Fatty Acids and Derivatives as Antimicrobial Agents

Abstract

The structural relationships of 30 straight-chain fatty acids and derivatives and their bactericidal properties were studied with 8 gram-negative and 12 grampositive organisms. Chain length, unsaturation ( cis, trans ), and functional group were all variables considered in this study. Our data indicate that C ₁₂ (lauric acid) is the most inhibitory saturated fatty acid against gram-positive organisms. Monoenoic acid (C _18:1 ) was more inhibitory than saturated fatty acid, but was less active than dienoic derivatives (C _18:2 ). Other unsaturated compounds were less active than C _18:2 . Alcohols and glyceryl esters were active only against gram-positive organisms. In general, esterification of the carboxyl group led to a compound which was less active; monoglycerides were the sole exception. Amine derivatives, contrary to results with fatty acids, esters, and amides, showed activity against both gram-positive and gram-negative organisms.