Bifidobacterial ß-galactosidase-mediated production of galacto-oligosaccharides: structural and preliminary functional assessments

This work was sponsored by FrieslandCampina. DS, VA, and FB are members of APC Microbiome Ireland, which is a research center funded by Science Foundation Ireland (SFI), through the Irish Government’s National Development Plan. The authors and their work were supported by SFI (Grant SFI/12/RC/2273), FEMS Research Grant FEMS-RG-2016-0103 and project AGL2017-84614-C2-1-R funded by the Spanish Ministry of Economy, Industry and Competitiveness. OH-H has received funding from the European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłodowska- Curie grant agreement no. 843950

Obras Preliminares-AR08-201700

El curso Obras Preliminares en la carrera de Arquitectura de carácter teórico-práctico dirigido a los estudiantes del cuarto ciclo que busca desarrollar la competencia general de razonamiento cuantitativo.Como arquitecto es importante conocer los materiales que conforman la obra arquitectónica las herramientas y equipos necesarios para su ejecución y los procesos constructivos. Este curso constituye una oportunidad única para introducir al estudiante en la rama constructiva ya que debido a dinámica del curso el estudiante puede experimentar en el taller lo que ha visto de manera teórica en clase adquiriendo así un aprendizaje significativo que le permitirá diseñar en función de las técnicas constructivas aprendidas. Es de destacar el uso de la tierra como principal material de construcción y el enfoque humanista económico y medioambiental de esta asignatura

Hydrolysis and transgalactosylation catalysed by β-galactosidase from brush border membrane vesicles isolated from pig small intestine: A study using lactulose and its mixtures with lactose or galactose as substrates

Enzymatic transgalactosylation, in different concentrated carbohydrate solutions, was investigated using brush border membrane vesicles (BBMV) from the pig small intestine. When lactulose was incubated with BBMV, the hydrolytic activity of the enzyme towards the disaccharide was observed to be very low compared to that towards the lactose, but the linkage specificity β-(1 → 3), previously observed in lactose solutions, was not significantly affected. As in the case of lactose, lactulose transgalactosylation by BBMV synthesizes the corresponding 3′-galactosyl derivative (β-Gal-(1 → 3)-β-Gal-(1 → 4)-β-Fru). Fructose released during lactulose hydrolysis was found to be good acceptor for the transgalactosylation reaction, giving rise to the synthesis of the disaccharide β-Gal-(1 → 5)-Fru. When incubating an 80/20 mixture of lactulose/galactose, the presence of galactose did not affect the qualitative composition of the transglycosylated substrate but enhanced the synthesis of β-Gal-(1 → 5)-Fru and decreased the synthesis of β-(1 → 3) glycosidic bonds. The marked tendency for synthesizing this linkage indicates that under hydrolytic conditions, β-Gal-(1 → 3)-Gal- and β-Gal-(1 → 5)-Fru glycosidic bonds would be preferentially digested.This work has been financed by the Spanish Ministry of Economy, Industry and Competitiveness (Project AGL2017-84614-C2-1-R) and the Spanish Ministry of Science, Innovation and Universities (Project RTI2018-101273-J-I00). Julio-González thanks the governorship of Bolivar-Colombia and CeiBA Foundation for the scholarship granted in the project “Bolívar Gana con Ciencia”

Enzymatic Synthesis and Structural Characterization of Novel Trehalose-Based Oligosaccharides

Trehalose, α-d-glucopyranosyl-(1↔1)-α-d-glucopyranoside, is a disaccharide with multiple effects on the human body. Synthesis of new trehalose derivatives was investigated through transgalactosylation reactions using β-galactosidase from four different species. β-galactosidases from Bacillus circulans (B. circulans) and Aspergillus oryzae (A. oryzae) were observed to be the best biocatalysts, using lactose as the donor and trehalose as the acceptor. Galactosyl derivatives of trehalose were characterized using nuclear magnetic resonance spectroscopy. Trisaccharides were the most abundant oligosaccharides obtained followed by the tetrasaccharide fraction (19.5% vs 8.2% carbohydrates). Interestingly, the pentasaccharide [β-Galp-(1→4)]3-trehalose was characterized for the first time. Greater oligosaccharide production was observed using β-galactosidase from B. circulans than that obtained from A. oryzae, where the main structures were based on galactose monomers linked by β-(1→6) and β-(1→4) bonds with trehalose in the ending. These results indicate the feasibility of commercially available β-galactosidases for the synthesis of trehalose-derived oligosaccharides, which might have functional properties, excluding the adverse effects of the single trehalose.This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness (Project AGL2017-84614-C2-1- R) and the Spanish Ministry of Science, Innovation and Universities (Project RTI2018-101273-J-I00). O.H.-H. has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska- Curie grant agreement no. 843950

