Enantioseparation of Racemic Mixtures Based on Solvent Sublation

Abstract

A method of solvent sublation was developed for the enantioseparation of racemic ofloxacin (rac Oflx) and racemic tryptophan (rac Trp). In this method, dibenzoyl-L-tartaric acid (L-DBTA) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) and sodium lauryl sulfate (SDS) were used as chiral coextractants and foamer, respectively. Several important parameters influencing the separation performances, such as pH in aqueous phase, concentrations of rac mixtures, L-DBTA, D2EHPA, and SDS, were investigated. Under the optimal operation conditions, the enantiomeric excess and enantioselectivity were 60.08% and 5.58 for Oflx and 65.09% and 6.31 for Trp, respectively. The yields of D-enantiomer and L-enantiomer were 34.23% and 8.54% for Oflx and 18.59% and 3.93% for Trp, respectively. The results suggest that the enantioselectivities have been enhanced compared with the traditional chiral extraction. This technique is an efficient chiral separation method, with many advantages such as low expenditures of organic solvent, low consumption of chiral extractant, and easy realization of multistage operation.

Extraction of Tryptophan enantiomers by aqueous two‐phase systems of ethanol and (NH4)2SO4

“…Also K and α behave similarly. Previous reports show that chiral discrimination in Equations (5) and (6) are greater than those in Equations (7) and (8) at the pI point. However, the increase of pH leads to a decrease of β ‐CD concentration in the lower phase.…”

Complex‐precipitation using functionalized chiral ionic liquids with L‐proline anion and chromatographic analysis for enantioseparation of racemic amino acids

“…In recent years, the study of their enantioseparation has been attracting more and more researchers, and various methods have been emerging that mainly include chemical resolution, 14 membrane resolution, [15][16][17] Huimin Zang and Shun Yao contributed equally to this work. enzymatic resolution, [18][19][20] chromatographic resolution, [21][22][23][24][25] extraction, 26,27 and molecular imprinting technique. 28 Among them, the solvent extraction method has the advantages of high separation efficiency, simple equipment, and low energy consumption, but a lot of organic solvents are used.…”