The chemical compositions of Corsican and Sardinian Eryngium maritimum L. essential oils were investigated using column chromatography, gas chromatography with flame ionization detection and gas chromatography–mass spectrometry in electron impact mode. Sixty‐three compounds were identified accounting for 85.8–95.7% of the total amount. With germacrene D (13.7–45.9%), three uncommon oxygenated sesquiterpenes, 4βH‐cadin‐9‐en‐15‐al (18.4–27.6%), 4βH‐cadin‐9‐en‐15‐ol (2.2–14.3%) and 4βH‐muurol‐9‐en‐15‐al (4.3–9.3%), were identified as main components of the essential oils obtained from the plant aerial parts. Relative to these, essential oils from the roots differed drastically with high contents of 2,4,5‐trimethylbenzaldehyde (39.8%), 2,3,6‐trimethylbenzaldehyde (29.0%) and α‐muurolene (23.5%). The chemical variability of Corsican and Sardinian E. maritimum essential oils was studied using statistical analysis. A direct correlation between the island of origin of the sample essential oils and their chemical compositions was assessed. Corsican essential oils exhibited higher amounts of hydrocarbon terpenes than Sardinian samples. Relative to other Eryngium species, Corsican and Sardinian E. maritimum essential oils exhibited original compositions with sesquiterpene aldehydes. These compounds, together with total essential oil, were tested for antioxidant properties using the DPPH and ABTS radical‐scavenging activity tests. No meaningful activity could be attributed to sesquiterpene aldehydes and the corresponding alcohols but the total essential oil and the oxygenated fraction of E. maritimum both demonstrated strong antioxidant properties. Copyright © 2013 John Wiley & Sons, Ltd.

Investigation of the essential oil of the aerial parts of Eryngium maritimum L. from Corsica led to the isolation of one known sesquiterpene (1) and three new oxygenated sesquiterpenes with a muurolane or cadinane skeleton (2-4). Structure assignments of 4 βH -muurol-9-en-15-al (1), 4 βH -cadin-9-en-15-al (2), 4 βH -muurol-9-en-15-ol (3) and 4 βH -cadin-9-en-15-ol (4) were carried out by GC/MS (EI and CI) and comprehensive 1D and 2D NMR spectroscopy. Antibacterial activity of Eryngium maritimum L. oil and column chromatography fractions have been investigated for the first time. The oxygenated fraction, which contains the four sesquiterpenes, was efficient against Listeria monocytogenes and Echerichia coli.

The study illustrates the contribution of integrated techniques for the characterisation of unusual essential oils.