Trans-β-galactosidase activity of pig enzymes embedded in the small intestinal brush border membrane vesicles

This work highlights the utility of brush border membrane vesicles (BBMV) from the pig small intestine as a reliable model for gathering information about the reaction mechanisms involved in the human digestion of dietary carbohydrates. Concretely, the elucidation of the transgalactosylation mechanism of pig BBMV to synthesize prebiotic galacto-oligosaccharides (GOS) is provided, unravelling the catalytic activity of mammalian small intestinal β-galactosidase towards the hydrolysis of GOS. This study reveals that pig BBMV preferably synthesizes GOS linked by β-(1 → 3) bonds, since major tri- and disaccharide were produced by the transfer of a galactose unit to the C-3 of the non-reducing moiety of lactose and to the C-3 of glucose, respectively. Therefore, these results point out that dietary GOS having β-(1 → 3) as predominant glycosidic linkages could be more prone to hydrolysis by mammalian intestinal digestive enzymes as compared to those linked by β-(1 → 2), β-(1 → 4), β-(1 ↔ 1) or β-(1 → 6). Given that these data are the first evidence on the transglycosylation activity of mammalian small intestinal glycosidases, findings contained in this work could be crucial for future studies investigating the structure-small intestinal digestibility relationship of a great variety of available prebiotics, as well as for designing tailored fully non-digestible GOS.This work has been financed by the Spanish Ministry of Economy, Industry and Competitiveness (Project AGL2017-84614-C2-1-R). Julio-González thanks the governorship of Bolivar-Colombia and CeiBA Foundation for the scholarship granted in the project “Bolívar Gana con Ciencia”.Peer Reviewe

Catalytic mechanism for hydrolysis and transglycosylation of digestive ß-galactosidase from pig small intestine

Resumen del trabajo presentado a la 6th International Conference on Food Digestion, celebrada en Granada (España) del 2 al 4 de abril de 2019.[lntroduction]: The high physiological and anatomical similarity of pig and human digestive tracts makes the use ot brush border membrane vesicles (BBMV) ot the pig small intestine an ideal model tor gathering intormation about the reaction mechanisms involved in the human digestion of GOS.[Objective]: The objective of this work has been to study the mechanisms of transgalactosylation of pig ß-galactosidase embedded in the small intestinal BBMV.[Methodology]: For this, GOS were synthesized using lactase in PBS, pH 7.3 (250 mg/ml) and lyophilized BBMV (180 mg/ml) at 37 oc in an orbital shaker at 900 rpm. To accomplish a comprehensive structural characterization of the main synthesized GOS, the monosaccharides were separated using activated charcoal and ethanol (5% v/v). The di- and trisaccharide fractions were isolated by HILIC-RID for further characterization by NMR.[Main findings]: The isolated pig small intestinal BBMV showed a considerable transgalactosylation activity under the experimental conditions used in this study, allowing the efficient synthesis of GOS with degree of polymerization 2 and 3. Likewise, pig BBMV preferably synthesizes GOS linked by ß-(1→3) bonds, since majar tri- and disaccharides were produced by the transfer of a galactose unit to the C-3 of the non-reducing moiety of lactase and to the C-3 of glucose, respectively. According to the reported data, dietary GOS having ß-(1→3) as predominant glycosidic linkages could be much more prone o hydrolysis by mammalian intestinal digestive enzymes as compared to those linked by ß-(1→2), ß-(1→4), ß-(1→1) or ß-(1→6) glycosidic bonds.[Conclusion]: these results are the first evidence of the transglycosylation activity of mammalian small intestinal glycosidases. The approach followed in this work could be extended to other substrates different from lactase for gaining knowledge of the mechanism of action of other intestinal glycosidases. This could be crucial for future research on the structure-function relationship of the great variety of potentially available prebiotics.Peer reviewe

