褐藻多酚羟基测定及抗氧化性质研究

IOCAS-IR > 海洋环流与波动重点实验室

	褐藻多酚羟基测定及抗氧化性质研究
	陈予敏
学位类型	博士
	1999
学位授予单位	中国科学院海洋研究所
学位授予地点	中国科学院海洋研究所
学位专业	海洋化学
关键词	褐藻多酚羟基连三羟基抗氧化自由基
摘要	羟基是褐藻多酚结构特征，以往只以间苯三酚为标准物对褐藻多酚中总羟基用FD法进行测量，核磁共振研究表明褐藻多酚中除间三羟基外还含有连三羟基（Ragan, et al, 1986），连三羟基的测量与它所占总羟基工比例是探讨褐藻多酚构效关系的基础，此类研究未有报道；关于褐藻多酚的抗氧化性，只有增重法和过氧化值法对其进行研究的报道，而关于抗氧化机理未有报道。采用FAS法、FD法对鼠尾藻（Sargassum. thunbergii)、海黍子(Sargassum. kjellmanianum)、裙带菜(Undaria pinnatifida)、海带(Laminaria japonica)中褐藻多酚连三羟基与总羟基含蓄量的比例进行了研究，结果依次为24.4%、25.6%、1.7%和2.6%;采用DPPH体系、羟基自由基体系、烷基自由基引发的亚油酸氧化体系、超氧阴离子自由基体系对海黍子高分子量褐藻多酚抗击氧化性质进行了研究，发现其清除DPPH活性、清除羟基自由基活性、抑制烷基自由基引发的亚油酸氧化的活性分别为77%、27%和21%，但它不具有清除超氧阴离子自由基的能力。褐藻多酚具有供氢能力且其连三羟基的供氢能力大于间三羟基，清除羟基自由基与其苯环提供的羟基自由基加成位点的数量有关。对褐藻多酚抑制A_3钢腐蚀进行了电化学研究，发现褐藻多酚可使海水中A_3钢腐蚀电位转正并与工作电极附近的溶解氧反应减缓腐蚀。本研究表明褐藻多酚的抗击氧化性与其羟基结构的苯环提供的羟基自由基加成位点的数量有直接关系。
其他摘要	Phlorotannins, also named as polyphloroglucinol, is a class of unique natural products in brown seaweeds with significant antioxidant activities, and yet, details on its antioxidant activity have not been elucidated by traditional weight-addition or P. O. V. method. NMR data have revealed that there exist different types of hydroxyl groups, including vicinal trihydroxyl and meta-hydroxyl (Ragan, et al, 1986), which implied that different types of hydroxyl may contribute differently on its antioxidant activity. However, most of previous studies, focusing on determination of total hydroxyls in phlorotannins, have not yet offered valuable information on hydroxyl characterization. This paper tried to quantify different hydroxyl group co-existing in phlorotannins, and studied the relationship between such structure characteristics and antioxidant activities in different assay systems. This paper, using FAS and FD methods, determined the ratios of quantity of vicinal trihydroxyl to that of total hydroxyl of phlorotannins from S. thunbergii, S. kjellmanianum, Undaria pinnatifida, Laminaria japonica with the results of 24.4%、25.6%, 1.7% and 2.6%, respectively. Antioxidant activity of high-weight phlorotannins from S. kjellmanianum was studied, using the assay systems of DPPH, hydroxyl radical, oxidation of linolic acid induced by alkane radical and superoxide radical. The results showed that hydroxyls in phlorotannins are hydrogen donors and the vicinal trihydroxyl is a more active hydrogen donor than meta-trihydroxyl, that hydroxyl radical scavenging capacity is closely related to the number of sites in phlorotannins' benzene rings for the addition of hydrogen radicals, and phlorotannins can inhibit linolic acid oxidation induced by alkane radicals and cannot scavenge superoxide radicals. Electrochemical experiments on A_3 steel corrosion showed that in seawater phlorotannins can turn positive the corrosive potential of A_3 steel and capture the dissolved oxygen, thus decelerate its corrosion. It is concluded in this paper that antioxidant activity of phlorotannins is closely related to its hydroxyl characterization and the number of sites on its benzene rings for the added hydrogen radicals.
页数	27
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/347
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	陈予敏. 褐藻多酚羟基测定及抗氧化性质研究[D]. 中国科学院海洋研究所. 中国科学院海洋研究所,1999.

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