SMALL-MOLECULE ANTIOXIDANTS IN MARINE ORGANISMS - ANTIOXIDANT ACTIVITY OF MYCOSPORINE-GLYCINE

The antioxidant activities of aqueous extracts of tissues from four different marine species containing mycosporine-like amino acids were examined by their peroxyl radical-trapping abilities using the phosphatidylcholine peroxidation inhibition assay, The coral trout (Plectropomus leopardus) lens extract had low oxidation inhibition activity; Porphyra tenera and Lissoclinum patella extracts had moderately strong inhibition activities while the aqueous extract of Palythoa tuberculosa showed the greatest oxidation inhibition activity of the extracts tested; the last two extracts contained mycosporine-glycine. In these sample extracts, mycosporine-glycine was reactive to peroxyl radicals whereas the iminomycosporine-like amino acids, shinorine, porphyra-334, palythine, asterina-330 and palythinol, were oxidatively robust. Purified mycosporine-glycine inhibited peroxyl radical-initiated autoxidation of phosphaditylcholine in a concentration-dependent manner. These results suggest that mycosporine-glycine may function as a biological antioxidant in marine organisms.