Articulos Institucionales de Impacto
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Examinando Articulos Institucionales de Impacto por Materia "Chemistry"
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Ítem Acceso Abierto Chemical composition and biotechnological properties of a polysaccharide from the peels and antioxidative content from the pulp of Passiflora liguralis fruits(2007) Tommonaro, G.; Segura Rodríguez, C.S.; Santillana, M.; Immirzi, B.; De Prisco, R.; Nicolaus, B.; Poli, A.A new polysaccharide with a high molecular weight (greater than 1 × 106 Da) was extracted and characterized from the peels of Passiflora liguralis (granadilla) fruits. Chemical composition of the biopolymer, performed by using a high pressure anion exchange-pulsed amperometric detector (HPAE-PAD), showed the presence of six different sugar residues: xylose, glucose, galactose, galactosamine, an unknown component, and fucose in the relative ratio of 1:0.5:0.2:0.06:0.05:trace. The optical rotation of this xyloglucan was [α]D 25°C = -186.42 (concentration of 1.4 mg/mL of H2O), and the viscosity was dependent on the concentration and pH, showing a maximum value of 1.4 η at a concentration of 3% in distilled water and a maximum value of 7.0 η in citrate buffer solution. Thermogravimetric analysis indicated that this biopolymer was very stable at high temperatures, showing a degradation temperature at 280°C. The characterization of the polysaccharide was also investigated by spectroscopic methods (1H NMR and IR) pointing out the complexity of this biopolymer and the presence of sugar residues in α-manno, α-gluco-galacto, and β-gluco-galacto configurations. The formation of a biodegradable film using this novel xyloglucan was reported, and the anticytotoxic activity of the polysaccharide was studied in a brine shrimp bioassay. Considerable antioxidant activity (Trolox equivalent antioxidant capacity (TEAC) value of 0.32 μM/mg fresh product) was noted in the lipophilic extracts of Passiflora liguralis fruits, indicating, in this fruit, an alternative source of bioactive compounds. © 2007 American Chemical Society.Ítem Acceso Abierto Contaminants in tracked seabirds showing regional patterns of marine pollution(2013) Ito, A.; Yamashita, R.; Takada, H.; Yamamoto, T.; Shiomi, K.; Zavalaga, C.; Abe T.; Watanabe S.; Yamamoto, M.; Sato K.; Kohno H.; Yoda, K.; Iida T.; Watanuki Y.Ocean-scale monitoring of pollution is challenging. Seabirds are useful indicators because they travel over a broad foraging range. Nevertheless, this coarse spatial resolution is not fine enough to discriminate pollution in a finer scale. Previous studies have demonstrated that pollution levels are higher in the Sea of Japan and South and East China Seas than the Northen Pacific Ocean. To test these findings in a wide-ranging animal, we tracked streaked shearwaters (Calonectris leucomelas) from four islands in Japan using global positioning system (GPS) and measured persistent organic pollutants (POPs) in the oil of their preen glands. The POPs did not change during 6 to 21 days when birds from Awashima were foraging only in the Sea of Japan, while it increased when they crossed to the Pacific through the Tsugaru Strait and foraged along the eastern coast of Hokkaido where industrial cities occur. These results indicate that POPs in the oil reflect relatively short-term exposure. Concentrations of POPs displayed greater variation among regions. Total polychlorinated biphenyls were highest in birds foraging in a small area of the semiclosed Seto Inland Sea surrounded by urbanized coast, p,p″- dichlorodiphenyltrichloroethane (DDT) was highest in birds foraging in the East China Sea, and total hexachlorocyclohexanes were highest in birds foraging in the Sea of Japan. All were lowest in birds foraging in the Pacific. This distribution of POPs concentration partly agrees with previous findings based on mussels, fish, and seawater and possibly reflects the mobility and emission sources of each type of POP. These results highlight the importance of information on the foraging area of highly mobile top predators to make them more effective monitors of regional marine pollution. © 2013 American Chemical Society.