Applications of tert-Butyloxycarbonyl-L-amino Acid-N-Hydroxysuccinimide Esters in the Chromatographic Separation and Determination of D,L-Amino Acids and Diastereomeric Dipeptides

Abstract

DL-Amino acids are converted into the LD, and LL diastereomeric dipeptides after reaction with a Boc-L-AA-OSu derivative. The dipeptides are subsequently separated by liquid chromatography using a reversed, bonded stationary phase. If the sample is a DL,DL-dipeptide, the products of the reaction are the LLL, LDD, LLD, and LDL tripeptide. Reaction conditions, structure of the BOC reagent, eluting conditions, and calibration procedures are the major parameters studied. In general, per cent conversion is greater than 95%; the determination of minor concentrations of one enantiomer in the presence of the other is possible.