Amino acid surfactants antimicrobial property

One important milestone in our research is the design and development of new amino acid-based surfactants with antimicrobial properties, which mimic natural amphiphilic cationic peptides [42,43]. To this end, Lys and Arg derivatives of long-chain A -acyl, COO-ester, and A-alkyl amide have been prepared. In particular, the A -acylarginine methyl ester derivatives series 1 (Scheme 1) have turned out to be an important class of cationic surface active compounds with a wide bactericidal activity, high biodegradability, and low toxicity profile. We have shown that essential structural factors for their antimicrobial activity include both the length of the fatty residue (akin with their solubility and surface activity) and the presence of the protonated guanidine function [43,44]. 

Biocompatible cationic surfactants from the amino acid lysine (hydrochloride salts of A -lauroyl-lysine methyl ester, IV -miristoyl-lysine methyl ester and A -palmitoyl-lysine methyl ester) show moderate antimicrobial activity against the Gram-positive bacteria. The haemolytic activity of these compounds is considerably lower than those reported for other cationic Ai -acyl amino acid analogues [64]. Taking into account the high biodegradation level and the low haemolytic activity, these compounds could be considered safe surfactants in relation to the cell of the human body. These properties make them suitable candidates for biological and medical applications [65]. 

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