Antimicrobial activity of carvacrol related to its chemical structure

Abstract

Aims: To investigate the relation between the chemical structure and the antimicrobial activity of carvacrol, eugenol, menthol and two synthesized carvacrol derivative compounds: carvacrol methyl ether and carvacryl acetate against bacteria, Escherichia coli, Pseudomonas fluorescens, Staphylococcus aureus, Lactobacillus plantarum, Bacillus subtilis, a yeast Saccharomyces cerevisiae and one fungi Botrytis cinerea. Methods and Results: The antimicrobial activity was tested in liquid and vapour phases, by both broth liquid and microatmosphere methods, respectively. The same classification of the compound's antimicrobial efficiency was found with both methods. Eugenol and menthol exhibited a weaker antimicrobial activity than carvacrol, the most hydrophobic compound. Carvacryl acetate and carvacrol methyl ether were not efficient, indicating that the presence of a free hydroxyl group is essential for antimicrobial activity. Conclusions: The different extents of antimicrobial aroma compounds’ efficiency showed that hydrophobicity is an important factor and the presence of a free hydroxyl group and a delocalized system allows proton exchange. Significance and Impact of the Study: This study has identified the importance of the hydrophobicity and the chemical structure of phenolic aroma compounds for antimicrobial activity and may contribute to a most rational use of these compounds as antimicrobial agent.

In vitro antimicrobial activities of cinnamon bark oil, anethole, carvacrol, eugenol and guaiazulene against Mycoplasma hominis clinical isolates

“…The antimicrobial action of carvacrol is similar to other phenolic substances: damage of the cyto- A Anethole MIC distribution E Guaiazulene MIC distribution plasmic membrane, disruption of the proton motive force, electron flow, active transport and coagulation of cell contents 17 . Carvacrol has been reported to possess inhibitory activity against Pseudomonas fluorescens, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Saccharomyces cerevisiae 19,20 . Eugenol, a major ingredient of the essential oil isolated from Syzygium aromaticum L., showed a lower efficiency than carvacrol (MIC 90 = MBC 90 = 1000 μg/mL).…”

Chemical composition and antibacterial activity of essential oil of a Croton rhamnifolioides leaves Pax & Hoffm

“…It is believed that monoterpene and sesquiterpene compounds, such as those found in C. rhamnifolioides essential oil, can accumulate in the bacterial membrane and cause a loss of integrity, leakage of the cytoplasmic contents, disruption of the proton motive force, lysis and cell death (BEN ARFA et al, 2006;SANTIESTEBAN-LÓPEZ;PALOU;LÓPEZ-MALO, 2007). Delamare et al (2007) stated that, in addition to the presence of major compounds, antimicrobial activity is also due to the presence of other components in low concentrations that can have additive, synergistic or antagonistic interactions.…”

Carvacrol and thymol components inhibiting Pseudomonas aeruginosa adherence and biofilm formation

“…Recently, scientific interest in the biological properties of carvacrol and thymol has increased remarkably (Ben Arfa et al, 2006;Chami et al, 2005;Dorman et al, 2002;Kordali et al, 2008;Lambert et al, 2001;Nostro et al, 2004;Ultee et al, 1998). In this study, we initially assessed the efficacy carvacrol and thymol on inhibiting the growth of planctonic P. aeruginosa strains.…”

“…The strong antimicrobial activity of some major components of essential oils, i.e. terpenes, has been described in several studies (Dorman et al, 2002;Ben Arfa et al, 2006). Carvacrol (2-methyl-5-(1-methylethyl) phenol) and thymol (2-isopropyl-5-methylphenol) are known for their wide spectrum of antimicrobial activity, which has been the subject of several investigations in vitro (Dorman et al, 2002;Lambert et al, 2001) and in vivo (Manohar et al, 2001;Adam et al, 1998).…”