Browsing by Autor "Maribel Lozano"

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A KINETIC APPROACH TO SAPONIN EXTRACTION DURING WASHING OF QUINOA (CHENOPODIUM QUINOA WILLD.) SEEDS
(Wiley, 2012) Issis Quispe‐Fuentes; Antonio Vega‐Gálvez; Margarita Miranda; Roberto Lemus‐Mondaca; Maribel Lozano; Kong Ah‐Hen
ABSTRACT The aim of this work was to show that the leaching process of saponins from quinoa ( Chenopodium quinoa Willd.) seeds during washing with water, as is generally practiced by people in South America, can be modeled using mathematical expressions related to Fick's second law. Experimental data were obtained through batch extraction with a ratio of quinoa to water of 1:10 under constant agitation for processing time between 15 and 120 min at 20, 30, 40, 50 and 60C. It was found that residual saponin concentration in the quinoa seeds decreased as washing temperature increased. Leaching rate followed the Arrhenius relationship, with calculated effective saponin diffusion coefficient between (5.05 ± 0.15) × 10 −10 and (32.50 ± 1.65) × 10 −10 m 2 /s as the temperature increased from 20 to 60C. Several mathematical models to describe the kinetic behavior of the leaching process were analyzed. The modified Henderson–Pabis model had the best fit quality as shown by statistical analysis. PRACTICAL APPLICATIONS During processing of quinoa for human consumption, a washing process is necessary to remove most of the bitter saponins found in the seeds, as this type of saponin is considered to be a serious antinutritional factor. For industrial scale‐up of this processing step, leaching behavior of the saponin is of crucial importance to find the best design parameters and the most cost‐effective process conditions. This helps reduce energy waste and optimize water flow rate in a continuous washing process. The present study used well‐known models to explain saponins' leaching kinetics from the quinoa seeds with water at different temperatures. The best mathematical model with its justification was also determined, which is generally the most economical way to proceed.
Analytical Methods for Identification and Quantification of Quinoa Saponins: A Review
(American Chemical Society, 2025) Rodrigo Villagomez; Maribel Lozano; Yonny Flores; Yasufumi Kobayashi; Yasunari Fujita; Giovanna R. Almanza
Quinoa saponins (SAPs) are key secondary metabolites occurring as complex mixtures mainly in the seed coat of Chenopodium quinoa Willd. Although traditionally removed due to their bitter taste and potential toxicity, quinoa SAPs display diverse biological activities, including anti-inflammatory, hypocholesterolemic, antifungal, molluscicidal, hemolytic, and cytotoxic effects, that support their potential applications in pharmaceuticals, functional foods, cosmetics, and biopesticides. Their amphiphilic nature also enables their use as natural emulsifiers. This review (1981-2024) summarizes advances in analytical methodologies for quinoa SAPs, emphasizing that while GC-MS and LC-MS/MS are widely applied for profiling, full structural elucidation still requires isolation and analysis by NMR and MS. We discuss key considerations for quinoa SAPs identification using GC-MS, LC-MS/MS, and NMR. Quantification remains challenging and is often based on relative estimations, with afrosymmetric, UV-vis, and GC-MS methods being the most frequently employed, while HPLC-DAD, LC-MS, and GC-MS/MS offer greater sensitivity. Ultimately, the selection of the analytical method and standard critically determines accuracy.
CUANTIFICACIÓN DE SAPONINAS EN RESIDUOS DE QUINUA REAL CHENOPODIUM QUINOA WILLD
(Lund University, 2012) Maribel Lozano; Edgar Freddy Quisbert Ticona; Cristhian Carrasco; Yonny Flores; Giovanna R. Almanza
"En el presente trabajo se realizó la cuantificación del rendimiento de extractos y de saponinas en residuos de escarificado generados en empresas exportadoras de quinua de los departamentos de La Paz, Oruro y Potosí, determinándose que los rendimientos de extracción varían desde 36,0 % hasta 39,4 % p/p, mientras que el porcentaje de saponinas en el extracto varía desde 47,3 % hasta 56,2 % y de saponinas en el mojuelo desde 17,3 % hasta 22,1 %. Adicionalmente, se optimizó un método de extracción de saponinas por maceración con mezclas hidroalcohólicas, considerando los siguientes parámetros: Relación masa/volumen de extracción; tiempo de extracción y relación porcentual EtOH/H2O (v/v), determinándose que la mejor relación m/v de extracción es 1/9. El tiempo de extracción óptimo es de 72 h y la mejor mezcla de extracción es con 50/50 EtOH/H2O. El porcentaje de saponinas se determinó utilizando los métodos de Espuma, Espectrofotométrico UV y por cromatografía HPLC, observándose que no hay grandes diferencias entre los 3 métodos aunque el método HPLC es el que tiene menos error y debería utilizarse como método de control para los otros métodos que son más baratos. Además, es muy importante utilizar como muestra de referencia un estándar de saponinas de quinua en todos los métodos."
