title: A thin-layer chromatography method for the identification of three different olibanum resins (Boswellia serrata, Boswellia papyrifera and Boswellia carterii, respectively, Boswellia sacra).
abstract: BACKGROUND
  Resins of the genus Boswellia are currently an interesting topic for pharmaceutical research since several pharmacological activities (e.g. anti-inflammatory, anti-microbial, anti-tumour) are reported for extracts and compounds isolated from them. Unambiguous identification of these resins, by simple and convenient analytical methods, has so far not clearly been verified.
  
  
  OBJECTIVE
  For differentiation and identification of three important Boswellia species (Boswellia serrata Roxb., Boswellia papyrifera Hochst. and Boswellia carterii Birdw., respectively Boswellia sacra Flueck.), possible even for minimally equipped laboratories, a thin-layer chromatography (TLC) method was developed, allowing unambiguous identification of the three species.
  
  
  METHODS
  Crude resin samples (commercial samples and a voucher specimen) were extracted with methanol or diethyl ether and subjected to TLC analysis (normal phase). A pentane and diethyl ether (2:1) with 1% acetic acid eluent was used. Chromatograms were analysed by UV detection (254 nm) and dyeing with anisaldehyde dyeing reagent. Significant spots were isolated and structures were assigned (mass spectrometry; nuclear magnetic resonance spectroscopy).
  
  
  RESULTS
  Incensole and incensole acetate are specific biomarkers for Boswellia papyrifera. Boswellia carterii/Boswellia sacra reveal ß-caryophyllene oxide as a significant marker compound. Boswellia serrata shows neither incensole acetate nor ß-caryophyllene oxide spots, but can be identified by a strong serratol and a sharp 3-oxo-8,24-dien-tirucallic acid spot.
  
  
  CONCLUSIONS
  The TLC method developed allows unambiguous identification of three different olibanum samples (Boswellia papyrifera, Boswellia serrata, Boswellia carterii/Boswellia sacra). Evidence on the specific biosynthesis routes of these Boswellia species is reported.
authors.affiliation: Organic Chemistry II, Universität des Saarlandes, Saarbrücken, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Paul
authors.forename: Gerit
authors.initials: G
authors.lastname: Brüning
authors.forename: Jochen
authors.initials: J
authors.lastname: Bergmann
authors.forename: Johann
authors.initials: J
authors.lastname: Jauch
mesh_terms: D029743:Boswellia / Q000737:chemistry* / Q000145:classification; D002855:Chromatography, Thin Layer / Q000379:methods*; D004224:Diterpenes / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D004986:Ether / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D015394:Molecular Structure; D000081223:Polycyclic Sesquiterpenes; D015203:Reproducibility of Results; D012116:Resins, Plant / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D012717:Sesquiterpenes / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D013045:Species Specificity
chemical_list: D004224:Diterpenes; D000081223:Polycyclic Sesquiterpenes; D012116:Resins, Plant; D012717:Sesquiterpenes; C530368:incensole acetate; D004986:Ether; C024714:caryophyllene; D000432:Methanol