Theranostic Gallium Siderophore Ciprofloxacin Conjugate with Broad Spectrum Antibiotic Potency
作者:Apurva Pandey、Chloé Savino、Shin Hye Ahn、Zhaoyong Yang、Steven G. Van Lanen、Eszter Boros
DOI:10.1021/acs.jmedchem.9b01388
日期:2019.11.14
Pathogenic bacteria scavenge ferric iron from the host for survival and proliferation using small-molecular chelators, siderophores. Here, we introduce and assess the gallium(III) complex of ciprofloxacin-functionalized desferrichrome (D2) as a potential therapeutic for bacterial infection using an in vitro assay and radiochemical, tracer-based approach. Ga-D2 exhibits a minimum inhibitory concentration of 0.23 mu M in Escherichia con, in line with the parent fluoroquinolone antibiotic. Competitive and mutant strain assays show that Ga-D2 relies on FhuA-mediated transport for internalization. Ga-D2 is potent against Pseudomonas aeruginosa (3.8 mu M), Staphylococcus aureus (0.94 mu M), and Klebsiella pneumoniae (12.5 mu M), while Fe-D2 is inactive in these strains. Radiochemical experiments with E. coli reveal that Ga-67-D2 is taken up more efficiently than (67)-Ga-citrate. In naive mice, Ga-67-D2 clears renally and is excreted 13% intact in the urine. These pharmacokinetic and bacterial growth inhibitory properties qualify Ga-D2 for future investigations as a diagnosis and treatment tool for infection.