LIGANDS WHICH BIND WEAKLY TO VANCOMYCIN - STUDIES BY C-13 NMR-SPECTROSCOPY

C-13 NMR chemical shifts of vancomycin have been used to obtain the as sociation constants for a number of ligands which bind weakly to the a ntibiotic. The change in these C-13 chemical shifts upon stepwise addi tion of ligands provides evidence that the ligands bind in a manner an alogous to natural cell-wall precursor analogues. The binding constant s obtained are in good agreement with those determined earlier by othe r methods. Where the ligands are-amino acids (glycine or alanine), a p otential alkylammonium to amide carbonyl interaction does not promote binding.