Composition and antibacterial activity of the essential oils of Helichrysum rupestre and H. ambiguum growing in the Balearic Islands (Part III)

The chemical compositions of the essential oils obtained from the aerial parts of Helichrysum rupestre and H. ambiguum were analysed by GC and GC/MS. From the forty-five identified constituents representing 90.21% and 93.90% of the two oils, respectively, manoyl oxide, dodecanal, nonanal, p-cymene, alpha-pinene, and 2,4,6-tris(1,1-dimethylethyl)benzoic acid, were found to be the major components. Furthermore, the oils were tested against six Gram (+/-) bacteria and it was found that one of them exhibited significant antibacterial activity.