New Phenolics from Baccharis Leaf Exudate

A previous study on the leaf resin composition of some Baccharis species revealed that the resinous material consists mostly of terpenoids, in which more or less lipophilic flavonoid aglycones are dissolved [1]. In B. salicifolia, a major terpenoid was found to be the rare triterpene maniladiol [2]. The major flavonoids were penduletin (6 -hydroxykaempferol3,6 ,7-trimethyl ether) and pinocembrin, accom­ panied by five flavones and seven flavonols [1], One further compound remained unidentified, due to the paucity of material, and was isolated only in a par­ tially purified state (mentioned as compound 6 in [1 ], The leaf resin of B. sarothroides A. Gray had been found to consist mostly of the trivial triterpene oleanolic acid and the rare diterpene hautriwaic acid and its 2-ß-hydroxy derivative [2]. The flavonoid aglycones found in this species were exclusively flavonols, most of them substituted at C 6 and/or C-8 , with 5,7,4'-trihydroxy-3,6,8-trimethoxy flavone prevailing [1]. In this material, a blue fluorescent spot (polyamide, UV366) remained unidentified in the earlier study. The two unidentified components from B. salicifolia and B. sarothroides have now