【作者】 何正春；

【导师】 潘远江；

【作者基本信息】 浙江大学 ， 有机化学， 2014， 博士

【摘要】 自上世纪六十年代起,随着一些天然植物药的相继研发成功,从天然植物中寻找药物或药物先导化合物,成了众多化学工作者从事的热门研究领域之一。我国植物资源丰富,其中部分植物作为我国的传统中药材,具有悠久的药用历史,为人们的健康做出了重要贡献。然而,对于其中许多非传统药用植物品种,至今我们尚未知其内的基础物质成分,为了充分发掘这些宝贵的植物资源,对它们的化学成分及成分的生物活性进行研究,为它们的入药提供科学依据,对于发扬我国传统中医药事业显得非常有必要和有意义。本论文主要对三种药用植物的化学成分进行了研究,其中的两种植物主要对其内的小分子化合物进行了提取分离和鉴定,并对部分所得化合物的肿瘤细胞毒活性进行了筛选。另一种植物主要对其内的大分子(多糖)成分进行了提取分离和鉴定,并对所得成分的免疫促进活性进行了测试。利用现代层析分离技术,分别对报春花科珍珠菜属植物小叶星宿菜(Lysimachia parvifolia Frahoh)和忍冬科鬼吹箫属植物鬼吹箫(Leycesteria formosa Wall)的乙醇提取物进行了分离,分别从该两种药用植物中分离得到22个化合物和22个化合物(共44个),通过化学分析及质谱(MS)、红外光谱(IR)、气质色谱(GC-MS)、以及1D/2D核磁共振谱等现代分析手段对它们的结构进行鉴定,最终,鉴定了其中41个化合物的结构。其中,有五个为新化合物,它们均分离自小叶星宿菜,分别鉴定为：13β-28-epoxy-3β,22α,23-trihydroxyolean-16-one (C30H4805)；13β-28-epoxy-22α,23-dihydroxyolean-3,16-dione(C30H4605)； anagalligenone-3-O-α-L-arabinopyranoside(C35H5608)；anagalligenone-3-O-[β-D--glucopyanosyl(1→4)-α-L-arabinopyranoside](C41H66013；anagalligenone-3-O--[β-D-xylopyranosyl(1→2)-β-D-glucopyranosyl(1→4) α-L-arabinopyranoside](C46H74O17)。根据所得化合物的结构特点,结合该类化合物活性相关的文献报道,我们选取了其中25个化合物,利用抗肿瘤药物体外敏感性活性筛选常用的MTT法,以六种人体常见的肿瘤细胞株为受试对象,对它们的肿瘤细胞毒活性进行了测试。结果表明,其中部分化合物对所测试的肿瘤细胞株均表现出很强的细胞毒活性。基于这一结果,我们选取其中活性最强的化合物10,以HepG2细胞为受试对象,对其可能的活性作用机理进行初步探究,通过流式细胞术对细胞的凋亡情况进行检测,再经PI和DAPI分别对样品处理前后的受试细胞进行染色,并在荧光显微镜下对细胞的型态变化进行观察。结果表明,化合物的细胞毒活性来源于其可破坏细胞骨架,使细胞膜破裂,导致细胞质外流而坏死,而非通过引起细胞程序性死亡(凋亡)来实现。利用热水提取醇沉的方法对佛手(Citrus medica L. var. sarcodactylis Swingle)中的多糖类成分进行提取,再通过DEAE Sepharose Fast Flow阴离子交换柱色谱和SephadexG系列凝胶柱色谱先后对其进行分离与纯化,最终,得到四个均一的多糖组分FCp-1、FCp-2、FCp-3和FCp-4;再经高效凝胶体积排阻色谱(HPGPC)对它们的纯度及分子量分布范围进行测试后,通过红外光谱(IR)、紫外光谱(UV)、气质色谱(GC-MS)及1D/2D核磁共振谱,结合酸水解、甲基化、乙酰化等化学分析法对它们的结构进行确定。结果表明,FCp-1为一杂多糖,含有阿拉伯糖、半乳糖、葡萄糖、鼠李糖和木糖,它们的摩尔比为3.0：7.0：4.1：1.0：1.5；FCp-2和FCp-4为具有→4)-α-D-GalpA(1→链接的半乳糖醛酸聚糖；而FCp-3则为具有→6)-α-D-Glcp(1→链接的葡聚糖。基于多糖普遍具有免疫促进活性,我们以大鼠离体脾细胞和胸腺细胞为受试对象,对所得四个组分的免疫促进活性进行考查。结果表明,其中的FCp-3组分对大鼠离体脾细胞和胸腺细胞具有很强的促进增殖作用,表明其具有较好的免疫促进活性,具有一定的开发利用价值。更多还原

