35 research outputs found

    Introducing Organic Chemistry Students to the Extraction of Natural Products Found in Vegetal Species

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    This work constitutes a new strategy for teaching-learning the chemistry of natural products, being the students active participants in the process. Results showed in this activity contributed not only to the understanding of the subject but also turned out to be an important pillar of motivation. An essential oil is any of a class of volatile oils that give plants their characteristic odor. Essential oils are also known as ethereal oil, volatile oil, aetherolea, or simply as the oil of the plant from which they are extracted, such as oil of clove. The oil is ?essential? in the sense that it contains the ?essence of? vegetal specie fragrance, the characteristic fragrance of the plant from which it is derived. These can be extracted from different parts of plants such as stems, leaves and flowers. In this work, two conventional methods (steam distillation and Soxhlet extraction) and one non-conventional method (microwave-assisted extraction), was developed under different conditions from clove. The yield of clove oil and yield of eugenol were obtained; and the concentration of eugenol present was assessed by gas chromatography. The main objective was that the experimental activity with the theoretical foundation will provide to the students of organic chemistry the ability to link concepts and develop skills in the laboratory.Fil: Guntero, Vanina Alejandra. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Química Orgánica; Argentina. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

    Polar Diels-Alder Reactions using Heterocycles as Electrophiles. Influence of Microwave Irradiation

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    In this work we studied a series of polar Diels-Alder reactions using different heterocycles derivatives acting as electrophiles joint to dienes of different nucleophilicity, analyzing the effect of the microwave irradiation in these processes. We employ the technique in two conditions: benzene as solvent and solvent free reactions. The last one presents the better yield in shorter time of reaction. Using microwave heating the aromatic cycloadducts are clearly predominant. It is possible to demonstrate that the microwave irradiation has a better influence on these cycloaddition reactions respect to those developed in thermal classical conditions.Fil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: López Baena, Anna Francesca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; ArgentinaFil: Della Rosa, Claudia Daniela. Universidad Nacional del Litoral. Facultad de Ingeniería Química; ArgentinaFil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentin

    Hydrophilic Isolates of Rye Flour as a Potential Matrix for the Use as a Vehicle of Active Compounds

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    The isolation of water-soluble polysaccharides and proteins solubilized during the treatment of rye flour in an isotonic aqueous medium is described. Protein and polysaccharide assays of the aqueous fractions showed the high extraction performance of these compounds. Then, nanoparticles were synthesized from these hydrophilic isolates using fluorescein as a model drug and sodium hexapolyphosphate as a cross-linker. The preparation process consisted of dispersion, desolvation, drug incorporation, crosslinking, and separation of nanoparticles. The physicochemical analysis revealed that nanoparticles were successfully synthesized with rye hydrophilic isolates using a desolvation method. These studies demonstrated that rye nanoparticles are a promising candidate as an active compounds vehicle system.Fil: Ferretti, Cristián Alejandro. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Celman, Mariana. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Noriega, Pablo. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentin

    Microwave-assisted embedding of bis-vanillin and bis-eugenol into SBA-15: Synthesis of chemosensors precursors for the detection of metal cations

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    In this work we evaluate the necessary experimental conditions to carry out the embedding of bis-vanillin and bis-eugenol, two potential precursors of chemosensors, in the porous structure of the mesoporous silica SBA-15 through a microwave assisted process. The physicochemical characterization of the developed bis-vanillin-SBA-15 and bis-eugenol-SBA-15 materials confirmed the successful immobilization of these molecules in the mesoporous composite. The most important characteristic of these systems is the possibility of activating the release of the organic molecules embedding into SBA-15, depending on the liquid medium in which these composites are suspended.Fil: Guntero, Vanina Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Espinoza Martinez, Dailenys. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Ferretti, Cristián Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentin

    In Silico Study of the Interaction between Casein with Tocopherols: Preliminary Evaluation of Lipophilic Substrate Inclusion on Proteic Matrix

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    Bovine casein is a family of milk proteins with hydrophilic and hydrophobic regions thatshow block distribution within the protein chain. These amphiphilic properties offer great potentialas a material for use as a matrix for transporting active materials such as tocopherol. In this work,we aimed to evaluate the interaction of α1-casein, the main fraction of casein, with vitamin E bydocking calculations. Docking studies were conducted using SwissDock and DockThor servers.Using specific scoring functions based on energy terms, the best protein?ligand binding modelswere obtained. The observed interactions between vitamin E and amino acid residues consisted ofseveral hydrophobic interactions (e.g., with Tyr119, Ala144, Trp179, Met211, Pro212). A few hydrogen bonds were observed between the phenyl group of vitamin E and the carboxylate group ofthe glutamic acid residue (e.g., with Glu85, Glu148). In conclusion, the results suggest that there isa major interaction of vitamin E with random coil structure and interaction with segments formedby α-helix and β-sheet. This implies that in random coil segments there is a predominance of hydrophobic domains.Fil: Guntero, Vanina Alejandra. Universidad Tecnológica Nacional. Facultad Regional San Francisco; Argentina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Gutierrez, Leandro Gabriel. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Ferretti, Cristián Alejandro. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentin

