The relationship between molecular size and antibacterial properties of flexible fluorescent ionic liquid derivatives and their inseminative antibacterial mechanism

On November 12, 2020, a team of Professor Xu Fujian of the School of Materials Science and Engineering of Beijing University of Chemical Engineering and Professor Zhang Zhengren of the School of Chemical Engineering worked together in J. Am. Chem. A research paper entitled "Molecular Sizes and Antibacterial Relationship Performances of Flexible Liquid Derivatives" was published on Soc.
has become one of the world's largest public health challenges in recent years. Among them, Glorans-negative bacteria have a highly organized bacterial membrane structure, which can effectively resist the binding and penetration of foreign invading molecules

. Infections caused by Glorene-negative bacteria are extremely difficult to cure. Therefore, it is of great significance to design antibacterial reagents for how to penetrate and destroy the bacterial membrane of Glorene-negative bacteria effectively. Mimi-based ionic liquid has a flexible and adjustable structure and good water solubility, at the same time, as a cation reagent with high-efficiency broad-spectrum antibacterial activity, can effectively kill Terrain-negative bacteria. Based on N-methyl metformine and fluorescent molecule pyridoxine (DPP), this work synthesizes a series of flexible fluorescent ion liquid derivatives (ILDs) with different molecular sizes (1.95 to 4.2 nm) by precisely regulating the length of the alkyl chain, and systematically explores the relationship between ILDs molecular size and antibacterial properties and their antibacterial properties through antimicrobial testing, fluorescence imaging, profiling, and molecular dynamics simulation.
results show that the molecular size of ILDs is closely related to its membrane penetration and destruction of bacteria. IlDs with different alkyl chain lengths are mainly manifested in membrane thinning and membrane disorders. IlD-6, with a relatively small molecular size, can cause the bacterial membrane to thin and enter the bacteria's internal interference with the bacteria's intracellal activity, showing fast and efficient antibacterial activity. With the increase of molecular size, ILDs are inserted into the bacterial membrane, which disturbs the stability of the double molecular layer of phospholipids in the bacterial membrane, thus undermining the integrity of the bacterial membrane to play an antibacterial role. The molecular size of ILD-8 is at a critical point, the molecule is inserted into the bacterial membrane, but does not cause the bacterial membrane to break, so it can not effectively kill the bacteria. Both ILD-6 and ILD-12 showed superior in vivo therapeutic effects on rat models infected with PAO1, while the poor performance of ILD-8 further confirmed the effect of molecular size on the antibacterial activity of ILDS and demonstrated its potential for future application. This work sheds light on the interactions between ionic liquid derivatives of different molecular sizes and Terrain-negative bacteria and will provide useful guidance for the rational design of high-performance antimicrobial agents.
Liang and Yu Yu, Ph.D. students in the School of Materials Science and Engineering, Beijing University of Chemical Engineering, and Dr. Li Jing of the School of Chemical Engineering are co-authors of this paper. Professor Xu Fujian and Associate Professor Yu Qiran of the School of Materials Science and Engineering, and Professor Zhang Zhengren of the School of Chemical Engineering are the authors of this paper. Beijing University of Chemical Engineering is the only completed unit. This research has been supported by the National Key Research and Development Program, the National Natural Science Foundation of China, the Beijing Program for Outstanding Young Scientists and the Central University Foundation for Basic Scientific Research.
source: Beijing University of Chemical