Chromatographic resolution of racemic α-amino acids: Chiral stationary phase derived from modified xanthan gum

Abstract

Enantiomeric resolution of α-amino acids into l-amino acid and d-amino acid via column chromatography using chiral stationary phase was performed. For this purpose, a dynamic chiral stationary phase prepared by grafting of methylmethacrylate onto xanthan gum (XG) was successfully employed in resolving various α-amino acids racemates. The peculiarities of the chromatographic behaviour of xanthan gum–graft-poly(methylmethacrylate)–amino acid interaction and the mechanism of their retention in column are discussed. The enantioselective properties of the xanthan gum–graft-poly(methylmethacrylate) in the separation of enantiomers of α-amino acids were studied using acidic solution of alanine, leucine, valine and tryptophan. The procedure is characterized by simplicity, efficiency and relatively low cost to analyze enantiomers of some amino acids.