title: Samvisterin, a new natural antiplasmodial betulin derivative from Uapaca paludosa (Euphorbiaceae).
abstract: BACKGROUND
  Uapaca paludosa is used in African traditional medicine for the treatment of malaria.
  
  
  METHODS
  A bioguided fractionation of U. paludosa trunk bark extracts was performed on the basis of their antiplasmodial activity against Plasmodium falciparum.
  
  
  RESULTS
  A new natural betulin derivative named samvisterin (2) was isolated. In addition, 12 already known compounds were isolated from U. paludosa and tested against P. falciparum: squalene (1); lupeol (3), betulonic acid methyl ester (4), β-sitosterol (5), stigmasterol (6), betulin (7), betulinic acid (8), pentadecanoic acid (9), palmitic acid (10), margaric acid (11), stearic acid (12), methyl palmitate (13). With the exception of betulinic acid, all were isolated for the first time from U. paludosa. Their chemical structures were established on the basis of spectroscopic analysis. The antiplasmodial activity of compounds 1-8 was confirmed on the chloroquine-resistant strain of P. falciparum, FcM29-Cameroon, with IC50 values ranging from 0.7μg/ml (for 1) to 30μg/mL (for 3). The cytotoxicity of the fractions and isolated compounds was also determined on KB and Vero cell lines in order to determine the cytotoxicity/activity ratio of each one.
  
  
  CONCLUSIONS
  The results obtained with samvisterin (2) show that this new compound is the most promising of the series, with a weak cytotoxicity leading to the best selectivity index values.
authors.affiliation: Institut de Chimie des Substances Naturelles (ICSN-CNRS) UPR2301, Gif-sur-Yvette Cedex, France; Centre d'Etude et de Recherche Médecins d'Afrique (CERMA), 43, rue des Glycines, 91600 Savigny sur Orge, France. Electronic address: medecins_afrique@yahoo.fr.
authors.forename: J T
authors.initials: JT
authors.lastname: Banzouzi
authors.affiliation: CNRS, LCC (Laboratoire de Chimie de Coordination) UPR8241, 205, route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France.
authors.forename: P Njomnang
authors.initials: PN
authors.lastname: Soh
authors.affiliation: Institut de Chimie des Substances Naturelles (ICSN-CNRS) UPR2301, Gif-sur-Yvette Cedex, France.
authors.forename: S
authors.initials: S
authors.lastname: Ramos
authors.affiliation: Institut de Chimie des Substances Naturelles (ICSN-CNRS) UPR2301, Gif-sur-Yvette Cedex, France.
authors.forename: P
authors.initials: P
authors.lastname: Toto
authors.affiliation: Centre de Biochimie Structurale (CBS), UMR 5048 CNRS/UM1- 554 Inserm/UM1, Montpellier Cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Cavé
authors.affiliation: Institut de Chimie des Substances Naturelles (ICSN-CNRS) UPR2301, Gif-sur-Yvette Cedex, France.
authors.forename: J
authors.initials: J
authors.lastname: Hemez
authors.affiliation: CNRS, LCC (Laboratoire de Chimie de Coordination) UPR8241, 205, route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France; Université de Toulouse III, UPS, INPT, F-31077 Toulouse cedex 4, France. Electronic address: Francoise.Vical@inserm.fr.
authors.forename: F
authors.initials: F
authors.lastname: Benoit-Vical
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D019665:Euphorbiaceae; D006801:Humans; D020128:Inhibitory Concentration 50; D016488:Medicine, African Traditional; D024301:Plant Bark; D010936:Plant Extracts; D010963:Plasmodium falciparum / Q000187:drug effects; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D014709:Vero Cells; D000094062:Betulinic Acid
chemical_list: D000962:Antimalarials; D010936:Plant Extracts; D014315:Triterpenes; C000609561:samvisterin; C002503:betulin; D000094062:Betulinic Acid
keywords: Antimalarial activity; Betulinic acid; Euphorbiaceae; Samvisterin; Traditional medicine; Uapaca paludosa