孔石莼多糖及其衍生物的研究

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	孔石莼多糖及其衍生物的研究
其他题名	STUDY ON POLYSACCHARIDE EXTRACTED FROM ULVA PERTUSA KJELLM (CHLOROPHYTA) AND ITS DERIVATIVES
	綦慧敏
学位类型	博士
	2007-06-02
学位授予单位	中国科学院海洋研究所
学位授予地点	海洋研究所
关键词	绿藻孔石莼多糖衍生化抗氧化调血脂
摘要	在中国，孔石莼应用于医药方面已有几千年的历史，其煎剂常被当地居民用来治疗中暑和泌尿方面的疾病。实验室以前所做的工作表明，孔石莼的水溶多糖具有很好的抗高血脂活性，本论文在此研究的基础上主要就多糖的长期毒性、一般药理、多糖的衍生化、不同分子量孔石莼多糖的抗氧化活性、衍生物的抗氧化活性和动物调血脂活性进行了研究。水提醇沉制备多糖，多糖主要由糖醛酸、鼠李糖、木糖、葡萄糖和硫酸根组成，还含有微量的半乳糖、甘露糖和阿拉伯糖。多糖中主要的二糖重复单位为[β-D-Glcp A-(1->4)- α-L-Rhap 3S] 和 [α-L-Idop A-(1->4)- α-L-Rhap 3S]。急性毒性实验表明，KM小鼠对孔石莼多糖的最大耐受量(MTD)大于4000 mg/kg，其腹腔注射雌性小鼠的半致死量(LD50)为408.7 mg/kg，雄性动物为432.7 mg/kg。长期毒性（6个月）实验表明孔石莼多糖无毒反应剂量为1.2 g/kg。一般药理研究表明孔石莼多糖对小鼠中枢神经系统无明显影响，对麻醉犬心血管系统和呼吸系统均无明显影响。采用过氧化氢降解的方法制备了不同分子量的孔石莼多糖，并且测定了体外抗氧化活性；制备了高硫酸根含量的孔石莼多糖、乙酰化和苯甲酰化孔石莼多糖衍生物，测定了体外抗氧化活性和动物调血脂试验。结果表明，不同分子量的孔石莼多糖其抗氧化活性是不同的，分子量低的孔石莼多糖表现出了较强的抗氧化活性。孔石莼多糖的衍生物其抗氧化活性要优于孔石莼多糖。调血脂动物试验表明，孔石莼多糖以及其衍生物都具有很好的调血脂效果。高硫酸根含量孔石莼多糖的中、低剂量组的调血脂活性要优于高剂量组（低剂量组降低低密度脂蛋白的能力要稍弱于原料），而且，中剂量组与原料组相比，小鼠血清TG明显降低（P＜0.05），LDL－C 明显降低（P＜0.01）。低剂量组乙酰化衍生物降低甘油三酯（TG）和低密度脂蛋白（LDL－C）的能力要优于中高剂量组。对于孔石莼多糖以及衍生物调血脂的机制还需进一步的研究。
其他摘要	Ulva pertusa has been utilizing for medical purpose for centuries in China. The decoction of algae was traditionally used by local inhabitants to treat sunstroke and urinary diseases etc. The previous work carried out showed that the water-soluble polysaccharide from U. pertusa has a favorably antihyperlipidemic action. Based on the literatures, studies were concentrated on subchronic (6 months) toxicity, general pharmacology, derivatives of ulvan, antioxidant activity of different molecular weight ulvans, antioxidant activity and antihyperlipedemia of derivatives. The polysaccharide was prepared by water extraction and ethanol precipitation. Polysaccharide was determined to be mainly composed of uronic acids, rhamnose, xylose, glucose and sulfate with smaller amounts of arabinose, manose and galactose. The predominantly repeating disaccharide units are [β-D-GlcpA-(1->4)- α-L-Rhap 3S] and [α-L-IdopA-(1->4)- α-L-Rhap 3S]. The acute and toxic tests of polysaccharide showed that MTD of KM mice was higher than 4000 mg/kg, and LD50 for female KM mice was 408.7 mg/kg and male animals 432.7 mg/kg, respectively. Subchronic toxicity (6 months) experiment showed that the no toxicity dose of ulvan from U. pertusa is 1200 mg/kg body weight per day. General pharmacology indicated that ulvan had no obvious influence on nerve system of rats and no obvious influence on breath and cardiovascular system of narcosis dogs. Different molecular weight ulvans were obtained by the degradation methods of hydrogen peroxide, and their antioxidant activity in vitro were determined. High sulfate content, acetylated and benzoylated derivatives of ulvan were prepared, and their antioxidant activity and antihyperlipedemia were determined. The results proved that different molecular weight ulvans had different antioxidant activity, moreover, the antioxidant activity increased with decreasing the molecular weight. The derivatives of ulvans showed stronger antioxidant activity than ulvan. The antihyperlipedemia animal experiment indicated that ulvan and its derivatives possessed antihyperlipedemic activity. furthermore, high sulfate content derivative had more pronounced activity than ulvan, but the difference was not considered to be statistically significant. Low and middle dose of high sulfate content ulvan have more pronounced antihyperlipedemic activity than high dose, except on LDL-C, moreover, the middle dose of HSU showed stronger activity on TG (P<0.01) and LDL-C (P<0.01) than ulvan. Low dose acetylated ulvan showed stronger activity on decreasing TG and LDL-C than high and middle dose. The antihyperlipedemic mechanism of ulvan and its derivatives needed to be further studied.
页数	100
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/1509
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	綦慧敏. 孔石莼多糖及其衍生物的研究[D]. 海洋研究所. 中国科学院海洋研究所,2007.

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