Química
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Item Moluscos de el charco Nariño: una mirada desde la exploración bioquímica(Universidad Santiago de Cali, 2020) Caicedo Perlaza, Yaneth Angélica; Nieto Ramírez, Luisa María; Pantoja Pulido, Kriss DayanaMollusks are non-segmented soft-bodied invertebrates protected by a shell and constitute the basis of the diet of many communities. Our objective was to determine the biochemical composition of two species of mollusks Littorina zebra (piacuil) and Anadara tuberculosa (piangua), which are an important nutritional source in El Charco, Nariño. In total, 30 samples of L. zebra with average sizes of approximately 3cm were collected, and 30 samples of A. tuberculosa differentiated by sex, identifying 13 females with average lengths of 8.4cm and 17 males with average lengths of 6.3cm. Mud samples were also collected from the mollusk habitat, from which the percentage of humidity and pH was determined. The bodies of the mollusks were separated from their shells and then lyophilized to carry out the determination of proteins by the method of BCA (Bicinconinic Acid) and polyacrylamide electrophoresis, extraction of total lipids by the Folch method and evaluation of these by layer chromatography fine (TLC). Finally, the total DNA extraction was carried out using a commercial kit and the quantification and evaluation of its quality using the Nanodrop equipment. In the soil samples a humidity of 23.4% and a pH of 6.25 were observed on average. An average value of total proteins of 3.27 g (± 0.65) was obtained for male A. tuberculosa, 3.73 g (± 0.14) for female A. tuberculosa and 4.69 g (± 0.11 ) for L. zebra per 100 g of lyophilized tissue, values that are lower than those reported in the literature. The amount of total lipids extracted was determined, obtaining an average of 2.1 g (± 0.8) for L. zebra, 2.45 g (± 0.3) for female A. tuberculosa and 2.35 g (± 0.7) for Male A. tuberculosa per 100 g of lyophilized tissue, values very similar to those found in the literature. A qualitative evaluation of lipids was carried out by TLC (Thin Layer Chromatography), where the presence of colored bands that demonstrated the oxidation of organic compounds and the presence of active compounds was observed. Finally, the DNA for L. zebra and A. tuberculosa male was successfully extracted, however, for the female it was not possible to obtain a DNA solution of satisfactory quality, for which the use of another methodology is recommended to eliminate pigments that affect Nanodrop quantification. This work was able to corroborate the ancestral knowledge of the Pacific communities that this type of species has a high protein content, particularly the L. zebra species and nutritional value; Therefore, it will be possible to bring documented information to the communities that allows them to validate their ancestral beliefs and to make good use of these natural resources.Item Estudio de las interacciones del péptido Alyteserin 1C y de su análogo catiónico con modelos de membranas(Universidad Santiago de Cali, 2020) Sanchez Arias, Kevin; Oñate Garzón, José Fernando; Polo Cerón, DorianAntimicrobial peptides are part of the innate immunity of most living things and have antimicrobial activity against bacterium, viruses, fungi and parasites. Their cationic characteristics make them selective towards bacterial membranes with anionic surfaces. In this study, the interaction of Alyteserin 1C peptides with a net charge of +2 and their net charge analogue +5 was evaluated on synthetic membrane models that simulate the membrane surface of Gram-negative bacterium and human erythrocytes. Using differential scanning calorimetry (DSC), the effect of the peptides on the thermotropic behavior of the membranes was determined. On the other hand, attenuated total reflection (Fourier transform infrared spectroscopy) (ATR-FTIR) was used to analyze the displacement of the vibrations of the carbonyl, methylene and phosphate groups of the phospholipids, as a consequence of the interaction with the peptide. Furthermore, the amide I band of the peptide was also analyzed before and after interacting with the membrane models to determine its secondary structure. The DSC results showed a decrease in the enthalpy (ΔH) and melting point (ΔTm) of the membrane models in the presence of both peptides. On the other hand, the vibrational frequency of the functional groups of the phospholipids increased in the presence of the peptides. Regarding the secondary structure, the +2 peptide exhibited a form of transition of β sheets / turns to structures of β sheets / α helix after binding with membrane models, while the +5 peptide had a transition of aggregation structures / not ordered to β-sheet structures / α helix after PC membrane binding and to non-ordered β sheet structures after PC / PG membrane binding.Item Extracción de alcaloides presentes en las semillas de Lupinus mutabilis y su actividad antibacteriana(Universidad Santiago de Cali, 2020) Martínez