ABSTRACT
Polymeric amino acid based surfactants have been recently employed as pseudostationary phases in capillary electrophoresis. These phases are effective for chiral separation of analytes in different charge states and hydrophobicities. This review paper focuses on polymeric dipeptide surfactants. The benefits of dipeptide over single amino acid micelle polymers are shown. Some aspects of dipeptide surfactants that are presented here includes the amino acid order, effect of number and position of chiral centers, and steric factors on enantiomeric separation of chiral compounds in different charge states. In addition, the preferential site of interaction of the chiral analyte using diastereomers of polymeric dipeptide surfactants is discussed.
Subject(s)
Chromatography, Micellar Electrokinetic Capillary/methods , Dipeptides/chemistry , Electrophoresis, Capillary/methods , Surface-Active Agents/chemistry , Amino Acids/chemistry , Fluorescent Dyes , Pharmaceutical Preparations/analysis , Polymers , Protein Conformation , StereoisomerismABSTRACT
Two polymeric dipeptide chiral surfactants (PDCSs), poly sodium N-undecanoyl isoleucyl-valinate (SUILV) with three chiral centers and poly sodium N-undecanoyl leucyl-valinate (SULV) with two chiral centers, have been evaluated and compared as chiral pseudo-stationary phases in electrokinetic capillary chromatography. The performance of these surfactants, in terms of enantioselectivity was examined using anionic, cationic and neutral analytes. Analyses of the data suggest that the enantiomeric resolutions of the analytes with these two PDCSs are dependent upon steric factors rather than number of stereogenic centers.
