: high‑molecular‑weight arabinogalactans (≈ 10–100 kDa) rich in β‑1,3/β‑1,6‑linked galactose residues.
• Other Constituents: The overall plant matrix contains flavonoids (e.g., luteolin‑7‑glucoside), sesquiterpene lactones (e.g., echinacoside), and a complex mixture of glycosides.
• Quantification: These constituents are typically quantified by HPLC‑UV or LC‑MS, with standards expressed as % alkylamides or % cichoric acid.

• Cultivation: Commercial Echinacea is cultivated primarily in the United States (North Dakota, Minnesota) and Canada, where E. purpurata and E. angustifolia are grown under Good Agricultural and Collection Practices (GACP).
• Harvesting: Harvesting occurs at the flowering stage for aerial parts or after 2–3 years for root material.
• Extraction Methods:
  • Ethanol‑water (30 %–70 %) extraction: for alkylamide‑rich root extracts.
  • Aqueous‑ethanol extraction: for cichoric‑rich aerial‑part extracts.
  • Super‑critical CO₂: for lipophilic alkylamides with minimal solvent residues.
• Quality Assurance: Quality assurance hinges on standardized alkylamide content (≥ 4 % total) and low microbial/metal contamination, verified by USP or EFSA monographs.
• Recommendations: Third‑party testing (e.g., USP‑verified, NSF Certified) is recommended to ensure consistency and safety.