Virtual Screening of Plant Volatile Compounds Reveals a High Affinity of Hylamorpha elegans (Coleoptera: Scarabaeidae) Odorant-Binding Proteins for Sesquiterpenes From Its Native Host

Indexación: Web of ScienceHylamorpha elegans (Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals. Here, we report the discovery of four OBPs in H. elegans as well as six new volatiles released by its native host Nothofagus obliqua (Mirbel). Molecular docking performed between OBPs and new and previously reported volatiles from N. obliqua revealed the best binding energy values for sesquiterpenic compounds. Despite remarkable divergence at the amino acid level, three of the four OBPs evaluated exhibited the best interaction energy for the same ligands. Molecular dynamics investigation reinforced the importance of sesquiterpenes, showing that hydrophobic residues of the OBPs interacted most frequently with the tested ligands, and binding free energy calculations demonstrated van der Waals and hydrophobic interactions to be the most important. Altogether, the results suggest that sesquiterpenes are interesting candidates for in vitro and in vivo assays to assess their potential application in pest management strategies.http://jinsectscience.oxfordjournals.org/content/16/1/3

Estudio computacional de la distribución del fluoróforo 7-[(6-bromohexilo)oxi]-2H-2-cromenona en una bicapa lipídica por Dinámica Molecular

54 p.Las cumarinas son una familia de moléculas que exhiben un amplio rango de actividades biológicas y propiedades de emisión de fluorescencia. Los derivados de las cumarinas se pueden utilizar como sondas fluorescentes altamente eficaces para el estudio biofísico de bicapas lipídicas y también como sensores de especies reactivas del oxígeno (ROS) capaces de detectar la peroxidación de lípidos, lo cual es uno de los procesos celulares más graves y degenerativos para la membrana lipídica. Las técnicas de fluorescencia son herramientas experimentales convenientes para el estudio de estos procesos en la membrana. Con el objetivo de obtener información detallada acerca de la perturbación en la estructura lipídica y la localización de la sonda fluorescente en la membrana, se ha realizado en este trabajo un estudio a nivel atómico mediante el método de dinámica molecular. Específicamente se describe el proceso de inserción y ubicación de las sondas fluorescentes derivadas de cumarinas (1) 3-acetil-7-[(6-romohexil)oxi]-2H-2-cromenona, (2) 7-[(6-bromohexil)oxi]-4-metil-2H-2-cromenona y (3) etil{7-[(6-bromohexil)oxi]-2-oxo-2H-2-cromen-4-il}acetato en una bicapa lipídica de 1-palmitoil-2-oleoil-sn-glicero-3-fosfocolina (POPC) completamente hidratada y se proporciona información detallada acerca de la ubicación de las mismas.A partir de los resultados obtenidos en dinámica molecular, ha sido posible determinar la posición de estas bromo-cumarinas, las cuales se localizan en la región de las cadenas carbonadas de los fosfolípidos, o en una zona más cercana de la superficie de la membrana. El grupo 6-bromohexiloxi se localiza en la matriz hidrofóbica de POPC y el grupo cumarina se encuentra interactuando cerca de la parte polar de la membrana. Las trayectorias obtenidas muestran que los tres compuestos se incluyen espontáneamente en la membrana, siendo el compuesto 3 el de mayor grado de inclusión. Además se observo cambios considerables en la estructura y conformación de la membrana POPC en presencia de estos compuestos.Palabras claves: Cumarinas, Sondas Fluorescentes, Membrana, Dinámica Molecular, Parametrización./ABSTRACT: Coumarins are a family of molecules that exhibit a wide range of biological activities and fluorescence emission properties. Coumarins derivatives can be used as highly efficient fluorescent probes for studying lipid bilayers biophysical and also as sensors reactive oxygen species (ROS) capable of detecting the lipid peroxidation, which is one of the most important cellular processes and degenerative to the lipid membrane.Fluorescence techniques are usefull experimental tool for the study of these type of processes in the membrane. In order to obtain detailed information about the disturbance in the lipid structure and the localization of the fluorescent probe on the membrane, this study was carried out at atomic level by the method of molecular dynamics. Specifically, it is describing the process of insertion and placement of the probes derived fluorescent coumarins (bromo-coumarins) 3-acetyl-7-[(6-bromohexyl) oxy]-2H-2-chromenone (compound 1), 7 - [(6-bromohexyl) oxy]-4-methyl-2H-2-chromenone (compound 2) and ethyl {7 - [(6-bromohexyl) oxy]-2-oxo-2H-2-chromen-4-yl} acetate (compound 3) in a lipid bilayer of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) fully hydrated and provides detailed information about the location from the probes.The results obtained from molecular dynamics were determined by these three bromo-coumarins which are located in the region of the carbon chains of the phospholipids, or in a zone nearest the surface of the membrane. The 6-bromohexyloxy group is located in the hydrophobic matrix of POPC and the coumarin groups are interacting near to the polar action of the membrane. The trajectories obtained show that all three compounds are included in the membrane spontaneously; however the compound number 3 show the highest level of inclusion. In addition, it was observed significant changes in the structure and conformation of POPC membrane in the presence of these compounds Keywords: Coumarins, Fluorescent probe, Membrane, Molecular dynamics, Parametrization

