Synergistic Effect Of Macromolecular Crowding Reagent And Deep Eutectic Solvent On Chiral Separation By Capillary Electrophoresis

Right-handed zopiclone can effectively treat insomnia.Therefore,it is significance to establish a fast,sensitive and effective enantiomer separation method.The aim of this project is to develop a new method capillary electrophoresis(CE)for the resolution of zopiclone enantiomers.Dextran,which can create the "macromolecular volume repulsion effect",was added to the separation system of β-cyclodextrin in this study.The results showed that the addition of dextran could improve the separation efficiency and shorten the detection time.When the dextran concentration was 5 mg/mL,the resolution of zopiclone enantiomers increased from 1.66 to 3.26,and the column efficiency reached 61,200 plates/m.Deep eutectic solvent is the representative of green solvent,which shows excellent performance in various research fields due to their characteristics of simple preparation process,low toxicity,recyclability and environmental friendliness.Therefore,deep eutectic solvents(DESs)were added to the β-cyclodextrin separation system.The results indicated that the DESs composed of choline chloride and ethylene glycol(ChCl-EG)improved reaction efficiency,made column efficiency could up to 12,1000 plates/m,and the resolution of zopiclone enantiomers could reach 4.80.We further investigated the synergistic effect of macromolecular crowding reagent and low eutectic solvent on the chiral separation of β-cyclodextrin.In the experiment,the effects of the concentration of macromolecular crowding agent and the composition and ratio of deep eutectic solvent on the on the enantiomeric separation of zopiclone were investigated.The results showed that when the concentration of dextran was 0.25 mg/mL and 0.5 mg/mL,and the composition of DESs was ChCl-EG with mole ratio of 1:3,resolution of zopiclone enantiomer was achieved 5.19 and 5.06 respectively,the column efficiency was up to 15,7000 plates/m.The effects of ChCl-EG on the resolution were investigated by adjusting the molar ratio of deep eutectic solvent under the condition of fixed glucan concentration and deep eutectic solvent types.According to the results,when the concentration of glucan was 0.25 mg/mL and the molar ratio of ChCl-EG was 1:4,the column efficiency reached 22,2000 plates/m and the resolution was 5.48,which was the optimal separation condition.In a word,the concept of "macromolecular crowding environment",which is a hot research topic in the field of life science,was introduced into the field of capillary electrophoresis.It was found that "macromolecular volume exclusion effect"significantly improved the chiral separation of β-cyclodextrin separation system,and the synergistic effect of macromolecular crowding reagent and low eutectic solvent could further improve the chiral separation.