ABSTRACT
The essential oil of wild Daucus carota L. obtained from aerial parts at the end of the flowering stage (DCEO) was reported as antimicrobial against the human enteropathogen Campylobacter jejuni. The aim of the present study was to extend this analysis to other Campylobacter species and to identify the active compounds of the essential oil, subjected to GC, GC-MS, and (13)C NMR analysis. A minimum inhibitory concentration assay was used to quantify the antimicrobial activity of DCEO and the major components, isolated on column chromatography. Growth of all the C. jejuni, Campylobacter coli, and Campylobacter lari strains tested, including one multidrug resistant C. jejuni, was inhibited to the same extent by DCEO. Molecules that were responsible for the antibacterial activity were identified as (E)-methylisoeugenol and elemicin. Moreover, the use of structural analogues of these compounds allowed us to identify important features that may account for the activity.
Subject(s)
Anisoles/pharmacology , Anti-Bacterial Agents/pharmacology , Campylobacter jejuni/drug effects , Daucus carota/chemistry , Oils, Volatile/chemistry , Pyrogallol/analogs & derivatives , Anisoles/analysis , Oils, Volatile/pharmacology , Pyrogallol/analysis , Pyrogallol/pharmacologyABSTRACT
A detailed analysis of Santolina corsica essential oil was carried out by combination of GC (RI), GC-MS and 13C NMR spectroscopy. After fractionation by column chromatography, 50 components were identified, accounting for 88.2% of the total amount of the oil. The chemical composition was dominated by monoterpene hydrocarbons, myrcene (34.6%), santolina triene (13.5%) and beta-phellandrene (11.7%). Beside the main compounds, we noted the occurrence of irregular mono and sesquiterpenes belonging to five families: santolinane, artemisane, chrysanthemane, lavandulane and sesquilavandulane. Three compounds, lyratyl butyrate, isolyratone and epi-isolyratol were isolated and their structure elucidated by 2D NMR. Antibacterial activity was tested against six bacteria strains. The essential oil was effective against Staphylococcus aureus and C. jejuni. Lyratol was identified as main responsive of the antibacterial activity. The content of lyratol was measured in 33 oil samples isolated from individual plants.
