Antibacterial activity, structure and CMC relationships of alkanediyl α,ω-bis(dimethylammonium bromide) surfactants

Summary Some α , ω -alkanediyl bis-dimethylammonium bromide compounds (gemini surfactants) referred as “ m–s–m ” have been synthesized, purified and characterized by usual spectroscopic methods. These compounds have been screened for antibacterial activity against Escherichia coli , Pseudomonas aeruginosa and Staphylococcus aureus . Their activity was compared. The compounds tested showed excellent in vitro antibacterial activity against Staphylococcus aureus ranging from 1.5 to 20 μg/ml and had variable activity against E. coli with minimum minimum inhibitory concentration (MIC) of 50 μg/ml. These compounds are less active against P. aeruginosa . On the other hand, contrary to the antibacterial activity of these products against S. aureus , a relation between the MIC and the critical micellar concentration (CMC) was found and relationship between chain's length and antibacterial activity was found.