Evaluation of the macrocyclic antibiotic LY333328 as a chiral selector when used as a mobile phase additive in narrow bore HPLC

The macrocyclic antibiotic LY333328 has been evaluated as a chiral selector for the enantioseparation of nine dansylated amino acids. This macrocyclic glycopeptide was used as a chiral mobile phase additive (CMPA) in conjunction with narrow bore high‐performance liquid chromatography (HPLC). The key mobile phase parameters of LY333328 concentration and buffer pH were varied, along with variations in stationary phases consisting of C8, phenyl, cyano, and silica. After observing and plotting changes in retention and resolution based on corresponding variation in these parameters, a better understanding of the behavior of this chiral selector was obtained. The pK_a values of the dansyl amino acid analytes and LY333328 were measured and used to gain a better understanding of the microenvironment in which these enantioseparations occur. Optimized conditions resulted in the baseline separation of eight of nine dansyl amino acids. Chirality 11:75–81, 1999. © 1999 Wiley‐Liss, Inc.