title: Structural requirements for the antimicrobial activity of carvacrol.
abstract: Carvacrol is a component of several essential oils and has been shown to exert antimicrobial activity. The structural requirements for the activity of carvacrol were determined by comparison to structurally related (nonessential oil) compounds. Removal of the aliphatic ring substituents of carvacrol slightly decreased the antimicrobial activity. The effect of the hydroxyl group of carvacrol on activity could not be determined by simply comparing it to p-cymene, because this compound is immiscible with water; therefore, 2-amino-p-cymene, the amino analogue of carvacrol, which has a similar hydrophobicity and structural characteristics, was used. 2-Amino-p-cymene had similar membrane disruption and bacterial killing characteristics as carvacrol showing that, contrary to previous reports, the hydroxyl group of carvacrol itself is not essential for the antimicrobial activity. However, the observed 3-fold lower activity for 2-amino-p-cymene as compared to carvacrol indicates special features in the antimicrobial mode of action of carvacrol due to the hydroxyl group.
authors.affiliation: Institute of Risk Assessment Sciences, Division of Public Health & Food Safety, and Department of Infectious Diseases and Immunology, Utrecht University, 3508 TD Utrecht, The Netherlands.
authors.forename: Edwin J A
authors.initials: EJ
authors.lastname: Veldhuizen
authors.forename: Johanna L M
authors.initials: JL
authors.lastname: Tjeerdsma-van Bokhoven
authors.forename: Cindy
authors.initials: C
authors.lastname: Zweijtzer
authors.forename: Sara A
authors.initials: SA
authors.lastname: Burt
authors.forename: Henk P
authors.initials: HP
authors.lastname: Haagsman
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D000081007:Cymenes; D004926:Escherichia coli / Q000187:drug effects; D006900:Hydroxylation; D039821:Monoterpenes / Q000737:chemistry* / Q000494:pharmacology*; D012995:Solubility; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: C509883:2-amino-p-cymene; D000890:Anti-Infective Agents; D000081007:Cymenes; D039821:Monoterpenes; C073316:carvacrol