Leaf essential oil compositions of bear’s foot, Smallanthus uvedalia and Polymnia canadensis

Abstract

The leaves of Smallanthus uvedalia and Polymnia canadensis, two members of the Asteraceae important in Native American traditional herbal medicine, were collected in north Alabama. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography – mass spectrometry. Caryophyllane sesquiterpenoids dominated the leaf essential oil of S. uvedalia, including (E)-caryophyllene (16.5-24.5%), caryophyllene oxide (14.2-19.8%), 14-hydroxy-9-epi-(E)-caryophyllene (6.2-8.9%), 14-hydroxy-9-epi-(Z)-caryophyllene (4.3-8.2%), caryophylla-4(12),8(13)-dien-5β-ol (2.3-5.5%), and caryophylla-4(12),8(13)-dien-5α-ol (0.9-2.0%). P. canadensis leaf oil, on the other hand, was rich in germacrene D (44.5-63.7%). The high concentrations of caryophyllane and germacrane sesquiterpenoids likely account for the traditional uses of these plants to reduce inflammation and swelling.