Fluorescence Properties And Analytical Methods Of Several Isoflavonoids

Isoflavone compounds are widely found in nature and in various foods and pharmaceuticals,and have a wide range of physiological and pharmacological activities.Isoflavonoids contain conjugated rigid structures in their molecules,which may generate endogenous fluorescence or produce sensitized fluorescence through the C-loop cleavage reaction.In this paper,the fluorescence properties of four isoflavones including ipriflavone,rotenone,corylin,and neobavaisoflavone were studied.The fluorescent methods for analysis of several isoflavones in pharmaceuticals or health products were explored.Three parts are included in this dissertation:1.The fluorescence properties of ipriflavone and rotenone were studied,and a new fluorescent method for analysis of ipriflavone was established.Ipriflavone itself is essentially non-fluorescent,but under hot and alkaline conditions,the C-loop cleavage reaction of ioplavone occurs,the cleavage product can produce fluorescence,the excitation wavelengths?_exare 250,290 nm,and the emission wavelength?_emis 388 nm,its fluorescence quantum yield is 0.012.Rotenone itself does not produce fluorescence,and can produce fluorescence by cleavage reaction under alkaline heating condition.The fluorescence peak is located at?_ex/?_em=255/396 nm,and the fluorescence quantum yield is 0.013.Based on the fluorescence properties of the ioplavone,a new fluorescence assay for the determination of ioplavone in Ipriflavone Tablets was established.The result was47.8%.Which was verified by UV spectrophotometry,and proved that the new method is reliable.2.The fluorescence properties of corylin and neobavaisoflavone were studied.In the range of pH 8.8-12.0,corylin produce stable and strong fluorescence with?_ex/?_em=334/464 nm.At the condition of pH 8.7,neobavaisoflavone produce stable and strong fluorescence with?_ex/?_em=337/460 nm.The fluorescence quantum yields of both were0.033 and 0.040,respectively.Based on the differences in the fluorescence properties of the two at different pH conditions,the three-dimensional fluorescence coupled with second-order correction?3DF-2OC?method was explored to determine the contents of corylin and neobavaisoflavone in chinese herbal medicine Psoraleae Fructus?Buguzhi?without preseparation.3.Based on the fluorescence properties of daidzein and daidzein,the fluorescence spectrophotometry and 3DF-2OC method were established for the determination of daidzin and daidzein in health products.The contents of daidzin in the health product Qingchun Capsules were determined to be 13.61%and 13.17%,and the daidzein content were 1.09%and 1.05%,the results of the two methods were consistent.The two methods were also used to determine daidzein content in the health product Dadouganyuanpian?Daidzein Tablets?,and the results were 9.19%and 9.20%,respectively.Verification by UV spectrophotometry proved that the results are accurate.