A study of the non-covalent interaction between flavonoids and DNA triplexes by electrospray ionization mass spectrometry

The binding interactions of 22 flavonoids (9 aglycones and 13 glycosides) with DNA triplexes were investigated using electrospray ionization mass spectrometry (ESI-MS). The results revealed that the hydroxyl positions of aglycones. the locations and numbers of saccharide, as well as the aglycone skeletons play roles in the triplex-binding properties of flavonoids. The presence of 3-OH, or 3'-OH, or replacement of 4'-OH with methoxy group in aglycones decreased the fraction of bound DNA sharply. Flavonoid glycosides exhibit higher binding affinities towards the DNA triplexes than their aglycone counterparts. Glycosylations of flavones at the 8-C position and isoflavones at the 7-O position show higher binding affinities than those on the other positions of ring A of aglycones. Glycosylation with a disaccharide on 0 position of flavonol results in higher binding affinity than that with monosaccharide. Flexibility of the ring B is favorable for its interaction with DNA triplex. According to sustained off-resonance irradiation collision-induced dissociation (SORI-CID) experiments, glycosylation and non-planarity of flavonoid aglycones lead to different dissociation pathways of the flavonoid/triplex complexes.

Patrones, generalización y estrategias inductivas de estudiantes de tercero y cuarto de Secundaria en el problema de las baldosas

En este trabajo describimos los patrones y la generalización que llevan a cabo 359 estudiantes de tercero y cuarto de Secundaria en la resolución del "problema de las baldosas". Prestamos especial atención a los tipos de patrones identificados, a la forma en que los estudiantes expresan la generalización y, mediante la descripción de las estrategias inductivas, presentamos algunas características de la generalización referentes a los elementos y a los sistemas de representación utilizados.

Infinite Dimensional Banach spaces of functions with nonlinear properties

The aim of this paper is to show that there exist infinite dimensional Banach spaces of functions that, except for 0, satisfy properties that apparently should be destroyed by the linear combination of two of them. Three of these spaces are: a Banach space of differentiable functions on Rn failing the Denjoy-Clarkson property; a Banach space of non Riemann integrable bounded functions, but with antiderivative at each point of an interval; a Banach space of infinitely differentiable functions that vanish at infinity and are not the Fourier transform of any Lebesgue integrable function.

II Concurso de materiales curriculares con valor coeducativo : premio Rosa Regás.

Contiene: Primer premio al IES Vega de Guadalete (Cádiz) por 'Testimonios reales de mujeres de la Barca'; Primer premio al CEPR Pablo de Olavide, de Prado del Rey (Cádiz) por 'Proyecto de coeducación: el aula hogar en el currículo de Educación primaria'; Mención especial al IES La Ribera de Almonte (Huelva) por 'coeducaweb'; Mención especial al CEPER Pintor Zuloaga (Cádiz) por 'Érase una vez... Desarrollo de la autoestima como prevención a los malos tratos'; Mención especial al CEIP Pablo Picasso de Manilva (Málaga) por 'Cuentos para pensar. Cuentos coeducativos para Educación Primaria'

Diez años de Peonza.

En el décimo aniversario de la Revista de Literatura Infantil, sus creadores hablan de los comienzos, la evolución y el desarrollo a lo largo de esta década. Mediante entrevistas, monográficos y antologías nos hacen partícipes del rico mundo de la Literatura Infantil.

