Screening of a library of novel N-hydroxylactams amenable by the Castagnoli-Cushman reaction identified four lead compounds that facilitated 55Fe transport into P. aeruginosa cells (one of these synthetic siderophores was found to be as efficient at promoting iron uptake as the natural siderophores pyoverdine, pyochelin or enterobactin). Conjugates of the four lead siderophores with ciprofloxacin were tested for antibacterial activity against P. aeruginosa POA1 (wild type) and the ∆pvdF∆pchA mutant strain. The antibacterial activity was found to be pronounced against the ∆pvdF∆pchA mutant strain grown in CAA medium but not for the POA1 strain. This may be indicative of these compounds being ‘Trojan horse’ antibiotics. Further scrutiny of the mechanism of the antibacterial action of the newly developed conjugates is warranted.
筛选一批新型N-羟基内酰胺库,通过Castagnoli-Cushman反应鉴定出四种引导化合物,可以促进55Fe进入P. aeruginosa细胞(其中一种合成铁载体与天然铁载体pyoverdine、pyochelin或enterobactin一样有效)。将这四种铁载体与环丙沙星结合,对P. aeruginosa POA1(野生型)和∆pvdF∆pchA突变株进行抗菌活性测试。发现抗菌活性对在CAA培养基中生长的∆pvdF∆pchA突变株非常显著,但对POA1株没有。这可能表明这些化合物是“特洛伊木马”抗生素。有必要进一步研究新开发的铁载体与抗生素结合物的抗菌作用机制。