Navegando por Assunto "Derris urucu"

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Acesso aberto (Open Access)
Dihydroflavonols from the leaves of Derris urucu (Leguminosae): structural elucidation and DPPH radical-scavenging activity
(2009) LÔBO, Lívia Trindade; SILVA, Geilson Alcantara da; FERREIRA, Malisson; SILVA, Milton Nascimento da; SANTOS, Alberdan Silva; ARRUDA, Alberto Cardoso; GUILHON, Giselle Maria Skelding Pinheiro; SANTOS, Lourivaldo da Silva; BORGES, Rosivaldo dos Santos; ARRUDA, Mara Silvia Pinheiro
Derris urucu is an Amazonian plant with insecticide and ichthyotoxic properties. Studies with this species show the presence of flavonoids, mainly rotenoids, as well as stilbenes. The ethanol extract of the leaves of Derris urucu (Leguminosae) afforded three new dihydroflavonols named urucuol A (1), B (2) and C (3), and the dihydroflavonol isotirumalin (4). Their structures were elucidated by extensive analysis of 1D and 2D NMR, UV and IR spectra and MS data and comparison with literature data. The isolated compounds (1-4) were evaluated for DPPH• radical scavenging activity and showed a relatively lower antioxidant ability compared to the commercial antioxidant trans-resveratrol.
Acesso aberto (Open Access)
Flavonoids from leaves of Derris urucu: assessment of potential effects on seed germination and development of weeds
(2013-09) SILVA, Ewerton Afonso Silva da; LÔBO, Lívia Trindade; SILVA, Geilson Alcantara da; SOUZA FILHO, Antonio Pedro da Silva; SILVA, Milton Nascimento da; ARRUDA, Alberto Cardoso; GUILHON, Giselle Maria Skelding Pinheiro; SANTOS, Lourivaldo da Silva; ARRUDA, Mara Silvia Pinheiro
In some previous studies, we described the isolation of nine compounds from leaves of Derris urucu, a species found widely in the Amazon rainforest, identified as five stilbenes and four dihydroflavonols. In this work, three of these dihydroflavonols [urucuol A (1), urucuol B (2) and isotirumalin (3)] were evaluated to identify their potential as allelochemicals, and we are also reporting the isolation and structural determination of a new flavonoid [5,3′-dihydroxy-4′-methoxy-(7,6:5″,6″)-2″,2″-dimethylpyranoflavanone (4)]. We investigated the effects of the dihydroflavonols 1-3 on seed germination and radicle and hypocotyl growth of the weed Mimosa pudica, using solutions at 150 mg.L–1. Urucuol B, alone, was the substance with the greatest potential to inhibit seed germination (26%), while isotirumalin showed greater ability to reduce the development of the hypocotyl (25%), but none of the three substances showed the potential to inhibit radicle. When combined in pairs, the substances showed synergism for the development of root and hypocotyl and effects on seed germination that could be attributed to antagonism. When tested separately, the trend has become more intense effects on seed germination, while for the substances tested in pairs, the intensity of the effect was greater on development of weed.