The aim of this study was to evaluate the seasonal effect on the foam index and the isolation and structural identification of a chemical constituent (flavone) of Baccharis trimera. The culture staminate samples of B. trimera were realized in the experimental cultivation area of the Universidade de Ribeirão Preto - Unaerp, in Ribeirão Preto, state of São Paulo, Brazil from January to December/1998 and were conduced in three blocks, which received 48 seedlings. The samples were harvested six months after installation (during the winter), three months after the first harvest (during the spring) and three months after the second harvest (during the summer). After the drying process and comminution, an assay to obtain the foam index was performed with the plant material. The results didn’t show any alteration, independently of harvest times. Part of the dried plant that had been harvested during the summer was extracted to isolate and identify structurally the chemical compound. The isolation from the methanol extracts of the aerial parts of B. trimera has been performed through chromatographic methods (CC and HPLC) and the identification through spectrometric methods (UV, ¹H and 13C NMR). A flavone was identified as 5,6-dihidroxy-7,3’,4’-trimetoxiflavone.
Baccharis trimera; Asteraceae; flavonoids; saponins; seasonal variability
