title: Cytotoxic glucosphingolipid from Celtis Africana.
abstract: BACKGROUND
  Literature survey proved the use of the powdered sun-dried bark and roots of Celtis africana for the treatment of cancer in South Africa.
  
  
  OBJECTIVE
  The aim of this study was to do further isolation work on the ethyl acetate fraction and to investigate the cytotoxic activities of the various fractions and isolated compound.
  
  
  METHODS
  Cytotoxicity of petroleum ether, chloroform, ethyl acetate, n-butanol fractions and compound 1 were tested on mouse lymphoma cell line L5178Y using the microculture tetrazolium assay.
  
  
  RESULTS
  One new glucosphingolipid 1 was isolated from the aerial parts of C. africana. The structure of the new compound was determined by extensive analysis by one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy and mass spectrometry. The ethyl acetate fraction and compound 1 showed strong cytotoxic activity with an EC50 value of 8.3 μg/mL and 7.8 μg/mL, respectively, compared with Kahalalide F positive control (6.3 μg/mL).
  
  
  CONCLUSIONS
  This is the first report of the occurrence of a cytotoxic glucosphingolipid in family Ulmaceae.
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 2457, Riyadh 11451, Saudi Arabia.
authors.forename: Shagufta
authors.initials: S
authors.lastname: Perveen
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 2457, Riyadh 11451, Saudi Arabia.
authors.forename: Areej Mohammad
authors.initials: AM
authors.lastname: Al-Taweel
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 2457, Riyadh 11451, Saudi Arabia ; Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt.
authors.forename: Ghada Ahmed
authors.initials: GA
authors.lastname: Fawzy
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt.
authors.forename: Azza Muhammed
authors.initials: AM
authors.lastname: El-Shafae
authors.affiliation: Department of Chemistry, COMSATS Institute of Information Technology, Abbottabad-22060, Pakistan.
authors.forename: Afsar
authors.initials: A
authors.lastname: Khan
authors.affiliation: Institute for Pharmaceutical Biology and Biotechnology, Heinrich-Heine-University Duesseldorf, Universitaets street 1, 40225 Duesseldorf, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Proksch
keywords: Celtis africana; Ulmaceae; glucosphingolipid; microculture tetrazolium assay