Field production of purple coneflower for beneficial phytochemicals

References

• Abbasi, B. H., Tian, C. L., Murch, S. J., Saxena, P. K., & Liu, C. Z. (2007). Light-enhanced caffeic acid derivatives biosynthesis in hairy root cultures of Echinacea purpurea. Plant Cell Reports, 26(8), 1367–1372. https://doi.org/10.1007/s00299-007-0344-5
   PubMed Web of Science ®Google Scholar
• Barnes, J., Anderson, L. A., Gibbons and, S., & Phillipson, J. D. (2005). Echinacea species (Echinacea angustifolia (DC.) Hell., Echinacea pallida (Nutt.) Nutt., Echinacea purpurea (L.) Moench): A review of their chemistry, pharmacology and clinical properties. The Journal of Pharmacy and Pharmacology, 57(8), 929–954. https://doi.org/10.1211/0022357056127
   PubMed Web of Science ®Google Scholar
• Barrett, B. (2003). Medicinal properties of echinacea: A critical review. Phytomedicine, 10(1), 66–86. https://doi.org/10.1078/094471103321648692
   PubMed Web of Science ®Google Scholar
• Bauer, R. (1999). Standardization of Echinacea purpurea expressed juice with reference to cichoric acid and alkamides. Journal of Herbs, Spices & Medicinal Plants, 6(3), 51–62. https://doi.org/10.1300/j044v06n03_05
   Google Scholar
• Bauer, V. R., Jurcic, K., Puhlmann, J., & Wagner, H. (1988). Immunologic in vivo and in vitro studies on Echinacea extracts. Arznei-Forschung, 38, 276–281. https://doi.org/10.1016/0378-8741(88)90021-9
   PubMed Web of Science ®Google Scholar
• Bauer, R., & Woelkart, K. (2005). Encyclopedia of dietary supplements. Echinacea Species. https://doi.org/10.1081/E-EDS-120022101
   Google Scholar
• Berbec, S., Krol, B., & Wolski, T. (1998). The effect of soil and fertilization on the biomass and phenolic acids content in coneflower (Echinacea purpurea Moench.). Herba Polonica, 4, 397–402.
   Google Scholar
• Binns, S. E., Arnason, J. T., & Baum, B. R. (2002). Phytochemical variation within populations of Echinacea angustifolia (Asteraceae). Biochemical Systematics and Ecology, 30(9), 837–854. https://doi.org/10.1016/s0305-1978(02)00029-7
   Web of Science ®Google Scholar
• Binns, S. E., Hudson, J., Merali, S., & Arnason, J. T. (2002). Antiviral activity of characterized extracts from Echinacea spp. (Heliantheae: Asteraceae) against herpes simplex virus (HSV-I). Planta medica, 68(9), 780–783. https://doi.org/10.1055/s-2002-34397
   PubMed Web of Science ®Google Scholar
• Binns, S. E., Livesey, J. F., Arnason, J. T., & Baum, R. R. (2002). Phytochemical variation in Echinacea from roots and flowerheads of wild and cultivated populations. Journal of Agricultural & Food Chemistry, 50(13), 3673–3687. https://doi.org/10.1021/jf011439t
   PubMed Web of Science ®Google Scholar
• Bodinet, C., Lindequist, U., Teuscher, E., & Freudenstein, J. (2002). Effect of an orally applied herbal immunomodulator on cytokine induction and antibody response in normal and immunosuppressed mice. Phytomedicine, 9(7), 606–613. https://doi.org/10.1078/094471102321616418
   PubMed Web of Science ®Google Scholar
• Broz, A. K., Broeckling, C. D., De la-Peña, C., Lewis, M. R., Greene, E., Callaway, R. M., Summer, L. W., & Vivanco, J. M. (2010). Plant neighbor identity influences plant biochemistry and physiology related to defense. BMC Plant Biology, 10(1), 115. https://doi.org/10.1186/1471-2229-10-115
   PubMedGoogle Scholar
• Brunetti, C., George, R. M., Tattini, M., Field, K., & Davey, M. P. (2013). Metabolomics in plant environmental physiology. Journal of Experimental Botany, 64(13), 4011–4020. https://doi.org/10.1093/jxb/ert244
   PubMed Web of Science ®Google Scholar
• Bundy, J. G., Davey, M. P., & Viant, M. R. (2009). Environmental metabolomics: A critical review and future perspectives. Metabolomics, 5(1), 3. https://doi.org/10.1007/s11306-008-0152-0
