Antibacterial products

A compound of formula IA,

• or a pharmaceutically-acceptable salt, solvate or clathrate thereof, wherein:
• R1 represents H, C1-6 alkyl, C1-6 acyl, benzyl or benzoyl;
• AA1, AA2 and AA5 to AA7 each independently represents a proteinogenic or non-proteinogenic amino acid;
• AA3 and AA4 each independently represents a proteinogenic or non-proteinogenic amino acid, diaminopropanoic acid, diaminobutanoic acid, or ornithine;
• R8 represents hydrogen or C1-4 alkyl;
• R9a, represents a proteinogenic or non-proteinogenic amino acid side chain, —CH2—NH2, —(CH2)2—NH2 or —(CH2)3—NH2;
• R10a represents a side chain of an amino acid selected from the group consisting of valine, isoleucine, leucine, methionine, phenylalanine, tyrosine and tryptophan, a hydrophobic non-proteinogenic amino acid side chain, hydrogen, or R10a is linked to the adjacent nitrogen atom to form a proline ring;
• R11a represents a proteinogenic or non-proteinogenic amino acid side chain;
• Z is —O— or —NH—;
• optionally wherein the compound of formula IA is covalently bonded to a delivery agent, which is either capable of covalently bonding to one or more structures on a bacterial cell membrane or comprises a hydrophilic portion capable of otherwise binding to one or more structures on a bacterial cell membrane.