Comparison of the in vitro antioxidant activity between the crude extracts and fractions of Pleurotus floridanus and Pleurotus pulmonarius.

Abstract

Antioxidant activity is highly associated to phytochemicals present in foods, where they are believed to significantly contribute towards the alleviation of diseases related to oxidative stress. With the phytochemical composition of edible mushrooms being highly associated to their functional properties, techniques such as fractionation became indispensable to highlight active ingredients from various phytoconstituents making up mushrooms. This work aimed at fractionating extracts of two edible mushrooms species (Pleurotus floridanus and Pleurotus pulmonarius), evaluating, and comparing the antioxidant potential of the fractions obtained to that of the extracts. Aqueous, ethanol and hexane extracts of both mushrooms were prepared and subjected to a phytochemical screening. Analytical chromatography of the extracts was performed as guideline for the subsequent column chromatography of the extracts deemed fractionable. The antioxidant potential of the extracts and fractions obtained were evaluated by; ABTS, DPPH, H2O2 and ferrozine assays. The results obtained showed that; the aqueous and ethanol extracts were rich in phytochemicals. Analytical chromatography however revealed the hexane extracts of both mushroom species as being most suitable for fractionation by chromatography with silica as adsorbent and with hexane and ethyl acetate as elution solvents. Fractionation by column chromatography resulted in many fractions with some presenting crystals. The evaluation of the antioxidant potential showed that an apparent synergy could exist between the compounds present in the Comparaison of… TSALA M. Jean-Antoine et al.