Patricia Manzano

The use of seaweed or macroalgae as plant biostimulants has increased in recent years. This study discusses the effect of seasonal sea temperatures on the phytohormone and flavonoid contents, and the antioxidant activity of Acanthophora spicifera and Ulva intestinalis from Ecuador. For the extraction, aqueous digestion (AD), ethanol digestion (ED), ethanol sonication (ES), and methanol digestion (MD) were used. Metabolites and antioxidant activity were quantified by liquid chromatography and spectrophotometry. Multivariate analysis revealed that U. intestinalis exhibited enhanced flavonoid (up to 67.73 mg/kg) and phytohormone (up to 20.79 mg/kg) accumulation in the dry season, while the antioxidant capacity (TPC, TFC, DPPH, and FRAP) increased during the wet season. Conversely, A. spicifera showed a slight increase in phytohormone levels (up to 8.68 mg/kg) during the wet season, particularly in 3-indoleacetic acid, and gibberellic acid. These findings contribute first insights into antioxidant responses to seasonal changes.

Introduction: Species of the genus Smilax are a vital source of potentially useful compounds that may be effective as nephroprotective agents, but there is little scientific evidence to support such claims.Objective: To analyze the chemical composition and nephroprotective activity of hydroalcoholic extracts of leaves and rhizomes of Smilax purhampuy. Methods: Hydroalcoholic extracts were elaborated by maceration and analyzed by gas chromatography-mass spectrometry (GC-MS). The gentamicin-induced nephrotoxicity model was tested in Wistar rats at a dose of 80 mg/kg i.p. and extracts were administered orally at doses of 100, 200 and 400 mg/kg. Serum creatinine and serum urea were quantified, and histopathological observations of the kidneys were performed. Results: In the extract of leaves, 33 compounds were identified, where the majority were palmitic, linoleic and linolenic acid. In the extract of rhizomes 23 phytoconstituents were recognized, predominantly stearic acid, dihydrocorinanteina and palmitic acid. There was evidence of a significant decrease in the level of creatinine and urea in the groups protected with extracts of leaves and rhizomes with respect to the gentamicin group in a direct relationship to the dose of the extracts. Renal histopathological changes were observed in the gentamicin group, while the groups receiving the extracts decreased the severity of damage. Conclusions: The results indicate that Smilax purhampuy has a potential role in improving gentamicin-induced kidney damage, providing the first findings on its nephroprotective activity. Las especies del género Smilax son una fuente vital de compuestos potencialmente útiles que pueden ser eficaces como agentes nefroprotectores, pero hay poca evidencia científica que respalde tales afirmaciones. Analizar la composición química y actividad nefroprotectora de extractos hidroalcohólicos de hojas y rizomas de Smilax purhampuy. Los extractos hidroalcohólicos se elaboraron mediante maceración y se analizaron mediante cromatografía de gases-espectrometría de masas (GC-MS). El modelo de nefrotoxicidad inducida por gentamicina se probó en ratas Wistar a una dosis de 80 mg/kg por vía intraperitoneal y los extractos se administraron por vía oral a dosis de 100, 200 y 400 mg/kg. Se cuantificaron la creatinina y la urea séricas y se realizaron observaciones histopatológicas de los riñones. En el extracto de hojas se identificaron 33 compuestos, donde la mayoría fueron ácido palmítico, linoleico y linolénico. En el extracto de rizomas se reconocieron 23 fitoconstituyentes, predominantemente ácido esteárico, dihidrocorinanteina y ácido palmítico. Se evidenció una disminución significativa en el nivel de creatinina y urea en los grupos protegidos con extractos de hojas y rizomas con respecto al grupo de gentamicina en relación directa con la dosis de los extractos. Se observaron cambios histopatológicos renales en el grupo de gentamicina, mientras que los grupos que recibieron los extractos disminuyeron la gravedad del daño. Los resultados indican que Smilax purhampuy tiene un papel potencial en la mejora del daño renal inducido por gentamicina, proporcionando los primeros hallazgos sobre su actividad nefroprotectora.

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.

