16 documents found, page 1 of 2
Differential expression on mitochondrial tryparedoxin peroxidase (mTcTXNPx) in ...
Kohatsu,Andréa A.N.; Silva,Flávia A.J.; Francisco,Acácio I.; Rimoldi,Aline; Silva,Marco T.A.; Vargas,Maria D.; Rosa,João A. da; Cicarelli,Regina M.B.Abstract Resistance to benznidazole in certain strains of Trypanosoma cruzi may be caused by the increased production of enzymes that act on the oxidative metabolism, such as mitochondrial tryparedoxin peroxidase which catalyses the reduction of peroxides. This work presents cytotoxicity assays performed with ferrocenyl diamine hydrochlorides in six different strains of T. cruzi epimastigote forms (Y, Bolivia, ...
Studies of the Colloidal Properties of Superparamagnetic Iron Oxide Nanoparticl...
Silva,Gustavo B. da; Marciello,Marzia; Morales,María del Puerto; Serna,Carlos J.; Vargas,Maria D.; Ronconi,Célia M.; Costo,RocíoThis work has focused on the synthesis of three nanosystems composed of superparamagnetic iron oxide nanoparticles (SPIONs) coated either with a carboxylate platinum(IV) complex (PD = cis,cis,trans-[Pt(NH3)2Cl2(HOOCCH2CH2COO)(OH)]) or with platinum(II) complex functionalized dextrans (DexPt1 = [Pt(Dex-NH2)Cl3] and DexPt2 = [Pt(Dex-NH2)(NH3)2(H2O)]). All nanosystems have shown superparamagnetic behavior. Powder ...
6-Aminocoumarin-naphthoquinone conjugates: design, synthesis, photophysical and...
Miranda,Fabio S.; Ronconi,Célia M.; Sousa,Mikaelly O. B.; Silveira,Gleiciani Q.; Vargas,Maria D.Four novel 6-aminocoumarin-naphthoquinone conjugates were synthesized and their photophysical and electrochemical properties, investigated. 2-Chloro-3-(2-oxo-2H-chromen-6-ylamino)-1,4-naphthoquinone 1 did not present appreciable fluorescence in solution in comparison with 6-aminocoumarin, 6-AC. In order to understand the reasons for the fluorescence quenching in this compound, two strategies were attempted. Fir...
Tautomerism in quinoxalines derived from the 1,4-naphthoquinone nucleus: acid m...
Gomez,Javier A. G.; Lage,Mateus R.; Carneiro,José Walkimar de M.; Resende,Jackson A. L. C.; Vargas,Maria D.The reaction of tert-butyl 2-(3-chloro-1,4-dioxo-1,4-dihydronaphthalen-2-ylamino) ethylcarbamate with CF3COOH/CH2Cl2 yields 5-chloro-3,4-dihydrobenzo[f]quinoxalin6(2H)-one which undergoes acid-promoted dehydrogenation in the presence of water to give novel 5-chlorobenzo[f]quinoxalin-6-ol. The molecular structure of 5-chlorobenzo[f]quinoxalin6-ol in the solid state, determined by an X-ray diffraction (XRD) study...
Novel 3-(aminomethyl)naphthoquinone mannich base-platinum(IV) complexes: synthe...
Silva,Gustavo B. da; Neves,Amanda P.; Vargas,Maria D.; Alves,Wagner A.; Marinho-Filho,José D. B.; Pessoa,Cláudia; Moraes,Manoel O.Three novel platinum(IV) complexes cis,cis,trans-[Pt(HL1-3)Cl2(OH)2] 1b-3b (HL = 2-hydroxy-3-[(R¹-amino)(pyridin-2-yl)methyl]-1,4-naphthoquinone, R¹ = n-butyl, HL1; n-heptyl, HL2 and n-decyl, HL3) have been obtained from the oxidation of the respective precursors cis-[Pt(HL1-3)Cl2] 1a-3a. Cyclic voltammetry studies of 1b-3b in MeCN showed the quasi-reversible naphthoquinonate (NQO-, i.e. , L-) redox process and...
