Abstract: 3-Substituted-(R,S)-β-alanines derivatized by 1-fluoro-2,4-dinitro-5-L-valinamide (Marfey’s reagent) were successfully separated by reversed-phase high performance liquid chromatography. The separations were performed with gradient elution. The mobile phase A was acetonitrile containing 0.1%(v/v) trifluoroacetic acid and the mobile phase B was 0.1%(v/v) trifluoroacetic acid aqueous solution. Thirty-two pairs of 3-substituted-(R,S)-β-alanine derivatives, phenyl, substituted phenyl, naphthyl, substituted pyridyl and thienyl, were separated. The mobile phase A content was changed from 35% to 75% in 20 min. All (R-L)-diastereomers were eluted prior to the (S-L) ones. Substituents with larger hydrophobic parameters (π) gave longer retention times (tR) for their derivatives than those with smaller ones except for 3-hydroxyphenyl and 4-hydroxyphenyl substituents. The positioning of the substituents on benzene ring of β-alanines (β-Ala) also influenced tR and separation. 4-Subsituted-phenyl-(R,S)-β-Ala derivatives gave longer tR and better separation than 2-substituted isomers. The enantiomer excess values of R- and S-β-Ala were also determined.

Key words: , 3-substituted-(R,S)-β-alanine derivatives, high performance liquid chromatography