The Hypolipidaemic Effect Of Curcuma Longa L. And The Full Characterization And Separation Of Curcuminoids Based On A Combinatorial LC-MS/MS Technologies

This dissertation is composed of four parts.Chapter1presented the separation and identification of curcuminoids in Curcuma longa L. based on the guide of LC-MS/MS technology. Chapter2established a novel strategy for discovery, identification, and characterization of compounds with similar chemical structures using LC-MS/MS (QTOF) and LC-MS/MS (QTRAP) in example of the analysis process of curcuminoids in Curcuma longa L. The third part is a correlation study between serum Lysophosphatidylcholine (LysoPC) levels and the hypolipidaemic effect of Curcuma longa L. based on the LC-MS/MS (QTOF) and LC-MS/MS (QTRAP). The serum LysoPC biomarkers of hyperlipidaemia were found and identified using a target methodology of lipidomics. Chapter4is a review about the methods used in lipidomics research, as well as its applications in the field of other medicine.1. The isolation and identification of curcuminoids in Curcuma longa L.Curcuma longa L. is a medicinal and edible Traditional Chinese medicine, and curcuminoids are the main active components. Other curcuminoids besides curcumin, demethoxycurcumin, and bisemethoxycurcumin are trace components. The three main curcuminoids are difficult used for clinical applications due to the poor oral absorption and low bioavailability. There, curcuminoids in trace amount which possessed the same or the better activity are need to be studied immediately. Twelve curcuminoids were isolated from Curcuma longa L., two of them are novel compound, and three of them were first obtained from the plant. The technology of1H NMR、13C NMR、DEPT、HSQC、HMBC、1H-1H COSY and HR-MS were combined to identify the chemical structure of curcuminoids. Finally, eleven of them were identified and one of the structure is still under identification.2. Full characterization and identification of curcuminoids using a combinatorial LC-MS/MS technologies Single mass spectrometry technology has some limitations. High resolution LC-MS such as Q-TOF MS, possessed good resolution, but it lacks target scan modes with high-sensitivity; The Q-Trap MS has a series of scan modes for the discovery of trace components, but accurate mass of compounds are not available. Therefore, the study trategically combine LC-MS/MS (Q-TRAP) with LC-MS/MS (Q-TOF) to characterize and identify all curcuminoids components.First, LC-MS/MS (Q-TOF) is used to analyze the total extract of curcuminoids with a full scan mode. The characteristic patterns of curcuminoids including accurate molecular weight of parent ion and product ions was used to heptane skeleton structures. Second, every situations of different phenyl-substituents are predicted by an arrangement of statistical methods. Then, the possible parent/produt ion-pairs are list to start the followed step using C-MS/MS (QTRAP) with a MRM-IDA-EPI scan mode. All the MRM ion pairs, retention time and the corresponding fragmentation chromatograms are obtained, and finally completed the full characterization and identification of curcuminoids based on the MRM ion pairs, retention time and the corresponding fragmentation chromatograms from LC-MS/MS (Q-TRAP) and LC-MS/MS (Q-TOF). As a result, ninety-six curcuminoids are identified by the novel strategy established in the study.3. The hypolipidaemic effect of Curcuma longa L. associated with a targeted lipidomics strategyAs second messengers in biology, Lyso PCs are transient metabolites with glycerophospholipids structure. The hypolipidaemic effect of Curcuma longa L. and the changes of serum LysoPC levels are correlated to investigate the Potential hyperlipidemia biomarkers of LysoPC and the hypolipidaemic effect of Curcuma longa L. First, seventy-four Lyso PCs were detected and identified by LC-MS/MS (QTOF) in mice serum; Second, among which fifty-nine Lyso PCs were relatively quantified. The results report regarding a targeted lipidomics approach for analyses of serum Lyso PCs and its application to interpretation of hypolipidaemic effect of Curcuma longa L. on mice hyperlipidaemia. The Lyso PCs biomarkers found in the study will provide new insights in the screen of hyperlipidemia biomarkers, and the established method can also be used in screening other biomarkers associated with diseases.