This work describes the flavonoids and biflavonoids found in species of Ouratea and Luxemburgia as chemical markers that serve to detect the difference between these taxa according to the linkage between the flavonoidal units. A rational nomenclature is proposed and the pharmacological potencial is discussed.

O fracionamento cromatográfico dos extratos das folhas de Ouratea hexasperma (Ochnaceae) forneceu, além do novo biflavonóide 5-hidróxi-7-metoxiflavona-(4'-O-8")-5",4"'-diidróxi-7" -metoxiflavona, a agathisflavona, 7"-metilagathisflavona, epicatequina, 6-C-glicopiranosil-luteolina e a 3-O-glicopiranosil-quercetina já registradas na literatura. As estruturas desses compostos foram estabelecidas através da análise dos dados espectrométricos de IV, EM e RMN.

Chromatographic fractionation of the extracts from the leaves of Ouratea hexasperma (Ochnaceae) afforded a new flavone dimer 5-hydroxy-7-methoxyflavone-(4'-O-8")-5",4"' -dihydroxy-7"-methoxyflavone besides known agathisflavone, 7"-methylagathisflavone, epicatechin, 6-C-glycopyranosyl-luteolin and 3-O-glycopyranosyl-quercetin. The IR, NMR and mass spectra data analyses were used to establish the structures of these compounds.