Modified chemotactic peptides: Synthesis and activity of an azaTic-containing fMLP-OMe analogue

Summary The synthesis and the biological activity of a pseudopeptide analogue of the chemotacticN-formyltripeptide fMLP-OMe, containing the aza Tic (3,4-dihydro-2(1H)-phthalazinecarboxylic acid) residue replacing the native phenylalanine, is described. Whereas pseudopeptides containing lineara-azaammo acids are currently studied, data on the new group of analogues containing cyclic-aza residues capable of limiting the rotameric distribution of the side chains (topological control) are just emerging in the literature. At our best knowledge, the here described [azaTic³]fMLP-OMe represents the first example of the introduction of this new type of-aza residue into a natural bioactive peptide.