In this paper, the structures and composition of phlorotannins with different molecular weights in juvenile and mature kelp (Saccharina japonica), as well as their relationship with antioxidant activity were comprehensively analyzed. Macroporous resin and ultrafiltration were used to obtain phlorotannins with different molecular weights. The structures of low molecular weight and high molecular weight phlorotannins in Sanhai kelp were analyzed using UHPLC-Q-Orbitrap-MS/MS and NMR techniques, respectively. In addition, the antioxidant capacity of phlorotannins with different molecular weights was determined by chemical and HepG2 cell oxidative damage models methods assays. Results showed that the content and molecular weight distribution of phlorotannins in Sanhai kelp were related to its growth stage. Seventeen low molecular weight phlorotannins were identified, and the composition types of the high molecular weight phlorotannins were fucols, phlorethols, fucophlorethols, fuhalols and eckols. In addition, high molecular weight phlorotannins exhibit higher antioxidant activity than low molecular weight phlorotannins.

中文翻译：

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三海海带（Saccharina japonica）中根皮单宁的分子量分布和结构分析及其抗氧化活性评价


本文综合分析了幼年和成熟海带 （Saccharina japonica） 中不同分子量根皮单宁的结构和组成，以及它们与抗氧化活性的关系。采用大孔树脂和超滤获得不同分子量的根皮单宁。采用 UHPLC-Q-Orbitrap-MS/MS 和 NMR 技术分别分析三海海带中低分子量和高分子量根皮单宁的结构。此外，通过化学和 HepG2 细胞氧化损伤模型方法测定不同分子量的根皮单宁的抗氧化能力。结果表明，三海海带中根皮单宁的含量和分子量分布与其生长阶段有关。鉴定出 17 种低分子量根皮单宁，高分子量根皮单宁的组成类型为岩藻、根皮酚、岩藻酚、岩藻醇和岩皮。此外，高分子量根皮单宁比低分子量根皮单宁表现出更高的抗氧化活性。