title: Chemical composition and phytotoxic effects of essential oils obtained from Ailanthus altissima (Mill.) swingle cultivated in Tunisia.
abstract: Ailanthus altissima Mill. Swingle (Simaroubaceae), also known as tree of heaven, is used in the Chinese traditional medicine as a bitter aromatic drug for the treatment of colds and gastric diseases. In Tunisia, Ailanthus altissima is an exotic tree, which was introduced many years ago and used particularly as a street ornamental tree. Here, the essential oils of different plant parts of this tree, viz., roots, stems, leaves, flowers, and samaras (ripe fruits), were obtained by hydrodistillation. In total, 69 compounds, representing 91.0-97.2% of the whole oil composition, were identified in these oils by GC-FID and GC/MS analyses. The root essential oil was clearly distinguishable for its high content in aldehydes (hexadecanal (1); 22.6%), while those obtained from flowers and leaves were dominated by oxygenated sesquiterpenes (74.8 and 42.1%, resp.), with caryophyllene oxide (4) as the major component (42.5 and 22.7%, resp.). The samara oil was rich in the apocarotenoid derivative hexahydrofarnesyl acetone (6; 58.0%), and the oil obtained from stems was characterized by sesquiterpene hydrocarbons (54.1%), mainly β-caryophyllene (18.9%). Principal component and hierarchical cluster analyses separated the five essential oils into four groups, each characterized by the major oil constituents. Contact tests showed that the germination of lettuce seeds was totally inhibited by all the essential oils except of the samara oil at a dose of 1 mg/ml. The flower oil also showed a significant phytotoxic effect against lettuce germination at 0.04 and 0.4 mg/ml (-55.0 ± 3.5 and -85.0 ± 0.7%, resp.). Moreover, the root and shoot elongation was even more affected by the oils than germination. The inhibitory effect of the shoot and root elongation varied from -9.8 to -100% and from -38.6 to -100%, respectively. Total inhibition of the elongation (-100%) at 1 mg/ml was detected for all the oils, with the exception of the samara oil (-74.7 and -75.1% for roots and shoots, resp.).
authors.affiliation: Laboratory of Genetics Biodiversity and Valorisation of Bioressources (LR11ES41), Higher Institute of Biotechnology of Monastir, University of Monastir, Rue Tahar Haddad, 5000 Monastir, Tunisia, (phone:+216-73-463711; 216-73-465404).
authors.forename: Asma
authors.initials: A
authors.lastname: El Ayeb-Zakhama
authors.forename: Saoussen
authors.initials: S
authors.lastname: Ben Salem
authors.forename: Lamia
authors.initials: L
authors.lastname: Sakka-Rouis
authors.forename: Guido
authors.initials: G
authors.lastname: Flamini
authors.forename: Hichem
authors.initials: H
authors.lastname: Ben Jannet
authors.forename: Fethia
authors.initials: F
authors.lastname: Harzallah-Skhiri
mesh_terms: D032268:Ailanthus / Q000737:chemistry*; D064089:Allelopathy; D016000:Cluster Analysis; D004305:Dose-Response Relationship, Drug; D035264:Flowers / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D018525:Germination / Q000187:drug effects; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D015394:Molecular Structure; D009822:Oils, Volatile / Q000032:analysis / Q000737:chemistry* / Q000633:toxicity*; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D025341:Principal Component Analysis; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D012717:Sesquiterpenes / Q000032:analysis; D014416:Tunisia
chemical_list: D009822:Oils, Volatile; D012717:Sesquiterpenes
keywords: Ailanthus altissima; Allelopathy; Essential oils; Hierarchical cluster analysis (HCA); Lactuca sativa; Principal component analysis (PCA)