    Electrochemical Reduction of Oxygen Using a Metal–Organic Complex of Cu2+

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    A biphenyl-based copper complex was evaluated as electrocatalyst for the oxygen reduction reaction (orr), for a possible application as cathode material in fuel cells. To carry out this evaluation, the complex was supported on Vulcan carbon and deposited as a film on a glassy carbon rotating disk electrode by drop-casting a 1-μL drop of a suspension of carbon in a solution of the complex in dimethyl sulfoxide containing Nafion as ionic conductive binder, and drying under vacuum. The cyclic voltammogram in 0.1 M NaOH solution showed voltammetric peaks between 0.8 and 1.0 V vs. reference hydrogen electrode, which suggest the existence of electron transfer processes from/toward the ligand. The orr was tested in oxygen-saturated (1 atm) solution by linear sweep voltammetry, which showed significant orr current at relatively low overpotential (around −0.4 V), demonstrating the ability of the complex to electrocatalyze the orrefficiently.Fil: Ormachea, Carla. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Fernandez, Jose Luis. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentin

    Encapsulation of Compounds Biphenyls Into SBA-15: Synthesis of Composites for Application

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    Two novel hybrid mesoporous material BVA-SBA and BEG-SBA were designed and synthesized by a process assisted by microwave. The nanoparticles were studied by UV-vis and fluorescence spectroscopy, elemental analysis, nitrogen adsorption-desorption, RMN and FTIR. The results obtained indicates the successful immobilization of BVA and BEG in the mesoporous composite. These systems present the possibility of activating the release of the organic molecules encapsulated into SBA-15, depending on the liquid medium in which the composite are suspended.Fil: Guntero, Vanina Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Ferretti, Cristián Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentin

    Synthesis and Encapsulation of bis-eugenol in a Mesoporous Solid Material: Enhancement of the Antioxidant Activity of a Natural Compound from Clove Oil

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    In the present work, microwave extraction conditions to recover high eugenol content in the crude extract from clove were investigated. The effect of factors like temperature, stirring, time, liquid: Solid ratio and solutions of solvent were evaluated with Taguchi?s method. The eugenol content was determined by gas chromatography. From the isolated eugenol, the bis-phenol was synthesized by the dimerization of eugenol. The encapsulation of bis-eugenol on the mesoporous silica was carried out by a microwave assisted process. Previously, mesoporous silica SBA-15 was prepared by hydrothermal synthesis using Pluronic P123 triblock copolymer as a surfactant. The bis-eugenol encapsulated in SBA-15 was characterized by physicochemical techniques. The results indicated that the encapsulation of bis-eugenol in the pores of silica occurred through weak interactions of an electrostatic nature without producing chemical changes in the antioxidant property. The antioxidative activity of eugenol, bis-eugenol and bis-eugenol/SBA-15 system was examined by phosphomolybdenum assay. Among these materials, a remarkably high antioxidant activity was found in bis-eugenol encapsulated in SBA-15. These resultas suggest the possibility of applying this system as an antioxidant active packaging in the future.Fil: Guntero, Vanina Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Ferretti, Cristián Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentin

    Morphological and Chemical Analysis of the Molecularly-Imprinted Polymer-Based D-Arabinose Sensor on a Modified Electrode with Functionalized Carbon Nanotubes

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    he sensors modified carbon nanotubes and molecularly imprinted polymers are an excellent choice for the determination of D-arabinose, because they have high selectivity and sensitivity for analysis. This allows the control and optimization of the second generation ethanol production process, given the clear understanding of the chemical changes that occur through the hydrolysis of lignocellulosic biomass. For this reason, the present work presents a chemical study of the functional groups of the chemical species present on the sensor surface by the Fourier transform infrared spectroscopy (FT-IR) technique and a morphological analysis by the scanning electron microscopy (SEM) technique.Fil: Sousa, Miguel S. P.. Universidade de Sao Paulo; BrasilFil: Ferretti, Cristián Alejandro. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Paim, Leonardo L.. Universidade de Sao Paulo; Brasi

    Mesoporous Materials as Supports of Active Molecules: A Versatile Strategy Of Functionalization of Inorganic Oxides

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    Ordered mesoporous silica and alumina were functionalized with vanillin, eugenol and their bis-compounds through a microwave assisted process. The physicochemical characterization of these materials confirmed the successful immobilization of these molecules onto the surface of these oxides, keeping the ordered mesopore structure of supports and the antioxidant activity of molecules. The results suggest the possibility of applying these materials as a new component of the packaging of aliment or cosmetic with antioxidant properties in the future.Fil: Guntero, Vanina Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Ferretti, Cristián Alejandro. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Mancini, Pedro Maximo Emilio. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; ArgentinaFil: Kneeteman, Maria Nelida. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentin
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