감태에서 분리된 2,7\\\\'-phloroglucinol-6,6'-bieckol 의 분리와 동정 및 항산화 효과 검색

Abstract

Ecklonia cava has been regarded as a useful material in the preventive or treatment of several human diseases in Jeju Island, Korea. Here we investigated its antioxidant activity, and isolated and identified its active compound. The antioxidant capacities of the diethyl ether fraction and the fractions were evaluated. Among the four organic fractions, diethyl ether fraction was the most potent in DPPH radical scavenging activity than other fractions. It was subject to further purification of active compoundby silica column chromatography using a gradient solvent system (chloroform: methanol, v/v; 2:1-0:1). 2,7”-phloroglucinol-6,6’-bieckol was isolated from ECE7 fraction of diethyl ether by RP-HPLC. The active compound, 2,7”-phloroglucinol-6,6’-bieckol (PHB) was identified on the base of LC-MS, 1H ,and 13C NMR spectroscopy. Antioxidant activities of PHB were evaluated by several in vitro assays such as radical scavenging activities (DPPH, alkyl, hydroxyl, superoxide) using electron spin resonance (ESR) spectrometry,intracellular reactive oxygen species (ROS) scavenging activity,and DNA damage. The results indicate that the PHB showed strong scavengingactivities on DPPH, alkyl, hydroxyl, superoxide radicals (IC50; 0.51 μM for DPPH, IC50; 2.07 μM for alkyl, IC50; 75.64 μM for hydroxyl,IC50; 57.19 μM for superoxide radical, respectively). The antioxidant activities of the PHB, which were evaluated by DPPH, alkyl, hydroxyl, superoxide radical scavenging activities,were found to be as high as antioxidant agent, ascorbic acid. Further, the PHB effectively inhibited H2O2-induced DNA damage. As a result, 2,7”-phloroglucinol-6,6’-bieckol should be useful for the development of natural antioxidant reagent.