Zwitterionic derivatization of rhamnolipids: An efficient and biologically friendly antibacterial agent

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-11, Vol.500, p.156954, Article 156954
• Main Authors: Zhao, Mengqian, Zheng, Yu, Wu, Yefei, Jiang, Jingjing, Lu, Jianwei, Yin, Jian, Long, Xuwei
• Format: Article
• Language: English
• Subjects: Antibacterial; Derivatization; Rhamnolipids; Zwitterionic
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.156954

[Display omitted] •A new zwitterionic rhamnolipids derivative was prepared.•This derivative was readily separated and purified without column chromatography.•This derivative had enhanced antibacterial activity but reduced hemolytic activity.•Selective biological activity of derivative may be endowed by zwitterionic property. The development of efficient and biocompatible antibacterial agents is crucial to address multidrug resistance resulting from the abundant abuse of antibiotics; however, this endeavor remains challenging. This study prepared a zwitterionic rhamnolipid derivative (di-RLs-Arg-OH) containing both guanidine and carboxyl groups via amide condensation and demethylation reactions. This new derivative manifested improved antibacterial activity and reduced cytotoxicity against blood and NIH/3T3 cells compared with di-rhamnolipids. The MIC of di-RLs-Arg-OH against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) was lowered to 32–256 mg/L, while the HC50 was as high as 917 mg/L. The involved mechanism might be attributed to the zwitterionic property of di-RLs-Arg-OH, which contains both carboxyl and guanidine groups. The findings in the present study facilitate the design of biosurfactant-based derivatives as bio-friendly antibacterial agents.