title: Cytotoxic Properties and Complete Nuclear Magnetic Resonance Assignment of Isolated Xanthones from the Root of Garcinia cowa Roxb.
abstract: OBJECTIVE
  To isolate compounds from the roots of Garcinia cowa and to evaluated their cytotoxic activity against breast (MCF-7), prostate (DU-145), and lung (H-460) cell lines.
  
  
  METHODS
  The ground air-dried root was sequentially macerated with hexane, dichloromethane (DCM), ethyl acetate (EtOAc), and methanol. The DCM soluble extract was fractionated by vacuum liquid chromatography, column chromatography, and radial chromatography over silica gel with hexane, EtOAc and methanol as eluent in progressively increasing polarity manner; to yield three compounds. Their structures were elucidated based on their spectroscopic data and their comparison with those of the literature. The cytotoxicity of isolated compounds was carried out against human cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. The extract was added at various concentrations (0.1, 1, 10 and 100 mg/ml). The level of cytotoxicity was determined by calculating the level of IC50 that was based on the percentage of the cell death following the 24 h incubation with the extract.
  
  
  RESULTS
  Phytochemical study on the roots of G. cowa yielded rubraxanthone (3), cowanine (4) and 1,5-dihydroxyxanthone (5). Compound 4 with an IC50 value of 4.1 ± 1.0 μM, 5.4 ± 2.3 μM and 11.3 ± 10.0 μM against MCF-7, H-460, and DU-145, respectively while compound 3 was found to be in active.
  
  
  CONCLUSIONS
  The results indicate that G. cowa roots could be important sources of natural cytotoxic compounds.
  
  
  CONCLUSIONS
  Isolation of cytotoxic compounds from Garcinia cowaCowanine is the active constituent from the roots of Garcinia cowaComplete nuclear magnetic resonance assignment of isolated compoundsMS fragmentation of rubraxanthone.
authors.affiliation: Faculty of Pharmacy, Andalas University, Kampus Limau Manis, Padang, West Sumatra 25163, Indonesia.
authors.forename: Fatma Sri
authors.initials: FS
authors.lastname: Wahyuni
authors.affiliation: Laboratory of Natural Products, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
authors.forename: Khozirah
authors.initials: K
authors.lastname: Shaari
authors.affiliation: Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
authors.forename: Johnson
authors.initials: J
authors.lastname: Stanslas
authors.affiliation: Laboratory of Natural Products, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
authors.forename: Nordin Hj
authors.initials: NH
authors.lastname: Lajis
authors.affiliation: Faculty of Pharmacy, Andalas University, Kampus Limau Manis, Padang, West Sumatra 25163, Indonesia; Faculty of Nursing, Andalas University, Padang, West Sumatra 25163, Indonesia.
authors.forename: Dachriyanus
authors.initials: D
authors.lastname: Hamidi
keywords: Cytotoxic activity; DU-145; Garcinia cowa Roxb.; H-460; MCF-7; nuclear magnetic resonance; spectroscopy; structure elucidation; xanthone