Determinantes sociales de la enfermedad diarreica aguda en niños menores de 5 años en países en desarrollo

Antecedentes: Cada año hay 2,5 billones de casos de diarrea en menores de 5 años y 1,3 millones de estos niños mueren; lo que constituye a la EDA como segunda causa de muerte en este grupo de edad Metodología: Análisis transversal transnacional multinivel de la Encuesta DHS y el Banco Mundial en 348.706 niños de 40 países Resultados: Prevalencia de EDA 14%. Inequidad (OR=1.335; IC 95% 1.117-1.663) y bajos ingresos en las naciones (OR=1.488; IC 95% 1.024-2.163) presentaron asociación con EDA. Vivir en un país pobre aumenta la asociación entre el índice de riqueza del hogar y EDA (OR=1.0961; IC 95% 1.003-1.207) y la asociación entre no educación de la madre y EDA (OR=1.310; IC 95% 1.035-1.601). Otros factores asociados con EDA fueron sexo femenino, (OR=0.922; IC 95% 1.900-0.944), edad de niño (OR=0.978; IC 95% 0.978-0.979), vacunación (OR=0.821; IC 95% 0.799-0.843), peso normal al nacer (OR=0.879; IC 95% 0.834-0.926), edad de la madre (OR=0.987; IC 95% 0.985-0.989), no educación de la madre (OR=1.416; IC 95% 1.283-1.564), madre trabajadora (OR=1.136; IC 95% 1.106-1.167), embarazo deseado (OR=0.774; IC 95% 0.753-0.795), familia nuclear (OR=0.949; IC 95% 0.923-0.975) e índice de riqueza del hogar (OR=0.948; IC 95% 0.921-0.977) Conclusiones: La desigualdad y los bajos ingresos de los países desarrollados se asocian con EDA, independientemente de las características del niño, la mamá o el hogar. El gasto en salud no presenta asociaciones con EDA. Esto se debe considerar en las campañas de salud pública orientadas al manejo de la EDA.

Avaliação da silagem de diferentes híbridos de milho (Zea mays, L.) por meio do desempenho de bezerros confinados em fase de crescimento

Objetivou-se avaliar, por meio do desempenho animal, silagens de três híbridos de milho (Zea mays, L.): Agroceres AG-5011, Braskalb XL-344 e Cargill C-806. Foram utilizados 27 machos, não-castrados, mestiços Nelore x Charolês, com idade média de 10 meses e peso médio inicial de 252 kg, confinados durante 84 dias, subdivididos em quatro períodos de 21 dias. As silagens dos híbridos testados corresponderam a 70% da matéria seca ofertada. Não houve interação do híbrido de milho testado com o período de avaliação em confinamento, para os parâmetros estudados. A dieta que incluiu a silagem do híbrido AG-5011 resultou em maior consumo voluntário médio diário de matéria seca, expresso por 100 kg de peso vivo e tamanho metabólico, e maior consumo médio diário de fibra em detergente ácido, expresso nas diferentes formas, em relação aos híbridos XL-344 e C-806, que, por sua vez, foram semelhantes entre si. As dietas que incluíram silagens dos híbridos AG-5011, XL-344 e C-806 apresentaram semelhanças quanto ao consumo voluntário de matéria seca, expresso em kg/animal/dia (6,73; 6,05; e 6,19), consumo médio diário de FDN, em kg/dia (3,054; 2,837; e 2,836), e energia digestível, expressa nas diferentes formas, ganho de peso médio diário, em kg/dia (1,283; 1,219; e 1,249), ganho em estado corporal, conversão alimentar (5,26; 4,98; e 4,97) e eficiência energética (14,02; 13,68; e 13,21). Os três híbridos são indicados como materiais genéticos de muito boa qualidade para produção de silagem, promovendo ganhos de peso diário superior a 1,2 kg/animal/dia, quando utilizados em dietas com relação volumoso:concentrado de 70:30.

Lead- and copper-complexing extracellular ligands released by Kirchneriella aperta (Chloroccocales, Chlorophyta)

The freshwater planktonic alga Kirchneriella aperta was grown in batch cultures to stationary growth phase. Copper and lead complexation properties of the exudate from stationary and exponential growth phases were determined by titrations monitored by ion-selective electrodes. Molecular weight fractionation dialysis) and analysis of the titration data (Scatchard Plot) revealed that K. aperta releases metal-complexing ligands. Copper is associated with low and high molecular weight compounds, whereas lead forms complexes with only high molecular weight compounds. Gas-liquid chromatography showed that mannose and rhamnose make up 74% of the total high molecular weight organic material, with uronic acids present at 19%.

