Orosz Tímea, Grecsó Nóra, Lajkó Gyula, Szakonyi Zsolt, Fülöp Ferenc, Armstrong Daniel W, Ilisz István, Péter Antal
Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 7, Hungary.
Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 7, Hungary; Institute of Pharmaceutical Chemistry, University of Szeged, H-6720 Szeged, Eötvös u. 6, Hungary.
J Pharm Biomed Anal. 2017 Oct 25;145:119-126. doi: 10.1016/j.jpba.2017.06.010. Epub 2017 Jun 21.
Polar-ionic and reversed-phase high-performance liquid chromatographic separations of limonene-based cyclic β-amino acid enantiomers were carried out by using macrocyclic glycopeptide-based chiral selectors applying Chirobiotic T, TAG and R columns. The effects of additives, concentration of the co- and counter-ions and the temperature in polar-ionic mobile phase systems were studied. The influence of pH, MeOH content and alcohol additives were investigated in the reversed-phase mode. The difference in the change in standard enthalpy Δ(ΔH°), entropy Δ(ΔS°), and free energy Δ(ΔG°) was calculated from the linear van't Hoff plots derived from the ln α vs 1/T curves in the temperature range 5-40°C. Unusual temperature behavior was observed on Chirobiotic TAG for most of the analytes: decreased retention times were accompanied with increased separation factors with increasing temperature, and separation was entropically-driven. For two of the studied analytes enthalpically-driven enantioseparations were observed. The elution sequence was determined in all cases, but no general rule could be established.
采用基于大环糖肽的手性选择剂（应用Chirobiotic T、TAG和R柱），对基于柠檬烯的环状β-氨基酸对映体进行了极性离子和反相高效液相色谱分离。研究了添加剂、共离子和抗衡离子浓度以及极性离子流动相体系温度的影响。在反相模式下研究了pH值、甲醇含量和醇类添加剂的影响。根据在5-40°C温度范围内由ln α对1/T曲线得到的线性范特霍夫图，计算了标准焓变Δ(ΔH°)、熵变Δ(ΔS°)和自由能变Δ(ΔG°)的差异。对于大多数分析物，在Chirobiotic TAG上观察到了异常的温度行为：随着温度升高，保留时间缩短，分离因子增加，且分离是由熵驱动的。对于两种被研究的分析物，观察到了由焓驱动的对映体分离。在所有情况下都确定了洗脱顺序，但无法建立通用规则。
