手性配体高效液相色谱拆分肌肽对映体

Enantioseparation of Carnosine by HPLC with Chiral Ligand-exchange Method

关键词:  手性配体  肌肽  对映体拆分

Key words:  chiral ligand  carnosine  enantiomer separation

摘要:

目的 建立手性配体高效液相色谱法对肌肽对映体进行拆分。方法 在Phenomenex chirex 3126 手性色谱柱上，以硫酸铜为手性配体流动相，考察了进样量、流动相有机添加剂、流速、柱温、Cu2+浓度等因素下肌肽色谱拆分行为和热力学特性，并初步探讨了溶质在配体手性柱上的识别机制。结果 检测波长在254 nm，流动相为2 mmol·L^-1 CuSO₄水溶液-乙腈(96∶4)，流速1.0 mL·min^-1可实现肌肽对映体的基线分离。其在色谱柱分离的焓变差值ΔΔHo与熵变差值ΔΔSo对手性识别都有贡献，拆分过程为焓控过程。其中L-肌肽与手性配体及Cu2+形成的络合物呈现出不稳定性，与典型的构像异构色谱行为一致。结论 肌肽对映体可采用手性配体色谱法实现基线分离，其中L-肌肽形成的配位体具不稳定性。

Abstract:

OBJECTIVE To establish a chiral ligand-exchange method by HPLC for the separation of carnosine enantiomers. METHODS Chromatography was carried out by chiral column (Phenomenex chirex 3126) with mobile phase composed of copper sulfate as chiral mobile phase ligands. The effect of sample volume, organic-additives, flow rate of mobile phase, copper concentration, column temperature and thermodynamics character were investigated. Chiral identify principle of solute was researched preliminarily. RESULTS Carnosine enantiomers can be separated on baseline with a mixture of 2 mmol·L^-1 CuSO₄-acetonitriles(96∶4) as mobile phase at a flow rate of 1.0 mL·min^-1 and detected at 254 nm. Both enthalpy change (ΔΔHo) and entropy change (ΔΔSo) have contributed to the chiral recognition. The process of chiral separation is the enthalpy-controlled. The comoles compound of L-carnosine, chiral ligands and Cu2+ present the instability, in accordance with the typical chromatographic behaviour of conformation change. CONCLUSOIN Carnosine enantiomers can be separated on baseline by chiral ligand-exchange method. The chiral ligand of L-carnosine is unstable.