The use of liquid organic amendments (biols) is a common practice for farmers due to the multiple benefits in the management and production of their crops, including the control of pests and diseases. The present study analyzes the chemical composition of the pure compound C1 and fractions F2 and F3 of local biols produced in two provinces of Ecuador and their antifungal activity against Moniliophthora roreri (Cif & Par). This work incorporates the use of Gas Chromatography coupled to Mass Spectrometry (GC-MS), Nuclear Magnetic Resonance (NMR) and in vitro inhibition assays for sample analysis. C1 was identified as Mannitol. The percentage of inhibition against M. roreri in F2 and F3 was 44.37% and 8.34%, respectively; and, for C1, 28.63%. The values of the median lethal dose (LD50) obtained corroborate that the F2 fraction was the one with the highest controlling activity against the pathogen. The 1,2-benzenedicarboxylic acid diisooctyl ester compound was the main compound in F2 (30.88%) and the Pentadecanoic acid, 14-methyl-, methyl ester in F3. Finally, all compounds obtained from the biol fractions were identified and it was determined that the fermentative process was suitable for producing bioactive compounds of interest to inhibit the growth of Moniliophthora roreri.

Ecuador is one of the major cocoa producers worldwide, but its productivity has lately been affected by diseases. Endophytic biocontrol agents have been used to minimize pathogenic effects; however, compounds produced by endophytes are minimally understood. This work presents the chemical characterization of the Trichoderma species extracts that proved inhibition against cocoa pathogens. Solid–liquid extraction was performed as a partitioning method using medium with the fungal mycelia of Trichoderma reesei (C2A), Trichoderma sp. (C3A), Trichoderma harzianum (C4A), and Trichoderma spirale (C10) in ethyl acetate individually. The extract of T. spirale (C10) exhibited the growth inhibition (32.97–47.02%) of Moniliophthora perniciosa at 10 µg/mL, while a slight stimulation of Moniliophthora roreri was shown by the extracts of T. reesei (C2A) and T. harzianum (C4A) at higher concentrations. The inhibitory activity could be related to alkaloids, lactones, quinones, flavonoids, triterpenes, and sterols, as indicated by chemical screening and antifungal compounds, such as widdrol, β-caryophyllene, tyrosol, butyl isobutyrate, sorbic acid, palmitic acid, palmitelaidic acid, linoleic acid, and oleic acid, which were identified by gas chromatography–mass spectrometry (GC-MS). The results showed that the extracts, particularly T. spirale (C10), have the potential as biocontrol agents against witches’ broom disease; however, further studies are needed to confirm their effectiveness.

Kappaphycus alvarezii es una de las especies de algas más cultivadas en el mundo, debido a su alto contenido de compuestos bioactivos con reportes antioxidantes y bioestimulantes. El presente estudio evaluó el efecto de las densidades de plantación sobre la composición bioquímica y antioxidante de K. alvarezii cultivada en un sistema de línea larga durante las estaciones seca y húmeda, con el fin de proporcionar una base científica para una cosecha óptima. Se midieron el contenido de humedad, cenizas, grasa, fibra, auxinas, fenoles, flavonoides, DPPH y ABTS. Los datos se analizaron mediante pruebas t, Wilcoxon, Kruskal-Wallis y ANOVA unidireccional. Los resultados mostraron un mayor contenido de grasa (2,01 % P.s), fibra bruta (5,21% P.s), contenido total de fenoles (324,09 μg GAE/g P.s) y ABTS (9,32 μg GAE/g P.s) durante la estación seca. Con respecto a la densidad de plantación, se produjo un aumento significativo del contenido en cenizas, fenoles totales y ABTS con una densidad de 10 líneas.célula-1 al mismo tiempo. Los contenidos de flavonoides, DPPH y auxina mostraron una tendencia estacional opuesta, alcanzando los niveles máximos en la estación húmeda. Este estudio aporta nueva información sobre las condiciones ambientales que pueden provocar cambios en la actividad antioxidante y la composición bioquímica de esta especie con vistas al desarrollo de bioproductos para diferentes sectores industriales como el alimentario, el farmacéutico y el de los fertilizantes en Ecuador. Palabras claves: Alga roja; Fenoles; Flavonoides; Antioxidante; Composición bioquímica; Variación estacional; densidad de siembra.