Common Names: Canada lettuce
Researchers isolated 19 sesquiterpene lactones from the roots of Lactuca canadensis L. Ten of the 19 were newly discovered, including three pairs of zaluzanin C-type guaianolides and six eudesmanolides. 1D and 2D NMR and high resolution mass spectroscopy were used to identify the new compounds as 3-epizaluzanin C-3-O-β-glucopyranoside and 11,13-dehydrolactuside C. The sesquiterpene lactone profile of the species is dominated by zaluzanin C-type guaianolides and eudesmanolides. The differences in this profile compared to other taxa in the genus are discussed.