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  • 學位論文

毛細管區帯電泳法對類黃酮分析物之分離及pKa値之探討

Studies of Separation and pKa values of Flavone in Capillary Zone Electrophoresis

指導教授 : 林萬寅

摘要


本論文利用毛細管區帶電泳法探討七種類黃酮分析物之分離及pKa値的效應。首先變化毛細管電泳的分離條件如pH值(7.0~11.0)、緩衝溶液種類(磷酸、硼酸或磷酸-硼酸混合)及濃度(25 ~ 75 mM)、添加之界面活性劑SDS濃度(3 ~ 15 mM)及施加電壓(20 kV),以尋找最適化之分離條件。實驗結果顯示,以25 mM磷酸-硼酸混合緩衝溶液( pH 9.2),加入3 mM SDS作為添加剤,施加20 kV之電壓,能有效分離七種類黃酮分析物。緩衝溶液的pH值和取代基推拉電子的效應對類黃酮分析物的分離及pKa值有很大的影響。經由電泳遷移率對pH值作圖之最佳曲線模擬,可得到分析物之pKa 值和極限遷移速率。由分離機制的討論中,單取代pKa大小為C3-OH flavone > C6-OH flavone > C4’-OH flavanone > C2’-OH flavanone > C7-OH flavone,經由添加3 mM SDS,由於解離後極性不同與SDS作用有差異,因此遷移順序為C3-OH flavone > C4’-OH flavanone > C2’-OH flavanone > C7-OH flavone > C6-OH flavone。此外,C4’-OH和C2’-OH flavanone的C2位置為chiral center,嘗試以β-CD、s-β-CD等作為對掌添加劑,探討緩衝溶液pH值與添加劑濃度影響,分離2’-OH flavanone 在50 mM 磷酸-硼酸混合緩衝溶液(pH 9.3),2.5 mM β-CD為最適分離結果。而4’-OH flavanone嘗試β-CD (0-15 mM)、HP-β-CD(1.5-25 mM)、γ-CD(10-25mM)變化pH範圍(9.3-10)都無法有好的對掌分離效果,在50 mM磷酸緩衝溶液(pH 3.0),3.5% s-β-CD 有最適的對掌分離結果。

並列摘要


The influence of pH on the electrophoretic behavior of seven flavone in capillary zone electrophoresis (CZE) was investigated. With the use of an appropriate mobility equation and with the aid of computer simulation through the analysis of mobility curves. The determination of pKa values allows us to rationalize the influence of pH on the electrophoretic behavior of these compounds in CZE. Capillary zone electrophoresis has proven to be a powerful technique for separation. In this study, seven flavone will be separation by using SDS as additive. The optimum electrolyte buffer of CZE was 25 mM mixing of phosphate and borate buffer(pH 9.2), 3 mM SDS, and apply 20 kV. In the other part, we focus on the enantioseparation of 2’-hytroxyflavanone and 4’- hydroxyflavanone with addition of β-CD and sulfate-substituted β-CD (MI-S-β-CD) and the optimization of separation.The optimum enantioseparation of 2’-hytroxyflavanone is 50 mM mixing of phosphate and borate buffer(pH 9.3), 2.5 mM β-CD.Then, the optimum enantioseparation of 4’-hytroxyflavanone is 50 mM phosphate buffer(pH 3.0), 3.5 % s-β-CD.

並列關鍵字

flavone capillary electrophoresis

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