Use of hydroxypropyl- and hydroxyethyl-derivatized beta-cyclodextrins for the thin-layer chromatographic separation of enantiomers and diastereomers

Abstract

Partially substituted hydroxypropyl-beta-cyclodextrin and hydroxyethyl-beta-cyclodextrin proved to be effective chiral mobile phase additives (CMAs) for the thin-layer chromatographic (TLC) resolution of racemic benzyl-2-oxazolidinone, 5-(4-methyl-phenyl)-5-phenylhydantoin, mephenytoin and several dansyl and beta-naphthylamide amino acids. Several diastereomeric compounds including steroid epimers and alkaloids were separated as well. The derivatized beta-cyclodextrins tended to be much more soluble in water and hydro-organic solvents than native beta-cyclodextrin. Their chromatographic selectivity also was somewhat different. The use of CMAs in TLC is a potentially useful and powerful method that has not been considered adequately. The relative lack of chiral stationary phases available in planar format makes the use of CMAs particularly attractive.