Peptides and their functionally equivalent derivatives, in salified or non-salified form, with the general formula L 1 -X 1 -X 2 -X 3 -X 4 , wherein: L 1 is H, or acyl, or any natural or non-natural amino acid, optionally N-acylated, N-alkylated and/or C±-alkylated； X 1 and X 3 , which are equal or different, are any natural or non-natural basic amino acid, optionally N-alkylated and/or C±-alkylated； X 2 is any natural or non-natural amino acid, optionally N-alkylated and/or C±-alkylated, with the proviso that it is not glycine and amino acids mono-substituted on the ± carbon atom with a linear or cyclic alkyl group, from 1 to 10 carbon atoms, and amino acids mono-substituted on the ± carbon atom with a linear or cyclic alkyl group containing 4 to 10 carbon atoms, or amino acids mono-substituted on the ± carbon atom with an alkyl group containing 1 to 8 carbon atoms, optionally substituted with a carbamoyl, hydroxyl or aromatic group； X 4 is any natural or non-natural hydrophobic amino acid, optionally C±-alkylated and/or amidated at the C-terminal end, or any hydrophobic amino alcohol, or a hydrophobic gem-diamine, optionally N'-alkylated or N'-acylated.
