title: Chemical composition and antimicrobial and allelopathic activity of Tunisian Conyza sumatrensis (Retz.) E.WALKER essential oils.
abstract: Conyza sumatrensis (Retz.) E.WALKER (Asteraceae) is a spontaneous annual herb, fairly widespread throughout Tunisia, which has rarely been studied or valued in any sector. Essential oils were obtained by hydrodistillation of different parts (flower heads, leaves, stems, and roots) of C. sumatrensis plants, which were collected in autumn (November 2007) at the flowering stage in the area of Monastir, Tunisia. In total, 98 compounds, representing 88.1-99.3% of the oil composition, were identified by GC-FID and GC/MS analyses. The root essential oil was distinguished by its high content in acetylenes (matricaria ester, 4; 74.3%), while those from flower heads and leaves were dominated by oxygenated sesquiterpenes (61.1 and 50.3%, resp.). The oils of C. sumatrensis from Tunisia belonged to a matricaria ester/caryophyllene oxide chemotype. All the oils were evaluated for antibacterial, antifungal, and allelopathic activities. The results indicate that the leaf oil exhibited significant in vitro antibacterial activity against Enterococcus faecalis, Staphylococcus aureus, and Proteus mirabilis and that the C. sumatrensis oils isolated from the aerial parts presented high mycelia-growth inhibition of Candida albicans and the filamentous fungi tested. Moreover, the essential oils of the different plant parts inhibited the shoot and root growth of Raphanus sativus (radish) seedlings. Indeed, the inhibition of the hypocotyl growth varied from 28.6 to 90.1% and that of the radicle from 42.3 to 96.2%.
authors: Laboratory of Genetic Biodiversity and Valorisation of Bioresources (LR11ES41), Higher Institute of Biotechnology of Monastir, University of Monastir, Rue Tahar Haddad, 5000 Monastir, Tunisia.
authors: Samia
authors: S
authors: Mabrouk
authors: Karima Bel Hadj
authors: KB
authors: Salah
authors: Ameur
authors: A
authors: Elaissi
authors: Lobna
authors: L
authors: Jlaiel
authors: Hichem Ben
authors: HB
authors: Jannet
authors: Mahjoub
authors: M
authors: Aouni
authors: Fethia
authors: F
authors: Harzallah-Skhiri
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D001424:Bacterial Infections / Q000188:drug therapy; D002176:Candida albicans / Q000187:drug effects; D035401:Conyza / Q000737:chemistry*; D013293:Enterococcus faecalis / Q000187:drug effects; D005658:Fungi / Q000187:drug effects; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008826:Microbial Sensitivity Tests; D009181:Mycoses / Q000188:drug therapy; D009822:Oils, Volatile / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011513:Proteus mirabilis / Q000187:drug effects; D031224:Raphanus / Q000187:drug effects / Q000254:growth & development; D013211:Staphylococcus aureus / Q000187:drug effects; D014416:Tunisia
chemical_list: D000890:Anti-Infective Agents; D009822:Oils, Volatile