Synthesis, physicochemical property, and antibacterial activity of novel nonionic 1-alkylaminoglycerol Gemini surfactants

Four novel nonionic 1-alkylaminoglycerol Gemini surfactants, represented by m-s-m (m = C8 and C12, s = 3 and 4), were synthesized through a two-step reaction in high yields, and confirmed by 1H NMR, 13C NMR, and HRMS. The synthesized Gemini surfactants exhibited low CMC (1.41-5.25 mmol/L), excellent surface-tension-reducing ability (25.45-26.83 mN/m), and wetting ability on hydrophobic interface. Gemini surfactants in aqueous solutions were in stable nanoscale dispersion, and exhibited strong and long-lasting foaming ability and emulsifying abilities for benzene/water and triacylglyceride/water systems. Especially, 12-4-12 solution displayed excellent tolerance to wide pH range and high salinity. Biological evaluation demonstrated that these Gemini surfactants, except for 8-4-8, showed significant antibacterial activities against Staphylococcus aureus and Escherichia coli at 25 and 50 µg/mL. Hence, these Gemini surfactants have the potential to be used in a varieties of fields as highly efficient agents.