Synthesis and biological activity of N63-carboxypeptides of teicoplanin and teicoplanin aglycone.

A series of peptide derivatives of teicoplanin A2 (CTA) and deglucoteicoplanin (TD) was prepared by condensation of the 63-carboxyl function with the alpha-amino group of selected amino acids and their derivatives. The modification of the ionic character of CTA and TD influenced their in vitro and in vivo antimicrobial properties to a different extent, depending on the structure of the amino acidic moiety at C-63. A certain effect on binding strength to Ac2-L-Lys-D-Ala-D-Ala, a synthetic model of the antibiotic's target peptide, was also observed.