Studies on the Constituents of Roots ofScutellaria planipes

From the roots of Scutellaria planipes (L.), three new flavonoids, 5,7,3',6'-tetrahydroxy-6,8,2'-trimethoxyflavone (1), (2R,3R)-3,5,7,2',5'-pentahydroxyflavanone (2) and 7,2'-dihydroxy-5-methoxyflavone (3) were isolated, together with ten known flavonoids, skullcapflavone I (4), wogonin (5), baicalein (6), norwogonin (7), viscidulin III (8), 5,7,2',6'-tetrahydroxyflavone (9), 3,5,7,2',6'-pentahydroxyflavone (10), wogonin 7-O-β-D-glucuronide (11), baicalin (12), baicalein 7-D-β-D-glucopyranoside (13), and three phenethyl alcohol glycosides, acteoside (14), martynoside (15), and jionoside D (16). The structures were elucidated by spectroscopic methods.