The Phenolic Hydroxyl Group of Carvacrol Is Essential for Action against the Food-Borne Pathogen Bacillus cereus

The natural antimicrobial compound carvacrol shows a high preference for hydrophobic phases. The partition coefficients of carvacrol in both octanol-water and liposome-buffer phases were determined (3.64 and 3.26, respectively). Addition of carvacrol to a liposomal suspension resulted in an expansion of the liposomal membrane. Maximum expansion was observed after the addition of 0.50 micromol of carvacrol/mg of L-alpha-phosphatidylethanolamine. Cymene, a biological precursor of carvacrol which lacks a hydroxyl group, was found to have a higher preference for liposomal membranes, thereby causing more expansion. The effect of cymene on the membrane potential was less pronounced than the effect of carvacrol. The…