CHIRAL SEPARATION OF 2,4-DINITROPHENYL AMINO-ACIDS USING 3-O-METHYL-BETA-CYCLODEXTRIN-BONDED STATIONARY-PHASE IN REVERSED-PHASE LIQUID-CHROMATOGRAPHY

Reversed-phase liquid chromatography (RPLC) separation factors for rac emic 2,4-dinitrophenyl (DNP) amino acids (Phe and Trp) having various substituents at different positions were measured on native beta-CD an d heptakis(3-O-methyl)-beta-CD as the chiral stationary phase in order to compare enantioselectivity of these phases. Both native beta-CD an d heptakis(3-O-methyl)-beta-CD showed good enantioselectivity for the DNP-amino acids investigated. Enantioselectivities of the two CD phase s for the DNP-amino acids vary with the type and position of the subst ituent on the DNP moiety of the amino acids. Heptakis(3-O-methyl)-beta -CD, the cavity of which is more electron-rich than that of native bet a-CD, showed in general much better enantioselectivity for the amino a cid derivatives studied. (C) 1998 Elsevier Science B.V. All rights res erved.