Daodi Study Of Lycii Fructus Based On Liquid Chromatography Mass Spectrometry

Lycii Fructus(Gouqizi in Chinese name),the dried ripe fruit of Lycium barbarum L.(Solanaceae),is well known for its extensive biological activities and is honored as“superfruit”.As the possible influencing factor of the accumulation of secondary metabolites in goji berries is the planting environment,the quality of the products not only closely relates to the origin of goji berries,but also from different places varies to different degrees.Zhongning County,Ningxia Province,as the Daodi production region of Lycii Fructus,the quality of Zhongning Goji berries(ZNG)enjoys high value and popularity over the world.However,ZNG is often illegally adulterated in the market by illegal traders by adding non Zhongning goji berries(NZNG).Consequently,the development of biomarker(s)is necessary for proper identification of ZNG and NZNG.Thus,in this thesis,focused on the scientific problems existing in the study of Lycii Fructus Daodi and innovative technologies that can identify the Lycii Fructus Daodi production region as the main objective.Based on data mining technology,we build a real-time compound database and use the UPLC-QTOF-MS technology to verify the ability of biomarkers to distinguish ZNG by biomarkers in ZNG explored by metabolomics and statistical analysis integration methods and the establishment of a model of receiver operating characteristic(ROC)discrimination;The first use of the new “ZNG biomarker” to identify ZNG and NZNG by LC-MS method and achieve quality control of ZNG by absolute quantification.So far,the results are the following:1.By reviewing the related literatures about Lycium genus compounds,the structure of the isolated compounds was collated.We established Lycium genus database including285 compounds of known structure with molecular weights ranging from 60 Da to 1374 Da,such as glycolipids,alkaloids,lignans,flavonoids,organic acids,nitrogenous compounds,etc.By comparing the secondary mass spectrometry data of the extracts of Lycium genus plants to be tested with this database,the composition of main compounds in the samples can be rapidly analyzed,making the processing analysis samples simpler and more intuitive.2.UPLC-Q-TOF-MS technology and integration of the targeted metabonomics and statistical analysis method excavate the ZNG and NZNG mass spectrum data and,a single variable,multi-factor statistical analysis combined with ROC of biomarker screening and validation method was established.7 biomarkers were identified by matching the plants of the Lycium genus small molecular mass spectrum database construction compound,and,one of which was an unreported compound(glycoside of pyrrolidine alkaloid).These markers could be used as single biomarkers for receiver operating characteristic(ROC)analysis.The unreported compound had great ability in distinguishing between ZNG and NZNG,and could almost be used as a feature biomarker.In addition,because pyrrole derivatives are currently only found in genus Lycium of the Solanaceae,this compound has great potential for application.In particular,two sets of combinative biomarkers were identified and were validated by means of the binary logistic regression model to have high sensitivity and specificity for distinguishing ZNG from NZNG.Moreover,there was a significant positive correlation between the two combinative biomarkers and the glycoside of pyrrolidine alkaloid.3.The quality control of ZNG was carried out with new “ZNG biomarkers” :quercetin and succinic acid as indicators.At the 95% confidence level,the optimal cutoff values for quercetin,succinic acid,and their combinative are 0.6989,51.5412,and 0.2902?g/g,respectively,which can be used to quickly and efficiently identify ZNG.The results above mentioned enrich the research contents of Lycii Fructus.The Lycium database established can quickly and accurately provide a large number of useful compound structure information of samples;The proposed multi-marker detection and verification method that relies on non-targeted metabolomics and biomarker validation methods confirms ZNG biomarkers;Biomarkers can be used as new quality standards for Chinese herbal medicines to ensure the quality;The site where the antioxidant activity of the polysaccharide is obtained is excavated.