Correa, Kelly Alejandra; Acosta Quiñonez, Roberth Yair; Pantoja Pulido, Kriss Dayana; López Parra, Lizbeth LorenaLupinus mutabilis is a plant with high nutritional properties and high agronomic potential derived from the protein content of its seeds and growing conditions in the soil. This plant biosynthesizes different secondary metabolites with antioxidant and antibacterial properties, making it potential for the development of antibacterial products. Due to the above, this research aims to extract alkaloids present in Lupinus mutabilis seeds grown in Valle del Cauca, to evaluate their antibacterial activity and compare them with seeds of the same type grown in Ecuador. For this, the Liquid-liquid acid extraction of the seeds was carried out and the presence of flavonoids, steroids, saponins and alkaloids was determined by phytochemical screening. As the main result, lupanin was evidenced as the most abundant alkaloid, followed by sparteine and 3β-hydroxylupanine. In addition, it was found that the crude alkaloid extract of seeds grown in Valle del Cauca, presents more alkaloid content 95.8% compared to 50.0% of seeds grown in Ecuador.Item Epoxidacion de los terpenos d-limoneno y b-pineno con participación de tetraacetiletilendiamina (TAED) y percarbonato de sodio (PCS) comerciales.(Universidad Santiago de Cali, 2020) Cuellar Lopera, Juan David; Delgado Millan, Roberto Andres; Franco, Jaime Martin; Flórez, EdwinThe epoxidation of D-limonene and b-pinene was successfully carried out using peroxyacetic acid produced in situ in a two-phase dichloromethane and water system, from the commercial reagents tetraacetylethylenediamine (TAED) and sodium peroxycarbonate (PCS) with sodium bicarbonate. The progress of the reaction was evaluated by thin layer chromatography (CCD) and separation by flash column chromatography (CCF), using silica gel 230-400 mesh. The TAED used in this study was previously purified by recrystallization, with a yield of 80%. The epoxides obtained were analyzed by nuclear magnetic resonance and mass spectrometry and the yields were 72% for D-limonene and 75% for -pinene epoxides.Item Síntesis solvotermal y caracterización de un nuevo polímero de coordinación a partir del ligando ácido 3-hidroxi-2,7-naftalenodisulfonato con aluminio(Universidad Santiago de Cali, 2020) Cerón Geovo, José David; D`Vries Arturo, Richard Fernando; Ríos, Jhon JaíroA new coordination polymer was synthesized from aluminum nitrate and the 3-hydroxy-2,7-naphthalenedisulphonate (3-OHNDS) acid ligand under solvotermal methodology using DMF as solvent. Brown crystals were obtained, which were characterized by FTIR spectroscopy, TGA / DSC thermal analysis and single crystal X-ray diffraction (SCDRX). Crystallographic data of the compound were obtained and from these the structure of the compound with general formula [Al2(3-OHNDS)2]∙3H2O. Additionally it was also determined that the compound crystallized in the Monoclinic system and belongs to the C2 space group. The polymer structure grows along [100] direction and it was finally concluded that the water molecules are responsible for the crystal packing of the molecule, because they can form hydrogen bonds responsible for joining the polymer chains and generate the crystal packing.Item Aplicación del diseño de mezclas en la formulación de sidra de manzana(Univerisad Santiago de Cali, 2020) Ramírez Naranjo, Nathalia; Sinisterra Amú, Diana; Ramirez Navas, Juan SebastiánCider is a drink with very marked characteristics with respect to other spirits; It has abundant carbon dioxide, but produces less foam than a regular beer, acquires shades of yellow in transparent and bright appearance. (Drilleau, 2005). Cider. 2. The objective of this research was to evaluate the ratio of cider mixtures from three varieties of apple (Malus Domestica): Gala, Golden and Green. This mixing design consisted of applying a planning and analysis methodology which could ensure that we obtain the knowledge and solutions. The adoption of this methodology aims to assess the influence of each component of the formulation on the selected response varieties. For this purpose, different physicochemical tests were performed on each mixture obtained: (pH, Density, Volatile Acidity, alcoholic Strength and Sugar Percentage) and from which the expected results were obtained with an average of pH between 3.6 - 3.8; Density between 0.99-1.02 g/mL; Volatile Acidity between 0.04 -0.09 g/L; Alcohol content between 0.73 - 2.4 %V; Microbiological: (Count of aerobic bacteria and mesophylls, mold count, yeast count and total coliforms) whose result of each test was <10 UCF/mL and Sensory Analysis in which preference was found for the sample called B, corresponding to the mixture 0,1/2,1/2 being this the mixture between green apple and gallium apple. The results obtained in each test were expected indicating that the drink does meet the requirements established by the Colombian technical standard NTC 222 and NTC 708, concerning alcoholic beverages and their general