Kai Guiqing, Chen Yan, Wang Yu, Yan Qinghua
School of Life Science, Anhui University, Feixi Road 3#, Heifei, China
School of Life Science, Anhui University, Feixi Road 3#, Heifei, China.
J Chromatogr Sci. 2014 Jul;52(6):532-8. doi: 10.1093/chromsci/bmt132. Epub 2013 Sep 12.
Many of oleanolic and ursolic pentacyclic triterpenoid isomers generally coexist. There is a small difference in their structures. Based on coordination chromatography theory, a reversed-phase high-performance thin-layer chromatography (HPLC) method has been investigated for improving the isomers' resolution by adding suitable agents in mobile phase, and the separation rule was summarized. With the calculation analysis, the space sizes of isomers were in the range of 3.77-5.65 Å. The total minimum energy in the inclusion of guest and β-CD had the biggest reduction, compared with the energy in the simple mixture of guest and β-CD (such as "asiaticoside-B" and "β-CD," from 196.4406 to 95.0670 kJ mol(-1)). So, β-CD (the cavity space size is in the range of 6.00-6.50 Å) and its derivatives were selected as the suitable agents. The experiment results showed that the resolution might be improved by adding the hydrophilic β-CD derivatives in mobile phase, such as Glu-β-CD, when the isomer structures carry big hydrophilic groups.
许多齐墩果烷型和乌苏烷型五环三萜异构体通常共存。它们的结构存在细微差异。基于配位色谱理论，研究了一种反相高效薄层色谱（HPLC）方法，通过在流动相中添加合适的试剂来提高异构体的分离度，并总结了分离规律。通过计算分析，异构体的空间尺寸在3.77 - 5.65 Å范围内。与客体和β-环糊精简单混合物（如“积雪草苷-B”和“β-环糊精”，从196.4406降至95.0670 kJ mol(-1)）的能量相比，客体与β-环糊精包合时的总最低能量降低最大。因此，选择β-环糊精（空腔空间尺寸在6.00 - 6.50 Å范围内）及其衍生物作为合适的试剂。实验结果表明，当异构体结构带有大的亲水基团时，在流动相中添加亲水性β-环糊精衍生物（如Glu-β-环糊精）可提高分离度。
