Vancomycin, a non-ribosomally synthesized peptide (NRP) in the glycopeptide antibiotic class, is one of the cornerstone drugs targeting cell wall synthesis, alongside other NRPs like polymyxins and gramicidins. Vancomycin's mechanism of action involves direct binding to the two D-Ala residues at the C-terminus of the pentapeptide region of Lipid II (shown in Figure ), thereby impeding cell wall synthesis. Structurally, vancomycin is a glycopeptide, with a relatively polar structure and a large molecular weight, impermeable to the Gram negative OM .