Supercritical CO₂ extraction of volatile oils from Sardinian Foeniculum vulgare ssp. vulgare (Apiaceae): chemical composition and biological activity

Abstract

This article reports the results on the composition and antifungal effect of volatile extracts obtained from the aerial parts of Sardinian wild fennel (Foeniculum vulgare Mill.), by supercritical fluid extraction (SFE) and by hydrodistillation (HD). The extracts were analysed by gas chromatography–mass spectrometry for qualitative composition and gas chromatography-flame ionisation detector to establish the percentage of constituents. The main components were fenchone (7.1% vs. 8.8%), estragole (34.9% vs. 42.6%) and (E)-anethole (24.6% vs. 43.4%) in the SFE and HD extract, respectively. Minimum inhibitory concentrations (MICs) were measured according to the reference Clinical and Laboratory Standards Institute (CLSI) broth macrodilution protocols. Minimum lethal concentrations were determined by subsequent subculturing of the same cell suspensions in solid medium. The essential oil was more active against Candida albicans, whereas the supercritical fluid extract possesses higher activity against Candida guillermondii and Cryptococcus neoformans, with MIC values of 0.32 μL/mL.

Keywords::

• Foeniculum vulgare
• essential oil
• supercritical carbon dioxide extract
• antifungal activity

Acknowledgements

The authors thank: The Istituto Tecnico Industriale M. Giua, Cagliari, ITI-GIUA for allowing the use of analytical instrumentations and methods within the collaboration agreement between DSCG-UNICA and ITI-GIUA; Dr Antonella Rosa, Dipartimento di Scienze Biomediche, Università degli Studi di Cagliari, for statistical analyses.

Notes

This work was presented to the 5th International Congress on Medicinal and Aromatic Plants, CIPAM 2014, 17–20 March 2014, Zarzis-Dejerba, Tunisia.