Fluorescence properties of a potential antitumoral benzothieno[3,2-b]pyrrole in solution and lipid membranes

Fluorescence properties of the antitumoral methyl 3-(benzo[b]thien-2-yl)-benzothieno[3,2-b]pyrrole-2-carboxylate (BTP) were studied in solution and in lipid bilayers of dipalmitoyl phosphatidylcholine (DPPC), dioleoyl phosphatidylethanolamine (DOPE) and egg yolk phosphatidylcholine (Egg-PC). BTP presents good fluorescence quantum yields in all solvents studied (0.20 ≤ ΦF ≤ 0.32) and a bathochromic shift in polar solvents. The results indicate an ICT character of the excited state, with an estimated dipole moment of μe = 7.38 D. Fluorescence (steady-state) anisotropy measurements of BTP incorporated in lipid membranes of DPPC, DOPE and Egg-PC indicate that this compound is deeply located in the lipid bilayer, feeling the difference between the rigid gel phase and fluid phases. BTP inhibits the growth of three human tumour cell lines, MCF-7 (breast adenocarcinoma), SF-268 (glioma) and NCI-H460 (non-small cell lung cancer), being significantly more potent against the NCI-H460 tumour cells.European Communitarian Fund (FEDER)Fundação para a Ciência e a Tecnologia (FCT) – projecto SeARCH (ref. REEQ/443/EEI/2005), bolsa SFRH/BPD/24548/2005, projecto PTDC/QUI/81238/200

Optimized extraction of a lectin from Crataeva tapia bark using AOT in isooctane reversed micelles

Crataeva tapia bark lectin was extracted from a crude extract into a reversed micelle phase of the anionic surfactant AOT in isooctane and back-extracted, to a final aqueous phase by addition of butanol. The effects of pH, ionic strength and surfactant concentration on the protein transfer process from the aqueous to the organic phase were characterized, being the best results obtained after 5 min of contact, under agitation, between the two phases, at pH 5.5 (10 mM citrate-phosphate buffer), 30 mM NaCl, and 5 mM AOT. Recovery to a new aqueous phase was performed with 5 min of contact, under agitation, 10 mM citrate-phosphate buffer at pH 5.5, 500 mM KCl and 5% of butanol. The overall yield obtained for the process was 80% for lectin activity and 56% for protein recovery. The efficiency of the process was confirmed by SDS-PAGE analysis.ALFA/VALNATURA; CNPq

Sulfated small molecules targeting EBV in Burkitt lymphoma: from in silico screening to the evidence of in vitro effect on viral episomal DNA

Epstein–Barr virus (EBV) infects more than 90% of the world population. Following primary infection, Epstein– Barr virus persists in an asymptomatic latent state. Occasionally, it may switch to lytic infection. Latent EBV infection has been associated with several diseases, such as Burkitt lymphoma (BL). To date, there are no available drugs to target latent EBV, and the existing broad-spec trum antiviral drugs are mainly active against lytic viral infection. Thus, using computational molecular docking, a virtual screen of a library of small molecules, including xanthones and flavonoids (described with potential for antiviral activity against EBV), was carried out targeting EBV proteins. The more interesting molecules were selected for further computational analysis, and sub sequently, the compounds were tested in the Raji (BL) cell line, to evaluate their activity against latent EBV. This work identified three novel sulfated small molecules capable of decreasing EBV levels in a BL. Therefore, the in silico screening presents a good approach for the development of new anti-EBV agents.info:eu-repo/semantics/publishedVersio

Pré-tratamento de resíduos agro-industriais e novas perspectivas na produção de bioprodutos

