En este trabajo se utilizó el diseño factorial de experimentos para la preparación de partículas de quitosano cargadas con la hormona vegetal ácido 1,3-indolacético (AIA) y posteriormente estudiar la liberación controlada en agua. Las partículas de quitosano cargadas se prepararon disolviendo la hormona y el quitosano en ácido acético haciéndose gotear luego en solución de NaOH con agitación constante. Se utilizó el Diseño Factorial 23 cuyos factores a estudiar fueron: la concentración de quitosano (% quitosano), tiempo de gelación en NaOH (tiempo en NaOH) y concentración de tripolifosfato de sodio (TPP) (% de TPP). Como respuesta se obtuvo la cantidad de hormona liberada en dos horas, medida espectrofotométricamente a 285 nm. Los resultados del diseño experimental indicaron que los tres factores influyen en la cantidad liberada de AIA en dos horas, en donde a mayor c...

El cáncer es una de las principales causas de muerte en todo el mundo. La búsqueda de compuestos bioactivos contra el cáncer se potencia con el uso de herramientas computacionales y las bases de datos moleculares. Clinopodium Revolutum (CR) es una planta empleada con fines medicinales en diferentes males, sin embargo, hacen falta mayores estudios científicos que respalden su bioactividad. En este trabajo se analizan 55 componentes en el aceite esencial de CR, identificados por GC-MS, con potencial actividad anticancerígena mediante estudios in silico. Se seleccionaron los receptores de fármacos anticancerígenos, como la quinasa dependiente de ciclina 2 (CDK-2), la quinasa dependiente de ciclina 6 (CDK-6), la topoisomerasa-I (Topo I), la topoisomerasa-II (Topo II), el linfoma B de células (Bcl-2) y el receptor 2 del factor crecimiento endotelial vascular (VEGFR-2). Todas estas est...

La Organización Mundial de la Salud a categorizado a Acinetobacter baumannii en la categoría de alta prioridad, debido a que urgen estrategias farmacológicas para combatir su resistencia a los antibióticos. La maquinaria bacteriana de adquisición de hierro ha sido empleada exitosamente en estudios previos con diferentes bacterias Gram-negativas, para internalizar metales abiogénicos coordinados a sideróforos mediante el efecto caballo de Troya, sin embargo, aún no hay reportes con A. baumannii. En este trabajo se realizó un estudio in silico para conocer las posibilidades de aplicación de este efecto en A. baumannii, específicamente analizando su receptor de hierro-sideróforo de tipo hidroxamato (FhuE), y el reconocimiento molecular de los complejos de aluminio-desferrioxamina (Al-DFO) y galio-desferrioxamina (Ga-DFO). Se realizó un análisis estructural y energético de los...

In this work we used the factorial design of experiments for the preparation of chitosan particles loaded with the vegetable hormone 1,3-indoleacetic acid (AIA) to study its controlled release in water. The chitosan particles were prepared by dissolving the hormone and chitosan in acetic acid and then dripping in NaOH solution with constant stirring. Factorial Design 23 was used to study the concentration of chitosan (% chitosan), gelation time in NaOH (time in NaOH) and sodium tripolyphosphate (TPP) concentration (% of TPP). In response, the amount of hormone released in 2 hours, measured spectrophotometrically at 285 nm, was obtained. The results of the experimental design indicated that the three factors influence the released amount of AIA in 2 hours, where a higher concentration of chitosan increases the rate of release, while the higher concentration of TPP and longer gelation time...

En los cursos de química general, el tema de estequiometría constituye un verdadero reto tanto para los estudiantes como para los profesores.  Con el presente trabajo, se trató de investigar los problemas que presenta el aprendizaje de este tema en la PUCP. Actualmente, en nuestra universidad, el curso de Química 1 (primer curso de química general) ya no se da bajo el sistema tradicional de dictado de cátedra, sino utilizando dos metodologías de enseñanza-aprendizaje: la metodología colaborativa y el ABP. Nuestros resultados mostraron que el trabajo colaborativo sí contribuye al aprendizaje de la estequiometría por parte de los estudiantes; sin embargo, también mostraron que este aprendizaje no es profundo y que no es a largo plazo. Esto resulta  especialmente preocupante si se considera que el tema de estequiometría es básico para los siguientes cursos de química genera...

avalderr@ulima.edu.pe;cjacinto@ulima.edu.pe

En la agricultura existen muchos métodos para poder administrar la hormona a la planta, sin embargo el encapsulamiento y el método de liberación controlada mejoran su distribución mediante la optimización del tiempo de liberación, evita desperdicios y la exposición a la luz o a otros agentes externos que pueden degradarla y disminuir su actividad. Por esta razón se hace necesario realizar estudios de matrices que logren encapsular la hormona y que luego la libere progresivamente. Durante el año 2016 en la Universidad de Lima se realizaron estudios para la preparación de micropartículas de quitosano y alginato cargadas con el ácido 1,3-indol acético utilizado como hormona vegetal modelo. Se ha concluido con la preparación de las perlas cargadas, además de hacer algunas pruebas en la liberación controlada en medio acuoso. Como complemento, durante este año se va a evaluar ...

avalderr@ulima.edu.pe;cjacinto@ulima.edu.pe

Chitosan and depolymerized chitosan films cross-linked with sodium tripolyphosphate were prepared and loaded with anthocyanin extracted from purple corn. The effect of sodium tripolyphosphate concentration, cross-linking time, thickness and molar mass of chitosan on the delivery of anthocyanin were studied. The results showed a lower percentage of available anthocyanin (from 29 % to 10 %) in the films more cross-linked, it staying the remaining anthocyanin in the film. This percentage was influenced by the other factors mentioned above. The release kinetics has been studied to elucidate the drug release mechanism. All films was controlled by Fick’s law when fitted to the Higuchi model. For the determination of the diffusion exponent, the results were fitted to the Korsmeyer-Peppas model. The films showed different mechanisms of release, including a Fickian and a non-Fickian diffusion p...