definitions, alcoholic beverages (Fruit wines) respectively.Item Capacidad antioxidante de la semilla de aguacate (Persea Americana Mill) variedad Hass en distintos grados de germinación(Univerisad Santiago de Cali, 2020) Rodriguez Sanchez, Yuly; Ramirez Navas, Juan SebastiánThe avocado seed has in its chemical composition active phytocomposites; but the food industry has been limited only to the use of pulp, discarding the avocado seed. Increasing volumes of this agroindustrial remnant are expected to be generated inevitably; as a result of the growing interest in products derived from the fruit. In this study, the total phenolic content and antioxidant activity in 4 stages of avocado germination were analyzed using spectrophotometric reference methods. The total phenolic content was determined by an internal reference material of gallic acid. The antioxidant activity is referred to as the stable free radical 1,1-diphenyl-2-picrilhydrazil. The results obtained show that the antioxidant capacity increases in each stage of germination.Item El árbol milagroso (Synsepalum dulcificum) como fuente potencial de un edulcorante natural y compuestos antioxidantes: Una revisión sistemática(Univerisad Santiago de Cali, 2020) Sandoval Moreno, Sebastián Felipe; Rodríguez Pacheco, Martina; Castillo, Jorge Enrique; Larrahondo, Jesús EliecerItem Avances en Materiales Electrocrómicos: Perspectiva Industrial en Colombia(Univerisad Santiago de Cali, 2021) Hurtado Palacios, Luis Felipe; Castro Narváez, Sandra PatriciaItem Obtención y caracterización de mezclas de almidón termoplástico funcionalizado y ácido poliláctico con potencial aplicación en empaques flexibles(Univerisad Santiago de Cali, 2021) Siachoque Meza, Laura Vanessa; Caicedo Cano, Carolina; Calambás Pulgarín, Heidy LorenaThe physico-mechanical properties of the mixture of thermoplastic starch and polylactic acid and its interaction with organic acids such as: oleic acid, lactic acid and acetic acid were determined. These biopolymers were obtained in the molten state in which TPS: PLA 70:30 ratios were used, for the plasticization of the starch a 70:30 ratio (starch: plasticizer) was used, and the acidic agents were added in mixtures, but in a total portion of 6%. These mixtures were obtained in a torque rheometer at a speed of 50 rpm, for 10 min at 150 ° C. Polylactic acid was able to effectively promote the gelatinization process by decreasing the available polar sites towards the surface of the material; As a result, there were higher values in the contact angle, these results were contrasted with the analysis performed by differential scanning calorimetry and scanning electron microscopy. The results derived from the rheological analysis show that there was an increase in the elastic component in thermoplastic starch with the presence of acids; this behavior favored gelatinization. The mixture of sorbitol with polylactic acid promoted lower values of the loss modulus, the storage modulus, and the complex viscosity, which means a lower residual energy in the transition from the viscous state to the elastic state; this allows the compounds to be scaled to the conventional polymer used in transformation processes.Item Espectrometría de masas aplicada en la estabilidad de un producto cosmético para el cabello(Univerisad Santiago de Cali, 2022) Chavez Espinosa, Yadid Milena; Velásquez García, Natalia; López Parra, Lizbeth LorenaFive different formulations of hair masks were made, varying the amount of Polysorbate 80 and Glyceryl Monostearate, in order to establish which surfactant presented the best stability in the emulsion. For the different hair masks, chemical stability tests were carried out under natural and accelerated conditions for 4 months, measurement of pH, creaming index, viscosity tests, centrifugation tests and analysis of volatile components at week 0 and week 16, by means of Gas chromatography coupled to CG-MS Mass Spectroscopy. It was observed that the ideal hair mask under natural and accelerated conditions to establish a formulation is the hair mask that has 5% Glyceryl Monostearate in its composition, due to the physicochemical stability it presented over time. Finally, it was established that the volatile components did not show significant degradation in the different hair masks.Item Estudio del método de extracción por sorción en disco rotatorio, compuestos bioactivos y extractos fitoquímicos de la fruta asaí “Euterpe oleracea”(Univerisad Santiago de Cali, 2021) Velasco Jaramillo, Valentina; López Parra, Lizbeth LorenaIn this article you can find specific information about the naidí fruit also known as asaí belonging to the genus Euterpe oleracea, as they are, new discoveries related to bioactive compounds, the phytochemistry of the fruit and beneficial biological activities for the human being. Therefore, a systematic review was carried out according to the PRISMA guidelines in order to verify the viability of a new rotary disk sorption extraction method (RDSE) compared to other old