School of Chemical Sciences, Universiti Sains Malaysia, Penang, Malaysia.
Electrophoresis. 2010 Sep;31(17):2957-63. doi: 10.1002/elps.201000266.
Binding constants for the enantiomers of modafinil with the negatively charged chiral selector sulfated-β-CD (S-β-CD) using CE technique is presented. The calculations of the binding constants employing three different linearization plots (double reciprocal, X-reciprocal and Y-reciprocal) were performed from the electrophoretic mobility values of modafinil enantiomers at different concentrations of S-β-CD in the BGE. The highest inclusion affinity of the modafinil enantiomers were observed for the S-enantiomer-S-β-CD complex, in agreement with the computational calculations performed previously. Binding constants for each enantiomer-S-β-CD complex at different temperatures, as well as thermodynamic parameters for binding, were calculated. Host-guest binding constants using the double reciprocal fit showed better linearity (r(2)>0.99) at all temperatures studied (15-30°C) and compared with the other two fit methods. The linear van't Hoff (15-30°C) plot obtained indicated that the thermodynamic parameters of complexation were temperature dependent for the enantiomers.
本文采用 CE 技术，展示了莫达非尼对映异构体与带负电荷的手性选择剂硫酸化-β-环糊精（S-β-CD）的结合常数。通过对不同浓度 BGE 中 S-β-CD 下莫达非尼对映异构体电泳迁移率值进行三种不同线性化图谱（双倒数、X 倒数和 Y 倒数）的计算，得出了结合常数。实验结果表明，S-对映异构体-S-β-CD 复合物对莫达非尼对映异构体具有最高的结合亲和力，这与先前进行的计算结果一致。此外，还计算了不同温度下每个对映体-S-β-CD 复合物的结合常数以及结合的热力学参数。使用双倒数拟合的主体-客体结合常数在所有研究温度（15-30°C）下都表现出更好的线性（r²>0.99），并且与其他两种拟合方法相比，也具有更好的线性。所得线性范特霍夫（15-30°C）图表明，对映异构体的配合物热力学参数随温度变化而变化。