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones: synthesis, ...
Casellato,Annelise; Neves,Amanda P.; Carneiro,J. Walkimar de M.; Vargas,Maria D.; Visentin,Lorenzo do C.; Magalhães,Alviclér; Câmara,Celso A.Novel 2-(R-phenyl)amino-3-(2-methyl-propenyl)-[1,4]-naphthoquinones (R = H, 4-OMe, 4-Ferrocenyl, 4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO2 and 3-NO2) derived from nor-lapachol [2-hydroxy-3-(2-methylpropenyl)-1,4-naphthoquinone] were obtained in good yields. Their structures were proposed on the basis of a single crystal X-ray diffraction study (R = OMe, 2b), ¹H and 13C NMR studies and calculations using the B3LYP...
Theoretical studies of the tautomerism in 3-(2-R-Phenylhydrazono)-naphthalene- ...
Francisco,Acácio I.; Vargas,Maria D.; Fragoso,Thaís P.; Carneiro,J. Walkimar de M.; Casellato,Annelise; Silva,Fernando de C. da; Ferreira,Vitor F.DFT calculations using the B3LYP and PBE1PBE functionals with the standard 6-31G(d) and 6-311+G(2d,p) basis sets were carried out for the 3-(2-phenylhydrazone)-naphthalene-1,2,4-trione system in solution (dmso) and in the gas phase, and showed the keto-hydrazone forms (rotamers Ia and Ib) to be more stable than the enol-azo forms (rotamers IIa and IIb, by about 14 kcal mol-1) and III (by approximately 6 kcal mo...
Novel aminonaphthoquinone mannich bases derived from lawsone and their copper(I...
Neves,Amanda P.; Barbosa,Cláudia C.; Greco,Sandro J.; Vargas,Maria D.; Visentin,Lorenzo C.; Pinheiro,Carlos B.; Mangrich,Antônio S.; Barbosa,Jussara P.A series of novel Mannich bases (HL1-HL13) derived from 2-hydroxy-1,4-naphthoquinone (lawsone), substituted benzaldehydes [C6H2R¹R²R³C(O)H] and various primary amines (NH2R4, R4 = n-butyl, benzyl, allyl, 2-furfuryl), and their Cu2+ complexes, [Cu(L1)2]-[Cu(L13)2], have been synthesized and fully characterized by analytical and spectroscopic methods. The structures of complexes 1(R¹ = R² = R³ = H; R4 = Bu), 2(R¹...
Molluscicidal activity of 2-hydroxy-[1,4]naphthoquinone and derivatives
Camara,Celso A.; Silva,Tania M.S.; da-Silva,Thiago G.; Martins,Rodrigo M.; Barbosa,Ticiano P.; Pinto,Angelo C.; Vargas,Maria D.The toxic profile of lawsone (2-hydroxy-[1,4]naphthoquinone) and a series of [1,4]naphthoquinone derivatives was evaluated against the brine shrimp Artemia salina and against the mollusk Biomphalaria glabrata, the main transmitting vector of schistosomiasis in Brazil. Of the seventeen compounds tested nine fell below the threshold of 100 µg/mL set for potential molluscicidal activity by the World Health Organiz...
Spasmolytic activity of lapachol and its derivatives, α and β-lapachone, on the...
Cavalcante,Fabiana A.; Silva,Joelmir L. V.; Carvalho,Viviane M. N.; Camara,Celso A.; Silva,Tania M. S.; Pinto,Ângelo C.; Vargas,Maria D.Lapachol, α and β-lapachone are naphthoquinones extracted from species of Tabebuia that have shown antiinflammatory, antibacterial, anticancer and trypanosomicidal properties. The aim of this work was to investigate the spasmolytic effect of these naphthoquinones on the guinea-pig ileum, since other naphthoquinones are known to depress the contractile activity of smooth muscles. Lapachol, α and β-lapachone inhi...