Studies On Mass Spectrometric Fragmentation Patterns Of Four Categories Of Compounds In TCMs And Pharmacokinetics Of QI-SHEN-YI-QI Formula

The chemical compositions of traditional Chinese medicines (TCMs) are material basis for exerting pharmacodynamic action. Qualitative analysis of chemical compositions of TCMs using HPLC-MS technologies will be helpful in deciphering it's pharmacodynamic action ingredients and mechanism of action. However, the absence of well universal mass spectra database for HPLC-MS analysis results in that it is difficult to infer the structure of compounds. Thus, it is essential to investigate mass spectrometric fragmentation patterns of various natural products in order to accumulate data and provide a reference for the identification of chemical compositions of TCMs. Pharmacokinetic studies on TCMs principally reveal the dynamic change of pharmacodynamic action ingredients in body, which will play an important role in elucidating the composition principle of TCMs and mechanism of action, and guiding reasonable clinical prescription. However, the chemical composition of TCMs is extremely complicated, and how to choose representative index compounds become one of the difficulty in the current pharmacokinetic investigation on TCMs.Hereby, in this thesis, four categories of compounds in TCMs, including flavonoids, phenolic acids, sesquiterpene lactones and lignans, that were qualitatively analyzed using HPLC-MS technologies, and their fragmentation patterns were deduced, in order to accumulate data for the identification of chemical compositions of TCMs. In addition, with the QI-SHEN-YI-QI (QSYQ) formula as an investigation carrier and object, qualitative analysis of chemical compositions and pharmacokinetic studies on TCMs were performed using HPLC-MS technologies in order to explore and obtain the feasible and key methods and techniques for the modernization innovation of TCMs.The main contents and academic contributions of this thesis are summarized as follows:1 The flavonoid O-diglycosides from Fructus aurantii and F. aurantii immaturus were analyzed using ESI-MS", and their fragmentation patterns were deduced. The previous literature for naringin located the loss of 120 Da to the glycan part, whereas the present study for naringin had shown that the [M-H-120] ion was principally produced by a retro-Diels-Alder reaction in ring C, and this fragmentation pattern was confirmed by the accurate mass measurement using TOF-MS.2 The dibenzocyclooctadiene lignans from Schisandra chinensis were analyzed by ESI-MS", especially for such compounds substituted with an angeloyloxy, tigloyloxy or benzoyloxy group, and their fragmentation patterns were deduced.25 dibenzocyclooctadiene lignans including 7 groups of isomers were identified or tentatively characterized in S. chinensis. One of them, propinquanin F, is reported as a compound of S. chinensis for the first time.3 Three categories of compounds including flavonoids, phenolic acids and sesquiterpene lactones in Ixeris sonchifolia were analyzed by the combined use of HPLC-ESI-TOF-MS and HPLC-ESI-IT-MS, and their fragmentation patterns were deduced. A total of 6 sesquiterpene lactones,6 phenolic acids and 7 flavonoids were identified or tentatively characterized. Among them,2 amino acid-sesquiterpene lactone conjugates, 11,13-dihydro-13-prolyl-ixerin Z and 11,13-dihydro-13-prolyl-ixerin Z1, that were found in the natural world and 4 phenolic acids from I. sonchifolia for the first time.4 The accurate mass measurements of compounds in QSYQ formula determined from LC-TOF-MS were used to obtain elemental compositions, and the information of multi-stage mass spectrometric fragments provided by LC-IT-MS was used to characterize the structure of these compounds further with the fragmentation patterns of flavonoids, phenolic acids, etc. above-mentioned as reference knowledge, in order to identify the nonvolatile components in this formula. On the other hand, with the aid of the commercial database of abundant EI-MS spectra accumulated for many years, the volatile oils of QSYQ formula have been identified using GC-MS. With this method, a total of 58 compounds in QSYQ formula were identified, which primarily elucidated the chemical compositions of this formula.5 Main pharmacodynamic action ingredients of TCM which were absorbed into blood were selected as representative index compounds in order to carry out pharmacokinetic studies of TCM formulae, which provides a constructive idea on the modernization research for TCM formulae. Hereby, pharmacokinetic studies on QSYQ formula were performed:(1) In silico assessment of permeability and solubility of the chemical compositions in QSYQ formula was carried out to evaluate their absorbability, which could be very useful in identifying the absorbable compounds and searching the origins of metabolites. (2) HPLC-ESI-TOF-MS, HPLC-ESI-IT-MS and GC-MS were utilized to screen and identify the absorbable compounds and metabolites in rats after administration of QSYQ formula. Based on the above identification results and on the literature, the metabolic pathways of absorbable compounds in QSYQ formula were proposed. (3) Four main pharmacodynamic action ingredients, which absorbed into blood, containing astragaloside IV, danshensu, ginsenosides Rg1 and Rb1, were used as representative index compounds to study further the pharmacokinetics and tissue disposition of QSYQ formula using HPLC-ESI-TQ-MS. (4) The disposition of volatile oils after oral administration of Dalbergia odorifera extract to rats was preliminarily investigated using GC-MS. In brief, the present study primarily profiled the fate of 4 pharmacodynamic action ingredients of QSYQ formula in body after oral adminastration of this formula.