Ac-muramyl-Ala-Glu-NH2 is a short peptide composed of two amino acids, the N-terminal and C-terminal of the peptide are both blocked. For such sequences, the first choice for peptide synthesis is liquid phase peptide synthesis. Although the amino and carboxyl groups in the peptide structure are both blocked, there are many active functional groups in the overall structure, such as the hydroxyl group and the side chain carboxyl group on Glu, which have strong activity.