LC-MS/MS Based Molecular Network Analysis Of The Flavoalkaloids In Six Traditional Tea Categories

It is a great significance for further exploring of the active components and developing of the economic value of tea to identify natural products from tea leaves with traditional natural product chemistry techniques or the chemical composition of tea was analyzed by modern high-flux chromatography-mass spectrometry.Tea alkaloids is an important component and related to the flavor and many biological functions of tea.A new study found a series of new type flavonoid alkaloids of white tea in white peony tea first time,its structural characteristics embodied in N-ethyl pyrrolidone in flavanol-3-alcohol six or eight.These alkaloids exhibit excellent biological activity in vitro,but their source in tea tree or distribution in commercial tea have not been investigated in detail.The molecular network technology based on LC-MS/MS has attracted more and more attention in the research field of natural products,but the research reports in the field of natural products of tea are very limited.Firstly,This paper analyzed the six traditional tea categories of the LC-MS technique,which were Huangshan maofeng tea(green tea),Huoshan huangdacha(yellow tea),Shoumei(white tea),Anxi tieguanyin(oolong tea),Dianhong(black tea)and Fu brick tea(dark tea).Secondly,convered the original liquid data,and then uploaded them to the GNPS analysis platform for molecular network analysis,Finally,analyzed the distribution of the new alkaloids in six traditional tea categories by the visualization technology of molecular network.This study found that both in Huangshan maofeng,Huoshan huangda cha,Shoumei,Anxi tieguanyin,Dianhong and Fu brick tea represented by green tea,yellow tea,white tea,oolong tea,black tea and dark tea,has contained the new type flavonoid alkaloids first of all.Secondly,these six traditional tea categories contained different amounts of flavonoid alkaloids.The flavonoid alkaloids was the most abundant in black tea fermented by microorganism.In yellow tea,white tea,oolong tea and green tea,the number of such alkaloids decreased,and black tea had the lowest number of such alkaloids.Therefore,we could speculate that the existence of the new type flavonoid alkaloids is related to the processing of tea.In this study,It is the first time to investigate the distribution of the new type flavonoid alkaloids in six traditional tea categories in detail by high-throughput liquid mass analysis technology.It lays a foundation for the further separation of new flavonoid alkaloids from these tea samples and provides clues for the study of the biosynthetic pathway of these alkaloids.