title: New antiplasmodial alkaloids from Stephania rotunda.
abstract: BACKGROUND
  Stephania rotunda Lour. (Menispermaceae) is a creeper growing in many countries of Asia and commonly found in the mountainous areas of Cambodia. As a folk medicine, it has been mainly used for the treatment of fever and malaria. The pharmacological activity is mostly due to alkaloids. Thus the aim of this study is to isolate new bioactive alkaloids from Stephania rotunda and to evaluate their in vitro antiplasmodial activity.
  
  
  METHODS
  Alkaloids were isolated and identified from dichloromethane and aqueous extracts using a combination of flash chromatography, high performance liquid chromatography, mass spectrometry and nuclear magnetic resonance. The purified compounds were tested for in vitro antiplasmodial activity on chloroquine-resistant W2 strain of Plasmodium falciparum.
  
  
  RESULTS
  A new aporphine alkaloid named vireakine (2) along with two known alkaloids stephanine (1) and pseudopalmatine (8), described for the first time in Stephania rotunda, and together five known alkaloids tetrahydropalmatine (3), xylopinine (4), roemerine (5), cepharanthine (6) and palmatine (7) were isolated and identified. The structure of the new alkaloid was established on the basis of 1D and 2D NMR experiments and mass spectrometry. The compounds were evaluated for their in vitro antiplasmodial and cytotoxic activities. All tested compounds showed significant antiplasmodial activities with IC(50) ranged from 1.2 μM to 52.3 μM with a good selectivity index for pseudopalmatine with IC(50) of 2.8 μM against W2 strain of Plasmodium falciparum and IC(50)>25 μM on K562S cells.
  
  
  CONCLUSIONS
  This study provides evidence to support the use of Stephania rotunda for the treatment of malaria and/or fever by the healers. Alkaloids of the tuber exhibited antiplasmodial activity and particularly cepharanthine and pseudopalmatine.
authors.affiliation: Aix-Marseille Univ, Laboratory of Pharmacognosy and Ethnopharmacology, UMR-MD3, Faculty of Pharmacy, 27 Bd Jean Moulin, CS 30064, 13385, Marseille cedex 5, France. beatrice.baghdikian@univ-amu.fr
authors.forename: Béatrice
authors.initials: B
authors.lastname: Baghdikian
authors.forename: Valérie
authors.initials: V
authors.lastname: Mahiou-Leddet
authors.forename: Sothavireak
authors.initials: S
authors.lastname: Bory
authors.forename: Sok-Siya
authors.initials: SS
authors.lastname: Bun
authors.forename: Aurélien
authors.initials: A
authors.lastname: Dumetre
authors.forename: Fathi
authors.initials: F
authors.lastname: Mabrouki
authors.forename: Sébastien
authors.initials: S
authors.lastname: Hutter
authors.forename: Nadine
authors.initials: N
authors.lastname: Azas
authors.forename: Evelyne
authors.initials: E
authors.lastname: Ollivier
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D020014:K562 Cells; D015394:Molecular Structure; D021261:Parasitic Sensitivity Tests / Q000379:methods; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010963:Plasmodium falciparum / Q000187:drug effects*; D031607:Stephania / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D000962:Antimalarials; D010936:Plant Extracts