Antibacterial activity of enrofloxacin and ciprofloxacin derivatives of β-octaarginine.

β(3) -Octaarginine chains were attached to the functional groups NH and CO2 H of the antibacterial fluoroquinolones ciprofloxacin (→1) and enrofloxacin (→2), respectively, in order to find out whether the activity increases by attachment of the polycationic, cell-penetrating peptide (CPP) moiety. For comparison, simple amides, 3-5, of the two antimicrobial compounds and β(3) -octaarginine amide (βR8 ) were included in the antibacterial susceptibility tests to clarify the impact of chemical modification on the microbiological activity of either scaffold (Table).