Studies on the Constituents of Scutellaria Species (XXII). Constituents of the Roots of Scutellaria amabilis HARA

From the roots of Scutellaria amabilis KARA, eleven new flavonoids, 5, 7, 2'-trihydroxy-8-methoxyflavone 7-O-β-D-glucopyranoside, 5, 7, 2'-trihydroxy-8-methoxyflavone 2'-O-β-D-glucopyranoside, 5, 7-dihydroxy-8, 2'-dimethoxyflavone 7-O-β-D-glucopyranoside, 5, 7, 2'-trihydroxyflavone 2'-O-β-D-glucopyranoside, 5, 7, 2', 5'-tetrahydroxyflavone 7-O-β-D-glucuronopyranoside, (2S)-5, 7, 2', 5'-tetrahydroxyflavanone, (2S)-5, 7, 2', 5'-tetrahydroxy-flavanone 7-O-β-D-glucopyranoside, (25)-5, 7, 2', 5'-tetrahydroxyflavanone 7-O-β-D-glucuronopyranoside, (2S)-7, 2'-dihydroxy-5-methoxyflavanone 7-O-β-D-glucuronopyranoside, (I-2S)-I-5, II-5, I-7, II-7, I-2', II-2', II-5'-heptahydroxy-[I-6, II-6']-flavanonylflavone and (I-2S)-I-5, II-5, I-7, II-7, I-2', II-2', I-5', II-5'-octahydroxy-[I-6, II-6']-flava-nonylflavone, were isolated, together with ten known flavonoids, wogonin (5, 7-dihydroxy-8-methoxyflavone), 5, 7-dihydroxy-8, 2'-dimethoxyflavone, (2S)-5, 7, 2'-trihydroxyflavanone, scutevulin (5, 7, 2'-trihydroxy-8-methoxy-flavone), 5, 7, 4'-trihydroxy-8-methoxyflavone, alpinetin ((2S)-7-hydroxy-5-methoxyflavanone), 5, 7, 2'-trihydroxy-flavone, 5, 7, 2', 5'-tetrahydroxyflavone, (2S)-7, 2'-dihydroxy-5-methoxyflavanone and 5, 7-dihydroxy-8, 2'-dimethoxy-flavone 7-O-β-D-glucuronopyranoside. The structures were determined on the basis of chemical and spectral data.