   Web of Science ®Google Scholar
• Burger, R. A., Torres, A. R., Warren, R. P., Caldwell, V. D., & Hughes, B. G. (1997). Echinacea-induced cytokine production by human macrophages. International Journal of Immunopharmacology, 19(7), 371–379. https://doi.org/10.1016/s0192-0561(97)00061-1
   PubMed Web of Science ®Google Scholar
• Cech, N. B., Eleazer, M. S., Shoffner, L. T., Crosswhite, M. R., Davis, A. C., & Mortenson, A. M. (2006). High performance liquid chromatography/electrospray ionization mass spectrometry for simultaneous analysis of alkamides and caffeic acid derivatives from Echinacea purpurea extracts. Journal of Chromatography, 1103(2), 219–228. https://doi.org/10.1016/j.chroma.2005.11.008
   Web of Science ®Google Scholar
• Cervantes-Hernández, F., Alcalá-González, P., Martínez, O., & Ordaz-Ortiz, J. J. (2019). Placenta, pericarp, and seeds of tabasco chili pepper fruits show a contrasting diversity of bioactive metabolites. Metabolites, 9(10), 206. https://doi.org/10.3390/metabo9100206
   PubMed Web of Science ®Google Scholar
• Chambers, M. C., Maclean, B., Burke, R., Amodei, D., Ruderman, D. L., Neumann, S., Gatto, L., Fischer, B., Pratt, B., Egertson, J., Hoff, K., Kessner, D., Tasman, N., Shulman, N., Frewen, B., Baker, T. A., Brusniak, M.-Y., Paulse, C. & Tabb, D. L. (2012). A cross-platform toolkit for mass spectrometry and proteomics. Nature Biotechnology, 30(10), 918–920. https://doi.org/10.1038/nbt.2377
   PubMed Web of Science ®Google Scholar
• Chen, S. L., Yu, H., Luo, H. M., Wu, Q., Li, C. F., & Steinmetz, A. (2016). Conservation and sustainable use of medicinal plants: Problems, progress, and prospects. Chinese Medicine, 11(1), 37. https://doi.org/10.1186/s13020-016-0108-7
   PubMedGoogle Scholar
• Chishaki, N., & Horiguchi, T. (1997). Responses of secondary metabolism in plants to nutrient deficiency. In Plant nutrition for sustainable food production and environment (pp. 341–345). Springer Netherlands. https://doi.org/10.1007/978-94-009-0047-9_101
   Google Scholar
• Currier, N. L., & Miller, S. C. (2000). Natural killer cells from aging mice treated with extracts from Echinacea purpurea are quantitatively and functionally rejuvenated. Experimental Gerontology, 35(5), 627–639. https://doi.org/10.1016/s0531-5565(00)00106-6
   PubMed Web of Science ®Google Scholar
• Dalby-Brown, L., Barsett, H., Landbo, A. K. R., Meyer, A. S., & Mølgaard, P. (2005). Synergistic antioxidative effects of alkamides, caffeic acid derivatives, and polysaccharide fractions from Echinacea purpurea on in vitro oxidation of human low-density lipoproteins. Journal of Agricultural & Food Chemistry, 53(24), 9413–9423. https://doi.org/10.1021/jf0502395
   PubMed Web of Science ®Google Scholar
• DiStefano, V., Pitonzo, R., Novara, M. E., Bongiorno, D., Indelicato, S., Gentile, C., Avellone, G., Bognanni, R., Scandurra, S., & Melilli, M. G. (2019). Antioxidant activity and phenolic composition in pomegranate (Punica granatum L.) genotypes from south Italy by UHPLC-Orbitrap-MS approach. Journal of the Science of Food and Agriculture, 99(3), 1038–1045. https://doi.org/10.1002/jsfa.9270
   PubMed Web of Science ®Google Scholar
• Du, Y., Wang, Z., Wang, L., Gao, M., Wang, L., Gan, C., & Yang, C. (2017). Simultaneous determination of seven phenolic acids in rat plasma using UHPLC-ESI-MS/MS after oral administration of Echinacea purpurea extract. Molecules, 22(9), 1494. https://doi.org/10.3390/molecules22091494
   PubMed Web of Science ®Google Scholar
• Eschenlauer, A., Sammons, K., Griffin, T. J., & Hegeman, A. D. (2019). Tools to facilitate untargeted metabolomics LC-MS data processing in the workflow4metabolomics framework. Preparation.
