利用基于核磁共振的代谢组学方法对植物药薤白的研究

发布时间：2018-12-19 12:59

【摘要】：基于核磁共振的植物代谢组学主要应用核磁共振检测手段,对植物体内大量代谢物同时定性和定量分析,全面系统地研究植物不同部位、不同时间、不同生长环境以及外界刺激对植物代谢的影响,从而对植物进行区分并且通过这些变化来推测相应的代谢途径和代谢网络,将植物的生理过程和外界影响联系起来。由于植物药具有“多成分,多靶点”的特点,结合代谢组学整体性和全面性的特色,因此代谢组学方法似乎是一种非常有利的研究工具。本论文以植物药薤白为研究对象,从代谢组学的方法入手,利用核磁共振技术结合多变量分析方法研究不同炮制过程中薤白代谢物的变化,为其中药制剂的制备过程提供了理论依据和指导作用。首先,由于植物药的储存需要,通常要进行干燥处理,而干燥过程必然会对其代谢成分产生影响。本论文研究了晒干、冻干和阴干过程对植物药薤白代谢物的影响。结果表明,不同干燥方式获得的代谢物种类大致相同,但是含量有差异。从核磁共振图谱中,一共检测到31种代谢物,其中包括2个未归属化合物,而且在薤白中首次报道检测到尿苷这种物质。与新鲜样本相比,脯氨酸的含量在三种干燥过程中都是升高的；糖类、氨基酸的含量在不同的干燥过程中变化趋势不同。此外,根据各代谢物的变化分析得到膜降解、腐胺的合成、三羧酸循环、糖质新生和莽草酸介导途径可能都会受到干燥过程的影响。N-反阿魏酰基酪胺,一种重要的潜在活性物质,在冻干处理样本中含量是最高的,这表明冻干过程可能是薤白处理中较为合适的干燥方式。其次,溶剂的提取对于药用植物来说是非常重要的步骤,不同的溶剂化学特性不同,在提取过程中得到的物质也不尽相同。本论文研究不同溶剂提取薤白代谢物的差异,为薤白中不同活性成分的提取提供理论依据。本课题选取了甲醇、水、正丁醇和乙酸乙酯四种提取溶剂,一共检测到43种代谢物,其中包括4种未归属化合物。甲醇和水提取物的谱图比较类似,主要包含初级代谢产物如糖类,氨基酸,有机酸。正丁醇提取物中主要有硫化物、半胱氨酸、十七烷酸、尿苷和腺苷。乙酸乙酯提取物中主要是脂类、N-反阿魏酰基酪胺和N-对香豆酰基酪胺。由于文献报道,植物药薤白中的潜在活性物质含硫化合物尤其是甲基烯丙基三硫能够降低血脂；腺苷、N-反阿魏酰基酪胺和N-对香豆酰基酪胺对血小板聚集有明显的抑制作用。结合我们的实验结果,正丁醇适宜提取薤白中含硫化合物和腺苷,乙酸乙酯适宜提取N-反阿魏酰基酪胺和N-对香豆酰基酪胺。
[Abstract]:The plant metabolomics based on nuclear magnetic resonance (NMR) mainly uses nuclear magnetic resonance (NMR) to detect a large amount of metabolites in plants simultaneously qualitatively and quantitatively, so as to comprehensively and systematically study different parts and times of plants. The effects of different growth environments and external stimuli on the metabolism of plants are distinguished and the corresponding metabolic pathways and metabolic networks are inferred through these changes. The physiological processes of plants are linked to the external effects. Because plant drugs have the characteristics of "multi-component, multi-target", combined with the characteristics of totality and comprehensiveness of metabonomics, the method of metabonomics seems to be a very favorable research tool. In this paper, macrostemon was used as the research object. The metabolites of Allium macrostemon during different processing were studied by nuclear magnetic resonance (NMR) and multivariate analysis. It provides theoretical basis and guidance for the preparation of traditional Chinese medicine preparations. Firstly, due to the storage requirement of plant medicine, drying is usually necessary, and the drying process will inevitably affect the metabolic composition of plant medicine. The effects of drying, freeze-drying and shade drying on metabolites of Allium macrostemon Bunge were studied in this paper. The results showed that the kinds of metabolites obtained by different drying methods were about the same, but the contents of metabolites were different. A total of 31 metabolites, including two unassigned compounds, were detected in NMR spectra, and uridine was detected for the first time in Allium macrostemon. Compared with fresh samples, the content of proline increased in all three drying processes, and the contents of carbohydrates and amino acids varied in different drying processes. In addition, according to the change of metabolites, membrane degradation, synthesis of putrescine, tricarboxylic acid cycle, glycosylation and shikimic acid-mediated pathway may all be affected by the drying process. An important potential active substance is the highest in freeze-dried samples, which indicates that the freeze-drying process may be a more suitable drying method in the treatment of Allium macrostemon Bunge. Secondly, solvent extraction is a very important step for medicinal plants. In this paper, the differences of metabolites extracted from Allium macrostemon in different solvents were studied, which provided theoretical basis for the extraction of different active components from Allium macrostemon Bunge. Four extraction solvents, methanol, water, n-butanol and ethyl acetate, were selected and 43 metabolites, including 4 unassigned compounds, were detected. The spectra of methanol and water extracts are similar and contain primary metabolites such as carbohydrates, amino acids and organic acids. N-butanol extracts are mainly sulfide, cysteine, heptadecanoic acid, uridine and adenosine. Ethyl acetate extracts are mainly lipids, N-trans-ferulic tyramine and N-p-coumaryl tyramine. As reported in the literature, the potential active substances in the plant drug Allium macrostemon, especially methyl allyl disulfide, can reduce blood lipids. Adenosine, N-trans-ferulic tyramine and N- p-coumaryl tyramine inhibited platelet aggregation significantly. Combined with our experimental results, n-butanol is suitable for extracting sulfur compounds and adenosine from Allium macrostemon, and ethyl acetate is suitable for extracting N-trans-ferulic tyramine and N-p-coumaryl tyramine.
【学位授予单位】：华中师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R282.71;R445.2

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