The flavonoids of Parthenium L.

The distribution of 34 flavonoids detected in the North American species of Parthenium L. is presented. Of the 27 flavonoids identified (some tentatively) all are flavonols: eight are based on kaempferol, seven on quercetin, four on 6-hydroxykaempferol and eight on the quercetagetin skeleton. Of the 34 flavonoids detected, 19 are glycosides and 15 are aglycones, primarily highly methylated compounds.