Chemical composition, antioxidant, antimicrobial and antiproliferative activity of Laureliopsis philippiana essential oil of Chile, study in vitro and in silico

Chilean Laureliopsis philippiana has been used in traditional medicine by the Mapuche and their ancestors. To evaluate its pharmacological activity, Laureliopsis philippiana leaf essential oil extract (LP_EO) was chemically and biologically characterized in the present study. In vitro antioxidant potential was analyzed, and antitumor activity was evaluated in non-tumor and tumor cell culture lines. Caenorhabditis elegans was used as a model for evaluating toxicity, and the chemical composition of the essential oil was analyzed using gas chromatography–mass spectrometry. The oil contains six major monoterpenes: eucalyptol (27.7 %), linalool (27.6 %), isozaphrol (19.5 %), isohomogenol (12.6 %), α-terpineol (7.7 %), and eudesmol (4.8 %). Based on quantum mechanical calculations, isosafrole and isohomogenol conferred in vitro antioxidant and antimicrobial activity to LP_EO. In addition, LP_EO showed antimicrobial activity against clinical Helicobacter pylori isolates (MIC 64 and MBC > 128 μg·mL−1), Staphylococcus aureus (MIC 32 and MBC > 64 μg·mL−1), Escherichia coli (MIC 8 and MBC 16 μg·mL−1) and Candida albicans (MIC 64 and > 128 μg·mL−1). LP_EO could selectively inhibit the proliferation of epithelial tumor cell lines but showed low toxicity against Caenorhabditis elegans (0.39 to 1.56 μg·mL−1). Therefore, LP_EO may be used as a source of bioactive compounds in novel pharmacological treatments for veterinary and human application, cosmetics, or sanitation.Fil: Bruna, Flavia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Diego Portales; ChileFil: Fernández, Katia. Universidad Diego Portales; ChileFil: Urrejola, Felipe. Universidad Diego Portales; ChileFil: Touma, Jorge. Universidad Diego Portales; ChileFil: Navarro, Myriam. Universidad Diego Portales; ChileFil: Sepúlveda, Betsabet. Universidad de Chile; ChileFil: Larrazabal Fuentes, María. Universidad de Antofagasta (uantof);Fil: Paredes, Adrián. Universidad de Antofagasta (uantof);Fil: Neira, Iván. Universidad de Antofagasta (uantof);Fil: Ferrando, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Osorio, José Manuel. Universidad Andrés Bello; Chile. Universidad Diego Portales; ChileFil: Yáñez, Osvaldo. Universidad de Las Américas.; Ecuador. Center of New Drugs for Hypertension; ChileFil: Bravo, Jessica. Universidad Diego Portales; Chil

