Synthesis and Encapsulation of bis-eugenol in a Mesoporous Solid Material: Enhancement of the Antioxidant Activity of a Natural Compound from Clove Oil
Vanina A. Guntero
IQAL (UNL-CONICET), Laboratorio Fester-QUIMICA ORGANICA (FIQ), Santiago del Estero 2829, Santa Fe, Argentina and UTN Facultad Regional San Francisco, Av. de la Universidad 501, San Francisco, Argentina
Cristián A. Ferretti
IQAL (UNL-CONICET), Laboratorio Fester-QUIMICA ORGANICA (FIQ), Santiago del Estero 2829, Santa Fe, Argentina and INCAPE (UNL-CONICET), Colectora Ruta Nac. 168, Km 0, Paraje El Pozo, Santa Fe, Argentina
Pedro M. Mancini
IQAL (UNL-CONICET), Laboratorio Fester-QUIMICA ORGANICA (FIQ), Santiago del Estero 2829, Santa Fe, Argentina
María N. Kneeteman *
IQAL (UNL-CONICET), Laboratorio Fester-QUIMICA ORGANICA (FIQ), Santiago del Estero 2829, Santa Fe, Argentina
*Author to whom correspondence should be addressed.
Abstract
In the present work, microwave extraction conditions to recover high eugenol content in the crude extract from clove were investigated. The effect of factors like temperature, stirring, time, liquid: Solid ratio and solutions of solvent were evaluated with Taguchi’s method. The eugenol content was determined by gas chromatography. From the isolated eugenol, the bis-phenol was synthesized by the dimerization of eugenol. The encapsulation of bis-eugenol on the mesoporous silica was carried out by a microwave assisted process. Previously, mesoporous silica SBA-15 was prepared by hydrothermal synthesis using Pluronic P123 triblock copolymer as a surfactant. The bis-eugenol encapsulated in SBA-15 was characterized by physicochemical techniques. The results indicated that the encapsulation of bis-eugenol in the pores of silica occurred through weak interactions of an electrostatic nature without producing chemical changes in the antioxidant property. The antioxidative activity of eugenol, bis-eugenol and bis-eugenol/SBA-15 system was examined by phosphomolybdenum assay. Among these materials, a remarkably high antioxidant activity was found in bis-eugenol encapsulated in SBA-15. These resultas suggest the possibility of applying this system as an antioxidant active packaging in the future.
Keywords: Antioxidant activity, encapsulation, mesoporous material, clove oil