Cytotoxicity of New Damsin Derivatives in Breast Cancer Cells
(Lund University, 2019) Maribel Lozano; Wendy Soria; Giovanna R. Almanza; Sophie Manner; Stina Oredsson; Juan R V Villagomez; Olov Sterner
Abstract As a follow-up of a previous investigation in which semisynthetic damsin derivatives were shown to possess up to 10 times higher cytotoxicity in JIMT-1 breast cancer cells compared to normal breast epithelial MCF-10A cells, a range of new derivatives were prepared and assayed toward the same cells. Damsin, a natural plant metabolite containing a??-methylene-?-lactone (or 3-methylenedihydrofuran-2(3H)-one) moiety, was modified in position 3 by Claisen-Schmidt condensations with aromatic aldehydes, mainly mono- or disubstituted benzaldehydes, without affecting the α-methylene-γ-lactone function. This lactone ring is a Michael acceptor that is known to affect biological processes such as cell proliferation, death/apoptosis, and cell migration, by interfering with nucleophilic sites in cell signalling pathways. However, although Michael acceptors are reactive, the Michael addition is reversible and it can be assumed that also other parts of the molecules will moderate the binding to and the release from any given nucleophilic site in a protein, and thereby moderate a specific biological activity. In this investigation, the cytotoxicity of 20 α-methylene-γ-lactones towards normal breast epithelial MCF-10A cells as well as breast cancer JIMT-1 cells is compared, by determining the inhibitory concentration 50 (IC50) from dose response curves. The IC50 values in the two cell lines were found to depend on the overall structure of the assayed compounds, although less in this subset of compounds compared to a previous investigation. Structure-activity relationships that may explain the observed differences in potency and selectivity are discussed.
DETERMINACIÓN DE PARÁMETROS DE SECADO POR ASPERSIÓN PARA LA OBTENCIÓN DE EXTRACTO SECO RICO EN SAPONINAS DE RESIDUOS DE ESCARIFICADO DE QUINUA
(2022) Silvia E. Ramos; Abel Gutiérrez; Yonny Flores; Maribel Lozano; Lizzet Chura; Rocío Mamani; Heriberto Castañeta; Giovanna R. Almanza; Lizzet Chura; Laboratorio de Fisicoquímica, Instituto de Investigaciones Químicas IIQ, Carrera de Ciencias Químicas, Facultad de Ciencias Puras y Naturales FCPN, Universidad Mayor de San Andrés UMSA, P.O. Box 303, Calle Andrés Bello s/n, Ciudad Universitaria Cota Cota, La Paz-Bolivia
Los residuos de escarificado de quinua se generan en gran cantidad en Bolivia y tienen un alto contenido de saponinas, compuestos con diversas propiedades que les dan un potencial uso en cosmética, agricultura, salud y otros. Por esta razón, es importante contar con métodos para obtener extractos secos ricos en saponinas a partir de estos residuos. En el presente trabajo, se han determinado los parámetros para el secado por aspersión de un extracto acuoso residual de un proceso de extracción hidroalcohólico EtOH:H2O (50:50) por 72 h, seguido de una eliminación del EtOH por rotaevaporación. Para esto, se utilizó un diseño experimental factorial 23, tomando como variables independientes: la concentración del extracto acuoso residual, la temperatura de secado y la velocidad del flujo de aire. Se determinó que las variables significativas para obtener un mayor rendimiento de extracción en el proceso de secado por aspersión son: la temperatura de secado (100°C) y la velocidad del flujo del aire (4192 rpm), con un flujo de alimentación de 8.0 mL/min. El producto seco obtenido tiene un rendimiento de 27.6% respecto a los residuos de quinua y 68.73 % de saponinas. La técnica de secado por aspersión presentó algunas ventajas respecto a la técnica de secado por liofilización, como el mayor porcentaje de saponinas en el extracto seco obtenido y el menor tiempo empleado para el secado.
DETERMINACIÓN DEL CONTENIDO FENÓLICO, Y EVALUACIÓN DE LA ACTIVIDAD ANTITIROSINASA, Y DE LOS ÍNDICES ANTIOXIDANTES DE CUATRO VARIEDADES DE QUINOA BOLIVIANA.