   Google Scholar
• Finch‐Savage, W. E., & Leubner‐Metzger, G. (2006). Seed dormancy and the control of germination. The New Phytologist, 171(3), 501–523. https://doi.org/10.1111/j.1469-8137.2006.01787.x
   PubMed Web of Science ®Google Scholar
• Fornara, D. A., & Tilman, D. (2009). Ecological mechanisms associated with the positive diversity–productivity relationship in an N‐limited grassland. Ecology, 90(2), 408–418. https://doi.org/10.1890/08-0325.1
   PubMed Web of Science ®Google Scholar
• Freund Saxhaug, K., Jungers, J. M., Hegeman, A. D., Wyse, D. L., & Sheaffer, C. C. (2020). Cultivation of native plants for seed and biomass yield. Agronomy Journal, 112(3), 1815–1827. https://doi.org/10.1002/agj2.20195
   Web of Science ®Google Scholar
• Goel, V., Chang, C., Slama, J. V., Barton, R., Bauer, R., Gahler, R., & Basu, T. K. (2002). Alkamides of Echinacea purpurea stimulate alveolar macrophage function in normal rats. International Immunopharmacology, 2(2–3), 381–387. https://doi.org/10.1016/s1567-5769(01)00163-1
   PubMed Web of Science ®Google Scholar
• Gray, D. E., Pallardy, S. G., Garrett, H. E., & Rottinghaus, G. E. (2003). Acute drought stress and plant age effects on alkamide and phenolic acid content in purple coneflower roots. Planta medica, 69(1), 50–55. https://doi.org/10.1055/s-2003-37026
   PubMed Web of Science ®Google Scholar
• Grevsen, K., Fretté, X. C., & Christensen, L. P. (2008). Concentration and composition of flavonol glycosides and phenolic acids in aerial parts of stinging nettle (Urtica dioica L.) are affected by nitrogen fertilization and by harvest time. European Journal of Horticultural Science, 73(1), 20.
   Web of Science ®Google Scholar
• Grimm, W., & Müller, H. H. (1999). A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. The American Journal of Medicine, 106(2), 138–143. https://doi.org/10.1016/s0002-9343(98)00406-9
   PubMed Web of Science ®Google Scholar
• Guitton, Y., Tremblay-Franco, M., Corguillé, G. L., Martin, J. F., Pétéra, M., Roger-Mele, P., Delabrière, A., Goulitquer, S., Monsoor, M., Duperier, C., Canlet, C., Servien, R., Tardivel, P., Caron, C., Giacomoni, F., & Thévenot, E. (2017). Create, run, share, publish, and reference your LC–MS, FIA–MS, GC–MS, and NMR data analysis workflows with the workflow4Metabolomics 3.0 Galaxy online infrastructure for metabolomics. The International Journal of Biochemistry & Cell Biology, 93, 89–101. https://doi.org/10.1016/j.biocel.2017.07.002
   PubMed Web of Science ®Google Scholar
• Hahn, R., & Nahrstedt, A. (1993). Hydroxycinnamic acid derivatives, caffeoylmalic and new caffeoylaldonic acid esters, from chelidonium majus. Planta medica, 59(1), 71–75. https://doi.org/10.1055/s-2006-959608
   PubMed Web of Science ®Google Scholar
• Haron, M. H., Tyler, H. L., Chandra, S., Moraes, R. M., Jackson, C. R., Pugh, N. D., & Pasco, D. S. (2019). Plant microbiome-dependent immune enhancing action of Echinacea purpurea is enhanced by soil organic matter content. Scientific Reports, 9(1), Rep–UK. 9. https://doi.org/10.1038/s41598-018-36907-x
   Google Scholar
• He, X. G., Lin, L. Z., Bernart, M. W., & Lian, L. Z. (1998). Analysis of alkamides in roots and achenes of Echinacea purpurea by liquid chromatography–electrospray mass spectrometry. Journal of Chromatography, 815(2), 205–211. https://doi.org/10.1016/s0021-9673(98)00447-6
