Qiu Xiaodan, Zhao Xuejia, Jia Qingying, Zheng Ruifang, Xing Jianguo, Yao Jing, Shan Guangzhi
Institute of Medicinal Biotechnology, Peking Union Medical College & Chinese Academy of Medical Sciences, Tian Tan Xi Li No.2, Beijing 100050, PR China.
Xinjiang Key Laboratory of Uygur Medical Research, Xinjiang Institute of Materia Medica, Xinhua South Road No.140, Urumqi 830004, China.
J Chromatogr A. 2025 Sep 13;1758:466220. doi: 10.1016/j.chroma.2025.466220. Epub 2025 Jul 13.
The mechanisms of retention and separation for protected amino acid (PAA) enantiomers on polysaccharide-based chiral stationary phases (CSPs) under supercritical fluid chromatography (SFC) have yet to be investigated. In this study, 18 pairs of PAAs were firstly enantioseparated using SFC with polysaccharide-based stationary phases, and the enantiorecognition mechanism of PAA on the polysaccharide-based CSPs were explored. The key parameters including the stationary phase, modifiers, additives, column temperature, and back pressure were optimized to achieve the baseline separation of PAA enantiomers, which facilitates a more in-depth investigation into the enantiorecognition mechanism. The ADH chromatographic column demonstrates superior separation capability for PAA enantiomers compared to other types of CSPs and subsequent investigations into the enantiorecognition mechanism were primarily centered on ADH. The calculated thermodynamic parameters indicated that for most enantiomers, the process of enantioseparation was primarily driven by enthalpy; however, for Fmoc-Gln(Trt)-OH specifically, entropy played a more significant role in its separation. Molecular docking study was conducted to explore the enantiorecognition mechanism and the results denoted the important role of hydrogen bond and π-π interactions. In addition, hydrogen bonds play a crucial role in the enhanced retention for PAA enantiomers, as well as in the reversal of the elution sequence among different PAAs. This study provides a valuable reference for the investigation and elucidation of the corresponding separation mechanisms associated with polysaccharide-based CSPs.
在超临界流体色谱(SFC)条件下,基于多糖的手性固定相(CSPs)上保护氨基酸(PAA)对映体的保留和分离机制尚未得到研究。在本研究中,首先使用基于多糖的固定相通过SFC对18对PAA进行了对映体分离,并探索了PAA在基于多糖的CSPs上的对映体识别机制。对包括固定相、改性剂、添加剂、柱温和背压在内的关键参数进行了优化,以实现PAA对映体的基线分离,这有助于更深入地研究对映体识别机制。与其他类型的CSPs相比,ADH色谱柱对PAA对映体表现出卓越的分离能力,随后对对映体识别机制的研究主要集中在ADH上。计算得到的热力学参数表明,对于大多数对映体,对映体分离过程主要由焓驱动;然而,对于Fmoc-Gln(Trt)-OH而言,熵在其分离过程中发挥了更重要的作用。进行了分子对接研究以探索对映体识别机制,结果表明氢键和π-π相互作用发挥了重要作用。此外,氢键在增强PAA对映体的保留以及不同PAA之间洗脱顺序的反转方面起着关键作用。本研究为研究和阐明与基于多糖的CSPs相关的相应分离机制提供了有价值的参考。