Sesquiterpene lactones from Scorzonera austriaca.

Six new sesquiterpene lactones, scorzoaustriacoside (1), scorzoaustriacin (2), scorzoaustriacin 3-O-beta-d-glucoside (3), 4-epi-dihydroestafiatol (4), 14-isovaleroxyscorzoaustricin (5), and 14-isovaleroxyscorzoaustricin sulfate (6), along with five known guaianolides, were isolated from an acetone extract of the roots of Scorzonera austriaca. The structures of the new compounds were elucidated mainly by interpretation of their 1D and 2D NMR and HRMS data. Several isolates obtained in this investigation were evaluated against a small panel of cancer cell lines.