   Web of Science ®Google Scholar
• Hu, C., & Kitts, D. D. (2000). Studies on the antioxidant activity of echinacea root extract. Journal of Agricultural & Food Chemistry, 48, 1466–1472. https://doi.org/10.1021/jf990677+
   PubMed Web of Science ®Google Scholar
• Kabganian, R., Carrier, D. J., Rose, P. A., Abrams, S. R., & Sokhansanj, S. (2003). Localization of alkamides, echinacoside and cynarin with Echinacea angustifolia. Journal of Herbs, Spices & Medicinal Plants, 10(2), 73–81. https://doi.org/10.1300/j044v10n02_08
   Google Scholar
• Karsch-Völk, M., Barrett, B., & Linde, K. (2015). Echinacea for preventing and treating the common cold. JAMA, 313(6), 618–619. https://doi.org/10.1002/14651858.cd000530.pub3
   PubMed Web of Science ®Google Scholar
• Kindscher, K. (2016). The biology and ecology of echinacea species. In Echinacea: 47-54 (pp. 47–54). Springer International Publishing. https://doi.org/10.1007/978-3-319-18156-1_5
   Google Scholar
• Kindscher, K., & Riggs, M. (2016). Cultivation of Echinacea angustifolia and Echinacea purpurea. In Echinacea: 21-33 (pp. 21–33). Springer International Publishing. https://doi.org/10.1007/978-3-319-18156-1_3
   Google Scholar
• Kohl, S. M., Klein, M. S., Hochrein, J., Oefner, P. J., Spang, R., & Gronwald, W. (2012). State-of-the art data normalization methods improve NMR-based metabolomic analysis. Metabolomics, 8(S1), 146–160. https://doi.org/10.1007/s11306-011-0350-z
   PubMedGoogle Scholar
• Korkina, L. G. (2007). Phenylpropanoids as naturally occurring antioxidants: From plant defense to human health. Cellular and Molecular Biology, 53, 15–25. https://doi.org/10.2174/138955711796575489
   PubMed Web of Science ®Google Scholar
• Kuhnert, N., Jaiswal, R., Matei, M. F., Sovdat, T., & Deshpande, S. (2010). How to distinguish between feruloyl quinic acids and isoferuloyl quinic acids by liquid chromatography/tandem mass spectrometry. Rapid Communications in Mass Spectrometry, 24(11), 1575–1582. https://doi.org/10.1002/rcm.4537
   PubMed Web of Science ®Google Scholar
• Kurkin, V. A., Akushskaya, A. S., Avdeeva, E. V., Velmyaikina, E. I., Daeva, E. D., & Kadentsev, V. I. (2011). Flavonoids from Echinacea purpurea. Russian Journal of Bioorganic Chemistry, 37(7), 905–906. https://doi.org/10.1134/s1068162011070120
   Web of Science ®Google Scholar
• Lavola, A. (1998). Accumulation of flavonoids and related compounds in birch induced by UV-B irradiance. Tree Physiology, 18(1), 53–58. https://doi.org/10.1093/treephys/18.1.53
   PubMed Web of Science ®Google Scholar
• Lee, J. (2010). Caffeic acid derivatives in dried Lamiaceae and Echinacea purpurea products. Journal of Functional Foods, 2(2), 158–162. https://doi.org/10.1016/j.jff.2010.02.003
   Web of Science ®Google Scholar
• Lenth, R., Singmann, H., Love, J., Buerkner, P., & Herve, M. (2018). Emmeans: Estimated marginal means, aka least-squares means. R package version. http://CRAN.R-project.org/package=emmeans
   Google Scholar
• Letchamo, W., Livesey, J., Arnason, T., Bergeron, C., & Krutilina, V. (1999). Cichoric acid and isobutylamide content in Echinacea purpurea as influenced by flower developmental stages. In Perspectives on New Crops and New Uses (pp. 494–498). Alexandria, VA: ASHS Press.
