Figure 1.

Schematic summary of the approach used and the motivation for this work. (a) Applications of triphenylphosphonium (TPP⁺, PPh₃). In this work: X = antibiotic (ciprofloxacin) used to enhance the effect of antibiotics against multidrug-resistant (MDR) bacteria. (b) A schematic diagram showing the mechanism of drug-resistance in bacteria and the mode of action towards ciprofloxacin (CFX) and the functioning mechanism of CFX-PPh₃ derivatives. (c) Chemical structure of CFX and its derivatives; CFX-ester-PPh₃, CFX-amide-PPh₃.