Ítem Acceso Abierto Evaluation of antimicrobial activity from native wine yeast against food industry pathogenic microorganisms [Evaluación de la actividad antimicrobiana de levaduras vínicas nativas contra microorganismos patógenos de la industria alimentaria](Taylor and Francis Ltd., 2017) Acuña-Fontecilla, A.; Silva-Moreno, E.; Ganga, M.A.; Godoy, L.Currently, there is a worldwide trend toward the food consumption without the use of preservatives. For this reason, biocontrols have emerged as a natural option to replace preservatives. We identify and select native wine yeasts with antimicrobial activity (AA) that work against pathogenic bacteria of food importance. We evaluated the antimicrobial capacity of 103 yeast against Salmonella typhimurium, Listeria monocytogenes, and Escherichia coli, by measuring the growth inhibition. AA was qualitatively determined by measuring the inhibition zone diameter accompanied by death zone of target cells. Results revealed that nine yeast strains showed AA against the three pathogens, being mainly of the genera Pichia, Candida, and Saccharomyces. To determine the type of AA, the viability was assessed by the method of SYTOX Green®. The results suggest that yeast exhibit AA bactericidal type. Thus, the use of yeasts arises as a natural and safe for the biocontrol of bacterial growth alternative. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Ítem Acceso Abierto New leishmanicidal stilbenes from a peruvian folk medicine, Lonchocarpus nicou(2013) Fuchino, H.; Kiuchi, F.; Yamanaka, A.; Obu, A.; Wada, H.; Mori-Yasumoto, K.; Kawahara, N.; Flores, D.; Palacios, O.; Sekita, S.; Satake, M.Two new stilbenes, 1 and 2, were isolated as leishmanicidal constituents from the methanolic extract of Lonchocarpus nicou leaves and stem, together with five known stilbenes and rotenoids. Their chemical structures were determined by spectral methods. Among them, the cis stilbene-type compounds 1 and 4 showed potent leishmanicidal activity (IC50: 5.5, 3.9μg/mL), while the trans stilbene-type compounds 2 and 5, and rotenoids 6 and 7, showed moderate activities (IC50: 9.9, 12.8, 22.6, 19.6μg/mL, respectively). © 2013 The Pharmaceutical Society of Japan.Ítem Acceso Abierto Subsistence strategies in traditional societies distinguish gut microbiomes(Nature Publishing Group, 2015) Obregon-Tito, A.J.; Tito, R.Y.; Metcalf, J.; Sankaranarayanan, K.; Clemente, J.C.; Ursell, L.K.; Zech, Xu Z.; Van Treuren, W.; Knight, R.; Gaffney, P.M.; Spicer, P.; Lawson, P.; Marin-Reyes, L.; Trujillo-Villarroel, O.; Foster, M.; Guija-Poma, E.; Troncoso-Corzo, L.; Warinner, C.; Ozga, A.T.; Lewis, C.M.Recent studies suggest that gut microbiomes of urban-industrialized societies are different from those of traditional peoples. Here we examine the relationship between lifeways and gut microbiota through taxonomic and functional potential characterization of faecal samples from hunter-gatherer and traditional agriculturalist communities in Peru and an urban-industrialized community from the US. We find that in addition to taxonomic and metabolic differences between urban and traditional lifestyles, hunter-gatherers form a distinct sub-group among traditional peoples. As observed in previous studies, we find that Treponema are characteristic of traditional gut microbiomes. Moreover, through genome reconstruction (2.2-2.5 MB, coverage depth × 26-513) and functional potential characterization, we discover these Treponema are diverse, fall outside of pathogenic clades and are similar to Treponema succinifaciens, a known carbohydrate metabolizer in swine. Gut Treponema are found in non-human primates and all traditional peoples studied to date, suggesting they are symbionts lost in urban-industrialized societies. © 2015 Macmillan Publishers Limited. All rights reserved.