Török Roland, Berkecz Robert, Péter Antal
Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary.
J Sep Sci. 2006 Nov;29(16):2523-32. doi: 10.1002/jssc.200600100.
Application of a cinchona alkaloid-based chiral anion-exchanger stationary phase for the direct high-performance liquid chromatographic enantioseparation of N-protected unusual phenylalanine analogs is reported. The N-benzyloxycarbonyl, N-3,5-dinitrobenzyloxycarbonyl, N-benzoyl and N-3,5-dinitrobenzoyl derivatives were well separable with high resolution. To achieve optimal separation of the enantiomers, the chromatographic conditions and temperature were varied. Linear van't Hoff plots were observed in the studied temperature range, 278-343 K, and the apparent changes in enthalpy, delta(deltaH degrees), entropy, delta(delta S degrees), and Gibbs free energy, delta(delta G degrees), were calculated. The values of the thermodynamic parameters depended on the nature of the N-acyl groups, on the structures of the compounds, and especially on the nature of the substituent on C3 of phenylalanine.
报道了一种基于金鸡纳生物碱的手性阴离子交换固定相用于直接高效液相色谱法对N-保护的异常苯丙氨酸类似物进行对映体分离。N-苄氧羰基、N-3,5-二硝基苄氧羰基、N-苯甲酰基和N-3,5-二硝基苯甲酰基衍生物能够以高分辨率良好分离。为实现对映体的最佳分离，对色谱条件和温度进行了改变。在278 - 343 K的研究温度范围内观察到线性范特霍夫图，并计算了焓变（ΔΔH°）、熵变（ΔΔS°）和吉布斯自由能变（ΔΔG°）。热力学参数的值取决于N-酰基的性质、化合物的结构，尤其取决于苯丙氨酸C3位上取代基的性质。
