Laboratoire d'Ecophysiologie et de Biotechnologies des Halophytes et des Algues Marines, Europeen Institute of Marine Studies-University of West Brittany, Technopole Brest-Iroise, place Nicolas Copernic, 29280 Plouzané, Brittany, France.
Phytochem Anal. 2010 Sep-Oct;21(5):399-405. doi: 10.1002/pca.1210.
Phenolic compounds are metabolites exhibited at high levels in Phaeophyceae. Although several studies have been conducted on total phenol contents, no one to our knowledge has dealt with the contents of phenolic compounds and antioxidant activities on purified fractions.
The purpose of this study was the extraction and purification of phenolic compounds from the brown seaweed Ascophylllum nodosum, to determine both their distribution and their radical-scavenging activities, and to obtain a sufficiently purified oligophenolic fraction to perform an RP-HPLC analysis on molecules with a molecular weight (MW) < 2 kDa.
Phenolic compounds were separated and purified by liquid-liquid extraction, tangential ultrafiltration and dialysis. Then, the contents of both phenolic compounds and radical-scavenging activities were measured by the Folin-Ciocalteu reagent, and DPPH and ABTS assays. NMR analysis was performed to validate the process. RP-HPLC with a C(18) column was performed on the oligophenolic fraction, using a novel method developed in this study.
Seven fractions were obtained as a function of polarity and molecular weight. Among them, the fraction containing phenolic compounds with a MW ≥ 50 kDa appeared to be the most active, correlated with the content of phenolic compounds.
This work constitutes a step forward in the separation and purification of bioactive phlorotannins and represents a prerequisite for further investigations into their structural characterisation and distribution in A. nodosum.
多酚类化合物是褐藻中含量较高的代谢物。虽然已经有几项关于总酚含量的研究，但据我们所知，还没有人研究过酚类化合物的含量和抗氧化活性在纯化馏分中的分布。
本研究旨在从褐藻马尾藻中提取和纯化多酚类化合物，确定其分布和自由基清除活性，并获得足够纯化的低聚多酚级分，以便对分子量（MW）<2 kDa 的分子进行反相高效液相色谱（RP-HPLC）分析。
多酚类化合物通过液液萃取、切向超滤和透析进行分离和纯化。然后，通过福林-肖卡尔特试剂、DPPH 和 ABTS 测定法测定多酚化合物的含量和自由基清除活性。进行 NMR 分析以验证该过程。使用本研究中开发的新方法，对低聚多酚级分进行 C（18）柱 RP-HPLC 分析。
根据极性和分子量得到了 7 个馏分。其中，含有 50 kDa 以上分子量的酚类化合物的馏分似乎最活跃，与酚类化合物的含量相关。
这项工作是在分离和纯化生物活性岩藻黄素方面迈出的一步，也是进一步研究其在马尾藻中结构特征和分布的前提条件。
