The composition and antibacterial activity of the essential oil of Levisticum officinale Koch. flowers and fruits at different developmental stages

Abstract

The composition and antibacterial activity of the essential oil of Levisticum officinale Koch. at different developmental stages (flower, immature fruit, green mature fruit and ripened fruit) is reported. The essential oils were obtained by hydrodistillation of air-dried samples and their antibacterial activities were tested against seven bacteria. The yield of oil (w/w %) in different stages was in the order: immature fruit (1.5 %) > green mature fruit (1.0 %) > ripened fruit (0.6 %) > flower (0.1 %). The essential oils were analyzed by GC and GC-MS. In total, 27, 31, 28 and 26 constituents were identified and quantified in the mentioned samples, respectively. Monoterpene hydrocarbons were the main group of compounds in the green mature fruit (79.2 %), immature fruit (78.4 %), ripened fruit (75.2 %) and flower (44.0 %). The antibacterial activity of the oils was evaluated by the disk diffusion method using M?ller-Hinton agar and determination of inhibition zones. The results of the bioassays showed some variations between the three tested oils in their inhibitory activity against the tested bacteria at a 10 ?l disc-1 concentration. The oils from mature and ripened fruit exhibited potent antibacterial activity against Bacillus subtilis, with minimum inhibitory concentration (MIC) values of 0.90 mg ml-1 in mature and ripen fruits.