海蒿子岩藻聚糖结构特征及其抗流感病毒活性

Structural characteristic of fucoidans from Sargassum pallidum and their anti-influenza virus activities

摘要:

采用热水提取法从海蒿子中提取粗多糖,再用Q-Sepharose Fast Flow和Sepharose 4B Fast Flow纯化得到一种硫酸化岩藻聚糖,命名为SF0。通过逐步部分酸水解,该岩藻聚糖SF0被进一步分为3种次级多糖SF1、SF2和SF3,硫酸基团的含量和相对分子质量依次降低。通过单糖组成、傅里叶红外光谱(FT-IR)和¹³C-NMR谱分析了4种多糖的结构特征,并探究了其抗甲型流感(H1N1)病毒的活性。结果表明,SF0主要由甘露糖、葡萄糖醛酸、葡萄糖、半乳糖、木糖和岩藻糖组成,摩尔比为10.8∶8.3∶3.0∶21.1∶21.2∶35.6,相对分子质量为628.1 ku,由α-D-1,2-Manp和β-D-1,4-GlcAp双糖重复单元构成核心骨架。抗甲型流感(H1N1)病毒检测表明,4种多糖都可以抑制MDCK细胞中的H1N1病毒复制。低分子量组分SF3比未降解岩藻聚糖抗病毒活性更好。初步认为该岩藻聚糖的抗H1N1病毒活性与其精细结构和分子量有关。

Abstract:

A sulfated fucoidan named as SF0, was isolated from Sargassum pallidum with hot water extraction and further purified by a strong anion exchange column and a gel filtration column. SF0 was further fractionated into three fractions SF1, SF2 and SF3 by stepwise partial acid hydrolysis. The content of sulfated group and molecular weight were decreased from SF0 to SF3. The structural features and anti-influenza A (H1N1) virus activities of all these fractions were determined. Results showed that SF0 was a homogeneous polysaccharide with a large molecular weight of 628.1 ku. It was mainly composed of mannose, glucuronic acid, glucose, galactose, xylose and fucose, in the molar ratio of 10.8∶8.3∶3.0∶21.1∶21.2∶35.6, SF0 has a backbone composed of α-D-1,2-Manp and β-D-1,4-GlcAp disaccharide repeat unit. The anti-influenza A (H1N1) virus assay showed that all these fractions inhibited H1N1 virus replication in MDCK cells. Moreover, the fraction SF3 with the low molecular weight had better activity than original fraction. It suggested that the anti-H1N1 virus activity of fucoidan was related to its fine structure and molecular weight.