Dedicated to the memory of Pascal A. Mathieu, our dear friend and colleagueThe recently improved conditions for solid-phase synthesis of b 3 -peptides by the Fmoc strategy were used to synthesize a b-tetracosapeptide (4, Scheme) composed of eight different b-amino acid residues; 11 of the 24 residues carry functionalized proteinogenic side chains (namely those of Glu, Lys, Ser, and Tyr). The highly H 2 O-soluble b-tetracosapeptide was identified by 1 H-NMR spectroscopy (in MeOH), analytical HPL chromatography, and ESI-mass spectrometry (Fig. 1). The expected 3 14 -helical secondary structure of the new b-peptide was designed to have one hydrophobic and two hydrophilic faces, and to be compared with other b-peptides (1 ± 3), two of which are also of amphipathic character in this secondary structure (Fig. 2). In the absence of NMR-structural proof, the CD spectra of the four b-peptides were compared (Figs. 3 and 4). The b-tetracosapeptide exhibits an unprecedented CD pattern (in MeOH and in H 2 O solution) that may arise from a new type of secondary structure or from an unordered conformation.