Abstract Phytohormones, also known as plant hormones, are naturally occurring chemical compounds that regulate various physiological processes in plants. In this work, a capillary electrophoretic coupled to a diode array detector (CE-DAD) method was developed and validated for the simultaneous quantification of abscisic acid (ABA), 3-indolacetic acid (IAA), and gibberellic acid (GA3) in commercial plant biostimulants. Sample preparation was carried out by liquid-liquid extraction using ethyl acetate. CE separation was performed in a fused-silica capillary and background electrolyte (BGE) consisting of borate buffer (50 mM, pH 9.3) applying a high voltage of 20 kV, a pressure of 50 mbar, and injection time of 35 s. The ABA, IAA, and GA3 were detected at 254, 220 and 195 nm respectively. The CE-DAD method validation results showed acceptable specificity, linearity, accuracy, and precision in the concentration range of 10-100 µg/mL for all compounds according to the (International Conference Harmonisation) ICH guidelines. The proposed method was satisfactory applied to the analysis of cited plant hormones in biostimulants and suggest that sample preparation is a reliable step for extraction of phytohormones containing carboxyl groups. Therefore, the developed and validated method could be implemented as a low-cost and fast analytical tool for quality control purposes.

RESUMEN El 2,2-difenil-1-picrilhidrazil (DPPH), el poder reductor férrico (FRAP) y los compuestos semivolátiles del extracto y fracciones de Conyza bonariensis L. son discutidos. Se obtuvo un extracto crudo en metanol mediante maceración y posteriormente se recogieron fracciones de n-hexano, cloroformo y acetato de etilo usando partición disolvente-disolvente. Los ensayos de fenoles totales, flavonoides y actividad antioxidante se efectuaron en un espectrofotómetro (UV-Vis) y los resultados se expresaron como equivalentes de Ácido gálico, Quercetina y Trolox, respectivamente. Los resultados indican que la fracción en acetato de etilo mostró la mayor capacidad de eliminación del radical DPPH (90,69±3,16%) a 500 μg mL-1 y redujo el complejo de tripiridiltriazina férrico (Fe3+-TPTZ) con valores entre 19,68 y 2355,37 mg equivalente de Trolox (TE) g-1. Se identificaron 28 fitoconstituyentes a través del análisis de cromatografía de gases-espectrometría de masas (CG-EM). La actividad antioxidante presentada puede correlacionarse principalmente con la presencia de eugenol, trans-isoeugenol, lucenina-2, salicilato de metilo y ácido siríngico detectado. Este estudio muestra que la fracción de acetato de etilo podría ser utilizada como una buena fuente de antioxidantes para el beneficio de la salud humana.

ABSTRACT The 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing power (FRAP), and semivolatile compounds of Conyza bonariensis L. leave extract and fractions are discussed. A methanolic crude extract was obtained through maceration, and subsequently, n-hexane, chloroform, and ethyl acetate fractions were collected using a solvent-solvent partition. Total phenols, flavonoids, and antioxidant activity assays were performed in an ultraviolet-visible (UV-Vis) spectrophotometer, and the results were expressed as Gallic Acid, Quercetin, and Trolox equivalents, respectively. The findings achieved indicate that ethyl acetate fraction showed the highest DPPH radical scavenging capacity (90.69±3.16%) at 500 µg mL-1, and reduced the ferric tripyridyltriazine complex (Fe3+-TPTZ) with values between 19.68 and 2,355.37 mg Trolox equivalent (TE) g-1. It was identified 28 phytoconstituents through Gas chromatography-mass spectrometry (GC-MS). The scavenging activity of ethyl acetate fraction could be correlated mostly to the presence of eugenol, trans-isoeugenol, lucenin-2, methyl salicylate, and syringic acid. This study reveals that the ethyl acetate fraction could be used as a good source of antioxidants for health benefits.

Abstract: The volume of global gross banana exports reached a record of 117.9 million tonnes in 2015 (FAO 2017), which agro-industrial wastes derived as the pseudo-stem, rachis and leaves do not have an industrial application instead they are discarded. This research study applies full factorial design and response surface methodology to determine the effect of pressing temperature and resin content on density (D), moisture (M), water absorption (WA), water swelling (WS), module of rupture (MOR), module of elasticity (MOE) and formaldehyde content (FC) of particle board made of banana pseudo-stem. A 22 factorial design was performed, factors considered were resin and temperature. The low level of resin was 15% in the coarse fiber (CF) and 35% in fine fiber (FF); high level as 25% CF and 45% FF. Temperature levels were 150ºC and 170ºC respectively. The boards met all quality parameters except ones with low resin content that didn’t meet WS parameter. Furthermore, resin affected positively on WA, FC and MOE, and decreased D, WS and MOR values. Meanwhile, temperature affected negatively on D, WS, and increased FC, WA, MOE, MOR properties; none of the factors affected M response. Process conditions were optimized to 162.61°C and 43.15% FF, 23.97% CF.

RESUMEN En este trabajo se discute la influencia del secado al aire (AD), el horno de convección (CO) y el secado solar (SOD) sobre las propiedades físicas y químicas de las hojas de Ilex guayusa. Se estimaron las cenizas totales (%), las cenizas insolubles en ácido (%), las cenizas solubles en agua (%), la humedad residual (%) y el contenido de cafeína (%). Además, se analizó la presencia los alcaloides, flavonoides, azúcares reductores, saponinas, esteroides, quinonas, grasas, fenoles y taninos en extractos de hojas secas. Los resultados revelaron que los parámetros del análisis físico no se vieron afectados por las técnicas de secado. La mayor cantidad de metabolitos secundarios se detectó en el extracto etanólico y acuoso. En general, las hojas secadas al horno de convección mostraron el mayor contenido de cafeína (3,71%) y el menor tiempo de secado (13 h) en comparación con los otros métodos de secado empleados. Los resultados obtenidos revelaron un método rápido para secar hojas de Ilex guayusa sin alterar el contenido de componentes bioactivos beneficiosos para la salud, estudios que no han sido reportados.

ABSTRACT The influence of air-drying (AD), convection oven (CO) and solar drying (SOD) on the physical and chemical properties of Ilex guayusa leaves is discussed. Total ash (%), acid-insoluble ash (%), water-soluble ash (%), residual moisture (%) and caffeine content (%) were estimated. Additionally, alkaloids, flavonoids, reducing sugars, saponins, steroids, quinones, fats, phenols and tannins detection of dry leaves extracts were assessed. The results revealed that parameters of physical analysis were not affected by the drying techniques. The highest amount of secondary metabolites in ethanol and aqueous extracts were detected. In general, convection oven dried leaves showed the highest caffeine content (3.71%) and the lowest drying time (13 h) compared to other drying methods. The results revealed a fast method to dry Ilex guayusa leaves and indicate that this species possess a variety of bioactive compounds beneficial for health. Our results revealed an effective quick method to dry Ilex guayusa leaves without altering the content of beneficial bioactive components.