Long chain carboxylic acids containing ether linkage: IV. The antibacterial activities of 0‐(2‐alkylaminoethyl)‐3‐oxypropionic and N‐(2‐alkyloxyethyl)‐3‐aminopropionic acids

The carboxylic amphoteric surfactants containing ether and substituted amine groups such as 0‐(2‐alkylaminoethyl)‐3‐oxypropionic‐and N‐(2‐alkyloxyethyl)‐3‐aminopropionic acids were synthesized, and their antibacterial activities in terms of growth inhibition ofStaphylococcus aureus andEscherichia coli were examined. The structural effect, such as bonding position of ether and amino groups, and the chain length effect between undecyloxy‐, dodecyloxy‐ and tridecyloxy radicals were examined, but no definite correlation between positional isomers and chain length and antibacterial activities was observed. Furthermore, to study the effect of the increase of the number of ether or amino groups on the antibacterial activities, N‐(2‐(2‐dodecyloxyethyl)‐aminoethyl)‐3‐aminopropionic acid and N‐(2‐(2‐dodecyloxyethyl)oxyethyl)‐3‐aminopropionic acid were synthesized. Their antibacterial activities were almost as effective as the corresponding amino or ether acids. Moreover aqueous solution of these substituted propionic acids showed better surface activities at pH 4.0, 7.0 and 10.0.