Synthesis and activity of HCO-Met-Leu-Phe-OMe analogues containing ß-alanine or taurine at the central position

New synthetic analogues of the chemotactic N-formyltripeptide HCO-Met-Leu-Phe-OMe have been synthesized. The reported new models, namely Boc-Met-β-Ala-Phe-OMe (1), HCO-Met-β-Ala-Phe-OMe (2), Boc-Met-Tau-Phe-OMe (3), HCO-Met-Tau-Phe-OMe (4) and HCl·Met-Tau-Phe-OMe (5), are characterized by the presence at the central position of a residue of β-alanine or 2-aminoethanesulfonic acid (taurine) replacing the native L-leucine. Whereas tripeptides 1 and 2 have been found quite inactive as chemoattractants, all the three models containing the Tau residue exhibit a remarkable activity. Superoxide anion production and lysozyme release have been also evaluated and the biological results are discussed together with the conformational preferences of the examined models. © 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.