Trypanocidal flavonoids from Trixis vauthieri.

The crude extract of Trixis vauthieri (Asteraceae) was active against the trypomastigote forms of Trypanosoma cruzi, the protozoan that causes Chagas' disease. Bioassay-guided fractionation of this extract afforded the trypanocidal flavonoids 5,4'-dihydroxy-7-methoxyflavanone (1) and 5,4'-dihydroxy-3,6,7-trimethoxyflavone (2) besides the inactive flavonoids 3,5,4'-trihydroxy-7-methoxyflavanone (3) and 5,4'-dihydroxy-3,6,7,8-tetramethoxy flavone (4). The trypanocidal activity of 1 and 2 and the presence of compounds 2 and 4 in Trixis vauthieri are reported here for the first time.