Chemical composition and antibacterial activity of the essential oils of Blainvillea rhomboidea (Asteraceae)

Abstract

The essential oils of Blainvellea rhomboidea (Asteraceae) were obtained by hydrodistillation and analyzed by GC/MS and GC/FID. Initially, the essential oil from the aerial parts was investigated. From the 18 identified components, 5-indanol (14.5%) followed by p-cymen-8-ol (10.1%), β-caryophyllene (9.6%), caryophyllene oxide (9.6%), limonene (8.6%), terpinolene (7.8%), and spathulenol (7.7%) were the major constituents. The oil was tested against seven bacterial strains and the results showed significant antimicrobial activity. As a consequence, the essential oils from leaves and from flowers were analyzed separately. The major constituents of the leaf oil were terpinolene (21.2%), β-caryophyllene (19.2%), spathulenol (9.1%), caryophyllene oxide (7.4%), and bicyclogermacrene (7.1%), while the oil of the flowers contained terpinolene (28.1%), 5-indanol (16.3%), p-cymen-8-ol (15.3%) and limonene (14.7%) as prevalent compounds. The oils were tested against the same bacterial strains and the flower oil was the more active. These results indicated that the components of the essential oil from flowers seem to be responsible for the activity