Fracionamento cromatográfico da fração em diclorometano obtida do extrato etanólico das folhas de Vernonia tweediana Baker (Asteraceae) conduziu ao isolamento de α-amirina, β-amirina, lupeol, β-sitosterol, estigmasterol e espinasterol. As estruturas foram identificadas através de técnicas espectroscópicas usuais, além da comparação com dados relatados na literatura. Os compostos isolados são relatados pela primeira vez para a espécie V. tweediana.

Fractionation of the dichloromethane -soluble fraction from the ethanol extract of the leaves of Vernonia tweediana (Asteraceae) led to the isolation of α-amyrin, β-amyrin, lupeol, β-sitosterol, stigmasterol and spinasterol. The structures of the isolates were elucidated by spectroscopic analysis and comparison with literature data. The isolated compounds are reported for the first time to the species V. tweediana.

Ilex paraguariensis is a native plant in Southern Brazil, whose leaves are utilized in beverages such as chimarrão and tererê. This study investigated variations of total methylxanthines in leaves from two Ilex populations collected at one-month intervals over the course of one year. The levels varied from 1.92 to 10.37 mg/g (Ijuí) and 1.77 to 9.17 mg/g (Santa Maria). Statistical analysis indicated a significative variation in the contents of all samples analysed, confirming seasonal fluctuations. These results show that the period of harvest might decisively influence the organoleptic characteristics of raw material used in industry and therefore in commercial products.