Phosphonopeptides as antibacterial agents: rationale, chemistry, and structure-activity relationships.

Peptide mimetics with C-terminal residues simulating natural amino acids have been designed as inhibitors of bacterial cell wall biosynthesis. The phosphonopeptide series consisting of various l and d residues of natural amino acids combined with 1-aminoalkyl (and aryl-alkyl-) phosphonic acid residues had the most interesting antibacterial properties when the C-terminal residue was l-1-aminoethylphosphonic acid. The in vitro antibacterial activities of representative phosphonodi- to phosphonohexapeptides were investigated. The antibacterial action of the active compounds has been explained in terms of transport into the bacterial cell and intracellular release of the alanine mimetic, which interferes with the biosynthesis of the peptidoglycan of the bacterial cell wall.