【Abstract】 Since1960s, with the successful development of some herbal medicines, it has been one hot research field for most chemists to find drug or leading compounds from natural plants. China is a country rich in natural plant resources and parts of them have been used in traditional Chinese medicine for a long history. As a multi-ethnic country, various ethnodrugs were developed and enriched the medicinal plant resources. However, little information on their chemical components is known for most of them. So it is believed that analysis and identification of chemical components in these plants is not only necessary but also important for the development of traditional Chinese medicines.This paper was composed of five sections, contents including extraction, isolation and identification of chemical components from three medicinal plants. Two of them were mainly focused on the small molecules and their cytotoxicities. The other plant was focused on its macromolecule constituents (polysaccharide) and their immunological activities.Phytochemical studies on Lysimachia Parvifolia Frahoh and Leycesteria formosa Wall were carried out using modern chromatographic methods, leading to the isolation of22and22compounds respectively. Their structures were elucidated on the basis of chemical analysis, ESI-MS, IR, GC-MS,1D/2D NMR spectra.41of them were identified and5of them were newly reported compounds, and they are elucidated as follows:13β-28-epoxy-3β,22a,23-trihydroxyolean-16-one (C30H48O5);13β-28-epoxy-22a,23-dihydroxyolean-3,16-dione(C3oH4605); anagalligenone-3-O-α-L-arabinopyranoside(C35H56O8); anagalligenone-3-O-[β-D-glucopyranosyl(1→4)-α-L-arabinopyranoside](C41H66013); anagalligenone-3-O-[β-D-xylopyranosyl(1→2)-β-D-glucopyranosyl(1→4)-α-L-arabinopyranoside](C46H74O17).According to the structural features of obtained compounds and the reports on the bioactivities of this type compound,25compounds were selected in evaluation of cytotoxicities in vitro on six human cancer cell lines, using conventional drug-sensitivity screening method (MTT). The results showed that some of them have strong cytotoxic activities on all tested cell lines. Considering the results, the most powerful compound10and GepG2cell lines were selected for possible mechanism exploration. Annexin-V/PI double staining was used for flow cytometry (FCM) to evaluate the apoptosis, and PI and DAPI staining were used for morphology observation. The results showed that compound10was acting on cell membrane to destroy the cytoskeleton in a short time, lead to break of cell membrane and cytoplasm flowed out, finally caused the cell necrosis.Four water-soluble polysaccharides, FCp-1, FCp-2, FCp-3and FCp-4were obtained from finger citron fruits (Citrus medica L. var. sarcodactylis) by hot-water extraction and ethanol precipitation, followed by conventional separation procedure. Based on the calibration curve, molecular weights of them were estimated to be113.9,32.6,140.3and177.1kDa respectively. The acid hydrolysis, methylation, IR, GC-MS and NMR experiments were used for composition analysis. FCp-1was a heteropolysaccharide composed of arabinose, galactose, glucose, rhamnose and xylose, with a molar ratio of3.0:7.0:4.1:1.0:1.5. FCp-2and FCp-4were→4)-α-D-GalpA(1→linking galacturonan differ in molecular weights. FCp-3was a→6)-α-D-Glcp(1→linking glucan. According to the results of in vitro assays, FCp-3showed significantly and moderately enhancing capacities towards the proliferation of splenocytes and thymocytes respectively. Thus, FCp-3or analogs may have potential application as immunomodulatory agents.更多还原