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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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| Esteves-Souza,A.; Figueiredo,D.V.; Esteves,A.; Câmara,C.A.; Vargas,M.D.; Pinto,A.C.; Echevarria,A.. |
| The cytotoxic activity of amino (3a-e), aza-1-antraquinone (4a-e) lapachol derivatives against Ehrlich carcinoma and human K562 leukemia cells was investigated. Cell viability was determined using MTT assay, after 48 (Ehrlich) or 96 h (K562) of culture, and vincristine (for K562 leukemia) and quercetin (for Ehrlich carcinoma) were used as positive controls. The results showed dose-dependent growth-inhibiting activities and that the amino derivatives were active against the assayed cells, whereas the 4a-e derivatives were not. The allylamine derivative 3a was the most active against Ehrlich carcinoma, with IC50 = 16.94 ± 1.25 µM, and against K562 leukemia, with IC50 = 14.11 ± 1.39 µM. The analogous lawsone derivative, 5a, was also active against Ehrlich... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Lapachol; Amino-lapachol derivatives; Cytotoxicity; DNA-topoisomerase; DNA-interactions. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001000013 |
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