Propargylglycine-based antimicrobial compounds are targets of TolC-dependent efflux systems in Escherichia coli.

A library of novel l-propargylglycine-based compounds were designed and synthesized with the goal of inhibiting the growth of Gram-negative bacteria by targeting LpxC, a highly conserved Gram-negative enzyme which performs an essential step in the lipid A biosynthetic pathway. These compounds were designed with and without a nucleoside and had varying tail structures, which modulate their lipophilicity. The synthetic scheme was improved compared to previous methods: a methyl ester intermediate was converted to a hydroxamic acid, which obviated the need for a THP protecting group and improved the yields and purity of the final compounds.