Investigation of fusidic acid as a chiral selector in capillary electrophoresis

In this short communication, we report the use of a steroid antibiotic, Fusidic Acid (Fus), as a novel chiral selector for enantioseparation in capillary electrophoresis (CE). Fus can be classified into the antibiotic chiral selector family but does not belong to any of the previously reported subfamilies. Factors influencing Fus in CE enantioseparations were systematically investigated including the composition of the background electrolyte (BGE), buffer pH, type and proportion of organic modifier, concentration of Fus, etc. The best separations were obtained with 50 mM phosphate buffer (pH 8.0) containing 60-70 mM Fus and 50% methanol. A preliminary analysis on the separation mechanism showed that Fus is especially suitable for the chiral analytes containing a rigid planar structure. The development of Fus as a novel chiral selector can be considered as a valuable work not only because of its unique enantioselectivity, but also because there are a number of steroids in nature that are structurally similar to Fus. This work indicates that the screening of high-efficient chiral selectors from these steroids is an attractive and promising research area.