Molecular Sizes and Antibacterial Performance Relationships of Flexible Ionic Liquid Derivatives

作者：Liang Zheng, Jing Li, Manman Yu, Weibin Jia, Shun Duan, Dapeng Cao, Xiaokang Ding, Bingran Yu, Xianren Zhang, Fu‐Jian Xu · 发表于：Journal of the American Chemical Society · 年份：2020 · DOI：10.1021/jacs.0c10771 · 被引用次数：230 · 研究领域：Ionic liquids properties and applications、Advanced Nanomaterials in Catalysis、Luminescence and Fluorescent Materials

Cationic agents, such as ionic liquids (ILs)-based species, have broad-spectrum antibacterial activities. However, the antibacterial mechanisms lack systematic and molecular-level research, especially for Gram-negative bacteria, which have highly organized membrane structures. Here, we designed a series of flexible fluorescent diketopyrrolopyrrole-based ionic liquid derivatives (ILDs) with various molecular sizes (1.95–4.2 nm). The structure–antibacterial activity relationships of the ILDs against Escherichia coli ( E. coli ) were systematically studied thorough antibacterial tests, fluorescent tracing, morphology analysis, molecular biology, and molecular dynamics (MD) simulations. ILD-6, with a relatively small molecular size, could penetrate through the bacterial membrane, leading to membrane thinning and intracellular activities. ILD-6 showed fast and efficient antimicrobial activity. With the increase of molecular sizes, the corresponding ILDs were proven to intercalate into the bacterial membrane, leading to the destabilization of the lipid bilayer and further contributing to the antimicrobial activities. Moreover, the antibacterial activity of ILD-8 was limited, where the size was not large enough to introduce significant membrane disorder. Relative antibacterial experiments using another common Gram-negative bacteria, Pseudomonas aeruginosa (PAO1), further confirmed the proposed structure-antibacterial activity relationships of ILDs. More impressively, both ILD-6 and ...