Synthesis, Characterization and Biological Activity of Sugar‐Based Gemini Cationic Amphiphiles

Two series of gemini cationic surfactants were synthesized based on glucose and fructose molecules. Their chemical structures were confirmed using micro‐elemental analysis, mass spectral fragmentation and FTIR spectroscopic analysis. The surface activities of these gemini amphiphiles were measured, including surface tension ( γ) , critical micelle concentration (CMC), effectiveness ( π cmc ), efficiency (pC 20 ), maximum surface excess (Γ max ) and minimum surface area ( A min ) at 25 °C. Adsorption and micellization free energies of these amphiphiles in their solutions showed a good tendency towards adsorption at the interfaces. The biological activity of the synthesized gemini amphiphiles showed good inhibition at concentrations of 1, 2.5 and 5 mg/mL. The synthesized amphiphiles showed antimicrobial activity on gram‐positive and gram‐negative bacteria and antifungal activity equal to or comparable to commercially available controls. The discussion rationalized the antimicrobial activities of these amphiphiles with the surface activity and the adsorption parameters. In addition, the effect of sugar nuclei was discussed based on the chemical structure of the bacterial and fungal cell membranes.