Hermund Ditte B, Plaza Merichel, Turner Charlotta, Jónsdóttir Rosa, Kristinsson Hordur G, Jacobsen Charlotte, Nielsen Kristian Fog
Division of Food Technology, National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
Centre for Analysis and Synthesis, Department of Chemistry, Lund University, SE 22100 Lund, Sweden.
Food Chem. 2018 Feb 1;240:904-909. doi: 10.1016/j.foodchem.2017.08.032. Epub 2017 Aug 10.
Brown algae are rich in polyphenolic compounds, phlorotannins, which have been found to possess high in vitro antioxidant capacity, especially DPPH radical scavenging activity, due to the high number of hydroxyl groups. Whereas, the overall antioxidant capacity of brown algae extracts has been widely studied, the antioxidant capacity of individual phlorotannins has been rarely explored. The aim of this study was to determine the structure dependant antioxidant capacity of phlorotannins from Icelandic brown algae, Fucus vesiculosus. The antioxidant capacity of individual phlorotannins was determined by an on-line method using liquid chromatography and an electrochemical detector followed by quadrupole Time of Flight mass spectrometry (UHPLC-DAD-ECD-QTOFMS). Tentative structural elucidation of 13 phlorotannin isomers from EAF was obtained by LC-DAD-QTOFMS, ranging from 374 to 870Da. On-line determination of antioxidant capacity of the individual phlorotannins generally showed that low molecular phlorotannins exhibited higher antioxidant capacity and that the capacity decreased with polymerisation.
褐藻富含多酚类化合物——岩藻黄素单宁，由于其含有大量羟基，已发现这类物质具有较高的体外抗氧化能力，尤其是对二苯基苦味酰基自由基（DPPH）的清除活性。尽管褐藻提取物的整体抗氧化能力已得到广泛研究，但对单个岩藻黄素单宁的抗氧化能力却鲜有探索。本研究的目的是确定来自冰岛褐藻——墨角藻的岩藻黄素单宁的结构依赖性抗氧化能力。通过使用液相色谱和电化学检测器并结合四极杆飞行时间质谱（UHPLC-DAD-ECD-QTOFMS）的在线方法，测定了单个岩藻黄素单宁的抗氧化能力。通过LC-DAD-QTOFMS对来自乙醇提取物（EAF）的13种岩藻黄素单宁异构体进行了初步结构解析，分子量范围为374至870Da。单个岩藻黄素单宁抗氧化能力的在线测定结果总体表明，低分子岩藻黄素单宁具有较高的抗氧化能力，且该能力随聚合作用而降低。
