Antibacterial and antioxidant activities of Origanum compactum essential oil

In the present study, essential oil of Origanum compactum was analysed and its chemical composition was identified by gas chromatography coupled to mass spectrometry (GC-MS). Among thirty two assayed constituents, carvacrol (30.53%), thymol (27.50%) and its precursor g-terpinene (18.20%) were found to be the major components. The oil was investigated for its in vitro antibacterial activity against a panel of standard reference strains using well diffusion and broth dilution methods. In solid medium, the oil was found to be remarkably active against all tested strains except Pseudomonas which showed resistance. In liquid medium the Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentration (MBCs) ranged from 0.0078 to 0.25% (v/v). The antioxidant activity was investigated by three different methods; 1,1-diphenyl-2-picryl-hydrasyl (DPPH) radical scavenging assay, -carotenebleaching test and reducing power. The results of this study revealed evidence that the essential oil of O. compactum possesses a good antioxidant effect with all assays; the antioxidant activity isdependent on the oil concentration and can be attributed to the phenolic compounds present in the oil

Essential oils as antibacterial agents against food-borne pathogens: are they really as useful as they are claimed to be ?

Original articleMost studies evaluating the use of essential oils (EO) as antibacterial agents focus mainly on minimal inhibitory concentrations (MIC) rather than minimal bactericidal concentrations (MBC). In this work, we compared MICs and MBCs of EO from condiment plants commonly used in Mediterranean Europe, namely Origanum vulgare, Salvia lavandulaefolia, Salvia officinalis, Salvia sclarea and Rosmarinus officinalis, aiming to evaluate their application as disinfecting agents in minimally processed produce. Outbreaks-related pathogens such as Listeria monocytogenes, Pseudomonas aeruginosa and Yarrowia lipolytica were used. Results showed that all EO were able to reduce bacterial growth in all bacterial strains tested, particularly O. vulgare. However, fewer EO exhibited bactericidal activities, and were only effective against one or two bacterial strains, hence eliminating the possibility to use them as broad range disinfectants. Furthermore, the necessary concentrations were too high for food application. Hence, our work suggests the need to evaluate MBC rather than MIC and questions EO usefulness in controlling undesired microorganisms. Overall, and despite the large volume of data published on EO, results obtained were not very encouraging for a realistic application on produce and question the viability of EOs as disinfecting agents in foodinfo:eu-repo/semantics/publishedVersio

Tributyl- and triphenyltin benzoates, phenylacetates, and cinnamates as anion carriers: an electrochemical assessment coupled to structural NMR studies and AM1 calculations

FLWINinfo:eu-repo/semantics/publishe