【作者】 王建军；

【导师】 赵宝玉；

【作者基本信息】 西北农林科技大学 ， 临床兽医学， 2007， 硕士

【摘要】 茎直黄芪(Astragalus strictus Grah ex Benth)隶属豆科,广泛分布于西藏各地,是我国疯草类植物的主要优势种之一。对于茎直黄芪化学成分的系统研究至今未见报道,通过对其化学成分的研究不仅可以丰富茎直黄芪化学成分的资料,还可以为种属植物的相关性及其种属植物化学研究提供基础资料,更能进一步为茎直黄芪乃至疯草类植物的开发利用提供理论基础和试验依据。本试验通过试管法和圆形滤纸法对茎直黄芪地上部分化学成分进行了系统预试验。在此基础上,以植物化学和现代化学分离纯化为理论基础,采用醇类溶剂提取、薄层色谱、柱色谱等常规技术和新技术相结合的方法对茎直黄芪大极性化学成分进行了分离纯化,得到了部分化合物;并通过理化性质测定、波谱分析等方法对分离得到的化合物进行结构鉴定。对茎直黄芪生物碱进行了系统的薄层色谱分析。采用琼脂扩散法和试管稀释法,对茎直黄芪提取物的体外抑菌活性进行了研究。研究获得以下结果:1.茎直黄芪化学成分的预试验利用系统预试和专项预试相结合对茎直黄芪所含的化学成分进行了预试验,结果表明茎直黄芪中含有酚类,鞣质,生物碱,黄酮及其苷类,糖、多糖及其苷类,氨基酸及多肽,皂苷,有机酸,甾体和三萜类物质,挥发油;不含蒽醌及其苷类,内酯,香豆素及其苷类,强心苷,氰苷及脂肪族硝基化合物。2.茎直黄芪正丁醇部分和水部分化学成分研究利用薄层层析、柱层析、重结晶等分离纯化技术对这两个部分进行了化学成分的系统分析,从正丁醇部分得到5个单体化合物,根据理化性质以及光谱特征鉴定为氧化氮苦马豆素,1-羟基吲哚里西啶,斑荚素,鼠李柠檬素-3-氧-β-D-半乳糖苷和3,5,7-三羟基-4′-甲氧基黄酮醇。从水部分得到5个单体化合物,目前鉴定出两种化合物,苦马豆素和角鲨烯。除苦马豆素外,其它6种化合物均为首次从茎直黄芪中分离得到,此外,鼠李柠檬素-3-氧-β-D-半乳糖苷,3,5,7-三羟基-4′-甲氧基黄酮醇和角鲨烯为首次从黄芪属植物得到。3.茎直黄芪生物碱薄层色谱分析对茎直黄芪生物碱进行系统提取,通过选择适宜的展开系统对各萃取段生物碱薄层色谱分析。结果表明,茎直黄芪中主要是吲哚里西啶类生物碱,且以大极性成分为主,同时也含有少量的中、小极性生物碱。氯仿部分有7种生物碱,乙酸乙酯部分有6种生物碱,正丁醇部分有4种生物碱。经与苦马豆素标准品对照,茎直黄芪生物碱各萃取段均含有苦马豆素。4.茎直黄芪提取物的体外抑菌活性研究采用琼脂扩散和试管稀释法,从定性和定量两个角度对茎直黄芪各提取物的抑菌活性进行了研究。结果显示茎直黄芪石油醚部分、氯仿部分、乙酸乙酯部分和正丁醇部分提取物对金黄色葡萄球菌、大肠埃希菌、无乳链球菌、沙门氏菌和多杀性巴氏杆菌等5种细菌有不同程度的抑菌作用,其中正丁醇部分抑菌作用较强。通过进一步试验表明正丁醇部分主要抑菌活性成分集中在20%乙醇和40%乙醇部分,尤其以后者抑菌活性最佳。40%乙醇部分对5种细菌的MIC均为6.25mg/mL,对大肠埃希菌的MBC为6.25mg/mL。对金黄色葡萄球菌、沙门氏菌和多杀性巴氏杆菌的MBC均为12.25mg/mL,对无乳链球菌的MBC为25.00mg/mL。苦马豆素对5种菌均有良好的抑制生长作用,对无乳链球菌MIC为0.50mg/mL,对其他4种菌的MIC均为1.00mg/mL。鼠李柠檬素-3-氧-β-D-半乳糖苷除对大肠埃希菌无抑制作用外,对其他4种菌均有良好的抑制和杀灭作用。对金黄色葡萄球菌MIC为0.50mg/mL;对沙门氏菌、无乳链球菌、多杀性巴氏杆菌MIC均为0.25mg/mL,对这三种菌的MBC均为1.00mg/mL。更多还原

