| Nowadays, the development of Chinese medicine industries faces with great opportunities and challenges. In order to accelerate the modernization of Chinese medicine, novel theory and techniques are required in material basis research of Chinese medicine and improvement of pharmaceutical technological level. Phenolic acids and flavonoids in Traditional Chinese Medicines (TCMs) have obtained more and more attention for their significant pharmacological activities, such as antioxidant, anti-inflammatory, anti-tumor, prevention of cardiovascular and cerebrovascular diseases etc. Phenolic acids and flavonoids undergo degradation and oxidation reactions during the manufacture process of Chinese medicine sometimes, and these reactions will influence the quality of Chinese medicine final products. Thus, the research of degradation of phenolic acids and flavonoids plays an important role in material basis research of Chinese medicine and the improvement of quality control of Chinese medicine. The main contents and achievements of this thesis are summarized as follows:1 A rapid method based on UPLC-QqTOF-MS/MS was developed for the analysis of Chinese herbal prescription Wen-Pi-Tang. The constituents in Wen-Pi-Tang were well separated in only 17 minutes.64 constituents of this prescription were identified and deduced according to accurate mass and mass spectrometric fragmentation mechanisms. The major constituents of this prescription included phenolic compounds from rhubarb, alkaloids from aconite root, triterpenoid saponins from ginseng and flavonoid glycoside from licorice. This method was suitable for material basis research of complex chemical system such as Chinese medicines. 2 An on-line UV spectroscopic collection system was established for recording reaction process spectra. Resolution of complex process spectra was performed with multivariate curve resolution (MCR), and spectra and kinetic profiles of reactant species were reconstructed. On-line UV spectra combined with MCR was applied to the degradation and transformation research of salvianolic acid B, salvianolic acid A and baicalin. The results included:1) the degradation process of salvianolic acid B at pH 8.5,90℃is likely a consecutive two-steps reaction in the form of A(?)B(?)C, the calculated first-order rate constants k1=0.0253 min-1, and k2 =0.0092 min-1. Based on spectra profiles and quadrupole mass spectrometry analy results, the possible degradation products of salvianolic acid B are mainly proposed to be lithospermic acid, danshensu and salvianolic acid A; 2) transformation processes of salvianolic acid A at different temperatures are likely one-order reactions in the form of A(?)B. The calculated rate constants at pH8.5,60℃,70℃,80℃and 90℃were 0.00348 min-1,0.00404 min-1,0.00586 min-1 and 0.00687 min-1, respectively. Based on direct mass spectrometry analysis and Mass workTM software process results, the possible transformation products of salvianolic acid A are mainly proposed to be four polyphenolic acids included salvianolic acid C, isosalvianolic acid C etc; 3) the research of baicalin transformation processes at different conditions indicated that these processes are likely consecutive two-steps reactions in the form of A(?)B(?)C, the calculated first-order rate constants k1 at 60℃,70℃,80℃and 90℃were 0.183 min-1,0.240 min-1,0.257 min-1 and 0.280 min-1, while k2 were 0.091 min-1,0.103 min-1,0.114 min-1 and 0.137 min-1, respectively. The possible transformation products of baicalin are mainly deduced to be 3 isomerides of baicalin, baicalein and dimmer of baicalein. They were deduced based on the analysis results of time-of-flight mass spectrometry and multistage mass spectrometry.3 Isothermal acceleration method was used to investigate the effects of danshensu and protocatechualdehyde on the stability of salvianolic acid B. It was indicated that addition of danshensu and protocatechualdehyde inhibits the degradation of salvianolic acid B. The degradation rate of salvianolic acid B decreased with the increase of amount of danshensu and protocatechualdehyde. Furthermore, with the same concentration of danshensu and protocatechualdehyde, the latter provided stronger protection effect. It was suggested that danshensu and protocatechualdehyde might be natural stabilizing agents of salvianolic acid B.4 Diffusion ordered nuclear magnetic resonance spectroscopy (DOSY-NMR) combined with parallel factor analysis (PARAFAC) was applied for monitoring degradation process of Chinese medicine constituents. As an example, the DOSY-NMR spectra of baicalin at 333 K, with 25% sulphuric acid were collected during its degradation process, pseudo-isolation and analysis of degradation mixture in NMR tube was implemented, and possible degradation products were deduced as baicalein and glucuronic acid. DOSY spctra data of degradation of baicalin was further processed with PARAFAC to resolve spectra and concentration time courses of components, and the results indicated that degradation process of baicalin is likely one-order reaction in the form of A(?)B, the calculated rate constant was 0.25 h-1. |
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