Free radical Scavenging Activity and Total Phenolic Compounds of Gracilaria changii

Abstract

The antioxidant activity of the marine algae G. changii from Malaysia was determined. The free radical scavenging activity of the 80% methanolic extract of G. changii was assessed with the aid of the stable DPPH (1,1-diphenyl-2-picrylhydrazyl) radical.The crude extract showed a low free radical scavenging capacities in comparison with commercial antioxidant BHT (butylated hydroxytoluene), and vitamin E. The IC50 values of the extracts of algae on DPPH scavenging activity was 14.70 mg/ml. The TLCDPPH study, exhibited only one DPPH radical scavenging bands out 7 major band of the extract and detected with Rf value 0.63. In
order to assess the role of polyphenolic components in the relevant activity, phenolic contents of the extract also determined and the value was 5.0 mg (gallic acid equivalent/1 g extract). This finding indicated that crude extract of G. changii was a starting material for the isolation of compound(s) with effective activities as radical’s scavengers.