Direct Polyphenol Attachment on the Surfaces of Magnetite Nanoparticles, Using Vitis vinifera, Vaccinium corymbosum, or Punica granatum

This study presents an alternative approach to directly synthesizing magnetite nanoparticles (MNPs) in the presence of Vitis vinifera, Vaccinium corymbosum, and Punica granatum derived from natural sources (grapes, blueberries, and pomegranates, respectively). A modified co-precipitation method that combines phytochemical techniques was developed to produce semispherical MNPs that range in size from 7.7 to 8.8 nm and are coated with a ~1.5 nm thick layer of polyphenols. The observed structure, composition, and surface properties of the MNPs@polyphenols demonstrated the dual functionality of the phenolic groups as both reducing agents and capping molecules that are bonding with Fe ions on the surfaces of the MNPs via –OH groups. Magnetic force microscopy images revealed the uniaxial orientation of single magnetic domains (SMDs) associated with the inverse spinel structure of the magnetite (Fe3O4). The samples’ inductive heating (H0 = 28.9 kA/m, f = 764 kHz), measured via the specific loss power (SLP) of the samples, yielded values of up to 187.2 W/g and showed the influence of the average particle size. A cell viability assessment was conducted via the MTT and NRu tests to estimate the metabolic and lysosomal activities of the MNPs@polyphenols in K562 (chronic myelogenous leukemia, ATCC) cells

Direct polyphenol attachment on the surfaces of magnetite nanoparticles, using Vitis vinifera, Vaccinium corymbosum, or Punica granatum

This article belongs to the Special Issue Functionalized Magnetite Nanomaterials — Synthesis, Properties, and Applications.This study presents an alternative approach to directly synthesizing magnetite nanoparticles (MNPs) in the presence of Vitis vinifera, Vaccinium corymbosum, and Punica granatum derived from natural sources (grapes, blueberries, and pomegranates, respectively). A modified co-precipitation method that combines phytochemical techniques was developed to produce semispherical MNPs that range in size from 7.7 to 8.8 nm and are coated with a ~1.5 nm thick layer of polyphenols. The observed structure, composition, and surface properties of the MNPs@polyphenols demonstrated the dual functionality of the phenolic groups as both reducing agents and capping molecules that are bonding with Fe ions on the surfaces of the MNPs via –OH groups. Magnetic force microscopy images revealed the uniaxial orientation of single magnetic domains (SMDs) associated with the inverse spinel structure of the magnetite (Fe3O4). The samples’ inductive heating (H0 = 28.9 kA/m, f = 764 kHz), measured via the specific loss power (SLP) of the samples, yielded values of up to 187.2 W/g and showed the influence of the average particle size. A cell viability assessment was conducted via the MTT and NRu tests to estimate the metabolic and lysosomal activities of the MNPs@polyphenols in K562 (chronic myelogenous leukemia, ATCC) cells.This work was partially supported by CONAHCyT through a PhD grant for A.E.M.–R. and a postdoctoral fellowship for M.L.A.-N., as well as through project 21067. This work was partially financed by a Cathedra Marcos Moshinsky 2018. M.P.-G. and S.A.T. are grateful to PROMEP–SEP (UAEH–PTC–826, “Apoyo a profesores con perfil deseable”, and PTC–246760).Peer reviewe

Trypanocidal constituents in plants: 7. Mammea-type coumarins

Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 g/ml. Coumarins with a cyclized ,-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 g/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds

Ética y ciudadanía - HU316 201801

Descripción: Ética y Ciudadanía es un curso de formación general, de carácter teórico-práctico, dirigido a estudiantes de ciclos iniciales de distintas carreras; que busca contribuir al desarrollo una de las competencias generales de nuestro modelo educativo: Ciudadanía en el nivel 1. Propósito: El curso pretende contribuir con el aprendizaje ético y ciudadano de los estudiantes invitándolos a conocer y explicar problemas éticos y de su vida cotidiana. Teniendo en cuenta que este curso se realiza bajo la modalidad semipresencial, se proponen diversas actividades educativas de tipo individual y grupal, tanto en las sesiones presenciales como en las sesiones virtuales, lo que supone una participación activa, organizada y permanente por parte de los estudiantes. Las estrategias a utilizarse incluyen: lectura y discusión de textos, análisis y evaluación de películas y documentales, resolución de casos, debates y exposiciones, foros virtuales. Siendo el docente la pieza clave para este proceso de aprendizaje, cumple con el rol de promover un ambiente colaborativo a través del diálogo, el respeto y la reflexión, partiendo del conocimiento previo y las fortalezas de los estudiantes para generar nuevas capacidades y desarrollar la competencia asociada al curso