title: Chemical composition and antibacterial activity of the essential oils from Launaea resedifolia L.
abstract: BACKGROUND
  Several species of the genus Launaea are used in folk medicine such as in bitter stomachic, skin diseases, and reported to have antitumor, insecticide, and cytotoxic activities. The antimicrobial activities of coumarin constituents and the neuropharmacological properties have been investigated as well. In this study, the chemical composition of essential oils from Launaea resedifolia L. has been identified using the ordinary GC-MS technique to reveal the presence of 19 compounds dominated by dioctyl phthalate. Moreover, the antibacterial activity of the crude oil has been carried out using disk diffusion method against seven bacteria strains.
  
  
  RESULTS
  Nineteen compounds of essential oil of L. resedifolia L. were identified, representing 86.68% of the total oil. The compounds were identified by spectral comparison to be mainly esters, alcohols, ketones, and terpenes. The principal constituents are dioctyl phthalate (39.84%), Decanoic acid, decyl ester (12.09%), 11-Octadecenal (11.24%), and Eucalyptol (07.31%), while others were present in relatively small amounts. As far as antibacterial essays are concerned, it was found that the oils are active against most of the tested bacterial strains.
  
  
  CONCLUSIONS
  A major constituent in visible parts was Dioctyl phthalate (39.84%) and the yield of essential oils was 0.9%. These extracts reveal in vitro antibacterial activity on the studied bacterial, confirmed by the inhibition zone diameter ranging from 11 to 37 mm and a MIC value between 0.09 and 0.69 depending on the microorganism being tested.
authors.affiliation: Laboratory of Biomolecules and Plant Breeding, Life Science and Nature Department, University of Larbi Ben Mhidi Oum El Bouaghi, Algeria. ngherraf@yahoo.com.
authors.forename: Amar
authors.initials: A
authors.lastname: Zellagui
authors.forename: Noureddine
authors.initials: N
authors.lastname: Gherraf
authors.forename: Segni
authors.initials: S
authors.lastname: Ladjel
authors.forename: Samir
authors.initials: S
authors.lastname: Hameurlaine