Evaluation and Comparison of m-Tolyl Isocyanate Teicoplanin and Teicoplanin Chiral Stationary Phase

A new HPLC chiral stationary phase (CSP), m-tolyl isocyanate telcoplanin (TI-TE), was synthesized from the macrocyclic glycopeptide teicoplanin CSP (TE), using a derivative agent, m-tolyl isocyanate. Evaluation and comparison of these two TE-based CSPs were carried out with 10 recemates, including 7 amino acids and 3 non-amino acid compounds (lamivudine, oxazepam and p-hydroxyphenylglycine), using RPLC mobile phase. The chromatographic results were given as the retention, selectivity, resolution factors and the enantioselective free energy difference corresponding to the separation of the two enantiomers. The effects of pH, organic modifier type and amount were discussed, and the stereoselectivities of the two TE-based CSPs were compared, and the chiral recognition mechanism of TE-based CSP was also discussed The retention for a-amino acids on TE was somewhat longer than that on TI-TE while chiral selectivity and resolution were bigger on TI-TE. The results show that the derivative CSP gets better selectivity than TE CSP under the RP mode.