N(2)-substituted D,L-cycloserine derivatives: synthesis and evaluation as alanine racemase inhibitors.

A select series of N(2)-substituted D,L-cycloserine derivatives were prepared a ndevaluated for inhibitory activity against purified alanine racemases (alr gene product) from Escherichia coli, Staphylococcus aureus, and Mycobacterium tuberculosis, as well as in a growth inhibition assay. N(2)-Modification led to loss of enzymatic inhibitory activity in most cases consistent with a recent proposal for cycloserine function.