Analysis of the Essential Oils of Some<i>Centaurea</i>Species (Asteraceae) Growing Wild in Algeria and Greece and Investigation of their Antimicrobial Activities

Abstract

Abstract The volatile composition of Centaurea pullata L., C. grisebachii (Nyman) Heldr. subsp. grisebachii and C. affinis Friv. have been studied. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC and GC-MS. Identification of the components was made by comparison of mass spectra and retention indices with literature records and by co-chromatography with authentic compounds. Their main constituents were caryophyllene oxide for C. pullata, 6,10,14-trimethyl pentadecan-2-one and spathulenol for C. grisebachi subsp. grisebachii, thymol and dodecanol for C. affinis. The essential oils were evaluated for their antimicrobial potential and showed a moderate activity against all microorganisms tested.