Analysis Of Three Dimensional Fluorescence Spectra And Determination Of Active Components Of Chinese Medicine Rhubarb

Fluorescence spectra of components of Rhubarb,such as chrysophanol,physcion and rhaponticin,were studied.The influence of experimental conditions on fluorescence stability of aloin aqueous solution was investigated.Based on the fluorescence property of rhaponticin, a fluorimetric method for determination of rhaponticin in Rheum tanguticum was proposed.A fluorimetric method for determination of aloe-emodin was also proposed.By comparing three-dimensional fluorescence spectra of anthraquinone compounds,the relationship between molecular structure and fluorescence wavelength were discussed.The main contents of the thesis were as follows:1.Fluorescence spectra of rhaponticin were studied.Influences of light,time,pH and additional reagents on fluorescence of rhaponticin were explored.The ionization constant of rhaponticin was determined to be pKa=9.37 by a fluorescent method.Three-dimensional fluorescence spectra of Rheum tanguticum and two other Rhubarbs were compared,and the differences between them were explained by fluorescence of rhaponticin.A fluorimetric method for determination of rhaponticin in Rheum tanguticum was proposed,and the content of rhaponticin in a Rheum tanguticum sample was determined to be 14.8%.The reliability of the new method was examined by TLC and HPLC methods,and the obtained results were basically coincident.2.Fluorescence spectra of chrysophanol and physcion were studied at different experimental conditions.The ionization constant of chrysophanol and physcion were determined to be pKa=8.92 and pKa=8.39,respectively.Based on the knowledge of fluorescence properties of five anthraquinones,a new method for analysis of aloe-emodin in rhubarb was proposed.The content of aloe-emodin in a Rhubarb sample was determined to be 0.625%.The new method was also used for determination of aloe-emodin in Aloe and Cassia occidentalis.3.Chemical components of Rheum palmatum,Medicinal rhubarb and Rheum tanguticum were compared,and the relationships between molecular structure and fluorescence wavelength were discussed.Three-dimensional fluorescence spectra of Rhubarbs were primarily analyzed.