Entity

Time filter

Source Type


Diogo E.B.T.,Federal University of Minas Gerais | Dias G.G.,Federal University of Minas Gerais | Rodrigues B.L.,Federal University of Minas Gerais | Guimaraes T.T.,Federal University of Rio de Janeiro | And 10 more authors.
Bioorganic and Medicinal Chemistry | Year: 2013

In our continued search for novel trypanocidal compounds, twenty-six derivatives of para- and ortho-naphthoquinones coupled to 1,2,3-triazoles were synthesized. These compounds were evaluated against the infective bloodstream form of Trypanosoma cruzi, the etiological agent of Chagas disease. Compounds 17-24, 28-30 and 36-38 are described herein for the first time. Three of these novel compounds (28-30) were found to be more potent than the standard drug benznidazole, with IC50/24 h values between 6.8 and 80.8 μM. Analysis of the toxicity to heart muscle cells led to LC50/24 h of <125, 63.1 and 281.6 μM for 28, 29 and 30, respectively. Displaying a selectivity index of 34.3, compound 30 will be further evaluated in vivo. The electrochemical properties of selected compounds were evaluated in an attempt to find correlations with trypanocidal activity, and it was observed that more electrophilic quinones were generally more potent. © 2013 Elsevier Ltd. All rights reserved. Source


Da Silva Jr. E.N.,Federal University of Rio de Janeiro | Da Silva Jr. E.N.,University of Brasilia | Cavalcanti B.C.,Federal University of Ceara | Guimaraes T.T.,Federal University of Rio de Janeiro | And 10 more authors.
European Journal of Medicinal Chemistry | Year: 2011

Thirty two compounds were synthesized in moderate to high yields and showed activity against cancer cells HL-60 (leukemia), MDA-MB435 (melanoma), HCT-8 (colon) and SF295 (central nervous system), with IC50 below 2 μM for some compounds. The β-lapachone-based 1,2,3-triazoles showed the best cytoxicity profile and emerge as promising anticancer prototypes. Insights about the reactive oxygen species (ROS) mechanism of anticancer action for some compounds were obtained by addition of 1-bromoheptane that deplete reduced glutathione (GSH) content and by using N-acetylcysteine that protects cells against apoptotic cellular death, as well by analysis of thiobarbituric acid reactive substances (TBARS) formation, and oxidative DNA damage after treatment detected by the comet assay with the bacterial enzymes formamidopyrimidine DNA-glycosylase (FPG) and endonuclease III (ENDOIII). Source


Wender H.,Federal University of Rio Grande do Sul | De Oliveira L.F.,Federal University of Rio Grande do Sul | Feil A.F.,Federal University of Rio Grande do Sul | Lissner E.,Federal University of Rio Grande do Sul | And 4 more authors.
Chemical Communications | Year: 2010

The sputtering of Au targets onto castor oil generates stable spherical gold nanoparticles (AuNPs) of 2.4 to 3.8 nm. The AuNP size increases with the discharge voltage and the mechanism of nucleation and growth are related to the energy of the atoms/clusters ejected from the target. © 2010 The Royal Society of Chemistry. Source


Da Silva M.J.,Federal University of Rio de Janeiro | Pinto M.D.C.F.R.,Federal University of Rio de Janeiro | De Simone C.A.,Institute Quimica e Biotecnologia | De Simone C.A.,University of Sao Paulo | And 8 more authors.
Tetrahedron Letters | Year: 2011

Bioactive naphthoquinone-derived heterocyclic compounds have been prepared. Herein, we describe the semisynthesis of a new phenazine, through modified Hooker's reaction, using lapachol as a precursor. This compound was characterised by 2D NMR spectroscopy methods and X-ray analysis. © 2011 Elsevier Ltd. All rights reserved. Source


Da Silva Jr. E.N.,University of Brasilia | De Deus C.F.,University of Brasilia | Cavalcanti B.C.,Federal University of Ceara | Pessoa C.,Federal University of Ceara | And 10 more authors.
Journal of Medicinal Chemistry | Year: 2010

Several 3-arylamino and 3-alkoxy-nor-β-lapachone derivatives were synthesized in moderate to high yields and found to be highly potent against cancer cells SF295 (central nervous system),HCT8 (colon), MDA-MB435 (melanoma), and HL60 (leukemia), with IC50 below 2 μM. The arylamino para-nitro and the 2,4-dimethoxy substituted naphthoquinones showed the best cytoxicity profile, while the orthonitro and the 2,4-dimethoxy substituted ones were more selective than doxorubicin and similar to the precursor lapachones, thus emerging as promising new lead compounds in anticancer drug development. © 2009 American Chemical Society. Source

Discover hidden collaborations