Laboratorio de Investigación y Desarrollo de Métodos Analíticos (LIDMA), División Química Analítica, Universidad Nacional de La Plata, Argentina.
J Chromatogr A. 2013 Jul 12;1298:103-8. doi: 10.1016/j.chroma.2013.05.030. Epub 2013 May 20.
A conventional nonchiral column was used for the enantioseparation of several racemic α-amino acids (native and derivatized) through the use of Cinchona alkaloids as chiral selectors along with Cu(II) ions in chiral ligand-exchange chromatography. The mobile phase composition (i.e., the organic modifier content and pH) was studied in order to modulate retention and enantioselectivity. Good enantioseparation of many amino acids was obtained using equimolar amounts of Cu(II) and either cinchonidine, quinine or quinidine as chiral selectors in the mobile phase. The molecular geometry of the diastereomeric complexes formed was modeled and energetic differences between both compounds were calculated by methods based on semi-empirical force-field. Good correlations were obtained between experimental enantioselectivity factors and calculated energetic differences.
一种常规的非手性柱通过使用金鸡纳生物碱作为手性选择剂与手性配体交换色谱中的 Cu(II)离子一起，对几种外消旋的α-氨基酸（天然和衍生的）进行对映体分离。研究了流动相组成（即有机改性剂含量和 pH 值），以调节保留和对映选择性。在流动相中使用等摩尔量的 Cu(II)和奎宁定、奎宁或辛可宁作为手性选择剂，可获得许多氨基酸的良好对映体分离。通过基于半经验力场的方法对形成的非对映体配合物的分子几何形状进行了建模，并计算了两种化合物之间的能量差异。实验对映选择性因子与计算的能量差异之间得到了很好的相关性。
