Antibacterial peptides

A peptidic compound having a length of up to 35 amino acid residues comprising an amino acid sequence represented by the general formula (Ib):

• Z-[K]n-K-I-R-V-R-L-S-A
• (SEQ ID NO:
• 26)
• wherein K is a lysine or another amino acid residue with a positively charged side chain,
• I is an isoleucine,
• R is an arginine or an amino acid residue with an N-alkyl substituted guanidine side chain,
• V is a valine,
• S is a serine,
• A is an alanine,
• L is a leucine,
• wherein one of the amino acid residues K, I, R, L, V and S may be replaced by an alanine,
• Z is the N-terminal group of the peptidic compound which comprises at least one amino acid residue and is selected from
• (i) an aromatic amino acid residue or a di-, tri- or tetrapeptidyl group comprising at least one aromatic amino acid residue, wherein the aromatic amino acid residue is particularly selected from tryptophane, N-methyltryptophane, phenylalanine, β-phenylalanine, naphthylalanine, β-naphthylalanine, β-diphenylalanine,β-(4,4′-biphenyl)alanine, β-anthracen-9-ylalanine and β-indol-3-ylalanine,
• (ii) a branched aliphatic amino acid residue or a di-, tri-, tetrapeptidyl group comprising at least one aliphatic amino acid residue, wherein the aliphatic residue is α-amino acid residue comprising a branched aliphatic side chain of at least 3 C-atoms,
• (iii) combinations of any one of (i)-(ii), and n is 0 or 1,
• and wherein the peptidic compound comprises L- and/or D-amino acid residue building blocks, which are selected from α-amino carboxylic acids, β-amino carboxylic acids, or ω-amino carboxylic acids.