| Yam, belongs to Genus of Dioscorea (Dioscoreaceae) is also called Dioscoreszingiberensis C. H. Wright. It was a kind of perennial twining herbaceous, and was the uniqueDioscorea type. Diosgenin and so on were kinds of plant secondary metabolites contained inthe rhizome, and applied mainly as the resource plant of extracting diosgenin at present. Yamtubers were wildly planted in the southern part of Shaanxi Province. Frist, extracted dioscinand flavonoids compounds by different concentrations ethanol, and then diosgenin obtainedfrom dioscin through acid hydrolysis. Second, determined the contents of diosgenin andflavonoids compounds with Chemiluminescence-Flow Injection Analysis (CL-FIA), andcompared with HPLC or UV mothed. Two kinds of CL-FIA system were set up to measurediosgenin and flavonoids compounds in Yam. The main results were as following:(1) Applied research of analysis diosgenin in Yam by the CL-FIA methodThe study found that diosgenin were oxidized by Ce4+and appeared smallChemiluminescence signal, and the signal was enhanced after adding Rhodamine6G. Thus,the new CL-FIA method was set up to determine the diosgenin in Yam. Under the bestexperimental conditions, the concentration of diosgenin was linear with chemiluminescenceintensity in the range from40to200μg/mL, the detection limit was0.057μg/mL. Thestandard deviation was2.41%(c=10μg/mL, n=11), and the average recovery rate was99.8%.The average yield of sample was1.125%, and standard deviation was3.69%.KMnO4in acid solution could appeare small Chemiluminescence signal, and the signalwas enhanced when adding diosgenin. Thus, the new CL-FIA method was established todetermine the diosgenin in Yam. Under the best experimental conditions, the concentration ofdiosgenin was linear with chemiluminescence intensity in the range from40to200μg/mL, thedetection limit was0.076μg/mL. The standard deviation was3.02%(c=10μg/mL, n=11), andthe average recovery rate was98.9%. The average yield of sample was1.008%, and standarddeviation was2.08%.Diosgenin in Yam was determined by HPLC method, the concentration of diosgenin waslinear with peak area in the range from40to200μg/mL. The standard deviation was0.63%(c=40μg/mL, n=5), and the average recovery rate was101.1%. The average yield of samplewas1.808%, and standard deviation was2.18%. Compared with the results from CL-FIA orHPLC determining, the content of diosgenin which measured by CL-FIA was lower then by HPLC method.(2) Research and analysis of flavonoids compounds in Yam using CL-FIA methodFlavonoids compounds were the metabolites of polyphenolic compounds, and had someeffects, such as antioxidant, anti-aging, clearing free radicals in body, etc. According to thescavenging action to H2O2, the Luminol-H2O2-Cu2+system were established to determine theflavonoids compounds in Yam. Under the best experimental conditions, the concentration ofrutin was linear with chemiluminescence intensity in the range from4.4to22.0μg/mL, thedetection limit was1.1×10-3μg/mL. The standard deviation was2.50%(c=1.0μg/mL, n=11),and the average recovery rate was98.1%. The average yield of sample was0.113%, andstandard deviation was1.35%.Na2SO3can be oxidized by Ce4+in acid solution and appeared Chemiluminescencesignal, the signal was weakened with flavonoids compounds. Thus, the Ce4+-Na2SO3-H+system was estabished to determined the flavonoids compounds in Yam.Under the bestexperimental conditions, the concentration of rutin was linear with chemiluminescenceintensity in the range from40to200μg/mL, the detection limit was0.054μg/mL. Thestandard deviation was3.38%(c=1.0μg/mL, n=11), and the average recovery rate was101.2%. The average yield of sample was0.105%, and standard deviation was1.90%.The flavonoids compounds in Yam were determined by UV method, the concentration offlavonoids compounds was linear with absorbance in the range from10to50μg/mL. Thestandard deviation was0.29%(c=0.01mg/mL, n=5), and the average recovery rate was99.2%.The average yield of sample was0.101%, and standard deviation was2.97%. Compared withthe results from CL-FIA or UV determining, the content of flavonoids compounds whichmeasured by CL-FIA was better than UV method.In all, new CL-FIA analysis methods were established to diosgenin and flavonoidscompounds in Yam by the method validation and comparison with three kinds of analysismethods which were CL-FIA, HPLC or UV. First, two kinds of detection methods were builtto detection diosgenin by CL system, and a new CL-FIA method was set up; Second, builttwo detections of flavonoids compounds by CL system, established the CL-FIA methodanalysis of flavonoids compounds. The results showed that the CL-FIA method ofdetermination of diosgenin, the accuracy is slightly less than HPLC method, but the method isfast, simple, and low cost; CL-FIA method for the determination of flavonoids, its accuracy isbetter than that of UV, and can be used in detection analysis of flavonoids compounds. |
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