In summary, peptide 15c exhibits a minimal tendency to aggregate in water and has a more structurally stable backbone than p1. Even in monomeric or low oligomeric states, substantial parts of the backbones in p3 and 15c are protected from solvent due to more stable conformations and more efficient shielding by the aromatic side chains, unlike p1. In water, peptide 15c shows a more structured backbone, particularly in the stable regions Arg1-Arg2 and arg4-Dip5, whereas p3 has only one short stable region Arg1-Arg2. Peptide p1 has the highest tendency for aggregation (at concentrations of 0.3 mM and above), with all backbone amides shielded from the solvent in the aggregated state. However, in the non-aggregated state (at 0.15 mM), the full exposure of all backbone amides to water indicates high backbone flexibility and less effective hydrophobic shielding by its side chains.