Derris urucu, belonging to the family Leguminosae / Fabaceae, is popularly known as
“timbó”. The roots of this species are commonly used as pesticides and poison to fish. From
Derris genus many phytochemical studies have been reported, the roots being of the most
studied part from the plants of this genus. The name “timbó” is most general for the species
Derris urucu and Derris nicou, which are the species that produce, in their roots, rotenoids
such as rotenone and deguelin, from which derives the importance of these plants. The
extracts, and the substances isolated from this genus are responsible for a wide range of
biological activities, mainly the insecticidal activity. From the ethanolic extract of leaves of
D. urucu, twelve compounds were isolated and purified by High Performance Liquid
Chromatography: five stilbenes, six dihydroflavonols and one flavanone. The structural
identification was based on the mass, 1H and 13C NMR spectrometric analysis and two
dimensional NMR, beyond comparison with literature data . The ethanolic extract of leaves of
D. urucu was submitted to bioassays to avaluate the allelophatic potential, presenting relevant
percentage of inhibition of seed germination and development of weeds in pastures. Aiming
to detect the substances responsible for allelophatic activity, three stilbenes and three
dihydroflavonols were selected and submitted to bioassays of inhibition of germination and
development of the radicle and hypocotyl of weeds. The allelophatic tests were performed
with the substances isolated and with the combination of them, aiming to assess the synergism
between them, but the magnitude of inhibition observed was very low. By other side, when
the substances were tested in mixtures there was a significant increase in the percentage of
inhibition, so these substances in mixtures, can be considered promising for future studies
involving allelophatic activity. An other test was carried out with the isolated compounds.
Three stilbenes and five dihydroflavonols were evaluated for DPPH radical scavenging
activity (antioxidant activity). In this bioassay, was not observed a significant antioxidant
activity, justified by the analysis in the structures of the substances tested.
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