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Search Results: 1 - 10 of 408876 matches for " Pinto Maria do Carmo F. R. "
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Trypanocidal activity of isolated naphthoquinones from Tabebuia and some heterocyclic derivatives: a review from an interdisciplinary study
De Moura Kelly C. G.,Emery Flávio S.,Neves-Pinto Cleverson,Pinto Maria do Carmo F. R.
Journal of the Brazilian Chemical Society , 2001,
Abstract: Naphthoquinones isolated from the wood of trees of the families Bignoniaceae and Verbenaceae have been subjected to an interdisciplinary study since the seventies, when Dr. Benjamin Gilbert, at the Federal University of Rio de Janeiro, launched a program on the chemistry of natural products active against endemic diseases. In this paper we describe the synthesis of five naphthoimidazoles, derived from this program and their activity towards T. cruzi, the etiologic agent of Chagas disease. We also review the influence of chemical structure on trypanocidal action of naphthoquinones and of derived heterocycles with imidazole, oxazole, phenoxazine, indole, dipyrane and cyclopentene rings. The overall analysis corroborates the tendency of trypanocidal activity in compounds with an imidazole or oxazole ring linked to a naphthopyrane structure. Two naphthoimidazoles presented higher activities (14.5x and 34.8x) than the standard crystal violet. Emphasis is given to the biodiversity of the Brazilian flora as a starting point for the development of an autonomous and creative medicinal chemistry.
Chemoselective oxidation of benzophenazines by m-CPBA: n-oxidation vs. oxidative cleavage
Silva, Raphael S. F.;Amorim, Mauro B. de;Pinto, Maria do Carmo F. R.;Emery, Flávio S.;Goulart, Marília O. F.;Pinto, Antonio V.;
Journal of the Brazilian Chemical Society , 2007, DOI: 10.1590/S0103-50532007000400014
Abstract: chemoselectivity is observed when a pyran-benzo[a]phenazine and a furan-benzo[a]phenazine from b-lapachone and nor-b-lapachone, respectively, were submitted to oxidation by m-cpba. the pyran phenazine furnished mainly macrolactones, while the furan one led exclusively to a phenazine n-8 oxide. to understand this difference in reactivity, we synthesized a new furan phenazine, with the reactive double bond site less hindered than that of the derivative from nor-beta-lapachone. this furan phenazine, upon oxidation with m-cpba, furnished mainly the expected macrolactone. these experimental results, along with preliminary analysis based on mechanical molecular calculations of the ground state of the substrates, allowed us to suggest that the observed chemoselectivity has a steric oxidant approach control origin, related to the presence of the geminal methyl groups in the phenazine structure. several of the synthesized compounds are, herein, reported for the first time.
Trypanocidal activity of isolated naphthoquinones from Tabebuia and some heterocyclic derivatives: a review from an interdisciplinary study
De Moura, Kelly C. G.;Emery, Flávio S.;Neves-Pinto, Cleverson;Pinto, Maria do Carmo F. R.;Dantas, Andrea P.;Salom?o, Kelly;Castro, Solange L. de;Pinto, Ant?nio V.;
Journal of the Brazilian Chemical Society , 2001, DOI: 10.1590/S0103-50532001000300003
Abstract: naphthoquinones isolated from the wood of trees of the families bignoniaceae and verbenaceae have been subjected to an interdisciplinary study since the seventies, when dr. benjamin gilbert, at the federal university of rio de janeiro, launched a program on the chemistry of natural products active against endemic diseases. in this paper we describe the synthesis of five naphthoimidazoles, derived from this program and their activity towards t. cruzi, the etiologic agent of chagas disease. we also review the influence of chemical structure on trypanocidal action of naphthoquinones and of derived heterocycles with imidazole, oxazole, phenoxazine, indole, dipyrane and cyclopentene rings. the overall analysis corroborates the tendency of trypanocidal activity in compounds with an imidazole or oxazole ring linked to a naphthopyrane structure. two naphthoimidazoles presented higher activities (14.5x and 34.8x) than the standard crystal violet. emphasis is given to the biodiversity of the brazilian flora as a starting point for the development of an autonomous and creative medicinal chemistry.