Schistosomicidal evaluation of flavonoids from two species of Styrax against Schistosoma mansoni adult worms

Context: Schistosomiasis is a major health problem worldwide. Thus, the search for new schistosomicidal agents from natural sources can provide prototypes for drug discovery. Objective: The present study investigated the chemical composition of the EtOAc fractions of Styrax pohlii Pohl (Styracaceae) (EF-SP) aerial parts and S. camporum A. DC. leaves (EF-SC), as well as schistosomicidal activities against Schistosoma mansoni adult worms, which have not yet been studied. Materials and methods: The crude ethanol extracts of S. camporum leaves and S. pohlii aerial parts (EE-SC and EE-SP) were partitioned with n-hexane, EtOAc, and n-BuOH. The EtOAc fractions were purified by preparative HPLC. The crude extracts, EtOAc fractions and pure compounds were tested against S. mansoni adult worms in vitro. Results: The purification procedure resulted in the isolation of kaempferol-3-O-(2 '',4 ''-di-O-(E)-p-coumaroyl)-beta-D-glucopyranoside (1), kaempferol-3-O-(2 '',6 ''-di-O-(E)-p-coumaroyl)-beta-D-glucopyranoside (2), quercetin (3), and kaempferol (4). The bioassay results indicated that EE-SC, EF-SC, EF-SP, and compounds 2 and 4 are able to separate coupled S. mansoni adult worms. Additionally, EE-SC, EF-SP, and compound 4 killed the adult schistosomes in vitro at 100 mu g/mL and 100 mu M. Discussion and conclusion: This is the first time that the presence of compounds 1-2 in S. pohlii and 3-4 in S. camporum has been reported. Additionally, biological results indicated that S. pohlii and S. camporum have great potential as a source of active compounds.

Development and validation of a high-performance liquid chromatography method for quantification of egonol and homoegonol in Styrax species

Styrax camporum Pohl, known in Brazil as estoraque do campo or cuia de brejo, has been used in the treatment of gastrointestinal diseases. The therapeutic action of S. camporum has been attributed to the ethyl acetate fraction, although the chemical composition of this fraction has not yet been analyzed. In this study, a high-performance liquid chromatography photodiode array detection (HPLC-PAD) method for analysis of Brazilian Styrax species has been developed. The compounds egonol (1) and homoegonol (2) were found to be present in all the samples investigated by HPLC. These compounds were isolated by open column chromatography followed by preparative TLC, and were identified by 1H NMR. Compounds 1 and 2 were thus proposed as phytochemical markers for Styrax, owing to their biological properties and presence in other Styrax species. The developed method has been validated and successfully applied for quantification of 1 and 2 in S. camporum dried leaves and crude ethanolic extracts from S. ferrugineus and S. pohlii aerial parts. Copyright (c) 2011 John Wiley & Sons, Ltd.

Cyclooxygenase inhibitory properties of nor-neolignans from Styrax pohlii

Chemical investigation of the n-hexane and EtOAc fractions of the ethanolic extract from Styrax pohlii (Styracaceae) aerial parts resulted in the isolation of the benzofuran nor-neolignan derivatives egonol (1), homoegonol (2), homoegonol gentiobioside (3), homoegonol glucoside (4) and egonol gentiobioside (5). This is the first report of compounds 1-5 in S. pohlii. Compounds 1-5, the acetyl derivatives 1a and 2a, the ethanolic extract (EE), the n-hexane fraction (HF) and EtOAc fraction (EF) were tested for their inhibitory activities against COX-1 and COX-2. The results showed that EE, HF, EF and compounds 1-5 and 1 a-2 a shown weak to moderate inhibition of COX-1 and COX-2. Among the assayed nor-neolignans, 4 gave a COX-1 inhibition of 35.7% at 30 mu M. Compound 5 displayed a COX-2 inhibition of 19.7% at 30 mu M.