A study on the antioxidant properties of mediterranean algae: preliminary chemical investigation of the sea grass Posidonia oceanica
Stoiculescu, R. A.
In the present study, the antioxidant properties of 17 Mediterranean algae were examined. The extracts of the algae were evaluated as radical scavengers on hydroxvl and 2, 2- Dipheny-l-picrylhydrazyl free radical (DPPH). The antiradical activity is expressed as the IC sub(50) (mg/ml) and EC sub(50) (mg/mg DPPH) values obtained from the corresponding extracts of the algae. Most of the algae species studied during this investigation showed moderate antioxidant activities by chemiluminescence and DPPH methods, with the exception of the brown alga Taonia atomaria and the sea grass Posidonia oceanica. On the basis of these findings it was decided to proceed with the investigation of Posidonia oceanica due to the striking anti-radical efficiency of methanol and aqueous methanol extracts compared with that of the other species and also due to the widespread presence of this algae in the Mediterranean basin. A second, large-scale extraction and a subsequent bioassay guided fractionation by column chromatography allowed us to separate three fractions (Fl, F2,F3). According to the chemiluminescent results, the fractions were ranked on the basis of their antioxidant activities. The initial column chromatography fractions were analysed by TLC and sup(1) HNMRR and on the basis of their profiles and spectral characteristics, it was feasible to identify the fraction containing secondary metabolites of chemical interest.
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Este registro bibliográfico ha sido proporcionado por Mediterranean Agronomic Institute of Chania