Molluscicidal hydroxynaphthoquinones and derivatives: correlation between their redox potentials and activity against Biomphalaria glabrata
Lima, Nadja M. F.;Correia, Clariane S.;Ferraz, Patrícia A. L.;Pinto, Ant?nio V.;Pinto, Maria do Carmo R. F.;Santana, Ant?nio Euzébio G.;Goulart, Marília O. F.;
Journal of the Brazilian Chemical Society , 2002, DOI: 10.1590/S0103-50532002000600015
Abstract: several 2-hydroxy-3-alkyl-1,4-naphthoquinones have been submitted to molluscicidal bioassays against the snail biomphalaria glabrata, intermediate host of schistosoma mansoni. cyclic voltammetric studies in aprotic medium (n,n-dimethylformamide plus tetrabutylammonium perchlorate) on hg and glassy carbon electrodes have been performed on these compounds in order to obtain information about their biological mechanism of action. several of the quinones assayed showed significant molluscicidal activities, and correlation of their activities and electrochemical parameters showed that the first wave reduction potential is an important parameter. the easily reduced quinones (>ep1c) were more active against adult snails and against their egg masses, whilst the 3-methylamino-2-hydroxy derivatives presented higher negative reduction potentials and were not active as molluscicides.
The preparation of a 10-membered ring macrolactone by selective ozonolysis and the role of the dihydropyran-substituent on the MCPBA-oxidation reaction profile of beta-lapachone phenazines
Silva, Raphael S. F.;Guimar?es, Tiago T.;Teixeira, Daniel V.;Lobato, Ana Paula G.;Pinto, Maria do Carmo F. R.;Simone, Carlos Alberto de;Soares, Janaína G.;Cioletti, Alessandra G.;Goulart, Marilia O. F.;Pinto, Antonio V.;
Journal of the Brazilian Chemical Society , 2005, DOI: 10.1590/S0103-50532005000600027
Abstract: the benzophenazine from b-lapachone was submitted to ozonolysis under conditions that selectively furnished the corresponding rigid macrocyclic lactone 7,7-dimethyl-7,8,9,10-tetrahydro-5h-benzo[3,4]oxecino[5,6-b]quinoxaline-5,10-dione in an yield of 52%. the effect of substituents located at the dihydropyrane moiety of the phenazines, namely c2'-oh, c2'-br and c2'-i, in the oxidation with mcpba, was also investigated.
Cytotoxic, trypanocidal activities and physicochemical parameters of nor-2-lapachone-based 1,2,3-triazoles
Silva Júnior, Eufranio N. da;Moura, Maria Aline B. F. de;Pinto, Antonio V.;Pinto, Maria do Carmo F. R.;Souza, Maria Cecília B. V. de;Araújo, Ana J.;Pessoa, Claudia;Costa-Lotufo, Letícia V.;Montenegro, Raquel C.;Moraes, Manoel Odorico de;Ferreira, Vitor F.;Goulart, Marilia O. F.;
Journal of the Brazilian Chemical Society , 2009, DOI: 10.1590/S0103-50532009000400007
Abstract: the cytotoxicities of five nor-2-lapachone-based 1,2,3-triazoles and the precursor azidonaphthoquinone were assayed against six neoplasic cancer cell lines: sf-295 (central nervous system), hct-8 (colon), mdamb-435 (melanoma), hl-60 (leukaemia), pc-3 (prostate) and b-16 (murine melanoma). ic50 values ranging from 0.43 to 9.48 μm were obtained. 3-(4-(1-hydroxycyclohexyl)-1h-1,2,3-triazol-1yl)-2,2-dimethylnaphtho[1,2-b]furan-4,5-dione proved highly cytotoxic to mdamb-435, with ic50 even lower than the one from doxorubicin (positive control). in an attempt to correlate physicochemical parameters (reduction potentials and calculated log p) with cytotoxic activity, electrochemical studies were conducted in acetate buffer, ph 4.5, using a vitreous carbon electrode and calculated log p values were obtained. despite the absence of a structural conjugative interaction between the two systems (quinone and triazole), the heterocyclic group was found to influence the voltammetric behaviour, as indicated by anodic shifts in the reduction potentials. no correlation was found between epic and cytotoxicity. in contrast, a comparison of epic with previously reported trypanocidal activities reconfirmed the trend for higher activity coupled with better quinone electrophilicity (> epic).a leading term in the correlation of cytoxicity, despite the absence of a linear correlation, was the calculated log p: the lower the lipophilicity, the lower the cytoxicity (> ic50).
Relato de uma experiência: recupera o e cadastramento de resíduos dos laboratórios de gradua o do Instituto de Química da Universidade Federal do Rio Grande do Sul
Amaral Suzana T.,Machado Patrícia F. L.,Peralba Maria do Carmo R.,Camara Maria Regina
Química Nova , 2001,
Abstract: An experience aiming to promote a residue interchange and recovery between the teaching laboratories of the Chemistry Institute of this University is described. At the present, several residues interchange have already appeared as advantageous. To make the work easier, a software has been developed in order to keep a record of all the residues generated by the teaching laboratories. Standard labels have been developed for the residues in order to organize them. The software and the label design are described.