   Google Scholar
• Liu, L., Gitz Iii, D. C., & McClure, J. W. (1995). Effects of UV‐B on flavonoids, ferulic acid, growth and photosynthesis in barley primary leaves. Physiologia plantarum, 93(4), 725–733. https://doi.org/10.1034/j.1399-3054.1995.930421.x
   Web of Science ®Google Scholar
• Liu, Y. C., Zeng, J. G., Chen, B., & Yao, S. Z. (2007). Investigation of phenolic constituents in Echinacea purpurea grown in China. Planta medica, 73(15), 1600–1605. https://doi.org/10.1055/s-2007-993742
   PubMed Web of Science ®Google Scholar
• Liu, L., Zhang, J., Zheng, B., Guan, Y., Wang, L., Chen, L., & Cai, W. (2018). Rapid characterization of chlorogenic acids in Duhaldea nervosa based on ultra-high-performance liquid chromatography-linear trap quadropole-Orbitrap-mass spectrometry and mass spectral trees similarity filter technique. Journal of Separation Science, 41(8), 1764–1774. https://doi.org/10.1002/jssc.201701047
   PubMed Web of Science ®Google Scholar
• Lopes-Lutz, D., Mudge, E., Ippolito, R., Brown, P., & Schieber, A. (2010). Purification of alkylamides from Echinacea angustifolia (DC.) Hell. roots by high-speed countercurrent chromatography. Journal of Agricultural & Food Chemistry, 59(2), 491–494. https://doi.org/10.1021/jf103436p
   PubMed Web of Science ®Google Scholar
• Lu, Y., Li, J., Li, M., Hu, X., Tan, J., & Liu, Z. H. (2012). Efficient counter-current chromatographic isolation and structural identification of two new cinnamic acids from Echinacea purpurea. Natural Product Communications, 7(10), 1934578X1200701026. https://doi.org/10.1177/1934578x1200701026
   Web of Science ®Google Scholar
• Luo, X. B., Chen, B., Yao, S. Z., & Zeng, J. G. (2003). Simultaneous analysis of caffeic acid derivatives and alkamides in roots and extracts of Echinacea purpurea by high-performance liquid chromatography–photodiode array detection–electrospray mass spectrometry. Journal of Chromatography, 986(1), 73–81. https://doi.org/10.1016/s0021-9673(02)01922-2
   Web of Science ®Google Scholar
• Luthria, D. L., Mukhopadhyay, S., & Krizek, D. T. (2006). Content of total phenolics and phenolic acids in tomato (Lycopersicon esculentum Mill.) fruits as influenced by cultivar and solar UV radiation. Journal of Food Composition & Analysis, 19(8), 771–777. https://doi.org/10.1016/j.jfca.2006.04.005
   Web of Science ®Google Scholar
• Maggini, V., De Leo, M., Granchi, C., Tuccinardi, T., Mengoni, A., Gallo, E. R., Biffi, S., Fani, R., Pistelli, L., Firenzuoli, F., & Bogani, P. (2019). The influence of Echinacea purpurea leaf microbiota on chicoric acid level. Scientific Reports, 9(1), 1–11. https://doi.org/10.1038/s41598-019-47329-8
   PubMedGoogle Scholar
• Maggini, V., De Leo, M., Mengoni, A., Gallo, E. R., Miceli, E., Reidel, R. V. B., Biffi, S., Pistelli, L., Fani, R., Firenzuoli, F., & Bogani, P. (2017). Plant-endophytes interaction influences the secondary metabolism in Echinacea purpurea (L.) Moench: An in vitro model. Scientific Reports, 7(1), 16924. https://doi.org/10.1038/s41598-017-17110-w
   PubMedGoogle Scholar
• Manayi, A., Vazirian, S., & Saeidnia, M. (2015). Echinacea purpurea: Pharmacology, phytochemistry and analysis methods. Pharmacognosy Reviews, 9(17), 63. https://doi.org/10.4103/0973-7847.156353
   PubMedGoogle Scholar
• Mari, A., Montoro, P., D’Urso, G., Macchia, M., Pizza, C., & Piacente, S. (2015). Metabolic profiling of Vitex agnus castus leaves, fruits and sprouts: Analysis by LC/ESI/(QqQ) MS and (HR) LC/ESI/(Orbitrap)/MSn. Journal of Pharmaceutical & Biomedical Analysis, 102, 215–221. https://doi.org/10.1016/j.jpba.2014.09.018
   PubMed Web of Science ®Google Scholar
• Martin, A. C., Pawlus, A. D., Jewett, E. M., Wyse, D. L., Angerhofer, C. K., & Hegeman, A. D. (2014). Evaluating solvent extraction systems using metabolomics approaches. RSC Advances, 4(50), 26325–26334. https://doi.org/10.1039/c4ra02731k
   Web of Science ®Google Scholar
• Matthias, A., Blanchfield, J. T., Penman, K. G., Toth, I., Lang, C. S., De Voss, J. J., & Lehmann, R. (2004). Permeability studies of alkamides and caffeic acid conjugates from echinacea using a Caco‐2 cell monolayer model. Journal of Clinical Pharmacy and Therapeutics, 29(1), 7–13. https://doi.org/10.1046/j.1365-2710.2003.00530.x
   PubMed Web of Science ®Google Scholar
• McKeown, K. A. (1999). A review of the taxonomy of the genus Echinacea. In J. Janick (Ed.), Perspectives on new crops and new uses (pp. 482–498). ASHS Press.