methods, this new technique requires little sample, very fast processes, little consumption of solvents and provides care to the environment supporting this research in databases such as ScienceDirect, Scopus, among others. What can be concluded from the research is that the acai really is a powerful fruit but still lacks scientific information to support each function. While effectively the rotary disk sorption extraction method complies with the parameters of green chemistry and allows a more efficient work.Item Síntesis y caracterización de derivados de m-fenilendiamina con los metales de transición Mn2+, Ni2+ y Cu2+ como potenciales materiales antibacterianos(Univerisad Santiago de Cali, 2021) Rendón Bolaños, Stiwenn Andrés; Flórez López, Edwin; Avila Torres, YennyIn the present research it was possible to synthesize and characterize by spectroscopy FTIR, UV-Vis thermal analysis TGA-DSC and atomic absorption, the ligand phenyl-1,3-N,N'-bisditiocarbamate of potassium, derived from m-phenyldiamine and its coordination compounds with metallic salts of Ni2+, Cu2+ and Mn2+. This spectroscopic analysis allowed to identify the bidentate coordination mode of the DTC with each of the metals and to suggest a flat square geometry for the 3 coordination compounds obtained.Item Conversión catalítica de alcohol fusel y etanol utilizando perovskitas del tipo LaM2+O3 como catalizadores(Univerisad Santiago de Cali, 2022) Rojas Rivas, Sofia; Orduña Ortega, Julieth; Mora Vargas, Jorge AndrésCurrently, the development of more environmentally friendly methodologies to produce value-added compounds (PVA) from renewable raw materials has been increasing, mainly for the production of derivatives from fossil sources. Among these raw materials, the products obtained from the industrial processing of sugar cane become important substrates for obtaining these compounds. Fusel alcohol (mixture of different low molecular weight alcohols), obtained as a by-product in the process of obtaining bioethanol via fermentation routes has become a raw material little explored to produce PVA. In addition, its use as a substrate in the Guerbet reaction (RG) has not yet been investigated, therefore, in this work it was proposed catalytic conversion by RG to obtain PVA, added, experiments were performed with ethanol, since this has already been used in GR with heterogeneous catalysts. For this, the use of catalysts possessing acid/base and hydrogenation/dehydrogenation properties such as perovskite type materials are necessary. For this reason, the synthesis, characterization (DRX, Raman, TGA, FTIR and SEM) was performed and use as heterogeneous perovskite catalysts of type LaM2+O3 where M2+ = Cu2+ or Co2+ in the catalytic conversion of fusel alcohol and ethanol using a low pressure fixed bed reactor in order to determine its influence on the type of pervoskitas and how it varies depending on the reaction conditions, added, the products obtained in both reactions were identified by means of CG-EM. They were obtained as main products in the reaction with fusel alcohol alkenes, aldehydes, ketones, alcohols and esters, on the other hand, in the reactions with ethanol, acetaldehyde and 1-butanol was obtained, among other products due to secondary reactions. In the first case, it is necessary to continue the investigation in order to determine some possible routes of formation of the mostly obtained compounds; in the second instance, reactions tended to follow the Guerbet reaction path along with secondary reactions based on the hydrogenation and dehydrogenation of molecules.Item Estudio de métodos de extracción y análisis de los cannabinoides CBD, CBN, ∆9-THC en la planta de Cannabis sativa L.(Univerisad Santiago de Cali, 2022) Mejia Rios, Luis Carlos; Amelines Sarria, Oscar FelipeThis study reviews the extraction methodologies applied to the plant of Cannabis sativa L. It describes the conditions of these methodologies and which of them presents better yields for the cannabinoids, cannabidiol (CBD), tetrahydrocannabinol (∆9-THC) and cannabinol (CBN), the methods of analysis of these and the medicinal uses are also examined. The systematic review was performed in accordance with PRISMA guidelines. The databases used were ScienceDirect, Springer, Scopus and Google Scholar. It has been reported that the cannabinoids CBD, ∆9-THC and CBN have pharmacological properties which can cover needs in certain pathologies such as cancer, glaucoma, epilepsy, Parkinson's and COVID-19. The supercritical carbon dioxide extraction methodology was found to be the most widely used and the most environmentally friendly. The HPLC-MS and GC-MS methods of analysis proved to be suitable for analyzing the cannabinoids studied in this systematic review.Item Deslignificación de tallo de plátano con organosolvente catalizado por FeCl3 para la producción de bioetanol de segunda generación(Universidad Santiago de Cali, 2023) Ordoñez Matamba, Osma Camilo; Zambrano Salgado, Yesid FabianThe pollution generated by the burning