Relationship of chemical structure and antimicrobial activity of alkyl amides and amines.

Contrary to the limited effects of alkyl amides and their corresponding N-derivatives, alkyl amines affected both gram-positive and gram-negative organisms. As with other alkyl derivatives the most sensitive gram-negative bacteria were usually more resistant than the most resistant gram-positive bacteria. Compounds with a chain-length of 11 to 15 are most active. Although some of the general properties relating the activity of fatty acids to their antimicrobial action are similar to those of amine compounds, the amines are unique in that monounsaturation does not increase compound activity. The possible modes of action of these compounds are discussed.