Optimisation of ultrasound-assisted extraction of phenolic antioxidants from Ilex guayusa Loes. leaves using response surface methodology.

The present study carried out the optimisation of the total polyphenol content (TPC) extraction assisted by ultrasound in Ilex guayusa leaves applying response surface methodology (RSM). Also, the evaluation of the antioxidant activity of the extract obtained under the optimal extraction conditions was performed. The effect of the variables like, time of sonication, temperature, ethanol/water ratio and solid/liquid relationship and the interactions between them were analysed through the use of a factorial design 2ˆ4. The significant factors were considered for the optimisation, employing a Box-Behnken Design, and the TPC as response variables. It was found that a quadratic model was adequate, with an adjusted R2 value of 0.9367. The optimal conditions proposed, by the response surface model were: an extraction temperature of 60 °C, sonication time of 29.9 min and ethanol/water ratio of 76.8/23.2. The optimised leaves extract of I. guayusa show a TPC of 3.46 (±0.17) g gallic acid equivalents/100 g d.w. Radical scavenger activity of the obtained extract at optimum conditions, was performed through the FRAP and ABTS methods, given as result: 0.080 mmol TROLOX equivalents/100 g d.w. and 40.71 µmol TROLOX equivalents/g d.w., respectively. Due to the present findings, I. guayusa extracts can be proposed as a promising component for functional beverages, cosmetic and pharmaceutical formulation.

Evaluation of the synergistic effects of antioxidant activity on mixtures of the essential oil from Apium graveolens L., Thymus vulgaris L. and Coriandrum sativum L. using simplex-lattice design.

Essential oils (EOs) are known for their antioxidant properties, and are widely employed in the food industry as preservatives. They can be used as condiments or as preservatives to achieve certain organoleptic effects for consumers. The aim of this research was to evaluate antioxidant activity in mixtures of three EOs: Apium graveolens L., Thymus vulgaris L. and Coriandrum sativum L., using the Simplex Lattice Mixture Design. Ultimately, a linear model was used, as it best adjusted to the experimental behavior, and it allowed the prediction of EOs mixtures antioxidant activity, determined by FRAP and ABTS techniques. The mixture of the three EOs that showed the best antioxidant activity and also had the highest synergistic effect, was composed of 66.7% of T. vulgaris, 16.7% of C. sativum and 16.7% of A. graveolens. The greatest contribution to the potentiation of antioxidant activity was shown by T. vulgaris followed by A. graveolens and then C. sativum.

Especificidad de la cromatografía líquida de alta eficacia para evaluar estabilidad química basada en partenina del follaje seco pulverizado de Parthenium hysterophorus L (escoba amarga) / Specificity of HPLC to assess the chemical stability based on partenine from Parthenium hysterophorus L powdered dry foliage (escoba amarga)

INTRODUCCIÓN: se requiere una técnica de análisis específica que permita dar seguimiento al estudio de la estabilidad intrínseca del follaje seco pulverizado de Parthenium hysterophorus L. (escoba amarga), para la obtención de una forma farmacéutica de utilidad antiparasitaria con los requisitos de calidad, seguridad y eficacia exigidos. OBJETIVO: demostrar la especificidad de la técnica analítica de cromatografía líquida de alta eficacia para la cuantificación de partenina en el polvo de P. hysterophorus para su aplicación en estudios de estabilidad. MÉTODOS: se aplicó cromatografía líquida de alta eficacia a muestras degradadas de P. hysterophorus, bajo condiciones degradativas en medio ácido, básico y oxidativo. Se evaluó la especificidad de la técnica de análisis para detectar el componente de interés sin interferencias de sus productos de degradación y su posible utilidad en estudios de estabilidad del polvo de la planta. RESULTADOS: la cromatografía líquida de alta eficacia para cuantificar partenina en el polvo de P. hysterophorus resultó específica en las condiciones de trabajo establecidas y puede emplearse en estudios de estabilidad del sólido en el polvo de la planta. CONCLUSIONES: la técnica de cromatografía líquida de alta eficacia propuesta es específica y se recomienda su utilización en los estudios de estabilidad del sólido en polvo de la planta(AU)