Design and development of a reconfigurable die for thermoforming process

According to the World Economic Forum (WEF), the nascent technologies such as Internet of Things (IoT), 3D printing, and advanced robotics represent between 70%-80% of the product market, manufacturing and services in North America and Europe. In this context, the designing and implementation of reconfigurable tools can generate more flexible processes, oriented to improve the productivity in manufacturing industry, especially in molding and thermoforming packaging. Consequently, a reconfigurable die based on shape-memory alloy actuators, is a solution for attending the industry challenges, due to its inclusion of a microstructural-based, temperature-based, and time-based constitutive model theory for its implementation. Within these challenges exists the need of fabrication of millions of pieces due to its limitation with a low-volume production, and high investment and maintenance tool costs. The objective of this thesis work is the development of a technology that allows manufacturing variable-shape packages through a reconfigurable die with a thermoforming process. The functionality and performance of the technology lie within the application of a shape-memory alloy theory for a reconfigurable system; the development of a functional prototype with both NiTi-based and stepper-based motion mechanisms; and the development of a technology roadmap that allows having a vision of the potential customer segment of the product and/or technology, according to their needs and opportunities

Comprensión y aplicación del dominio cognitivo de la taxonomía de Benjamín Bloom : caso : de los profesores de establecimientos educacionales de la Provincia de Cachapoa

Tesis (Magíster en Liderazgo de Gestión y Administración Educacional)Este trabajo consiste en una investigación de estudio exploratorio, que tiene como objetivo conocer la Comprensión y Aplicación del Nivel Cognoscitivo de la Taxonomía de Bloom, de los profesores de establecimientos educacionales municipales, subvencionados gratuitos y subvencionados compartido de la Provincia de Cachapoal. La muestra estuvo constituida por cien profesores de distintos colegios de la provincia. La recolección de la información se hizo a través de una entrevista escrita con preguntas abiertas y cerradas. Los datos obtenidos fueron procesados y analizados en una matriz da vaciado de datos. La información obtenida nos permite concluir que la Taxonomía de Bloom se encuentra plenamente vigente y que es utilizada frecuentemente por los profesores, como marco referencial importante para la planificación y evaluación de los objetivos educacionales. Cada vez que se conocen los resultados de las pruebas estandarizadas que rinden los estudiantes chilenos, tales como SIMCE, PSU y otras internacionales como TIMS y PISA; entre las causas principales, de los resultados deficientes que cada años obtienen nuestros estudiantes, se resalta las malas prácticas pedagógicas de los profesores, que no llevan a los alumnos a obtener aprendizajes de calidad, de altos niveles cognitivos. Una critica general, es que los profesores no alcanzan a desarrollar niveles de complejidad más allá de la memoria y la comprensión; también se señala la mala calidad de la gestión docente, con deficiencias significativas en la preparación de las actividades de las clases y en la construcción de los instrumentos para evaluar los aprendizajes. Ahora bien, siendo la Taxonomía de Bloom como ya dijimos, una herramienta útil que usan los profesores para planificar y evaluar los aprendizajes que desean lograr en sus alumnos y atendiendo a las críticas antes expuestas, surgen las preguntas ¿ Cuál es la comprensión que tiene lo profesores sobre esta Taxonomía? ¿En qué medida la utilizan en sus prácticas pedagógicas?. Estas dos preguntas dan origen a nuestro trabajo de investigación, que tiene como objetivo conocer la comprensión y aplicación del dominio cognoscitivo de la Taxonomía de Bloom de los profesores de distintos establecimiento educacionales de la Provincia de Cachapoal. Como objetivo especifico buscamos también conocer cuáles son las variables que influyen en la comprensión y aplicación de la Taxonomía, en la muestra de docentes consultados. Creemos que esta investigación podrá arrojarnos información relevante no sólo para contestar las preguntas antes mencionadas, sino que también para proponer y dirigir las áreas de capacitación docente relacionadas con Planificar y Evaluación de Aprendizaje, el reconocimiento explicito de la Taxonomía de Bloom como un referente teórico importante, que merece ser considerada, estudiada a fondo para ser utilizada en forma eficiente y de la manera como fue concebido por sus autores. En este trabajo incluimos como marco referencial información muy importante obtenida en una entrevista a tres prestigiados Académicos Chilenos que tuvieron el privilegio de ser discípulos y trabajar con Benjamín Bloom, ellos son: Carlos Ávalos Valenzuela, Doctor en Educación de la Universidad de Chicago, profesor de Matemática y especialista en Evaluación Educacional; Mario Leyton Soto, Magíster en Administración de la Universidad de Chicago, especialista en Curriculum y Don Eduardo Cabezón, Doctor en Filosofía de la Universidad de Chicago, especialista en Medición, Evaluación y Análisis Estadístico