【Abstract】 Astragalus strictus Grah ex Benth belong to the Leguminosae which extensively distributed in Tibet. It’s a dominant species of Locoweed in China.The chemical constitutents’systematical research of Astragalus strictus hasn’t ever been seen. The research of chemical constitutents can enrich the materials of Astragalus strictus, provide the basic information about dependablity of species and its chemical constitutents, and supply rationale and experiment gist for exploiture and utilization of Astragalus strictus and even Locoweed. The chemical constituents of Astragalus strictus were pretested systematically by means of tube-test and PC-test. Based on the principles of photochemistry, modern chemical isolation and purification methods, some certain compounds were separated and purified from the extractum. Then, structural identification of them was elucidated by the physicochemical properties and spectral analysis, alkaloids was analyzed systemisticly by thin-layer chromatography (TLC). Finally, their bacteriostatic efficacies were tested in vitro with agar diffusion and tube dilution methods. The results were given as follows:1. Pre-experiment on Chemical Composition of Astragalus strictusThe chemical constitutes were preliminary tested through systematic and special pre-experiment. The results showed that plenty of Phenols, tannins, alkaloids, flavones and its glycosides, saccharides polysaccharides and glycosides, amino acids and opypeptides, saponins, organic acids, sterides and triterpenes, volatile oils existed in Astragalus strictus, anthraquinone and its glycoside, lactone, coumarin and its glycoside, cardiotonic glycoside, cyanophoric glycoside and aliphatic series nitrocompound were not involved in.2. The chemical constituents research of n-butanol fraction and water fractionThe chemical constituents were analyzed by TLC, column chromatography, recrystallization and other separation and purification technology. Five compounds were yielded from the fraction of n-butanol, which were identified as swainsonine N-oxide, l-hydroxyindolizidine, Lentiginosine, Rhamnocitrin-3-O-β-D-galactoside and Kaempferol-4-methylether. Other five compounds were also obtained from the fraction of water. Up to now, two compounds were identified as swainsonine and squalene. In a word, except for swainsonine, other compounds isolated from Astragalus strictus yielded in this protocol, were first reported. In addition, Rhamnocitrin-3-O-β-D-galactoside, Kaempferol-4-methylether and squalene were obtained from the plant of Astragalus Linn for the first time.3. The alkaloids analysis of Astragalus strictus by TLCUsing systematic extraction methods and selection eligible development system, alkaloids extracted by different solvent were analyzed by TLC. The results indicated that the major alkaloids in Astragalus strictus were indolizidine compounds. Furthermore, there were minimum, neutral and maximum polarity indolizidine alkaloids, and the last one holded the first place. There were seven, six, four kinds of alkaloids from the chloroform, EtOAc, n-butanol fractions respectively. And swainsonine was contained in all the fractions compared with the standard preparation.4. Experimental study on antimicrobial effects of extractives from Astragalus strictus in vitroIn order to study the bacteriostatic activity of extractives from Astragalus strictus, agar diffusion and tube dilution method were used to observe its bacteriostatic efficacy in vitro. The results showed four kinds of extractives, extracted by petroleum ether, CHCl3, EtOAc and n-butanol, had different bacteriostatic activity to Staphylococcus aureus, Escherichia coli, Streptococcus agalactia, Salmonella and Pasteurella multocida, and the extractum from n-butanol had a significant inhibition capacity in vitro. Advanced test demonstrated that the major activity components from n-butanol existed in 20% and 40% EtoH fraction, especially in the latter one. As to the 40% EtoH fraction, the MIC to five bacteria of is 6.25mg/mL. The MBC to Escherichia coli, Staphylococcus aureus, Salmonella, Pasteurella multocida and Streptococcus agalactia is 6.25mg/mL, 12.25mg/mL, 12.25mg/mL, 12.25mg/mL and 25.00 mg/mL, respectively. Moreover, swainsonine also had significant bacteriostatic activity to five kinds of bacteria in vitro, the MIC to Streptococcus agalactia is 0.50 mg/mL, to other bacteria is 1.00 mg/mL. Rhamnocitrin-3-O-β-D-galactoside has profound property on inhibiting and killing bacteria in vitro excepted Escherichia coli, the MIC to Staphylococcus aureus is 0.50 mg/mL, to other bacteria is 0.25 mg/mL, and the MBC to Salmonella, Streptococcus agalactia, Pasteurella multocida is1.00mg/mL.更多还原