title: Phytochemical Analysis of a Cytotoxic Fraction of Quassia silvestris using LC-HR-ESI-MSn.
abstract: BACKGROUND
  The genus Quassia is a promising source of secondary metabolites with biological potential including antimalarial and cytotoxic activities. Limited data are available on the phytochemistry and pharmacology of Quassia silvestris Cheek & Jongkind, a Cameroonian medicinal plant used to treat various ailments.
  
  
  OBJECTIVE
  To carry out the bioassay-guided fractionation and LC-HR-ESI-MS analyses of the leaves extract from Q. silvestris; to purify the active fractions and isolate the major compounds using different chromatographic and spectroscopic methods. The obtained compounds will be evaluated for their biological activity.
  
  
  METHODS
  Following the cytotoxic screening and LC-HR-ESI-MS profiling of fractions obtained from partition of the methanolic extract of Q. silvestris leaves, the CH2Cl2-soluble fraction which exhibited the highest cytotoxicity was retained for further investigations.
  
  
  RESULTS
  Sixteen squalene-derived metabolites were identified with oxasqualenoid derivatives being the most predominant. Among the isolates, structure elucidation of two new oxasqualenoids quassiols E (1) and F (2), were achieved by NMR (one-dimensional (1D) and two-dimensional (2D)) and MS methods. The newly characterised compounds 1 and 2, together with the known tetraol (3) and 3-oxo-oleanoic acid (16) displayed moderate cytotoxicity.
  
  
  CONCLUSIONS
  The identification and structural characterisation of highly oxidised squalene derived metabolites from this plant may provide important insight data for further pharmacological investigations. The LC-HR-ESI-MSnmethod reported here could be developed as a rapid and efficient tool for the analyses of structurally related compounds in the genera Quassia, Simarouba, and Eurycoma of the subfamily Simarouboideae. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Chemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.|State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, P.R. China.
authors.forename: Michel Feussi
authors.initials: MF
authors.lastname: Tala
authors.affiliation: Institute of Environmental Research (INFU) of the Faculty of Chemistry and Chemical Biology, TU Dortmund, Otto-Hahn-Str. 6, D-44221, Dortmund, Germany.
authors.forename: Ferdinand Mouafo
authors.initials: FM
authors.lastname: Talontsi
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, P.R. China.
authors.forename: Guang-Zhi
authors.initials: GZ
authors.lastname: Zeng
authors.affiliation: Department of Chemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.
authors.forename: Hippolyte Kamdem
authors.initials: HK
authors.lastname: Wabo
authors.affiliation: Institute of Environmental Research (INFU) of the Faculty of Chemistry and Chemical Biology, TU Dortmund, Otto-Hahn-Str. 6, D-44221, Dortmund, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller
authors.affiliation: Department of Chemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.
authors.forename: Ning-Hua
authors.initials: NH
authors.lastname: Tan
authors.affiliation: Department of Chemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.
authors.forename: Pierre
authors.initials: P
authors.lastname: Tane
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000494:pharmacology; D045744:Cell Line, Tumor; D005591:Chemical Fractionation; D002853:Chromatography, Liquid / Q000379:methods*; D005663:Furans / Q000737:chemistry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010936:Plant Extracts / Q000032:analysis; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D011714:Pyrans / Q000737:chemistry; D032271:Quassia / Q000737:chemistry* / Q000145:classification; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013185:Squalene / Q000737:chemistry
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005663:Furans; D010936:Plant Extracts; D011714:Pyrans; C000621700:quassiol E; C000621701:quassiol F; D013185:Squalene
keywords: Quassia silvestris; Simaroubaceae; cytotoxicity; high-resolution mass spectrometry; oxasqualenoids; triterpenoids