A major impediment to developing effective antimicrobials against Gram-negative bacteria like Salmonella is the ability of the bacteria to develop resistance against existing antibiotics and the inability of the antimicrobials to clear the intracellular bacteria residing in the gastrointestinal tract. As the critical balance of charge and hydrophobicity is required for effective membrane-targeting antimicrobials without causing any toxicity to mammalian cells, herein we report the synthesis and antibacterial properties of cholic acid-derived amphiphiles conjugated with alkyl chains of varied hydrophobicity. Relative to other hydrophobic counterparts, a compound with hexyl chain (6) acted as an effective antimicrobial against different Gram-negative bacteria. Apart from its ability to permeate the outer and inner membranes of bacteria; compound 6 can cross the cellular and lysosomal barriers of epithelial cells and macrophages and kill the facultative intracellular bacteria without disrupting the mammalian cell membranes. Oral delivery of compound 6 was able to clear the Salmonella-mediated gut infection and inflammation, and was able to combat persistent, stationary, and multi-drug-resistant clinical strains. Therefore, our study reveals the ability of cholic acid-derived amphiphiles to clear intracellular bacteria and Salmonella-mediated gut infection and inflammation.
开发有效的抗革兰氏阴性细菌(如沙门氏菌)抗菌药物的主要障碍是这些细菌能够对现有抗生素产生耐药性,以及抗微
生物药物无法清除肠道内的细菌。由于有效的膜靶向抗微
生物药物需要在不对哺乳动物细胞造成毒性的情况下,维持电荷和疏
水性的关键平衡,因此我们在此报告了合成的
胆酸衍生的两亲分子,这些分子与具有不同疏
水性的烷基链结合。与其他疏
水性相对物相比,具有己基链(6)的化合物对不同的革兰氏阴性细菌表现出有效的抗菌作用。除了能够渗透细菌的外膜和内膜之外,化合物6还可以穿越上皮细胞和巨噬细胞的细胞和溶酶体屏障,杀死兼性细胞内细菌,而不会破坏哺乳动物细胞膜。化合物6的口服投递能够清除沙门氏菌引起的肠道感染和炎症,并且能够抵抗持续、静止及多药耐药的临床菌株。因此,我们的研究揭示了
胆酸衍生的两亲分子清除细胞内细菌以及沙门氏菌引起的肠道感染和炎症的能力。