两种褐藻中褐藻多糖硫酸酯的结构解析与活性研究

IOCAS-IR > 实验海洋生物学重点实验室

	两种褐藻中褐藻多糖硫酸酯的结构解析与活性研究
	张文静
学位类型	博士
导师	张全斌
	2016-05-25
学位授予单位	中国科学院大学
学位授予地点	北京
学位专业	海洋生物学
关键词	笼目海带鼠尾藻褐藻多糖硫酸酯结构解析抗补体抗肝癌
摘要	笼目海带（Kjellmaniella crassifolia）和鼠尾藻（Sargassum thunbergii）是两种重要的褐藻，所含的多糖研究相对较少。本文通过不同提取方法对笼目海带和鼠尾藻进行多糖提取，发现笼目海带和鼠尾藻褐藻多糖硫酸酯均以岩藻糖为主，还含有适量的甘露糖、半乳糖和葡萄糖醛酸等杂糖。采用部分降解、部分脱硫等方法处理，结合电喷雾电离质谱等技术对多糖进行结构解析，发现部分脱硫后的笼目海带褐藻多糖硫酸酯是由硫酸化岩藻寡糖和硫酸化半乳岩藻寡糖组成，其中主链骨架为1→3连接的岩藻聚糖，硫酸根主要为4位。部分脱硫后的鼠尾藻褐藻多糖硫酸酯也是由硫酸化岩藻寡糖和硫酸化半乳岩藻寡糖组成，主链骨架为1→3连接的岩藻聚糖，硫酸根在C4位。半乳岩藻聚糖的主链骨架为Gal 和 Fuc交替连接或是 (Gal)n 和 (Fuc)n交替连接的结构。通过稀酸水解，可以发现鼠尾藻多糖含有甘露葡萄糖醛酸寡糖，葡萄糖醛酸寡糖，岩藻葡萄糖醛酸寡糖等，说明鼠尾藻多糖中可能含有的甘露葡萄糖醛酸聚糖，葡萄糖醛酸聚糖，岩藻葡萄糖醛酸聚糖等。对笼目海带和鼠尾藻褐藻多糖硫酸酯的抗补体活性研究结果表明：笼目海带和鼠尾藻褐藻多糖硫酸酯均具有很好的抗补体活性，其活性呈剂量正相关；低分子量多糖和部分脱硫后多糖的抗补体活性明显降低，说明分子量和硫酸根与抗补体活性密切相关。通过测定不同系列的鼠尾藻褐藻多糖硫酸酯（不同提取方法，不同地区，不同分子量，不同分级组分，不同硫酸化程度，羧基还原）的抗肝癌细胞增殖活性，结果表明：不同提取方法在化学组分上差异不大，但是活性相差较大，以水提活性最高；不同地区的多糖在化学组分和活性方面差异不大，以青岛地区多糖活性最高；在高浓度条件下，抑制细胞增殖活性不受分子量的影响，而在低浓度条件下，随着分子量的降低而减小；通过DEAE-Bio Gel Agarose FF离子型填料进行分级，分级组分的活性远远小于粗多糖的活性，推测鼠尾藻褐藻多糖硫酸酯的抗肝癌细胞增殖活性依赖于多个组分的协同作用。通过比较不同硫酸化程度的鼠尾藻褐藻多糖硫酸酯，发现硫酸根与抗肝癌细胞增殖活性有关。由于鼠尾藻多糖中含有一部分糖醛酸类物质，鼠尾藻褐藻多糖硫酸酯进行羧基还原后抗肝癌细胞增殖活性降低，推测糖醛酸与其抑制肝癌细胞生长活性密切相关。
其他摘要	Researches on the polysaccharides from two species of brown algae, Kjellmaniella crassifolia and Sargassum thunbergii were rarely concerned. In this study, polysaccharides were extracted from K. crassifolia and S. thunbergii by dilute hydrochloric acid and hot water, respectively. Chemical analysis showed that these polysaccharides consisted of fucose mainly, accompanying with galactose, mannose and glucuronic acid. Electrospray ionization mass spectrometry (ESI-MS) showed that the desulfated fucoidan from K. crassifolia was composed of sulfated fucooligosaccharides and sulfated galactofucooligosaccharides. The backbones of these oligosaccharides were 3-linked and the sulfation pattern was at C4. The desulfated fucoidanfrom S. thunbergii has the same compositions and structure features. In addition, it was important to note that the galactofucan consisted of a backbone of either alternating Gal and Fuc or alternating (Gal)_n and (Fuc)_n. Moreover, the samples, obtained by acid hydrolysis, contained glucuronomanno-oligosaccharides, glucurono-oligosaccharides and fucoglucurono-oligosaccharides, suggesting that it contained glucuronomannan, glucuronan and fucoglucuronan. The activities of polysaccharides from K. crassifolia and S. thunbergii against the hemolytic activity of both the classical and alternative complement pathways were determined. The results showed that the crude polysaccharides from two algae exhibited good anti-complement activity in concentration dependent manner. In addition, the degraded and desulfated polysaccharides displayed lower activities, indicating that molecular weight and sulfate had an effect on the activity. Anti-liver cancer activities of polysaccharides from different extractions, locations and fraction components were determined. In addition, the activities of polysaccharides with different molecular weight, sulfate content and UA content were also tested. It was shown that polysaccharides, extracted by dilute hydrochloric acid, dilute sodium carbonate and hot water, showed slightly differences in the chemical composition, however, they showed different activities. Polysaccharide extracted by water had the highest activity. Polysaccharides, obtained from different locations, also had little difference in the chemical composition and the activity. Polysaccharides with different molecular weight exhibited no differences at the high concentration (1 mg/mL), while showed evident differences at the concentration of lower than 1 mg/mL. After fractionation on the DEAE-Bio Gel Agarose FF gel, all fractions showed less activity, presuming that the activity was attributed to synergy. The activities of desulfated and over-sulfated polysaccharides were lower than the native polysaccharide’s, indicating that sulfate influence the activity. Compared with the decarboxylated polysaccharide, the native polysaccharide had better activity, suggesting that uronic acid was related to the activity.
学科领域	生物学
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/116996
专题	实验海洋生物学重点实验室
作者单位	中国科学院海洋研究所
第一作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	张文静. 两种褐藻中褐藻多糖硫酸酯的结构解析与活性研究[D]. 北京. 中国科学院大学,2016.

条目包含的文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
论文终稿-打印版-上传.pdf（3741KB）	学位论文		限制开放	ODC PDDL	浏览