Características agron?micas e produtividade de amendoim em diferentes espa?amentos e épocas de semeadura no Rec?ncavo Baiano
Peixoto, Clovis Pereira;Gon?alves, Joaquim Alves;Peixoto, Maria de Fátima da Silva Pinto;Carmo, Darcilúcia Oliveira do;
Bragantia , 2008, DOI: 10.1590/S0006-87052008000300016
Abstract: the vegetative and productive performance of peanut plants, cultivated under different spacing and planting densities, at two sowings dates, in the raining season (march-june) and by july-october were evaluated in the agro ecologic conditions of the rec?ncavo region of the state of bahia, brazil. the experiment was carried out at the experimental station of the school of agronomy, federal university of rec?ncavo of bahia, in a randomized complete block design, with the following factorial arrangement: 3 x 3 + 1 (three plant densities: 5, 10, and 15 plants m-1 x three plant spacing: 0.50 m, 0.65 m, and 0.80 m, plus a control treatment with planting holes of approximately 0.25 m x 0.30 m, with four replications. the following agronomic characteristics were studied: final plant height, number of final branches, leaf number. ten plants per plot were sampled for the evaluations, and the volume of fresh pods and grain yield was determined based on the final plant population of each plot. it was concluded that: the decision on the plant arrangement that gives the highest yield of pods and grains depends on the farmer's commercial interests (volume or mass) and also on the sowing dates. the utilization of new planting arrangements by the farmers from the rec?ncavo region of bahia is necessary, since the conventional planting system in holes (0.25 x 0.30), presents the lowest productivity, at both sowings dates.
Prevalence of Frailty Syndrome in the Elderly and Associated Factors in Brazil  [PDF]
Anna Ferla Monteiro Silva Passos, Iris do Céu Clara Costa, Fábia Barbosa de Andrade, Maria do Carmo Eulálio, Anita Liberalesso Neri, R?mulo Lustosa Pimenteira de Melo, Adrianna Ribeiro Lacerda
Health (Health) , 2015, DOI: 10.4236/health.2015.711172
Abstract: This paper aims to identify the prevalence of frailty syndrome and its association with demographic, economic, health, psychological and functional variables in Brazilian population. The study was cross-sectional and composed of 385 elderly aged from 65 years, an average age of 73.92 years. A multivariate Poisson regression was used to check for conditions associated with frailty and to determine the prevalence (α = 0.05). The prevalence of frailty was 8.7% and pre-frailty of 50.4%. The frail and pre-frail older adults showed larger and increasing prevalence ratios for marital status, difficulty performing instrumental activities of daily living, old age, involuntary loss of feces, depression and negative affections. These results can guide the establishment of preventive measures and the development of intervention strategies aimed at minimizing the adverse effects of frailty in elderly people.
Spatial and temporal variation of the nutrients in the sediment and leaves of two Brazilian mangrove species and their role in the retention of environmental heavy metals
Bernini, Elaine;Silva, Maria A. B. da;Carmo, Tania M. S. do;Cuzzuol, Geraldo R. F.;
Brazilian Journal of Plant Physiology , 2010, DOI: 10.1590/S1677-04202010000300005
Abstract: spatial and temporal variation of the nutrient concentrations in leaves and sediment between the roots of laguncularia racemosa (l.) gaertn. f and rhizophora mangle l. was analyzed in the mangrove forest of the estuary of s?o mateus river, espírito santo, brazil. in leaves, the nutrients followed the sequence: n> ca> k> mg> s> p> fe> mn> zn> cu, and there were significant differences between species and sites studied. in general, the levels of k were higher in the dry season compared to the rainy season for both species analyzed while ca and cu showed higher concentrations in the rainy season for laguncularia racemosa. in the sediment, the nutrients followed the sequence: mg> ca> fe> k> mn> p> zn> cu, in general, with lower concentrations at the site where the sediment was sandier. we observed a significant variation of nutrient concentrations in the sediment between the periods analyzed, but the seasonal pattern was not clear for all nutrients. nutrient concentration profile found in leaves of both plant species was not correlated with concentrations found in the respective sediments. the concentration factor was less than 1.0 for fe and between 1.0 and 3.7 for mn, zn and cu. these results provide physiological evidences about the relevance of these tree species for the role of mangroves as biogeochemical barriers to the transit of heavy metals.
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