Chemical composition and antibacterial activity of essential oils from Daucus sahariensis Murb. roots and stems.

Daucus genus (Apiaceae) comprises economically relevant plants distributed in temperate regions. These plants are used mainly as food but are also known for their biological properties. Here, the essential oils (EOs) obtained by hydro-distillation of roots and stems of D.sahariensis Murb. growing in Algerian Sahara were studied by GC-MS analysis. Fifty-two and fifty-five compounds were identified from the roots and stems, representing 95.1% and 93.8% of the whole EOs respectively. The main constituents of the EO from roots were myristicin (29.2%), (E)-anethole (14.2%), cis-chrysanthenyl acetate (8%) and estragol (7.5%). In the EO from stems, the main constituents were α-pinene (18.6%), myrcene (16.7%), limonene (13.7%) and myristicin (8%). The antibacterial activity of EOs was evaluated by disc diffusion method and tested against Gram-positive and Gram-negative bacteria. Results showed a mild activity against Bacillus subtilis and Klebsiella pneumoniae for both EOs, which can be potentially used as antibacterial in phytotherapy.

A new chemotype with high tricyclene content from the essential oil of Salvia aegyptiaca L. growing in Algerian Pre-Sahara.

The essential oil obtained by hydrodistillation from the aerial parts of Salvia aegyptiaca L. (Lamiaceae) growing wild in pre-Saharan region of Algeria, was analysed by GC-MS. Forty-one compounds were detected, representing 87.9% of the whole oil. The essential oil of S. aegyptiaca is characterized by the predominance of monoterpene derivatives (70.6%). The major constituents were tricyclene (22.9%), followed by limonene (17.5%), ß-pinene (7.4%), caryophyllene oxide (3.2%) and ß-caryophyllene (3.1%). Tricyclene, the main component in our analysis is generally absent in the volatile oils from other Salvia species, therefore, the Algerian accession of S. aegyptiaca may be categorized as a new chemo-type.[Formula: see text].

Chemical constituents and anticholinesterase activity of the essential oil of Algerian Elaeoselinum thapsioides (Desf.) maire.

Elaeoselinum thapsioides (Desf.) Maire (Apiaceae) is an Algerian medicinal plant used in traditional medicine to treat different diseases. The essential oil obtained by hydrodistillation from the aerial parts of Elaeoselinum thapsioides growing wild in Algeria, was analyzed by GC-MS for the first time. Forty-five compounds were detected, accounting for 93.8% of the total oil, which was characterized by a high content of hydrocarbons derivatives of monoterpenes (75.9%). Myrcene (61.0%) was the principal constituent of the essential oil, followed by germacrene D (10.3%), α-pinene (6.5%) and ß-pinene (2.9%). In vitro anticholinesterase activity of the essential oil was investigated by the Ellman method that evidenced a low acetylcholinesterase and butyrylcholinesterase inhibitory effect.[Formula: see text].

Effect of growth stage on essential-oil yield and composition of Daucus sahariensis.

The essential oils obtained by hydrodistillation from Daucus sahariensis Murb. harvested at three different growth stages were characterized by GC/MS analysis. In total, 88 compounds were identified, with myristicin (29.8-51.7%), myrcene (6.7-31.1%), α-pinene (11.6-14.8%), and limonene (5.3-11.5%) as main constituents. Monoterpene hydrocarbons were the most represented compounds in the oils of the plant samples collected during the flower-budding and full-flowering periods. On the contrary, during the fruiting stage, the oils were dominated by phenylpropanoids. The essential oils were subject of considerable variation in their composition during the various developmental stages, particularly concerning the content of myrcene that decreased significantly passing from the vegetative to the fruiting stage. Conversely, for myristicin, the opposite trend was observed. Furthermore, the essential-oil yields were quite low during the flower-budding phase (0.27%), but rapidly increased during plant development (0.63 and 0.68% for the flowering and fruiting phases, resp.).

A myristicin-rich essential oil from Daucus sahariensis growing in Algeria.

The essential oils obtained by hydrodistillation from leaves and fruits of Daucus sahariensis Murb. were analyzed by GC/MS. The main constituents of the essential oil from the leaves were myristicin (34.3%), alpha-pinene (5.4%), cis-chrysanthenyl acetate (5.3%) and epi-alpha-bisabolol (4.8%), and those from the fruits myristicin (43.9%), alpha-pinene (13.1%), limonene (9.4%), and cis-chrysanthenyl acetate (7.4%). Myristicin, the main constituent of both essential oils, is generally absent in the oils from other Daucus species, permitting the hypothesis that this compound is a chemical marker of this Saharan species.