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| Grynberg,N.F.; Carvalho,M.G.; Velandia,J.R.; Oliveira,M.C.; Moreira,I.C.; Braz- Filho,R.; Echevarria,A.. |
| Topoisomerase inhibitors are agents with anticancer activity. 7"-O-Methyl-agathisflavone (I) and amentoflavone (II) are biflavonoids and were isolated from the Brazilian plants Ouratea hexasperma and O. semiserrata, respectively. These biflavonoids and the acetyl derivative of II (IIa) are inhibitors of human DNA topoisomerases I at 200 µM, as demonstrated by the relaxation assay of supercoiled DNA, and only agathisflavone (I) at 200 µM also inhibited DNA topoisomerases II-alpha, as observed by decatenation and relaxation assays. The biflavonoids showed concentration-dependent growth inhibitory activities on Ehrlich carcinoma cells in 45-h culture, assayed by a tetrazolium method, with IC50 = 24 ± 1.4 µM for I, 26 ± 1.1 µM for II and 10 ± 0.7 µM for IIa.... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Biflavonoids; Amentoflavone; 7"-O-Methyl-agathisflavone; DNA topoisomerases; Ehrlich carcinoma; Human K562 leukemia. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000700009 |
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| Gonçalez,E.; Felicio,J.D.; Pinto,M.M.. |
| The biflavonoids 6,6"-bigenkwanin, amenthoflavone, 7,7"-dimethoxyagastisflavone and tetradimethoxybigenkwanin isolated from Ouratea species were tested for inhibitory activity on Aspergillus flavus cultures. Suspensions of Aspergillus flavus spores were inoculated into 50 ml of YES medium at different biflavonoid concentrations: 5 and 10 µg/ml for 6,6"-bigenkwanin, amenthoflavone and 7,7"-dimethoxyagastisflavone, and 5, 10, 15 and 20 µg/ml for tetradimethoxybigenkwanin. The four biflavonoids showed inhibitory activity on aflatoxin B1 and B2 production (P<0.001), but did not inhibit fungal growth at the concentration tested (P>0.05). These results show that biflavonoids can be used for the development of agents to control aflatoxin production. |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Ouratea sp; Aspergillus flavus; Biflavonoids; Aflatoxins. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001001100013 |
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