Separación bioguiada de extractos orgánicos de Macleania rupestris (Joyapa) y evaluación de su potencial nutracéutico

Abstract

Macleania rupestris Kunth is an endemic species mostly located in the Andean region of Colombia and Ecuador. Currently, there is little information about its chemistry and bioactivity. The purpose of this study was to carry out an analysis of the antioxidant and antimicrobial activity of M. rupestris by using a bioguided fractionation that could justify its biological activity. For this effect, organic extracts were prepared using Soxhlet and maceration methods. The fractionation was carried out by applying open column chromatography and under pressure column chromatography. For the evaluation of the antioxidant activity, the ABTS free radical capture method was applied, whereas the micro-dilution plate technique was used to determine the antimicrobial activity. The obtained extracts yield showed higher efficiency of the Soxhlet method over the maceration method. However, the bioactivity of M. rupestris extract obtained by maceration was higher than the Soxhlet extract. After the fractionation of the extract by permeation in a silica column and the subsequent antioxidant test, it was shown that the antioxidant activity presented by the organic extracts was concentrated in the most polar fractions. This result implies that the antioxidant metabolites of M. rupestris are polar. The tested extracts did not show antioxidant activity against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). The results show the potential of M. rupestris as a source of antioxidant metabolites, so it is recommended to continue with the study of this species in order to characterize its bioactive metabolites