   Google Scholar
• Melchart, D., Clemm, C., Weber, B., Draczynski, T., Worku, F., Linde, K., Weidenhammer, W., Wagner, H., & Saller, R. (2002). Polysaccharides isolated from Echinacea purpurea herba cell cultures to counteract undesired effects of chemotherapy—a pilot study. Phytotherapy Research: PTR, 16(2), 138–142. https://doi.org/10.1002/ptr.888
   PubMed Web of Science ®Google Scholar
• Miller, S. C., Yu, H. C., Miller, S. C., & Yu, H.-C. (2004). Echinacea: The genus Echinacea. CRC Press. https://doi.org/10.1201/9780203022696
   Google Scholar
• Mudge, E., Lopes-Lutz, D., Brown, P., & Schieber, A. (2011). Analysis of alkylamides in Echinacea plant materials and dietary supplements by ultrafast liquid chromatography with diode array and mass spectrometric detection. Journal of Agricultural & Food Chemistry, 59(15), 8086–8094. https://doi.org/10.1021/jf201158k
   PubMed Web of Science ®Google Scholar
• Pellati, F., Benvenuti, S., Melegari, M., & Lasseigne, T. (2005). Variability in the composition of anti‐oxidant compounds in Echinacea species by HPLC. Phytochemical Analysis, 16(2), 77–85. https://doi.org/10.1002/pca.815
   PubMed Web of Science ®Google Scholar
• Pellati, F., Epifano, F., Contaldo, N., Orlandini, G., Cavicchi, L., Genovese, S., Bertelli, D., Benvenuti, S., Curini, M., Bertaccini, A., & Bellardi, M. G. (2011). Chromatographic methods for metabolite profiling of virus- and phytoplasma-infected plants of Echinacea purpurea. Journal of Agricultural & Food Chemistry, 59(19), 10425–10434. https://doi.org/10.1021/jf2025677
   PubMed Web of Science ®Google Scholar
• Perry, N. B., van Klink, J. W., Burgess, E. J., & Parmenter, G. A. (1997). Alkamide levels in Echinacea purpurea: A rapid analytical method revealing differences among roots, rhizomes, stems, leaves and flowers. Planta medica, 63(1), 58–62. https://doi.org/10.1055/s-2006-957605
   PubMed Web of Science ®Google Scholar
• Pietta, P., Mauri, P., & Bauer, R. (1998). MEKC analysis of different Echinacea species. Planta medica, 64(7), 649–652. https://doi.org/10.1055/s-2006-957540
   PubMed Web of Science ®Google Scholar
• Pinheiro, J., Bates, D., DebRoy, S., Sarkar, D., & R Core Team. (2018). Nlme: Linear and nonlinear mixed effects models. R package version. http://CRAN.R-project.org/package=nlme.
