Fluorescent Properties of Arctiin and Arctigenin and Fluorimetric Analysis of Arctiin in Traditional Chinese Medicine Arctii Fructus

KeyWord:arctiin  arctigenin  Arctii Fructus£¨AF£©  fluorimetric analysis  3D fluorescence

Abstract:

      In three-dimensional(3D) fluorescence spectra,both arctiin and arctigenin presented two fluorescence peaks with excitation wavelengths£¨¦Ëex£© of 230 nm and 280 nm,separately,and all peaks with emission wavelength£¨¦Ëem£© of 310 nm.The fluorescence intensity of arctiin was much stronger than that of arctigenin.Acidity possesses great influence on fluorescence intensities of arctiin and arctigenin.When pH was larger than 13.0,the fluorescence of arctiin was enhanced,but the fluorescence of arctigenin was quenched.The 3D fluorescence spectrum and the thin layer fluorescence chromatogram of Arctii Fructus(AF) crude drugs revealed that the fluorescent component of AF was mainly arctiin,whereas arctigenin and other components had no interference with the fluorescence of arctiin in strong alkaline condition.Accordingly,methanol was used as solvent to extract arctiin from AF sample,and the extraction solution was diluted properly with water and adjusted to pH 13.0.Then,the content of arctiin was determined at wavelengths of ¦Ëex/¦Ëemequal to 280 nm/310 nm.The calibration curve for arctiin was linear in the concentration range of 0.014 5-2.03 mg?L-1,the regression equation was IF=2.7+148.7¦Ñ(mg?L-1),with correlation coefficient(r) of 0.999.The method was applied in the analysis of arctiin in an AF control medicinal materials,with a content of 6.01% and a spiked recovery of 98.1%.The method was verified by a thin layer chromatography-fluorescence scanning method,and the results demonstrated that this method was reliable,and could be used for the quality evaluation of AF crude drugs.