Self-aggregation and antimicrobial activity of saccharide-cationic surfactants

Saccharide-amide cationic surfactants containing hydroxyethyl group and a sugar moiety N-methyl-N-hydroxyethyl group-N [3-(gluconamide)-propyl]-N-alkylammonium bromide (CnMHGPB where n represents hydrocarbon chain lengths of 10, 12, and 14) were synthesized and the effect of the alkyl chain length on aggregation and antimicrobial activity were investigated. Static/dynamic surface tension and conductivity were applied to study the adsorption and aggregation behavior. The antimicrobial activity was evaluated against Escherichia coli and Staphylococcus aureus. The most surprising result is that the cmc values of CnMHGPB are higher with the longer chains. The results showed that dynamic surface tension results are affected more by the hydrophobic head group. The saccharide-amide cationic surfactants containing 10–14 carbon atoms in the alkyl chain showed antimicrobial activity at the concentration of 50–100 ppm, and C12MHGPB surfactant had the best antimicrobial activity.