A guaianolide alloside and other constituents from Picris kamtschatica.

From Picris kamtschatica two new guaianolide glycosides, including a beta-allopyranosyl analogue of ixerin F, were isolated, in addition to ten known sesquiterpene lactones and six phenolic compounds. This is the first time a sesquiterpene lactone alloside has been described from plants. The compounds were characterized based on mass, 1D and 2D NMR spectral data.