Echinacea pallida (Nutt.) Nutt. - syn. Brauneria pallida (Nutt.); Rudbeckia pallida Nutt. - Asteraceae \\
pale echinacea, pale purple-coneflower, pale-flower echinacea, **Blassfarbener Sonnenhut**, Prärie-Igelkopf, Blasser Igelkopf, Blassfarbene Kegelblume

Perennial herb, up to 1m high, native in central North America, naturalized in eastern North America, also cultivated; sparsely to densely hairy, stems green to purplish (rarely branched); leaves elliptic to lanceolate, entire; paleae 9-14mm, tips purple, sharp-pointed; rays pink to pale reddish purple, laminae reflexed, up to 9cm long; disc corollas 5-7mm, lobes usually pink to purple, pollen usually white, rarely lemon yellow; cypselae tan or bicolored, 2.5-5mm. [[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242416464]]

"Preparations and extracts are taken orally and used in supportive therapy for colds and influenze. In Germany, only E.pallida is an approved herb, not E.angustifolia... The immun stimulant effects are mainly derived from in vitro experiments with immune cells, showing increased mobility and phagocytosis... Controlled clinical studies with patients suffering from flu have shown efficacy for the stated indications; the duration of illness was significantly shortened." \\
[Medicinal Plants of the World. Ben-Erik Van Wyk and Michael Wink, Pretoria 2004, 129]

"The chemistry of echinacea is well documented... The three species are chemically dissimilar. E. purpurea and E. angustifolia both contain alkamides as their major lipophilic constituents, but of differing structural types. By contrast, the lipophilic fraction of E. pallida is characterized by polyacetylenes and contains only very low concentrations, if any, of alkamides. The alkene constituents are stated to be susceptible to auto-oxidation resulting in the formation of artefacts during storage (Wichtl 2004)." \\
[Echinacea species (Echinacea angustifolia (DC.) Hell., Echinacea pallida (Nutt.) Nutt., Echinacea purpurea (L.) Moench): a review of their chemistry, pharmacology and clinical properties., Barnes, J., Anderson, L.A., Gibbons, S., Phillipson, J.D., Journal of Pharmacy and Pharmacology, 57(8), 2005, 929-954] 

"Bioassay-guided fractionation of n-hexane extracts of Echinacea pallida (Asteraceae) roots led to the isolation and structure elucidation of two polyacetylenes (1, 3) and three polyenes (2, 4, 5). Two are known hydroxylated compounds, namely 8-hydroxy-pentadeca-(9E)-ene-11,13-diyn-2-one (1) and 8-hydroxy-pentadeca-(9E,13Z)-dien-11-yn-2-one (2). Two dicarbonylic constituents, namely pentadeca-(9E)-ene-11,13-diyne-2,8-dione (3) and pentadeca-(9E,13Z)-dien-11-yne-2,8-dione (4), were isolated and characterized for the first time. Furthermore, the structure elucidation of pentadeca-(8Z,13Z)-dien-11-yn-2-one (5) is described." \\
[Isolation and structure elucidation of cytotoxic polyacetylenes and polyenes from Echinacea pallida., Pellati, F., Calò, S., Benvenuti, S., Adinolfi, B., Nieri, P., Melegari, M., Phytochemistry, 67(13), 2006, 1359-1364]

{{:pentadeca8z13zdien11yn2one.jpg| pentadeca-(8Z,13Z)-dien-11-yn-2-one }} pentadeca-(8Z,13Z)-dien-11-yn-2-one

Cytotoxic acetylenes are present in E. pallida lipophilic extracts but essentially absent in extracts from E.angustifolia and E.purpurea. Bioassay-guided fractionation of the n-hexane extract of E. pallida roots lead to the isolation of 8-hydroxy-pentadeca-(9E)-ene-11,13-diyn-2-one, pentadeca-(9E)-ene-11,13-diyne-2,8-dione, 8-hydroxy-pentadeca-(9E,13Z)-dien-11-yn-2-one, pentadeca-(9E,13Z)-dien-11-yne-2,8-dione and pentadeca-(8Z,13Z)-dien-11-yn-2-one. Apoptotic cell death was found to be involved in the cytotoxic effect of the most active compound, pentadeca-(8Z,13Z)-dien-11-yn-2-one. \\
[Cytotoxic activity of polyacetylenes and polyenes isolated from roots of Echinacea pallida., Chicca, A., Pellati, F., Adinolfi, B., Matthias, A., Massarelli, I., Benvenuti, S., Nieri, P., British journal of pharmacology, 153(5), 2008, 879-885] [[http://onlinelibrary.wiley.com/doi/10.1038/sj.bjp.0707639/full]]


{{:echinacea_pallida.jpg?700}} \\
Echinacea pallida [[https://creativecommons.org/licenses/by-sa/3.0/de/|CC BY-SA 3.0]], Author: Llez  \\ [[https://commons.wikimedia.org/wiki/Category:Echinacea_pallida?uselang=de#/media/File:Echinacea_pallida_003.JPG]]