Extraction, separation and isolation of volatiles from Vitex agnus-castus L. (Verbenaceae) wild species of Sardinia, Italy, by supercritical CO₂

Abstract

Isolation of volatile concentrates from leaves, flowers and fruits of Vitex agnus-castus L. have been obtained by supercritical extraction with carbon dioxide. The composition of the volatile concentrates has been analysed by GC/MS. In all plant organs, the extracts are composed chiefly of α-pinene, sabinene, 1,8-cineole, α-terpinyl acetate, (E)-caryophyllene, (E)-β-farnesene, bicyclogermacrene, spathulenol and manool. The main difference observed was in the content of sclarene, which was not present in the samples from flowers or fruits. To complete the investigation, a comparison with the hydrodistilled oil has been carried out. The minimal inhibitory concentration (MIC) and the minimal lethal concentration were used to evaluate the antifungal activity of the oils against dermatophyte strains (Trichophyton mentagrophytes, Microsporum canis, T. rubrum, M. gypseum and Epidermophyton floccosum). Antifungal activity of the leaf essential oil was the highest, with MIC values of 0.64 µL mL⁻¹ for most of the strains.

Keywords:

• Vitex agnus-castus L
• supercritical extraction
• hydrodistillation
• antifungal activity

Acknowledgements

This work was supported by funds from the Progetto PON 1.4L-2006-16 ‘NATURALMENTE SARDEGNA’.