Li Yong, Qian Zhong-Ji, Ryu BoMi, Lee Sang-Hoon, Kim Moon-Moo, Kim Se-Kwon
Marine Bioprocess Research Center, Pukyong National University, Busan, Republic of Korea.
Bioorg Med Chem. 2009 Mar 1;17(5):1963-73. doi: 10.1016/j.bmc.2009.01.031. Epub 2009 Jan 21.
Seven phlorotannins were isolated and characterized from an edible marine brown alga Ecklonia cava (EC), along with three common sterol derivatives (fucosterol, ergosterol, and cholesterol) according to the comprehensive spectral analysis of MS and NMR data. Compounds 5 (7-phloro eckol) and 7 (6,6'-bieckoll) of phlorotannin derivatives were obtained for the first time with the high yields. No reports of compound 3 (Fucodiphloroethol G) was published up to date. The antioxidant properties of all phlorotannins were assessed by total antioxidant activity in a linoleic acid model, free radicals scavenging assay using electron spin resonance spectrometry (ESR) technique, cellular reactive oxygen species (ROS) assay by DCFH-DA, membrane protein oxidation assay; measurement of cellular glutathione (GSH) level in RAW264.7 cell line, and myeloperoxidase (MPO) assay in HL-60 cell line. The results revealed that all phlorotannins had antioxidant properties in vitro, especially, compounds 7 (6,6'-bieckol), 6, and 3 showed the significant activities compared to the other phlorotannins. Furthermore, the structure-activity relationship (SAR) was discussed based on the structural differences of the tested phlorotannins which have polymeriged phloroglucinal units with diverse skeletons and linkages. It could be suggested that phlorotaninns from this genus would be more potential candidates for the development of unique natural antioxidants for further industrial applications as functional foods, cosmetics and pharmaceuticals. As well as our results makes it clear to understand the reason behind the use of EC as traditional folk herb for a long history.
根据质谱（MS）和核磁共振（NMR）数据的综合光谱分析，从可食用的海洋褐藻昆布（EC）中分离并鉴定出7种间苯三酚单宁，以及3种常见的甾醇衍生物（岩藻甾醇、麦角甾醇和胆固醇）。间苯三酚单宁衍生物中的化合物5（7 - 氯eckol）和7（6,6'- 二eckoll）首次以高产率获得。截至目前，尚未有关于化合物3（岩藻二氯乙酚G）的报道。通过亚油酸模型中的总抗氧化活性、使用电子自旋共振光谱（ESR）技术的自由基清除试验、2',7'-二氯二氢荧光素二乙酸酯（DCFH - DA）法检测细胞活性氧（ROS）、膜蛋白氧化试验、测量RAW264.7细胞系中的细胞谷胱甘肽（GSH）水平以及HL - 60细胞系中的髓过氧化物酶（MPO）试验，评估了所有间苯三酚单宁的抗氧化性能。结果表明，所有间苯三酚单宁在体外均具有抗氧化性能，尤其是化合物7（6,6'- 二eckol）、6和3与其他间苯三酚单宁相比表现出显著的活性。此外，基于所测试的间苯三酚单宁的结构差异，讨论了构效关系（SAR），这些间苯三酚单宁具有不同骨架和连接方式的聚合间苯三酚单元。可以认为，该属的间苯三酚单宁更有可能成为开发独特天然抗氧化剂的潜在候选物，用于进一步的工业应用，如功能性食品、化妆品和药品。同时，我们的结果也清楚地解释了EC作为传统民间草药长期使用的原因。
