Armstrong introduced macrocyclic glycopeptides (also known as glycopeptide antibiotics) as a new class of chiral selector for liquid chromatography in 1994. At present, vancomycin, teicoplanin and ristocetin are available under the brand names Chirobiotic V, Chirobiotic T and Chirobiotic R respectively. These cyclic glycopeptides have multiple chiral centers and a cup-like inclusion area to which a floating sugar lid is attached. Similar to protein chiral selectors, the amphoteric cyclic glycopeptides consist of peptide and carbohydrate binding sites leading to possibilities for different modes of interaction beside the formation of inclusion complexation. In this chiral selector the cavities are shallower than that of CDs and hence the interactions are weaker, allows more rapid solute exchange between phases, higher column efficiency. operates in normal phase, reversed-phase and polar organic phase.
The complex structural nature of glycopeptide antibiotic class of CSP has made the understanding of the mechanism of chiral recognition at molecular level tricky. For instance, vancomycin molecule has 18 stereogenic centers in the molecule and offers a complex cyclodextrin-like chiral environment. In comparison to a single basket of cyclodextrins, vancomycin consists of three baskets, resulting in a more complex inclusion of appropriate guest molecules. The attractive forces include π-π interactions, hydrogen bonding, ionic interactions, and dipole stacking. A carboxylic acid and a secondary amine group located on the rim of the cup and can participate in ionic interactions. Vancomycin stationary phases operate in reversed, normal and polar organic phase modes.
Wide range of chiral analysis has been done using chirobiotic CSPs. The antihypertensive drugs viz. oxprenolol, pindolol, propranolol have been separated using vancomycin and teicoplanin chirobiotic CSPS. The NSAID drugs ketoprofen and ibuprofen has been separated using ristocetin CSP.