Proposal of a simple and effective local reactivity descriptor through a topological analysis of an orbital-weighted fukui function

The prediction of reactivity is one of the long-standing objectives of chemistry, contributing to enforce the link between theory and experiment. In particular, the regioselectivity of aromatic molecules has motivated the proposal of different reactivity descriptors based on foundational theories, like Frontier Molecular Orbital (FMO) theory and density functional theory, to predict and rationalize such regioselectivity. This article examines cases where reactivity descriptors, based on FMO theories, are known to have failed, specifically on electrophilic aromatic substitution reactions, through a simple but effective new reactivity model: the Orbital-weighted Fukui function ((Formula presented.)) and its topological analysis. Interestingly, this descriptor proves to be effective in adequately predicting regioselectivities where other approximations failed

Design, synthesis and cellular dynamics studies in membranes of a new coumarin-based "turn-off" fluorescent probe selective for Fe2+

Artículo de publicación ISIA new coumarin-based ‘turn-off’ fluorescent probe, 7-(diethylamino)-N-(1,3-dihydroxy-2-(hydroxymethyl) propan-2-yl)-2-oxo-2H-chromene-3-carboxamide (AGD) was synthesized. This compound is highly selective for ferrous ions (Fe2þ) and can reversibly detect them in aqueous medium. The probe localizes to the cell membrane in living cells, where it can detect changes in Fe2þ concentration. Molecular dynamics (MD) simulations indicate that AGD interacts with the lipid bilayer at the level of the glycerol moieties

Biofuels: Environment, technology and food security

The imminent decline of the world's oil production, its high market prices and environmental impacts have made the production of biofuels to reach unprecedent volumes over the last 10 years. This is why there have been intense debates among international organizations and political leaders in order to discuss the impacts of the biofuel use intensification. Besides assessing the causes of the rise in the demand and production of biofuels, this paper also shows the state of the art of their world's current production. It is also discussed different vegetable raw materials sources and technological paths to produce biofuels, as well as issues regarding production cost and the relation of their economic feasibility with oil international prices. The environmental impacts of programs that encourage biofuel production, farmland land requirements and the impacts on food production are also discussed, considering the life cycle analysis (LCA) as a tool. It is concluded that the rise in the use of biofuels is inevitable and that international cooperation, regulations and certification mechanisms must be established regarding the use of land, the mitigation of environmental and social impacts caused by biofuel production. It is also mandatory to establish appropriate working conditions and decent remuneration for workers of the biofuels production chain.Biofuel production Environment Technology Food security

Machine Learning-Driven Classification of Urease Inhibitors Leveraging Physicochemical Properties as Effective Filter Criteria

Urease, a pivotal enzyme in nitrogen metabolism, plays a crucial role in various microorganisms, including the pathogenic Helicobacter pylori. Inhibiting urease activity offers a promising approach to combating infections and associated ailments, such as chronic kidney diseases and gastric cancer. However, identifying potent urease inhibitors remains challenging due to resistance issues that hinder traditional approaches. Recently, machine learning (ML)-based models have demonstrated the ability to predict the bioactivity of molecules rapidly and effectively. In this study, we present ML models designed to predict urease inhibitors by leveraging essential physicochemical properties. The methodological approach involved constructing a dataset of urease inhibitors through an extensive literature search. Subsequently, these inhibitors were characterized based on physicochemical properties calculations. An exploratory data analysis was then conducted to identify and analyze critical features. Ultimately, 252 classification models were trained, utilizing a combination of seven ML algorithms, three attribute selection methods, and six different strategies for categorizing inhibitory activity. The investigation unveiled discernible trends distinguishing urease inhibitors from non-inhibitors. This differentiation enabled the identification of essential features that are crucial for precise classification. Through a comprehensive comparison of ML algorithms, tree-based methods like random forest, decision tree, and XGBoost exhibited superior performance. Additionally, incorporating the “chemical family type” attribute significantly enhanced model accuracy. Strategies involving a gray-zone categorization demonstrated marked improvements in predictive precision. This research underscores the transformative potential of ML in predicting urease inhibitors. The meticulous methodology outlined herein offers actionable insights for developing robust predictive models within biochemical systems