Chemical structure/property relationship in single-chain arginine surfactants

In this paper, a systematic investigation into the structure-property relationship of long-chain N-alkyl amide 1, O-alkyl ester arginine 2, and N-acyl arginine methyl ester analogues 3 is reported. The surface properties were studied by adsorption isotherm curves. Biological properties such as antimicrobial activity, hemolysis, ocular irritation, aquatic toxicity, and biodegradability are discussed and correlated with some specific parameters of the surfactants. These surfactants constitute a novel class of bio-based materials of low toxicity, excellent surface properties, and a wide antimicrobial activity. They selectively disrupt bacteria membranes at submicellar concentrations, but not erythrocytes or skin cell membranes. The presence of two positive cationic charges enhances the antimicrobial activity. The incorporation of ester functionality accelerates biodegradation, From the data obtained, it was concluded that the hydrophobicity is a negative parameter for the toxicity and biodegradability of these surfactants.