title: Isolation and structural elucidation of cytotoxic compounds from the root bark of Diospyros quercina (Baill.) endemic to Madagascar.
abstract: OBJECTIVE
  To isolate and characterize the cytotoxic compounds from Diospyros quercina (Baill.) G.E. Schatz & Lowry (Ebenaceae).
  
  
  METHODS
  An ethno-botanical survey was conducted in the south of Madagascar from July to August 2010. Bio-guided fractionation assay was carried out on the root bark of Diospyros quercina, using cytotoxicity bioassay on murine P388 leukemia cell lines as model. The structures of the cytotoxic compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.
  
  
  RESULTS
  Biological experiments resulted in the isolation of three bioactive pure compounds (named TR-21, TR-22, and TR-23) which exhibited very good in vitro cytotoxic activities with the IC50 values of (0.017 5±0.0060) µg/mL, (0.089±0.005) µg/mL and (1.027±0.070) µg/mL respectively. Thus, they support the claims of traditional healers and suggest the possible correlation between the chemical composition of this plant and its wide use in Malagasy folk medicine to treat cancer.
  
  
  CONCLUSIONS
  The ability of isolated compounds in this study to inhibit cell growth may represent a rational explanation for the use of Diospyros quercina root bark in treating cancer by Malagasy traditional healers. Further studies are, therefore, necessary to evaluate the in vivo anti-neoplastic activity of these cytotoxic compounds as effective anticancer drugs.
authors.affiliation: Department of Organic Chemistry, Faculty of Sciences, P.O. Box 187, University of Toliara, 601 Toliara, Madagascar.
authors.forename: Fatiany Pierre
authors.initials: FP
authors.lastname: Ruphin
authors.affiliation: Malagasy Institute of Applied Research, Avarabohitra Itaosy lot AVB 77, P. O. BOX 3833, 102 Antananarivo, Madagascar.
authors.forename: Robijaona
authors.initials: R
authors.lastname: Baholy
authors.affiliation: Antananarivo Poly-technique High School, University of Antananarivo, 101Antananarivo, Madagascar.
authors.forename: Randrianarivo
authors.initials: R
authors.lastname: Emmanuel
authors.affiliation: Department of Organic Chemistry, Faculty of Sciences, P.O. Box 906 University of Antananarivo, 101Antananarivo, Madagascar.
authors.forename: Raharisololalao
authors.initials: R
authors.lastname: Amelie
authors.affiliation: Institute of Natural Products Chemistry, National Centre for Scientific Research CNRS 91198, Gif Sur Yvette-Paris, France.
authors.forename: Marie-Therese
authors.initials: MT
authors.lastname: Martin
authors.affiliation: Department of Biology, Faculty of Science, University of Kinshasa, P.O. BOX 190 Kinshasa XI, Democratic Republic of the Congo.
authors.forename: Ngbolua
authors.initials: N
authors.lastname: Koto-Te-Nyiwa
keywords: (E)-5,6-Dimethyl-2-(2-methyl-3-(prop-1-enyl) phenyl)-2H-Chromene; 3′-dihydroxy-4; 6-dimethyl-1,2′-binaphthyl-2,5′,8,8′tetraones; 6′-Ethoxy-1′; Cytotoxic activities; Diospyros quercinia; Isodiospyrin; Madagascar