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Four flavonoids have been identified from the leaf and stem resin produced by Baccharis bigelovii (Asteraceae) in addition to twelve previously described aglycones. A flavonol (alnusin) and a dihydroflavonol (alnustinol) with 3,5,7-trihydroxy substitution had both been reported only twice before. The novel compound 2β,5,7-trihydroxy-flavanone is remarkable for its 2β-substitution at the heterocyclic ring. 7-Benzoyl-chrysin is the first flavone aglycone found as ester and the first flavonoid aglycone at all that is esterified with an aromatic acid.

Seven species of the genus Baccharis have been analyzed for flavonoid aglycones. Many known methylated flavones, flavonols and flavanones were identified. From B. sarothroides, two novel flavonols were isolated and elucidated as 5,7,4′-trihydroxy-3,6,8-trimethoxyflavone and its methyl ether, 5,4′-dihydroxy-3,6,7,8-tetramethoxyflavone. Previous literature reports on flavonoids in Baccharis are summarized and their distribution and external occurrence is discussed. One novel diterpene and one rare triterpene were found in the terpenoid fractions that constitute most of the exudate material in these and other Compositae.

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The resinous material excreted by aerial parts of snakeweed, Gutierrezia sarothrae, was analyzed for flavonoid aglycones. Six major flavonoids were characterized by their spectral data; nine minor flavonoids were identified by direct comparisons with markers. The major flavones form three pairs of isomeric products, five of which are 6,8-methoxylated.