Visando contribuir para a melhoria das condições ambientais pela eliminação dos resíduos agrícolas/agroindustriais, bem como proporcionar a formação de uma linha de pesquisa com propósito de captar e disseminar informações técnicas e tecnológicas agregando maior valor nestes subprodutos ou resíduos é que o presente trabalho foi realizado. Deste modo, o sabugo de milho in natura foi submetido a dois diferentes processos de prétratamento para a extração das hemiceluloses, como etapa inicial de aplicação integral do resíduo, onde posteriormente estudos e aplicação do complexo celulose-lignina resultante seriam realizados. Dentro deste contexto, o objetivo deste trabalho foi determinar a eficiência de extração de frações de hemiceluloses de sabugo de milho por processos alcalinos (0,75 a 1,25 mol/L em 42,5ºC/180 min), e processos de autohidrólise (165 a 185ºC, razão líquida de 10:1p/p por 40 min). Este procedimento indicou o potencial de pré-tratamentos, em especial dos licores hemicelulosicos obtidos, como parte de um processo que conduza à utilização de materiais lignocelulósicos em diferentes processos biotecnológicos

Genotipagem de multilocus de Cryptosporidium hominis associado a surto diarréico em creche de São Paulo

A number of species of Cryptosporidium are associated with diarrhea worldwide. Little data exists regarding the genotypes and species of Cryptosporidium associated with cases of infections in Brazil. PURPOSE: In the present study, we ascertained by molecular methods the species and the genotype of Cryptosporidium sp from a diarrhea outbreak diagnosed in a day care at the Hospital Clínicas, São Paulo University Medical School. MATERIALS AND METHODS: Specific identification and typing of the isolates associated with the outbreak was done by DNA sequencing analysis of fragments amplified by polymerase chain reaction (PCR) from 3 different Cryptosporidium loci: the SSUrRNA coding region, the Cryptosporidium oocyst wall protein (COWP) gene, and the microsatellite locus 1 (ML1), a tandem GAG-trinucleotide repeat containing substitutions that differentiate the genotypes of Cryptosporidium parvum and Cryptosporidium hominis. RESULTS: A total of 29 positive samples from the outbreak were studied by the molecular methods described. Our study revealed the presence of a single genotype of Cryptosporidium hominis in all samples. CONCLUSION: The molecular analysis reinforced the hypothesis that the transmission of Cryptosporidium hominis during the period the samples were collected occurred in an outbreak pattern, possibly by person-to-person contact through the fecal-oral route. As far as we know, this is the first time that molecular tools have been used to identify the species and the genotype of isolates showing the presence of the ML1 genotype in samples from Brazilian patients.Mundialmente, diferentes espécies de Cryptosporidium estão relacionadas com doenças diarréicas. No Brasil há poucos dados sobre os genótipos das espécies de Cryptosporidium associadas a infecções. OBJETIVO: No presente estudo, caracterizamos, por métodos moleculares, a espécie e o genótipo de Cryptosporidium sp diagnosticado em surto diarréico ocorrido na creche do Hospital das Clínicas, São Paulo, Brasil. MATERIAL E MÉTODOS: Identificação específica e tipagem dos isolados associados ao surto foram feitos a partir do seqüenciamento de fragmentos de DNA amplificados por PCR dos seguintes loci: a região que codifica o SSUrRNA, o gene que codifica uma proteína do envoltório dos oocistos de Cryptosporidium (COWP), e o locus de microsatélite ML1, representado por seqüências repetitiva de três nucleotídeos GAG contendo substituições que diferem entre os genótipos de Cryptosporidium parvum e Cryptosporidium hominis. RESULTADOS: Um total de 29 amostras positivas para Cryptosporidium associadas ao surto diarréico foi analisado com base nos métodos moleculares acima descritos. O estudo revelou a presença do genótipo ML1 de Cryptosporidium hominis. DISCUSSÃO: A análise molecular reforçou a hipótese de que a transmissão de Cryptosporidium hominis durante o surto diarréico ocorreu de pessoa a pessoa através da rota fecal oral. Esta é a primeira vez que ferramentas moleculares são utilizadas para identificação de espécies e genótipos de isolados acusando a presença do genótipo ML1 em pacientes brasileiros