Obtención de extractos fenólicos de Theobroma cacao L. con actividad antifúngica y antioxidante
Fecha
2016-07-08
Autores
La Rosa González, Susett
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Editor
Universidad Central "Marta Abreu" de Las Villas. Facultad de Ciencias Agropecuarias. Departamento de Biología
Resumen
Las plantas son fuente de metabolitos secundarios con usos potenciales en la agricultura, la
alimentación y formulación de medicamentos. Se conoce que los alimentos derivados de
Theobroma cacao L. (T. cacao), son ricos en productos naturales de alto valor agregado entre los
que se destacan los compuestos fenólicos. En el Centro de Bioplantas se desarrollaron un
conjunto de experimentos con el objetivo de obtener extractos fenólicos crudos con actividad
antifúngica y antioxidante a partir de la selección del mejor solvente y método de extracción en
hojas y semillas de T. cacao. Para ello se determinó el contenido de compuestos fenólicos en
extractos etanólicos y metanólicos de hojas y semillas de T. cacao, obtenidos de extracciones con
y sin soxhlet. Se seleccionó el solvente y método de extracción, de acuerdo a los perfiles
metabólicos determinados por cromatografía de capa fina (TLC) y se determinó la actividad
antifúngica y antioxidante in vitro de extractos fenólicos de hojas y semillas seleccionados. Los
mayores contenidos de compuestos fenólicos se registraron para los extractos metanólicos de
semillas de T. cacao y extracción con soxhlet, seguidos por los de hojas. En los extractos de
semillas y hojas analizados por TLC, se demostró la presencia de altos contenidos de compuestos
fenólicos de naturaleza química diferente, sin diferencias entre los metanólicos y etanólicos. Se
seleccionó como solvente el etanol comercial y como método de extracción el soxhlet. Se
demostró que los extractos evaluados tienen actividad antioxidante y antifúngica, en relación con
su composición química. Los extractos de semillas presentaron mayor actividad antioxidante y
antifúngica (contra Stemphylium solani y Sarocladium oryzae) que los de hojas. Los extractos
de hojas solo fueron activos frente a Rhizoctonia solani.
Plants are a source of secondary metabolites with potential uses in agriculture, food and drug formulation. It is known that foods derived from Theobroma cacao L. (T. cacao), are rich in natural products with high added value among which include phenolic compounds. The experiments were developed in Bioplantas Center, with the aim of obtaining phenolic extracts with antifungal and antioxidant activity from the selection of the best solvent and extraction method for leaves and seeds of T. cacao. For this, the content of phenolic compounds in methanolic and ethanolic extracts of leaves and seeds of T. cacao, obtained with and without soxhlet extractions were determined. The solvent and extraction method, according to metabolic profiles by thin layer chromatography (TLC) was selected. In vitro antifungal and antioxidant activity of selected leaves and seeds phenolic extracts were determined. The higher content of phenolic compounds were recorded for the methanol extracts of T. cacao seeds and soxhlet extraction, followed by leaves. In extracts of seeds and leaves analyzed by TLC, the presence of high levels of phenolic compounds of different chemical nature showed no differences between the methanolic and ethanolic extracts. It was selected as the commercial ethanol solvent and the soxhlet extraction method. It showed that evaluated extracts have antioxidant and antifungal activity, in relation to its chemical composition. Seed extracts showed higher antioxidant and antifungal activity (against Stemphylium solani and Sarocladium oryzae) than leaves. The leaf extracts were only active against Rhizoctonia solani.
Plants are a source of secondary metabolites with potential uses in agriculture, food and drug formulation. It is known that foods derived from Theobroma cacao L. (T. cacao), are rich in natural products with high added value among which include phenolic compounds. The experiments were developed in Bioplantas Center, with the aim of obtaining phenolic extracts with antifungal and antioxidant activity from the selection of the best solvent and extraction method for leaves and seeds of T. cacao. For this, the content of phenolic compounds in methanolic and ethanolic extracts of leaves and seeds of T. cacao, obtained with and without soxhlet extractions were determined. The solvent and extraction method, according to metabolic profiles by thin layer chromatography (TLC) was selected. In vitro antifungal and antioxidant activity of selected leaves and seeds phenolic extracts were determined. The higher content of phenolic compounds were recorded for the methanol extracts of T. cacao seeds and soxhlet extraction, followed by leaves. In extracts of seeds and leaves analyzed by TLC, the presence of high levels of phenolic compounds of different chemical nature showed no differences between the methanolic and ethanolic extracts. It was selected as the commercial ethanol solvent and the soxhlet extraction method. It showed that evaluated extracts have antioxidant and antifungal activity, in relation to its chemical composition. Seed extracts showed higher antioxidant and antifungal activity (against Stemphylium solani and Sarocladium oryzae) than leaves. The leaf extracts were only active against Rhizoctonia solani.
Descripción
Palabras clave
Theobroma cacao, Soxhlet, Fenoles, Antifúngica, Antioxidante