Enantiomeric separation by MEKC using dodecyl thioglycoside surfactants: Importance of an equatorially oriented hydroxy group at C-2 position in separation of dansylated amino acids

To investigate the influence of stereogenic centers of sugar‐based surfactants for enantiomeric separation, four n‐dodecyl thioglycoside sulfates (CMC 1.5–3.6 mM) were chosen as micelle‐forming surfactants and five dansylated hydrophobic amino acids were used as test analytes. The analytes were mutually separated by these micelles exhibiting almost similar migration times independent of the used surfactant. Baseline separations of all enantiomers were achieved using both β‐D‐glucose and β‐D‐galactose derivates that have an equatorially oriented hydroxy group at C‐2 position. In contrast, the ability of enantioseparation was markedly decreased in the case of β‐D‐mannose and 2‐deoxy‐β‐D‐glucose derivatives. These results suggested that the structure of C‐2 position of the sugar unit, namely presence of an equatorially oriented hydroxy group, is highly important for the enantiomeric separation of the chosen hydrophobic dansylated amino acids.