[Studies on the structures of new flavonoids from the root of Scutellaria amoena]

From the root of Scutellaria amoena C.H. Wright, two new flavonoids (I, II) and six known flavonoids (III-VIII) were isolated. On the basis of spectroscopic analysis (UV, 1HNMR, 13CNMR, MS and CD) and chemical evidences, the structures of I and II were elucidated as (2S)-2',5,6'-trihydroxy-7-methoxyflavanone-2'-O-beta-D-glucopyrano side (I) and (2R, 3R)-2',3,5,7-tetrahydroxyflavanone (II) respectively. The other six known compounds were identified as (2S)-5,7,8-trihydroxyflavanone (III), (2S)-2',5,6',7-tetrahydroxyflavanone (IV), (2R, 3R)-2',3,5,6',7-pentahydroxyflavanone (V), 2',5,6',7-tetrahydroxyflavone (VI) norwogonin (VII) and oroxylin-A (VIII) respectively. Compounds III-VIII were obtained from this plant for the first time.