N-Acetylmuramic acid

N-Acetylmuramic acid, or MurNAc, is the ether of lactic acid and N-acetylglucosamine with a chemical formula of C11H19NO8. It is part of a biopolymer in the bacterial cell wall, built from alternating units of N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc), cross-linked with oligopeptides at the lactic acid residue of MurNAc. This layered structure is called peptidoglycan.

MurNAc is a monosaccharide derivative of N-acetylglucosamine.

Clinical significance
Unlike most bacterial cell walls, Chlamydial cell wall lacks muramic acid. For this reason penicillin is not very effective in treating chlamydial infection. Protein synthesis blockers like doxycycline or azithromycin are used instead.

Synthesis is inhibited by fosfomycin.