基于质谱分子网络结合 UPLC-DAD/MS-SPE及NMR去重复技术的八棱脆海棠果化学成分研究

	基于质谱分子网络结合 UPLC-DAD/MS-SPE及NMR去重复技术的八棱脆海棠果化学成分研究; Studies on dereplication discovery of composition of Malus robusta Rehd based on MS-molecular network combined with UPLC-DAD/MS-SPE and NMR
	陈鹏瑀
导师	胡凯锋
摘要	Crabapples (Malus robusta Rehd) are widely distributed in Asia, Europe and North America. Crabapple fruits contains a lot of polyphenolics such as flavonoids, coumarins, caffeoylquinic acids, etc., so crabapple fruit extracts show significant antioxidant activity, which can prevent atherosclerosis and chronic cardiovascular. Crabapple fruits also contain a certain amount of triterpenoids, such as oleanolic acid, ursolic acid, maslinic acid and other compounds, which have significant anti-tumor, anti-inflammatory and anti-diabetic effects. UPLC-MS has been widely used in the dereplication analysis of natural products in recent years. Mass spectrometry is a powerful tool with high sensitivity and high throughput. UPLC-DAD/MS-SPE is an efficient targeted separation technology that can target low-concentration compounds. Matching NPid customized database also to dereplicate compounds in genus Malus. The main goal of this thesis is to use UPLC-DAD/MS-SPE and NMR, molecular networking technology and MS/MS databases to quickly identify the compounds in crabapple fruits, to discover and isolate unknown compounds and determine their structure. LC-MS and LC-MS/MS data files were converted to .mzXML format using DataAnalysis 4.1 (Bruker, Germany) and analyzed by the online GNPS workflow (https://gnps.ucsd.edu). GNPS analysis of LC-MS/MS data can simultaneously generate molecular network and quickly screen and dereplicate known compounds in the mixture. Compounds with similar MS/MS pattern were clustered together in the molecular network. MS/MS molecular networking developed in recent years is a powerful technique for dereplication of natural products, which can combine with other dereplication tools, such as MS/MS spectral libraries, and UPLC-DAD/MS-SPE to rapidly identify known compounds and targetedly isolate unknown compounds. Following Global Natural Products Social (GNPS) Molecular Networking workflow, compounds with similar MS/MS spectrum pattern cluster together and multiple clusters of natural product show up in the molecular network. Screening the precursor ions in the clusters, some compounds can be identified by referencing their MS/MS fragment ions to spectral libraries, including the GNPS inherent spectral libraries, customized MS/MS spectral libraries of natural products from crabapples and public third-party MS/MS spectral libraries, such as HMDB. With those identified compounds serving as seeds, the identities of large part of other precursor ions in the clusters can be quickly deduced based on the similarity of the MS/MS spectrum pattern.
	2020-05
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74112
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	陈鹏瑀. 基于质谱分子网络结合 UPLC-DAD/MS-SPE及NMR去重复技术的八棱脆海棠果化学成分研究, Studies on dereplication discovery of composition of Malus robusta Rehd based on MS-molecular network combined with UPLC-DAD/MS-SPE and NMR[D],2020.

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