In this work, the studies were performed to measure the sorption capacity of metal ions Cd (II) and Hg (II) using the specie Eichhornia crassipes (water hyacinth). This study includes assays where the nutrient concentration, the pH and the metal ion concentration were optimized. This tests were carried out at room temperature and with aqueous solutions of Cd (II), Hg (II), in which the samples of Eichhornia crassipes were placed. To confirm the removal of these metals, the waste solutions after the treatment with the Water Hyacinth species were treated using the method APHA 3030-e. However, Eichhornia crassipes samples were treated using the EPA 200.3 method. The concentration of Cd (II) was determined by a ICP-OES spectrometer and Hg (II), by an atomic absorption spectrophotometer. The results showed: Optimal dosage 1 mL of A and 0,5 mL of B, optimum pH 5, optimum concentration of Cd (I...

The octanol-water partition coefficient (logP) is a crucial indicator in the study of lipophilicity and cell permeability, making it a recurring molecular descriptor in empirical rules for evaluating a molecule's pharmacokinetics. Siderophores are pharmacologically relevant molecules due to their potential Trojan horse effect; however, two major challenges arise: their molecular weight often exceeds 500 Daltons, and there is a lack of databases containing atomic coordinates of their three-dimensional structures and molecular descriptors. In this work, we have created a database containing the SMILES codes of siderophores, their names, associated microorganisms, molecular descriptors, among other information, which is available in our repository at https://github.com/inefable12/siderophores_database. We have also developed a web page to visualize the 2D and 3D structures (https://siderofo...

In the present work, it was proposal a process for the extraction of sodium alginate, which was obtained from the brown macroalgae Macrocystis pyrifera collected in La Punta-Callao. The extraction process presented a yield of 12 % and the alginate obtained was characterized by FT-IR and 13C NMR techniques in solid state, which was compared with a commercial alginate. The evaluation of the presence of mannuronic and guluronic blocks has been carried out through the use of the 2nd derivative, obtaining characteristic signals at 894 cm-1 for C1-H α – L – guluronic in AlgM and at 885 cm-1 for C1-H anomeric region of the β-D-mannuronic in AlgC. Moreover, characteristic signals were assigned for the algae spectrum at 902 cm-1 and at 812 cm-1 corresponding to vibrations of the α – L – guluronic blocks. By 13C NMR in solid state, a characteristic peak was obtained at 102.4 ppm for Alg...

We have studied and characterized the structure of hydrolysable tannins of commercial powder tara, performed by means ultra-high-resolution mass spectrometry (MALDI/FT-ICR) without using separation techniques. Our experimental results, supported by computational calculations at DFT/ M05-2X level of theory, show that the identified species are basically oligomeric structures of polygalloyquinic acids, of the (C7H4O4)n(C7H12O6) type, composed by a chain of polygallic esters (depside) linked, via ester bond, to one quinic acid.

In this study, two new cobalt with pyrazinamide (PZA) coordination compounds: Co-PZA (1) and Co-PZA (2) were synthesized from two cobalt precursor salts. The aim of this study is to elucidate the chemical structure of each synthesized complex by using characterization techniques, as well as to evaluate their anti-tuberculous activity compared to pyrazinamide. The characterization techniques comprised, C, H and N elemental analysis, atomic absorption spectroscopy of cobalt, thermogravimetric analysis, magnetic susceptibility, UV-Visible, infrared and Raman spectroscopy. The antibiotic activity was tested by determining the minimum inhibitory concentration in a Mycobacterium tuberculosis culture. The predicted molecular formulas from characterization results were: [Co(PZA)2Cl2] for Co-PZA (1) complex and [Co(PZA)2(NO3)2].H2O for Co-PZA (2) complex. The two complexes showed a higher antimic...

En 2020, la agroindustria en Perú generaba aproximadamente 4.7 millones de empleos directos e indirectos. A pesar de su importancia económica y social, el sector agrario enfrenta debilidades estructurales y la amenaza del cambio climático, lo que constituye un problema público. Esto requiere que el Estado adopte medidas para garantizar la sostenibilidad agraria y en este aspecto, la innovación agraria juega un rol clave. Por ello, se tiene como objetivo general determinar cómo la política pública actual del Sistema Nacional de Innovación Agraria (SNIA) peruano al 2024 puede contribuir a la sostenibilidad del sector agrario ante el cambio climático. Para ello, se han trazado los siguientes objetivos específicos: • Identificar y analizar las principales políticas públicas orientadas al desarrollo del SNIA peruano al 2024. • Determinar cómo el SNIA peruano actual promueve ...

Objective: To determine the inhibitory effect of the methanolic fraction of propolis from Oxapampa, Peru, on different genotypes of Streptococcus mutans in children diagnosed with caries. Materials and methods: 150 oral swab samples were collected, seeded for isolation of S. mutans and then identified by biochemical tests of carbohydrate fermentation, Api 20 Strep (bioMérieux) and conventional PCR. The 138 strains isolated and identified from patients and the S. mutans ATCC® 25175™ control were confronted with the methanolic fraction by the disk diffusion method, having as positive control 0.12% chlorhexidine and negative control Milli-Q water and DMSO (1:1). Results: It was found that the inhibition diameter of the strains extracted from children diagnosed with caries against the methanolic fraction showed greater diameter (14.13 mm) in relation to the strain of S. mutans ATCC® 251...