Liquid Chromatography - Macrocyclic Glycopeptide Phases 1
Macrocyclic Glycopeptide Phases
The concept of using macrocyclic glycopeptides as chiral stationary phases was first introduced by Armstrong . One method of preparation is to covalently bond Vancomycin to the surface of silica gel particles. Vancomycin contains 18 chiral centers surrounding three 'pockets' or 'cavities' which are bridged by five aromatic rings. Strong polar groups are proximate to the ring structures to offer strong polar interactions with the solutes. This type of stationary phase is stable in mobile phases containing 0–100% organic solvent. The proposed structure of Vancomycin is shown in figure 49.
A, B and C are inclusion cavities. Molecular weight 1449. Chiral centers 18. pK's 2.9, 7.2, 8.6, 9.6, 10.4, 11.7. Isoelectric point 7.2
Courtesy of ASTEC Inc.
Figure 49 The Proposed Structure of Vancomycin