Author(s):
Cerqueira, M. A. 
; Martins, Joana ; Quintas, Mafalda A. C. ; Ferreira, António C. ; Teixeira, J. A. ; Vicente, A. A. ; Souza, B. W. S.
Date: 2011
Persistent ID: http://hdl.handle.net/1822/16738
Origin: RepositóriUM - Universidade do Minho
Subject(s): Antioxidant; Seaweeds; Phenolic content
Description
In this work, in vitro antioxidant activity of two Brazilian red seaweeds, Gracilaria birdiae and Gracilaria cornea, was
characterized. The total phenolic content, the radical-scavenging activity and the antioxidant activity were determined in two solvent
extracts of the algae. Liquid chromatography mass spectrometry (LC MS/MS) allowed identification of important antioxidant
compounds. The ethanol extract of G. birdiae was found to have the highest value of total phenolic content: 1.13 mg of gallic acid equiv
(GAE)/g of extract.The radical-scavenging activity of G. birdiae and G. cornea extracts has been evaluated at different extract concentrations;
the IC50 values of ethanolic extracts of G. cornea and G. birdiae were 0.77 and 0.76mgmL 1, respectively, while formethanolic extracts, the
IC50 values of G. cornea and G. birdiae were 0.86 and 0.76mgmL 1, respectively. The antioxidant activities of these two seaweeds’ extracts as
assessed by the ß-carotene linoleic acid assay were equally high, achieving values of ß-carotene oxidation inhibition of up to 40%. Finally,
in the methanolic extracts, LC MS/MS allowed identification in both algae of two important antioxidants: apigenin and gallic acid.
