Syntheses of Several Muramyl Peptides in Relation to Chemical Structures of Less Immunoadjuvant Bacterial Cell Walls

Abstract

Various structural analogs of N-acetylmuramyl-L-alanyl-D-isoglutamine, which had been shown to be the minimum structure required for the immunoadjuvant activity of bacterial cell walls, were synthesized in order to investigate in more detail the relationship between the activity and chemical structures. Particularly, the compounds of the structures corresponding to the cell walls of special bacteria without immunoadjuvant activity were prepared in this study. Several novel procedures including the preparation of a branched glutamyl peptide were newly exploited to accomplish the syntheses of muramyl peptides with complicated structures. As a result of this synthetic study, new informations were obtained on the structural requirement for the immunoadjucant activity.