Isolation and identification of novel compound, 2,7?phloroglucinol-6,6?bieckol from brown algae, Ecklonia cava and its antioxidant effect

Abstract

Ecklonia cava has been regarded as a useful material in the prevention or treatment of several human diseases in Jeju Island, Korea. In this study, we investigated its antioxidant activity, and isolated a novel antioxidative compound, which was identified as 2,7?phloroglucinol-6,6?bieckol (PHB) on the basis of LC/MS, as well as 1H and 13C NMR spectroscopy results. The antioxidant activities of PHB were evaluated via several in vitro assays, such as radical scavenging activities (DPPH, alkyl, hydroxyl, and superoxide) using ESR spectrometry, intracellular ROS scavenging activity, and DNA damage assays. PHB evidenced profound scavenging activities on DPPH, alkyl, hydroxyl, and superoxide radicals (IC50; 0.51, 2.07, 75.64 and 57.19 ？ for DPPH, alkyl, hydroxyl and superoxide radical, respectively). The antioxidant activities of PHB were higher than that of ascorbic acid. Furthermore, PHB effectively inhibited H2O2-induced DNA damage. The results of this study indicate that PHB may prove useful as a novel natural marine antioxidant.