Muramyl Dipeptide Derivatives with Multiprenylacetyl Group. Synthesis and Immunological Activities

Abstract
Several linear and branched all-trans-multiprenylacetic acids were synthesised, and introduced to the 6 position of the sugar moiety of muramyl dipeptide and its analog, via an amino acid as a linking unit. Compared with the saturated stearoyl derivative, all the compounds having a multiprenylacetyl group exhibited more potent adjuvant activity on the induction of delayed-type hypersensitivity to N-acetyl-3-(4-arsonophenylazo)-l-tyrosine. The derivatives with larger branched side chains tended to have increased activity.