THE CYCLOLINOPEPTIDE-A ANALOGS WITH D-PHE, D-TYR, AND L-TRP AND D-TRPRESIDUES

A series of nine linear and nine cyclic analogues of cyclolinopeptide A (CLA), in which the Phe residues were substituted by the aromatic D- residues (D-Phe, D-Tyr, D-Trp) or by the L-Trp residue, was synthesize d by SPPS method. The peptides were tested for their influence on humo ral and cellular immune response in mice. Most of thr analogues show s ome immunosuppressive activity similar to that of CLA. High biological activity was observed for the cyclic peptides modified in position 9, especially [D-Phe(9)]CLA. This col responds well with the peptide CD spectrum, which shows that the backbone conformation of this analogue resembles most the conformation of CLA.