of fossil fuels and its effect on global warming has driven the search for renewable materials to produce biofuels that partially replace fossil fuels. The great abundance and low cost of lignocellulosic materials have awakened the interest of scientists to produce biofuels such as ethanol, which is liquid and can be mixed with gasoline for the automotive sector. However, lignocellulosic material has a protective barrier in the cell wall, lignin, which makes it difficult to obtain sugars from the cellulose contained in the biomass, so a first stage of delignification is necessary. This work intends to use an organ solvent delignification technique by means of FeCl3 catalyzation; Taking into account the little information available on it, its effectiveness is studied and compared with other methods to validate its efficiency. Similarly, the effect of the variable’s temperature, reaction time, ethanol and FeCl3 concentrations was studied through a factorial experimental design. It was found that the variables analyzed have a significant effect on the amount of final (residual) lignin, but that the ones with the greatest impact were the ethanol concentration and the temperature.Item Propiedades electrocrómicas de películas de WO3 obtenidas por deposición electroquímica.(Univerisad Santiago de Cali, 2022) Valencia Marín, Jose Manuel; Castro Narváez, Sandra PatriciaContributions are made to scientific-technological research oriented towards sustainability, specifically in the construction of smart windows. The influence of different acids (HCl, H2SO4, HNO3, HClO4 and CH3COOH) on the morphology and composition in the synthesis of WO3 was studied. Infrared (IR-TF), scanning electron microscopy (SEM) and X-ray diffraction (XRD) results establish that the acids form flat-faced oxides with edges, resembling their crystalline habit to prismatic and in the case of H2SO4 and HNO3, agglomerates are observed that are configured in crystalline niches with nanoflower-like pores in which multistage decomposition is present. The crystalline composition of the xerosols was hydrated and unhydrated tungstite. In spectroelectrochemical studies, electrochemical deposition of WO3 films on FTO substrates and sintering between 300 and 500°C exhibit high transmittance (85 - 100%), thicknesses between 600 and 712nm and dark yellow coloration in the colored state, which are independent of the acidulation source of WO3 xerosol synthesis. The optical band gaps ranged from 3.19eV to 2.20eV and electrochemical band gaps from 2.47eV to 2.69eV. The coloring efficiency of the deposited films shows a slight dependence on the acidity of the acid source used in the xerosol synthesis and on the sintering temperature. The oxides synthesized with CH3COOH and HClO4 presented better contrast and optical density.Item Oxidación electroquímica de 2-Tiazolamina Y 2-Oxazolamina en electrodo modificado con ferritas ternarias mixtas de metales de transición(Universidad Santiago de Cali, 2021) Silgado Cortázar, Daniel Gerardo; Morales Morales, Jimmy AlexanderItem Evaluación de la eficiencia de extracción de antocianinas a partir de Milpesillos (Oenocarpus mapora H. Karst.) utilizando solventes eutécticos naturales(Universidad Santiago de Cali, 2022) Soto Alvarez, Angie Karime; Torres Castañeda, Harlen Gerardo; López Parra, Lizbeth LorenaFor the extraction of anthocyanins from Oenocarpus mapora, natural deep eutectic solvents (NaDES) were studied as an ecological alternative to conventionally used extraction solvents. Different NaDES solvents based on choline chloride were prepared. The extraction technique assisted by micromaceration (EAMM) was used to extract the different metabolites. The results obtained were compared with 70% EtOH with 0.5% acetic acid. Monomeric anthocyanins (CAM), total phenolic compounds (CTF) and antioxidant activity were determined. CCAL was chosen as the solvent to work with. The optimal conditions for the process were found; 90 mg/mL, 20 minutes, and 60% water.Item Síntesis y determinación estructural de aminoésteres derivados de benzaldehído y salicilaldehído, y estudio teórico de sus compuestos de coordinación con Sb (III)(Universidad Santiago de Cali, 2021) Ágredo Bolaños, Ana Ivette; Flórez López, Edwin; Ávila Torres, Yenny PatriciaA condensation reaction was carried out between benzaldehyde and salicylaldehyde with the hydrochloride of the glycine aminoester, followed by reduction with NaBH4 to obtain two α-aminoesters with yields of 81% and 91% respectively, the products were characterized by IR, 1H NMR, 13C and Mass Spectrometry. In addition to this, a theoretical analysis was carried out using the MM2 force field stability method, which allowed determining the energetic properties of the ligands and the viability of coordinating to Sb (III). Taking into account that structures with a low total energy and a high difference between EHOMO and ELUMO are characterized as stable, three structures of coordination complexes between α-aminoesters and Sb (III) are proposed.