College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, 310032, China; Department of Food Science and Nutrition, Hallym University, 1 Hallymdeahak-gil, Chuncheon, 24252, Republic of Korea.
College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, 310032, China.
J Chromatogr A. 2020 Aug 16;1625:461332. doi: 10.1016/j.chroma.2020.461332. Epub 2020 Jun 9.
Two structural isomeric pentacyclic triterpenes, oleanolic acid and ursolic acid, were considered as the models for the quality control of many traditional Chinese herbal medicines and they have been proved to own important pharmacological activities. In the present work, liquid chromatographic and liquid-liquid chromatographic separation with high peak resolution of structural isomeric oleanolic acid and ursolic acid using hydroxypropyl-β-cyclodextrin as mobile phase additive was successfully achieved, respectively. A high peak resolution, R=8.143, was achieved for the two structural isomeric compounds by conventional reverse phase high performance liquid chromatography, which was greatly improved compared with the published values. Meanwhile, a biphasic solvent system composed of n-hexane-ethyl acetate-0.1 mol/L hydroxypropyl-β-cyclodextrin (9:1:10, v/v) was selected for liquid-liquid chromatography, which provided a high peak resolution, R = 6.573, for analytical apparatus and R = 8.500 for semi-preparative apparatus after optimization by liquid-liquid extractions. Two elution modes including reverse phase mode and normal phase mode were investigated for preparative separation of two acids from crude exact of Eriobotrya japonica Thunb. Furthermore, the inclusion complex between each of the two structural isomers and hydroxypropyl-β-cyclodextrin were also investigated for high performance liquid chromatography and liquid-liquid chromatography, respectively, in which formation constants were determined for oleanolic acid and ursolic acid.
两种结构异构的五环三萜酸，齐墩果酸和熊果酸，被认为是许多中药质量控制的模型，并且已经证明它们具有重要的药理活性。在本工作中，使用羟丙基-β-环糊精作为流动相添加剂，成功地实现了结构异构的齐墩果酸和熊果酸的液相色谱和液-液色谱分离，分别具有高的峰分辨率。通过常规反相高效液相色谱，两种结构异构化合物达到了高的峰分辨率，R=8.143，与已发表的值相比有了很大的提高。同时，选择了由正己烷-乙酸乙酯-0.1 mol/L 羟丙基-β-环糊精（9:1:10，v/v）组成的双相溶剂系统用于液-液色谱，通过液-液萃取优化后，分析仪器的 R 值为 6.573，半制备仪器的 R 值为 8.500。研究了反相模式和正相模式两种洗脱模式，用于从粗提的枇杷叶中分离两种酸。此外，还分别对两种结构异构体与羟丙基-β-环糊精的包合复合物进行了高效液相色谱和液-液色谱研究，确定了齐墩果酸和熊果酸的形成常数。