(2020) Alejandra Navia; Peggy Ormachea; Lily Salcedo; Maribel Lozano; Santiago Tarqui; Yonny Flores; Giovanna R. Almanza; Giovanna R Almanza
Four varieties of Bolivian quinoa (QJG Quinoa Jacha Grano, QRB Quinoa Real Blanca, QRN Quinoa Real Negra and QRR Quinoa Real Roja) have been studied in order to valorize them through the establishment of the phenolic contents and consequently by their antioxidant indexes. In addition, and in this pathway, the antityrosinase activity of the four varieties was measured. One important quinoa-endemic glycosylated flavonoid, mauritianin 1 (Kaempferol-3-O-(2,6-di-O--ramnopyranosyl--galactopyranoside) was isolated, and identified by cromatographic and spectroscopic methods and it was quantified. The four quinoa samples were treated by means of solid-liquid extractions with hydro-alcoholic 8:2 solvents. Quantifications and evaluations were done in the samples of the four varieties of quinoa and in phenolic rich fractions from the extract of QJG, and in compound 1, coming from the QJG extract. In a series of in vitro tests, antioxidant indexes, by means of the total phenolic content and ABTS methods, and antityrosinase activities, by using the fungal tyrosinase method, of phenolic rich fractions and of the pure compound 1 were evaluated, 1 showed an important antityrosinase activity (74.73% I at 1.67 mg/mL) and antioxidant (826.68 mg GAE/g and 1141.38 M Trolox/g), as well as the phenolic rich fraction from the extract of QJG named as EEW-1 that showed 69.89% I of the enzyme tyrosinase and significant antioxidant activity (246.08 mg GAE/g and 569.21 uM trolox/g), suggesting that these products could have a potential application in dermatology, cosmetics and food processing.
Quantification of saponins by GC/MS in quinoa genotypes, Chenopodium quinoa Willd, from the southern highlands of Bolivia
(2024) Carolina Triguero; Giovanna R. Almanza; Santiago Tarqui; Maribel Lozano; Santiago Tarqui; Instituto de Investigaciones Químicas IIQ, Universidad Mayor de San Andrés UMSA, Av. Villazón Nro. 1995, La Paz, Bolivia, 0201-0220, iiq@umsa.bo; Maribel Lozano; Instituto de Investigaciones Químicas IIQ, Universidad Mayor de San Andrés UMSA, Av. Villazón Nro. 1995, La Paz, Bolivia, 0201-0220, iiq@umsa.bo
Se realizó la cuantificación del contenido de saponinas en granos de siete genotipos de Quinua Real del Altiplano Sur de Bolivia: Quinua Real Blanca (QRB), Quinua Real Amarilla (QRA), Quinua Real Pandela (QRP), Quinua Real Toledo (QRT), Quinua Real Luki (QRL), Quinua Real Negra (QRN) y Quinua Real Rojo Pasankalla (QRRP), mediante la implementación de un método por Cromatografía de gases acoplada a espectrometría de masas (GC/MS). Ácido oleanólico, ácido serjánico, hederagenina y ácido fitolacagénico, de residuos de escarificado de quinua, fueron aislados y empleados como estándares. Se obtuvo extractos de sapogeninas de los 7 genotipos de Quinua Real, que fueron sililados a los trimetilsilil derivados y cuantificados por GC/MS. En todos los casos los valores de saponinas determinados resultaron altos, entre 0,8 y 1,4 %, confirmando que todas quinuas analizadas son quinuas amargas que deben ser sometidas a un proceso de beneficiado.
Selective Cytotoxicity of Dams in Derivatives in Breast Cancer Cells
(2019) Maribel Lozano; Maribel Lozano; Wendy Soria; Wendy Soria; Giovanna R. Almanza; Sophie Manner; Stina Oredsson; Rodrigo Villagomez; Olov Sterner
Cancer is the leading cause of death worldwide, and there is a constant need for new treatment strategies. Sesquiterpene lactones containing a 3-methylenedihydrofuran-2(3H)-one (or a-methylene-g-lactone) moiety, for example damsin (1), are Michael acceptors that affect biological processes such as cell proliferation, death/apoptosis, and cell migration, by interfering with cell signalling pathways. Although the reactivity of the α-methylene-γ-lactone moiety is important for these effects, the Michael addition is reversible and it can be assumed that also other parts of the molecules will moderate any given biological activity. In this investigation, the cytotoxicity of 23 a-methylene-g-lactones towards normal breast epithelial MCF-10A cells as well as breast cancer JIMT-1 cells is compared. Most of the investigated compounds are semisynthetic derivatives prepared by the condensation of the natural product damsin (1) with aldehydes. The two cell lines were treated with various concentrations of the compounds in dose response assays, and the 50 % inhibitory concentration (IC50) was determined from dose response curves. The IC50 values were found to depend strongly on the overall structure. The ratio between the IC50 values for MCF-10A and JIMT-1 cells, as a measure for the selectivity of a compound to kill cancer cells, was calculated, and found to vary between just over 1 to more than 10. The most potent derivatives formed from the condensation of 1 with aromatic aldehydes towards JIMT-1 cells are 3a and 3i, both with ratios between the IC50 values for MCF-10A and JIMT-1 cells close to 5. Also some aldol condensation products with acyclic aldehydes, i.e. 3r and 3u, were equally potent, and the latter showed the highest selectivity (ratio > 10). Structure-activity relationships that may explain the observed differences in potency and selectivity are discussed.
Sesquiterpene lactones from Ambrosia arborescens Mill. inhibit pro-inflammatory cytokine expression and modulate NF-κB signaling in human skin cells
(Elsevier BV, 2018) Daniel Svensson; Maribel Lozano; Giovanna R. Almanza; Bengt‐Olof Nilsson; Olov Sterner; Rodrigo Villagomez