   Google Scholar
• Pires, C., Martins, N., Carvalho, A. M., Barros, L., & Ferreira, I. C. (2016). Phytopharmacologic preparations as predictors of plant bioactivity: A particular approach to Echinacea purpurea (L.) Moench antioxidant properties. Nutrition, 32(7–8), 834–839. https://doi.org/10.1016/j.nut.2016.01.005
   PubMed Web of Science ®Google Scholar
• Pomponio, R., Gotti, R., Hudaib, M., & Cavrini, V. (2002). Analysis of phenolic acids by micellar electrokinetic chromatography: Application to Echinacea purpurea plant extracts. Journal of Chromatography, 945(1–2), 239–247. https://doi.org/10.1016/s0021-9673(01)01488-1
   Web of Science ®Google Scholar
• Qu, L., Chen, Y., Wang, X., Scalzo, R., & Davis, J. M. (2005). Patterns of variation in alkamides and cichoric acid in roots and aboveground parts of Echinacea purpurea (L.) Moench. HortScience, 40(5), 1239–1242. https://doi.org/10.21273/hortsci.40.5.1239
   PubMed Web of Science ®Google Scholar
• R Core Team. (2018). R: A language and environment for statistical computing. R Foundation for Statistical Computing. https://www.R-project.org/
   Google Scholar
• Riggs, M., & Kindscher, K. (2016). The Echinacea market. In Echinacea (pp. 165–175). Springer International Publishing. https://doi.org/10.1007/978-3-319-18156-1_11
   Google Scholar
• Salek, R. M., Steinbeck, C., Goodacre, M. R., Dunn, W. B., & Dunn, W. B. (2013). The role of reporting standards for metabolite annotation and identification in metabolomic studies. Gigascience, 2(1), 2047–217X. https://doi.org/10.1186/2047-217x-2-13
   Google Scholar
• Sampaio, B. L., Edrada-Ebel, R., & Da Costa, F. B. (2016). Effect of the environment on the secondary metabolic profile of Tithonia diversifolia: A model for environmental metabolomics of plants. Scientific Reports, 6(1), 29265. https://doi.org/10.1038/srep29265
   PubMedGoogle Scholar
• Scherling, C., Roscher, C., Giavalisco, P., Schulze, E. D., Weckwerth, W., & Chave, J. (2010). Metabolomics unravel contrasting effects of biodiversity on the performance of individual plant species. PLoS One, 5(9), e12569. https://doi.org/10.1371/journal.pone.0012569
   PubMed Web of Science ®Google Scholar
• Schoop, R., Klein, P., Suter, A., & Johnston, S. L. (2006). Echinacea in the prevention of induced rhinovirus colds: A meta-analysis. Clinical Therapeutics, 28(2), 174–183. https://doi.org/10.1016/j.clinthera.2006.02.001
   PubMed Web of Science ®Google Scholar
• Sharma, M., Anderson, S. A., Schoop, R., & Hudson, J. B. (2009). Induction of multiple pro-inflammatory cytokines by respiratory viruses and reversal by standardized Echinacea, a potent antiviral herbal extract. Antiviral Research, 83(2), 165–170. https://doi.org/10.1016/j.antiviral.2009.04.009
   PubMed Web of Science ®Google Scholar
• Sherrard, M. E., Elgersma, K. J., Koos, J. M., Kokemuller, C. M., Dietz, H. E., Glidden, A. J., Carr, C. M., & Cambardella, C. A. (2019). Species composition influences soil nutrient depletion and plant physiology in prairie agroenergy feedstocks. Ecosphere, 10(7). https://doi.org/10.1002/ecs2.2805
   Web of Science ®Google Scholar
• Smith, T., Kawa, K., Eckl, V., Morton, C., & Stredney, R. (2018). Herbal supplement sales in US increase 8.5% in 2017, topping $8 billion. HerbalGram, 119, 62–71. https://abc-media.mcnines.net/media/xxod5ku4/issue119.pdf
   Google Scholar
• Spelman, K., Wetschler, M. H., & Cech, N. B. (2009). Comparison of alkylamide yield in ethanolic extracts prepared from fresh versus dry Echinacea purpurea utilizing HPLC–ESI-MS. Journal of Pharmaceutical & Biomedical Analysis, 49(5), 1141–1149. https://doi.org/10.1016/j.jpba.2009.02.011
   PubMed Web of Science ®Google Scholar
• Stuart, D. L., & Wills, R. B. H. (2000). Alkylamide and cichoric acid levels in Echinacea purpurea tissues during plant growth. Journal of Herbs, Spices & Medicinal Plants, 7(1), 91–101. https://doi.org/10.1016/s0308-8146(99)00129-6
