Synthesis of 6-O-Acyl Derivatives of Immunoadjuvant Active N-Acetylmuramyl- l -alanyl- d -isoglutamine

Seven acyl derivatives of N-acetylmuramyl-l-alanyl-d-isoglutamine, which had previously been shown to be a minimum structure required for the immunoadjuvant activity, were synthesized in order to evaluate the significance of lipophilicity on the adjuvant activity and on the possible antitumor effect. Among them, are included 6-O-docosanoyl, stearoyl, lauroyl, octanoyl, butyryl, acetyl, and 4,6-di-O-acetyl derivatives. Some of these compounds were found to serve an improvement in the administration method to living body.