Browsing by Author "Fajardo Carmona, Sandra Isabel"

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Desarrollo de un modelo predictivo mediante fingerprint cromatográfico para evaluar el potencial antibacteriano para el género Hypericum
(2017-09-01) Fajardo Carmona, Sandra Isabel; León Tamariz, Fabián
The genus Hypericum includes 469 species, which possess diverse bioactivities, including antibacterial activity. The present study intend to establish a predictive model of antibacterial activity for species of the genus Hypericum from the chromatographic fingerprint of H. laricifolium and H. quitense and use data of IC50 against MRSA strains, using multivariate analysis tools. The tests were carried out on 29 extracts of H. laricifolium and 20 extracts of H. quitense. The predictive model was tested on 10 extracts of H. decandrum. Genetic identification of H. quitense and H. decandrum was performed using the genetic barcode technique. The loci rbcL and ITS1 were sequenced. Extracts of the aerial parts of the species under study were obtained by means of supercritical fluids using as CO2 solvent with 10% of ethanol. The evaluation of antibacterial activity was carried out using the microdilution technique in broth against MRSA (strain ATCC BAA 44). The HPLC-DAD method was developed to separate the components present in the species under study and to obtain their chromatographic fingerprint using optimized chromatographic conditions. Samples were analyzed at four wavelengths, resulting at 254 nm the best for analysis. To create the multivariate regression model we used Partial least squares. Using the regression coefficients of the model, the predictor of antibacterial activity was established. The model developed did not have good predictive properties, which can be attributed to the different chemical composition among the species under study.
Evaluation of the variables altitude, soil composition and development of a predictive model of the antibacterial activity for the genus Hypericum by chromatographic fingerprint
(2019) Ortega Puma, Carmen Maribel; Fajardo Carmona, Sandra Isabel; Ortiz Ulloa, Silvia Johana; Tobar Solano, Vladimiro Alexis; Quito Ávila, Diego; Santos Ordóñez, Efrén; Jerves Andrade, María de Lourdes; Cuzco Quizhpi, Nancy Mirian; Wilches Arizabala, Isabel Maria; León Tamariz, Fabián
H. laricifolium Juss is a native shrub from the Andes used for the treatment of antibacterial infections among other illnesses. Nowadays, due to the growing need of new antibiotic substances, this medicinal plant would represent an important source for the investigation of antibacterial activity due to the wide medicinal potential of its genus, property that can be analyzed through its chemical fingerprint profile. The objectives of this research were, to develop a predictive model for the antibacterial potential of the genus Hypericum using chromatographic fingerprinting with three Hypericum species collected at Ecuadorian Andes (H. laricifolium, H. quitense R. Keller and H. decandrum Turcz); and to evaluate the influence of natural variables such as altitude and soil composition on the pharmacological effect of lipophilic extracts of H. laricifolium. Antibacterial activity of the plants extracts was assessed by plate microdilution technique against Methicillin-resistant Staphylococcus aureus (MRSA). The fingerprint was obtained by HPLC-DAD. The predictive model was constructed from the chromatographic fingerprint of H. laricifolium and H. quitense and their IC50 values using the “Partial least squares” multivariate analysis tool. Using the regression coefficients of the model, the predictive equation of antibacterial activity for new samples of H. decandrum was established. The extracts of H. laricifolium exhibited a high antibacterial activity with the pH and the organic matter as main factors influencing the activity. The prediction model obtained did not have predictive ability to different Hypericum species, which could be explained by differences in the chemical composition of the three species.
Valor nutritivo y funcional de la harina de amaranto (amaranthus hybridus) en la preparación de galletas
(2010) Criollo Minchalo, Priscila Guadalupe; Fajardo Carmona, Sandra Isabel; Astudillo Machuca, Adelina