   Google Scholar
• Thomsen, M. O., Christensen, L. P., & Grevsen, K. (2018). Harvest strategies for optimization of the content of bioactive alkamides and caffeic acid derivatives in aerial parts and in roots of Echinacea purpurea. Journal of Agricultural & Food Chemistry, 66(44), 11630–11639. https://doi.org/10.1021/acs.jafc.8b03420
   PubMed Web of Science ®Google Scholar
• Thomsen, M. O., Fretté, X. C., Christensen, K. B., Christensen, L. P., & Grevsen, K. (2012). Seasonal variations in the concentrations of lipophilic compounds and phenolic acids in the roots of Echinacea purpurea and Echinacea pallida. Journal of Agricultural & Food Chemistry, 60(49), 12131–12141. https://doi.org/10.1021/jf303292t
   PubMed Web of Science ®Google Scholar
• Thygesen, L., Thulin, J., Mortensen, A., Skibsted, L. H., & Molgaard, P. (2007). Antioxidant activity of cichoric acid and alkamides from Echinacea purpurea, alone and in combination. Food Chemistry, 101(1), 74–81. https://doi.org/10.1016/j.foodchem.2005.11.048
   Web of Science ®Google Scholar
• Turner, R. B., Riker, D. K., & Gangemi, J. D. (2000). Ineffectiveness of Echinacea for prevention of experimental rhinovirus colds. Antimicrobial Agents and Chemotherapy, 44(6), 1708–1709. https://doi.org/10.1128/aac.44.6.1708-1709.2000
   PubMed Web of Science ®Google Scholar
• van Dam, N. M., & van der Meijden, E. (2018). A role for metabolomics in plant ecology. Annalen Plant Review, 87–107. https://doi.org/10.1002/9781444339956.ch4
   Google Scholar
• Verdonk, J. C., De Vos, C. R., Verhoeven, H. A., Haring, M. A., van Tunen, A. J., & Schuurink, R. C. (2003). Regulation of floral scent production in petunia revealed by targeted metabolomics. Phytochemistry, 62(6), 997–1008. https://doi.org/10.1016/s0031-9422(02)00707-0
   PubMed Web of Science ®Google Scholar
• Vimalanathan, S., Kang, L., Amiguet, V. T., Livesey, J., Arnason, J. T., & Hudson, J. (2005). Echinacea purpurea. aerial parts contain multiple antiviral compounds. Pharmaceutical Biology, 43(9), 740–745. https://doi.org/10.1080/13880200500406354
   Web of Science ®Google Scholar
• Vimalanathan, S., Schoop, R., & Hudson, J. (2013). High-potency Anti-influenza therapy by a combination of Echinacea purpurea fresh herb and root tinctures. Journal Application Pharmaceut Science, 3, 001–005. https://doi.org/10.1055/s-0033-1352301
   Google Scholar
• Wagenius, S., & Lyon, S. P. (2010). Reproduction of Echinacea angustifolia in fragmented prairie is pollen‐limited but not pollinator‐limited. Ecology, 91(3), 733–742. https://doi.org/10.1890/08-1375.1
   PubMed Web of Science ®Google Scholar
• Wang, Y., Hao, H., Wang, G., Tu, P., Jiang, Y., Liang, Y., Dai, L., Yang, H., Lai, L., Zheng, C., Wang, Q., Cui, N., & Liu, Y. (2009). An approach to identifying sequential metabolites of a typical phenylethanoid glycoside, echinacoside, based on liquid chromatography–ion trap-time of flight mass spectrometry analysis. Talanta, 80(2), 572–580. https://doi.org/10.1016/j.talanta.2009.07.027
   PubMed Web of Science ®Google Scholar
• Wills, R. B. H., & Stuart, D. L. (1999). Alkamide and cichoric acid levels in Echinacea purpurea grown in Australia. Food Chemistry, 67(4), 385–388. https://doi.org/10.1016/s0308-8146(99)00129-6
   Web of Science ®Google Scholar
• Wist, T. J., & Davis, A. R. (2005). Floral nectar production and nectary anatomy and ultrastructure of Echinacea purpurea (Asteraceae). Annals of Botany, 97(2), 177–193. https://doi.org/10.1093/aob/mcj027
   PubMed Web of Science ®Google Scholar
• Zheng, Y., Dixon, M., & Saxena, P. K. (2006). Growing environment and nutrient availability affect the content of some phenolic compounds in Echinacea purpurea and Echinacea angustifolia. Planta medica, 72(15), 1407–1414. https://doi.org/10.1055/s-2006-951720
   PubMed Web of Science ®Google Scholar