| Natural medicine, which is exploited from natural resources (such as plants, animals), is an important part of medicine. The chemical constituents in natural medicine that have biological activity are named bioactive constituents. The content of bioactive constituents affects the clinical curative effect of natural medicine directly, thus, the development of the rapid, sensitive, reliable qualitative and quantitative method for the analysis of bioactive constituents which are from the different sources and exist in the complex sample matrix is a hot research area in the study of natural medicine. This thesis includes four parts. The first part is a review of the progress in the analysis of bioactive constituents (such as flavonoids and alkaloids) in natural medicine. The comment on the advantage, shortcoming and trend of the different analytical methods has also been given in this part. The second part is the applications of acidic potassium permanganate chemiluminescence (CL) system in the analysis of alkaloids. The optimum conditions for the chemiluminescent reaction between alkaloids and potassium permanganate were studied in detail. A new simple, rapid and sensitive CL method has been developed for the determination of berberine, palmatine, jatrorrhizine, piperine, sinomenine, and synephrine, and this method has been successfully applied to the determination of the total amount of alkaloids in cortex phellodendri, rhizoma coptidis, fructus pireris, caulis sinomeni and fructus aurantii. In addition, a possible mechanism of this CL reaction was proposed on the basis of the investigation of CL, fluorescent and UV spectra of alkaloids in acidic solution containing potassium permanganate. The third part is the study on the electrochemical behavior of some bioactive constituents and its application. (1) The electrochemical behavior of synephrine at the multi-walled carbon nanotubes –Nafion modified glassy carbon electrode has been studied. A sensitive different pulse voltammetry was developed for the determination the total amount of alkaloids in fructus aurantii immaturus. The oxidation mechanism of synephrine was also investigated; (2) The electrochemical behavior of twelve flavonoids (quercetin, morin, fisetin, luteolin, isorhamnetin, myricetin, hyperoside, quercitrin, puerarin, farrerol, naringenin and hesperidin) was investigated. The method for the determination of flavonoids was developed by using different pulse voltammetry, and the detection limit was in the range of 10-7~10-9 mol/L. This method has been successfully employed to determine the total amount of flavonoids in pericarpium citri reticulatae and quercetin in the spiked human blood plasma samples. The oxidation reaction mechanism of flavonoids was also discussed. The fourth part is the study on the capillary electrophoresis behavior of some bioactive constituents and its application. (1) The capillary electrophoresis behavior of 19 flavonoids has been studied in detail. A capillary electrophoresis with amperometric detection (CE-AD) system was developed to separate and determine the above flavonoids. This method is simple, sensitive and reproducible, which will be a useful quantitative method for the analysis of flavonoids in natural medicine; (2) A capillary electrophoresis with amperometric detection system was employed to determine flavonoids in rhizoma saururi herba saururi, herba houttuyniae, herba portulacae, herba leonuri, herba agrimoniae and bioactive constituents (flavonoids and chlorogenic acid) in herba artemisiae scopariae. The results indicated that CE-AD was a rapid and sensitive analytical method for the quality control of the above medicinal plants. |
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