Five flavonoid glycosides and two derivatives were isolated from the herbs of Scorzonera austriaca Wild by silica gel column chromatography and preparative HPLC. Their structures were identified, using chemical and spectroscopic methods, as 5,7,4'-trihydroxyflavone 6-C-(2''-O-β-d-glucopyranosyl β-d-glucopyranoside) (1), 5,7,3',4'-tetrahydroxyflavone 6-C-(2''-O-β-d-glucopyranosyl β-d-glucopyranoside) (2), quercetin 3-O-rutinoside (3), 5,7,4'-trihydroxyflavone 6-C-β-d-glucopyranoside (4), 3'-methoxy-5,7,4'-trihydroxyflavone 6-C-β-d-glucopyranoside (5), 5,7,4'-trihydroxyflavone 8-C-(6''-O-trans-caffeoyl β-d-glucopyranoside) (6), and 5,7,3',4'-tetrahydroxyflavone 8-C-(6''-O-trans-caffeoyl β-d-glucopyranoside) (7). Compounds 6 and 7 are new flavonoid glycoside derivatives, and compounds 1-5 were isolated from the herbs of Scorzonera austriaca for the first time. Compounds 6 and 7 were also assayed for their hepatoprotective activities with rat hepatocytes in vitro.
Keywords: Scorzonera austriaca; flavonoids; hepatoprotective activities.