title: Three new natural compounds from the root bark essential oil from Xylopia aethiopica.
abstract: BACKGROUND
  In the course of on-going work on the characterisation of aromatic plants from the Ivory Coast we investigated the composition of the root oil from Xylopia aethiopica.
  
  
  OBJECTIVE
  The aim of this work was to investigate the chemical composition of X. aethiopica root oil and elucidate the structure of two new compounds.
  
  
  METHODS
  Analysis of the essential oil was carried out using a combination of chromatographic (CC, GC with retention indices) and spectroscopic techniques (MS, (13)C-NMR, 2D-NMR).
  
  
  RESULTS
  Twenty seven components, accounting for 95.6% of the whole composition, were identified including various compounds for which spectroscopic data were absent on commercial computerised MS libraries. Three compounds are reported for the first time as natural compounds and the structure of two new compounds, 4,4-dimethyl-2-vinylcyclohexene and endo-5-methoxy-3-patchoulene, has been elucidated using extensive two-dimensional NMR spectroscopy.
  
  
  CONCLUSIONS
  The composition of X. aethiopica root oil is dominated by two dimethylvinylcyclohexene isomers. It differs drastically from the composition of leaf and fruit oils of the same plant. The combination of analytical techniques appeared crucial for a fruitful analysis.
authors.affiliation: Laboratoire de Chimie Organique Biologique, UFR-SSMT, Université de Cocody-Abidjan, BPV 34, Abidjan, Côte d'Ivoire.
authors.forename: Thierry Acafou
authors.initials: TA
authors.lastname: Yapi
authors.forename: Jean Brice
authors.initials: JB
authors.lastname: Boti
authors.forename: Barthelemy Koffi
authors.initials: BK
authors.lastname: Attioua
authors.forename: Antoine Coffy
authors.initials: AC
authors.lastname: Ahibo
authors.forename: Ange
authors.initials: A
authors.lastname: Bighelli
authors.forename: Joseph
authors.initials: J
authors.lastname: Casanova
authors.forename: Félix
authors.initials: F
authors.lastname: Tomi
mesh_terms: D007560:Cote d'Ivoire; D053138:Cyclohexenes / Q000032:analysis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009822:Oils, Volatile / Q000032:analysis / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D010938:Plant Oils / Q000032:analysis / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry; D011083:Polycyclic Compounds / Q000032:analysis / Q000737:chemistry; D045789:Sesquiterpenes, Guaiane; D014753:Vinyl Compounds / Q000032:analysis / Q000737:chemistry; D054336:Xylopia / Q000737:chemistry*
chemical_list: C580610:4,4-dimethyl-2-vinylcyclohexene; D053138:Cyclohexenes; D009822:Oils, Volatile; D010938:Plant Oils; D011083:Polycyclic Compounds; D045789:Sesquiterpenes, Guaiane; D014753:Vinyl Compounds; C580611:endo-5-methoxy-3-patchoulene