Fluorimetric Analysis Of Active Components Of Chinese Medicine Houpu

Fluorescence spectra of Magnolol and Honokiol, active components of Officinal Magnolia Bark (Houpu), were studied in this thesis, and influences of experimental conditions on fluorescence spectra were also investigated. According to the difference between fluorescence properties of Magnolol and Honokiol, a fluorimetric method was established for the determination of Magnolol and Honokiol in Houpu sample directly without preseperation. Three-dimensional fluorescence spectra of Houpu were also investigated for identifacation of Houpu crude drugs.Four parts were included in this thesis:1. Fluorescence spectra of Magnolol and Honokiol were studied. The influence of acidity, surfactant and solvent on fluorescent property and the linear relation between fluorescence intensity and solution concentration were investigated. Ionization constant of Magnolol was determined to be pK_a = 7.67 by a pH-absorption method, and pK_a = 7.54 by a pH-fluorimetric method. Using L-tryptophan as a reference and in near nertral condition, fluorescence quantum yield of Magnolol was measured to be 0.36 at maximum excitation wavelenthg 286 nm, and fluorescence quantum yield of Honokiol was 0.31 at maximum excitation wavelenthg 258 nm.2. Fluorescence spectra of Houpu extraction were studied. According to the spectral properties of Houpu, Magnolol and Honokiol, a fluorimetric method was established for analysis of Magnolol and Honokiol in Houpu sample directly without preseperation. Using this new method, the content of Magnolol in Houpu was determined to be 0.97%, and the content of Honokiol was 0.75%.3. A thin-layer scanning method was established for the analysis of Magnolol and Honokiol in Houpu sample, and the contents of Magnolol and Honokiol in Houpu sample were determined to be 0.98% and 0.77%, respectively. The result was coincident with that obtained by solution fluorescent method.4.Three-dimensional fluorescence spectra of Houpu were studied, the robustness of the analytical method, the reproducibility and specificity of fluorescence spectra were also investigated to establish the best conditions, thereby a new method using three-dimensional fluorescent fingerprint spectra was established for the qualitative and quantitative analysis of Houpu crude drugs.