GlcNAcbeta1-4MurNAc-(L-Ala-gamma-D-Glu-A2pm-D-Ala-D-Ala)-alpha-undecaprenyl diphosphate LMPR03030003 Lipid II (undecaprenyl diphosphate-MurNAc-pentapeptide-GlcNAc)