【作者】 罗维；

【导师】 赵谋明；

【作者基本信息】 华南理工大学 ， 食品科学， 2010， 博士

【摘要】 余甘子（phyllanthus emblica L.）是大戟科（Euphorbiaceae）叶下珠属（Phyllanthus）的果实,富含多种对人体有益的生物活性物质,包括多酚、黄酮、甾醇、生物碱、活性多糖、维生素、氨基酸以及微量元素。具有化痰止咳、健胃消食、清热生津、保肝解毒等功效,被广泛用于抗氧化、抗肝损伤、降脂减肥、抗肿瘤和抗菌抗炎等方面。本研究目的在于探讨惠州产地野生余甘子干果的化学成分组成,并对其药理及生物活性进行研究,为其在食品行业和医药行业的应用和开发提供一定的理论依据,以便更好地综合开发和利用我国大量的野生余甘子资源及发展我国传统中药。本课题采用有机溶剂分级、硅胶柱层析、Sephadex LH-20凝胶柱层析、制备TLC和制备HPLC等分离方法。从惠州产地余甘子干果95%乙醇提取物中共分离得到18种化合物。利用一维和二维核磁共振波谱、质谱和红外光谱等方法分别鉴定为Mallotusinin （C1）、柯子宁（C2）、柯黎勒酸（C3）、异柯里拉京（C4）、粘酸-1,4-内酯-3-O-没食子酸酯（C5）、槲皮素（C6）、槲皮素-3-O-β-葡萄糖苷（C7）、柚皮素（C8）、云香苷（C9）、没食子酸（C10）、鞣花酸（C11）、焦性没食子酸（C12）、β-谷甾醇（C13）、β-谷甾醇棕榈酸酯（C14）、β-胡萝卜苷（C15）、桂皮酸（C16）、5-羟基甲基糠醛（C17）、二十六烷酸（C18）。其中化合物C1、C2、C8、C9、C14、C17、C18为首次从余甘子中分离得到,C1为首次从该植物属中分离得到。采用体外抗氧化实验方法,对余甘子干果中提取得到的单体化合物清除DPPH?自由基、ABTS?+自由基和超氧阴离子自由基的能力进行了研究。结果表明,余甘子中提取得到的多酚化合物都具有较强的自由基清除活性。其中mallotusinin对自由基的清除活性最强。清除DPPH?自由基和超氧阴离子自由基的IC50值分别为3.99μM和2.27μM,清除ABTS?+自由基的TEAC值为6.15。同时还讨论了余甘子中提取化合物自由基清除能力与化合物分子结构之间的构效关系。本文还考察了余甘子中的多酚化合物对Fe²⁺离子的螯合能力以及对Fe²⁺引发的亚油酸脂质过氧化反应的抑制能力。结果显示,各多酚化合物均可螯合Fe²⁺并能抑制Fe²⁺引发的亚油酸过氧化反应,而且其抑制脂质过氧化能力与螯合Fe²⁺能力一致。采用MTT方法,利用人乳腺癌细胞（MCF-7）及人肝癌细胞（HepG-2）两种细胞系,以抑制细胞增殖为目标,对余甘子干果中的多酚类化合物进行了抑制细胞增殖的活性研究。结果显示,余甘子干果中的多酚类化合物对MCF-7乳腺癌细胞和HepG-2肝癌细胞的增殖均有不同程度的抑制作用,且不同多酚化合物对癌细胞增殖的抑制效果各不相同。在测试浓度范围内,余甘子多酚化合物对MCF-7乳腺癌细胞增殖的影响大于对HepG-2肝癌细胞增殖的影响（P < 0.05）。其中单宁化合物mallotusinin对MCF-7乳腺癌细胞增殖抑制效果最好,且与浓度呈现良好的量效关系, IC50值为0.055mM。更多还原

【Abstract】 Emblica, a dry fruit of plant phyllanthus emblica L. （Phyllanthus） of Euphorbiaceae, is a good source of polyphenolic, flavone, tannin and other bioactive substances. Emblica fruit has been used widely in many local traditional medicinal systems and believed to increase defense against diseases, its actions include moistening the lung and relieving cough, cleaning heat and detoxifying fire poison. Similarly, it has application as antioxidant, immunomodulatory, antipyretic, analgesic, cytoprotective and etc. The study was conducted to understand the chemical constituents of the dried fruit of wild emblica. The objective was to screen the biological and pharmacological activities, and provide a theoretical basis in the food and pharmaceutical industry. It would serve as a basis for value-added development and utilization of emblica resources, as well as promote Chinese traditional medicine.Through our research work, 18 compounds were isolated from the 95% ethanol extract of the dried fruit of emblica by repeated column chromatography and elucidated on the basis of various spectral analyses （1D-NMR, 2D-NMR, MS, IR etc.）. The structure of them have been elucidated as: Mallotusinin（C1）、Chebulanin（C2）、Chebulagic acid （C3）、Isocorilagin （C4）、Mucic acid 1,4- Lactone-2-o-gallate （5）、Quercetin （C6）、Quercetin-3-O-β-D-glucoside （C7）、Naringenin （C8）、Rutin （C9）、Gallic acid （C10）、Ellagic acid （C11）、Pyrogallo （C12）、β-Sitosterol （C13）、β-Sitosterol palmitate （C14）、β-Daucosterol （C15）、β-Phenylacrylic acid （C16）、5-Hydroxymethylfurfural （C17）、Hexacosanol acid （C18）. Among the isolated compounds, compound C1、C2、C8、C9、C14、C17 and C18 were isolated for the first time in this plant and compound C1 were isolated for the first time in Phyllanthus.The antioxidant activities of purified compounds were evaluated by in vitro experiments using scavenging assays of DPPH radicals, ABTS radicals, and superoxide anion radicals, chelating ability of ferrous ion and inhibition capability of Fe （II）-induced lipid peroxidation, respectively. Most of the purified compounds showed strong radical scavenging activity. Amongst, mallotusinin showed the highest radical sanvenging ablitily than other purified compounds. The IC50 values for DPPH radicals and superoxide anion radicals were 3.99μM and 2.27μM, respectively. The TEAC value for ABTS radical sanvenging was 6.15. Mallotusinin showed significantly higher radical sanvenging capacity compared to TBHQ, BHT and VC （P < 0.01）. All phenolics from emblica fruit showed good potency to chelate Fe²⁺ and could inhibit microsomal lipid peroxidation induced by Fe²⁺.The in vitro cytotoxicity of phenolics compounds from emblcia against MCF-7 breast cancer cell lines and HepG-2 hepatic carcinoma cell lines were evaluated by MTT assay. The resulted showed that all the tested compounds exibitied varying degree cytotoxity to the cell line MCF-7 and HepG-2. Amongst, mallotusinin showed higher antiproliferation capacity against MCF-7 cancer cell lines compared to other purified compounds （P < 0.05） and showed in a dose-dependent manner;更多还原