New flavonoids from Inula cappa

Extraction of Inula cappa DC. yielded three new flavonoids with an unusual ring B substitution pattern, namely (2R,3R)-5′-methoxy-3,5,7,2′-tetrahydroxyflavone, (2S)-5,7,2′,5′-tetrahydroxyflavanone and 7.5′-dimethoxy- 3,5,2′-trihydroxyflavone. Structures were established by chemical correlation, spectroscopic studies and degradation.