Hydrolysis and transglycosylation activities of glycosidases from small intestine brush-border membrane vesicles

In order to know the catalytic activities of the disaccharidases expressed in the mammalian small intestinal brush-border membrane vesicles (BBMV) high concentrated solutions of sucrose, maltose, isomaltulose, trehalose and the mixture sucrose:lactose were incubated with pig small intestine disaccharidases. The hydrolysis and transglycosylation reactions generated new di- and trisaccharides, characterized and quantified by GC–MS and NMR, except for trehalose where only hydrolysis was detected. In general, α-glucosyl-glucoses and α-glucosyl-fructoses were the most abundant structures, whereas no fructosyl-fructoses or fructosyl-glucoses were found. The in-depth structural characterization of the obtained carbohydrates represents a new alternative to understand the potential catalytic activities of pig small intestinal disaccharidases. The hypothesis that the oligosaccharides synthesized by glycoside hydrolases could be also hydrolysed by the same enzymes was confirmed. This information could be extremely useful in the design of new non-digestible or partially digestible oligosaccharides with potential prebiotic properties.This work has been financed by the Spanish Ministry of Economy, Industry and Competitiveness (Project AGL2017-84614-C2-1-R). O.H-H. thanks to the Spanish Ministry of Science, Innovation and Universities for the JIN project (Project RTI2018-101273-J-I00). C.J-G. thanks the governorship of Bolívar-Colombia and CeiBA Foundation for the scholarship granted in the project “Bolívar Gana con Ciencia”.Peer reviewe

Albañilería Simple Y Armada-AR216-201900

Descripción:Este curso estudia los principales sistemas constructivos de albañilería y de concreto armado utilizados en el Perú para la construcción de edificaciones de mediana altura. De cada sistema constructivo conoceremos los materiales las herramientas los procesos constructivos y la normativa existente. Este curso también te brindará las competencias necesarias para que puedas participar en el desarrollo de proyectos en sus niveles de diseño construcción y de valorización o presupuesto valorando el trabajo en equipo y la Ética profesional. El curso Albañilería Simple y Armada forma parte de los cursos de construcción de la carrera de arquitectura es de carácter teórico ¿ práctico es decir que parte del curso se desarrolla en el salón de clase y en el taller de construcción espacio en donde el estudiante interactúa con los materiales herramientas y personal calificado lo que te brindará un conocimiento integral de los sistemas constructivos. Propósito:El presente curso tiene como propósito desarrollar en el futuro arquitecto la habilidad de buscar soluciones o alternativas a diferentes situaciones o circunstancias que se producen en el desarrollo de las diferentes etapas de un proyecto de una edificación.Se busca contribuir directamente al desarrollo de la competencia General de la UPC de Razonamiento cuantitativo y de las competencias específicas de Desarrollo de prácticas habilidades técnicas y conocimiento; y de la práctica profesional todos en nivel 2. Tiene como requisito el curso Obras Preliminare

Long-acting contraceptive agents: Norethisterone esters of monoalkenyl and monoalkynyl acids

9 pages, 1 table, 1 scheme.-- Available online 10 January 2003.The synthesis of nine new esters of norethisterone (17α-ethynyl-17β-hydroxyestr-4-en-3-one) is described, with the esterifying acids bearing an acetylenic or olefinic function in a chain of eight or nine carbon atoms, for evaluation as long-acting contraceptive agents.We thank the World Health Organization for financial support of this work

Long-acting contraceptive agents: norethisterone esters of arylcarboxylic acids

12 pages, 1 table, 1 scheme.-- PMID: 6658878 [PubMed].The synthesis of esters of norethisterone (17α-ethynyl-17β-hydroxy-estr-4-en-3-one) with acids containing a benzene ring is described, two methods of esterification being compared in terms of yield and convenience. The activities of these esters as long-acting contraceptive agents have been evaluated.This work, involving synthetic chemists from four countries, received financial grants from the World Health Organization, under the WHO Special Programme of Research, Development and Research Training in Human Reproduction