Study On Simultaneous Detection Of Bioactive Constituents In Forsythiae Fructus By Capillary Electrophoresis With UV And Contactless Conductivity Detector

As an important traditional Chinese medicine,Forsythiae Fructus?FF?is the fruit of Forsythia suspensa?Thunb.?Vahl.,it has already been documented in the Chinese Pharmacopoeia as an antipyretic,antidotal,and anti-inflammatory agent for the treatment of ulcers and infections.According to their maturity degrees,FF could be classified into green FF?GF?and ripe FF?RF?,which are named Qingqiao and Laoqiao in Chinese.According to the previous studies,the principal components in GF and FF,such as forsythoside A,phillyrin have already been studies as the suitable index for quality control of FF.Some studies have indicated the observed anti-inflammatory activity of this Chinese herbal medicine might be ascribed to the type of pentacyclic triterpene acids?PTAs?,which includes oleanolic acid?OA?,ursolic acid?UA?and betulic acid?BA?.Besides anti-inflammatory activities,there are the increasing evidences indicated that OA,UA and BA have their own biological activities such as the active role of liverprotection,anti-diabetes and anti-HIV according to pharmacological studies.Hence,in order to improve the quality control system of FF,we investigated the separation and detection of PTAs in FF.As an alternative separation tool,capillary electrophoresis?CE?is becoming popular since its advantages of speed,strong resolution,and low consumption of chemicals.At the same time,the micro elements in FF also have some important functions.This study was aim at developing a simple and fast method for separation and detection of PTAs.Then using the PTAs as the marker compounds and applying some Chemometrics methods to evaluate the quality of FF collected from different locations and maturity.In addition,we investigate the working mechanism of peak-transfer when we using the CE-Capacitively coupled contactless conductivity detection?CE-C⁴D?to detect the metal ions.Chapter one introduced the basic structure and principles of CE,the research development of FF,the theory of ?-cyclodextrin??-CD?when it employed into chiral separation,and the Chemometrics methods.In this chapter we summarized different chromatography methods of separation and detection of PTAs,by comparing those methods,we found that CE have many advantages to separate PTAs.Chapter two developed a CE-UV method for separating and detecting PTAs.We investigated the types and concentration of background electrolyte?BGE?and chiral selector.And emphatically discussed the chiral separation mechanism of ?-CD and PTAs,and the binding constants have been calculated successfully which can conduct the separation.At last,we obtained the optimized the separation condition: using 50 mmol/L borax and 0.5 mmol/L ?-CD,the PTAs can be separated at p H value of 9.5.The proposed method do not need any derivatization processes and allowed the LODs of PTAs were averaged at 1.50 ?g/m L with UV detection?200 nm?,the inter-day RSD of migration time and peak area were around 2.0% and 5.3%?n=5?,respectively.Chapter three on account of the optimized method and apply it to detect PTAs in 19 samples of FF which is collected from 12 different geographical locations in China.And then,some Chemometrics methods,such as hierarchical cluster analysis?HCA?and principal component analysis?PCA?,have been applied to evaluate the quality of GF and RF,and to compare the FF from different locations.Through this way we found that the total contents of PTAs in GF is much higher than RF,and the content of UA is the mainly compounds in PTAs,also the BA was founded in all the RF.So,using the contents of PTAs as the marker compounds supplied a new method and tool to quality control of FF.Chapter four was focus on establishing a CE-C⁴D to detect the micro elements,such as Mg²⁺?Zn²⁺?Cu²⁺.CE-C⁴D can detect the metal ions based on the difference of analytes and BGE.Comparing with atomic absorption spectrometry?AAS?which is the widely use method for detecting metal ions,the proposed method is much more cheap and convenient.The point is that we investigated the working mechanism of peak-transfer by changing the composition of BGE and its p H.Chapter five is the conclusion and outlook of this study.