Enantiomeric separation of drugs by affinity electrokinetic chromatography using dextran sulfate

Abstract

Dextran sulfate (sodium salt), which is a mixture of a linear a-(1,6)-linked D-glucose polymer having a sulfate group in the molecule, has been employed as a chiral selector in affinity electrokinetic chromatography (EKC) for the separation of enantiomers of drugs. Enantiomers of trimetoquinol hydrochloride and its positional isomer have been successfully separated by the method using a 3-5% dextran sulfate buffer solution of pH 5.5 within 20 min. The effects of buffer pH, concentration of dextran sulfate, and additives (such as an organic solvent, urea and a surfactant) on the enantioselectivity were investigated. The choice of pH and the concentration of dextran sulfate has been important for the

Enantiomeric Separations in Capillary Electrophoresis Using 18-Crown-6-tetracarboxylic Acid (18C6H4) as Buffer Additive

“…Other natural polymers, like saccharides, were applied to CE separation of enantiomers in two modes. The first is CE with an electrically neutral [21,22] maltodextrin and the second is affinity EKC with an ionic polysaccharide like chondroitin sulfate sodium salt and heparin sodium salt [23,24].…”

Separation of enantiomers by capillary electrophoresis using pentosan polysulfate

“…1). Another chiral selector that lacks free hydroxyl groups for hydrogen bonding is dextran sulfate, with which only a few enantioseparations have been reported [19,21,22]. The relatively high pH (pH > 5) of the run buffer in these reports may explain why fewer separations were achieved with dextran sulfate.…”

“…Furthermore, there is a wide range of different linear carbohydrates to choose from, each providing unique characteristics for enantioseparations. Successful examples in this group include chondroitin sulfates [6,19,20], dextrans [6,19,21,22], dextrins [6,23], aminoglycosides [6,24], and heparin [6,19,22,25]. A new linear polysaccharide, pentosan polysulfate, will be examined as a chiral selector in CE.…”

Chiral separations in capillary electrophoresis

“…Later, it was used for the separation of the oxaminic enantiomers [75] and, together with dextran sulfate, for the resolution of the chloroquine and chloropheniramine enantiomers [76]. Dextran sulfate was effective in the simultaneous separation of enantiomers of trimetoquinol and of its positional isomer [77]. Chondroitin sulfate C [78] and chondroitin sulfate A [79] were effective in the separation of sterically different forms of a family of cationic compounds, namely diltiazem, trimetoquinol and related compounds.…”