INTRODUCTION: it is required a specific analysis technique allowing the follow-up to stability study intrinsic of Parthenium hysterophorus L. (escoba amarga) powdered dry foliage to achieve in a pharmaceutical way a antiparasitic usefulness with the quality, safety and effectiveness demanded requirements. OBJECTIVE: to demonstrate the specificity of analytical technique of high-performance liquid chromatography for quantization of partenine in the powder of P. hysterophorus for its application in stability studies. METHODS: high performance liquid chromatography was applied to P. hysterophorus degraded samples under degradation conditions in an oxidative, basic and acid medium.The analysis technique specificity was assessed to detect the interest component without interferences of its degradation products and its possible usefulness in studies on solid stability in the plant powder. RESULTS: high-performance liquid chromatography to quantify the presence of partenine in the P. hysterophorus powder was specific in established work conditions and may be used in solid stability studies of plant powder. CONCLUSIONS: the high-performance proposed is specific and it is recommended in solid stability studies of solids in plant powder(AU)

Especificidad de la cromatografía líquida de alta eficacia para evaluar estabilidad química basada en partenina del follaje seco pulverizado de Parthenium hysterophorus L (escoba amarga) / Specificity of HPLC to assess the chemical stability based on partenine from Parthenium hysterophorus L powdered dry foliage (escoba amarga)

INTRODUCCIÓN: se requiere una técnica de análisis específica que permita dar seguimiento al estudio de la estabilidad intrínseca del follaje seco pulverizado de Parthenium hysterophorus L. (escoba amarga), para la obtención de una forma farmacéutica de utilidad antiparasitaria con los requisitos de calidad, seguridad y eficacia exigidos. OBJETIVO: demostrar la especificidad de la técnica analítica de cromatografía líquida de alta eficacia para la cuantificación de partenina en el polvo de P. hysterophorus para su aplicación en estudios de estabilidad. MÉTODOS: se aplicó cromatografía líquida de alta eficacia a muestras degradadas de P. hysterophorus, bajo condiciones degradativas en medio ácido, básico y oxidativo. Se evaluó la especificidad de la técnica de análisis para detectar el componente de interés sin interferencias de sus productos de degradación y su posible utilidad en estudios de estabilidad del polvo de la planta. RESULTADOS: la cromatografía líquida de alta eficacia para cuantificar partenina en el polvo de P. hysterophorus resultó específica en las condiciones de trabajo establecidas y puede emplearse en estudios de estabilidad del sólido en el polvo de la planta. CONCLUSIONES: la técnica de cromatografía líquida de alta eficacia propuesta es específica y se recomienda su utilización en los estudios de estabilidad del sólido en polvo de la planta.

INTRODUCTION: it is required a specific analysis technique allowing the follow-up to stability study intrinsic of Parthenium hysterophorus L. (escoba amarga) powdered dry foliage to achieve in a pharmaceutical way a antiparasitic usefulness with the quality, safety and effectiveness demanded requirements. OBJECTIVE: to demonstrate the specificity of analytical technique of high-performance liquid chromatography for quantization of partenine in the powder of P. hysterophorus for its application in stability studies. METHODS: high performance liquid chromatography was applied to P. hysterophorus degraded samples under degradation conditions in an oxidative, basic and acid medium.The analysis technique specificity was assessed to detect the interest component without interferences of its degradation products and its possible usefulness in studies on solid stability in the plant powder. RESULTS: high-performance liquid chromatography to quantify the presence of partenine in the P. hysterophorus powder was specific in established work conditions and may be used in solid stability studies of plant powder. CONCLUSIONS: the high-performance proposed is specific and it is recommended in solid stability studies of solids in plant powder.