Lipid-Based Quaternary Ammonium Sophorolipid Amphiphiles with Antimicrobial and Transfection Activities

Twelve new quaternary ammonium sophorolipids with long alkyl chains on the nitrogen atom were synthesized starting from oleic and petroselinic acid-based sophorolipids. These novel derivatives were evaluated for their antimicrobial activity against selected Gram-negative and Gram-positive bacteria and their transfection efficacies on three different eukaryotic cell lines in vitro as good activities were demonstrated for previously synthesized derivatives. Self-assembly properties were also evaluated. All compounds proved to possess antimicrobial and transfection properties, and trends could be observed based on the length of the nitrogen substituent and the total length of the sophorolipid tail. Moreover, all long-chain quaternary ammonium sophorolipids form micelles, which proved to be a prerequisite to induce antimicrobial activity and transfection capacity. These results are promising for future healthcare applications of long-chained quaternary ammonium sophorolipids.