Gram-negative bacteria’s resistance such as Pseudomonas aeruginosa and the Burkholderia group to conventional antibiotics leads to therapeutic failure. Use of siderophores as Trojan horses to internalize antibacterial agents or toxic metals within bacteria is a promising strategy to overcome resistance phenomenon. To combat the Pseudomonas sp, we have synthesized and studied two piperazine-based siderophore mimetics carrying either catecholate moieties (1) or hydroxypyridinone groups (2) as iron chelators. These siderophore-like molecules were prepared in no more than four steps with good global yields. The physicochemical study has highlighted a strong iron affinity since their pFe values were higher than 20. 1 possesses even a pFe value superior than those of pyoverdine, the P. aeruginosa endogenous siderophore, suggesting its potential ability to compete with it. At physiological pH, 1 forms mainly a 2:3 complex with iron, whereas two species are observed for 2. Unfortunately, the corresponding Ga(III)-1 and 2 complexes showed no antibacterial activity against P. aeruginosa DSM 1117 strain. The evaluation of their siderophore-like activity showed that 1 and 2 could be internalized by the bacteria.
革兰氏阴性细菌的抗药性,如
铜绿假单胞菌和伯克霍尔德菌群对传统抗生素的抵抗导致治疗失败。利用
铁载体作为特洛伊木马将抗菌剂或有毒
金属内化到细菌内部是克服抵抗现象的一种有前景的策略。为了对抗
铜绿假单胞菌,我们合成并研究了两种基于
哌嗪的
铁载体模拟物,分别携带
邻苯二酚基团(1)或
羟基吡啶酮基团(2)作为
铁螯合剂。这些类似
铁载体的分子在不超过四个步骤中制备,全球产率良好。物理
化学研究强调了它们与
铁的亲和力很强,因为它们的pFe值高于20。1甚至具有比
铜绿假单胞菌内源性
铁载体
吡沃德因更高的pFe值,表明它有潜力与之竞争。在生理pH下,1主要形成与
铁的2:3络合物,而2观察到两种物种。不幸的是,对应的Ga(III)-1和2络合物对
铜绿假单胞菌DSM 1117菌株没有抗菌活性。它们的类似
铁载体活性评估表明1和2可以被细菌内化。