Volatile components of roots, stems, leaves, and flowers of Echinacea species

The headspace volatile components of roots, stems, leaves, and flowers of E chinacea angustifolia, E. pallida, and E, purpurea were analyzed by capilla ry gas chromatography/mass spectrometry (GC/MS). Over 70 compounds were ide ntified in the samples. All plant tissues, irrespective of the species, con tain acetaldehyde, dimethyl sulfide, camphene, hexanal, beta-pinene, and li monene. The main headspace constituents of the aerial parts of the plant ar e beta-myrcene, alpha-pinene, limonene, camphene, beta-pinene, trans-ocimen e, 3-hexen-1-ol, and 2-methyl-4-pentenal. The major headspace components of root tissue are alpha-phellandrene (present only in the roots of E. purpur ea and E. angustifolia), dimethyl sulfide, 2-methylbutanal, 3-methylbutanal , 2-methylpropanal, acetaldehyde, camphene, 2-propanal, and limonene. Aldeh ydes, particularly butanals and propanals, make up 41-57% of the headspace of root tissue, 19-29% of the headspace of the leaf tissue, and only 6-14% of the headspace of flower and stem tissues. Terpenoids including alpha- an d beta-pinene, beta-myrcene, ocimene, limonene, camphene, and terpinene mak e up 81-91% of the headspace of flowers and stems, 46-58% of the headspace of the leaf tissue, and only 6-21% of the roots. Of the 70 compounds identi fied, >50 are reported in Echinacea for the first time.