title: Identification of chemical constituents of Zanthoxylum heitzii stem bark and their insecticidal activity against the malaria mosquito Anopheles gambiae.
abstract: BACKGROUND
  Zanthoxylum heitzii bark extracts have insecticidal properties and have been reported to be used against malaria in Western Africa. Previously, it has been shown that a hexane extract of the bark is toxic to adult females of the mosquito Anopheles gambiae, a malaria vector. As part of our project on the control of malaria vectors using plant extracts, the phytochemistry of Z. heitzii bark hexane extract has been investigated with the aim to identify the major components with adulticidal and larvicidal effects on An. gambiae.
  
  
  METHODS
  Z. heitzii stem bark was extracted with hexane, and the extract was fractionated to isolate major components from the bark, identified by NMR spectroscopy. Isolated compounds were tested for toxicity towards adult female An. gambiae mosquitoes and for larvicidal effects towards An. gambiae.
  
  
  RESULTS
  The alkaloid dihydronitidine, the sesquiterpenoid caryophyllene oxide, the amide pellitorine and the lignan sesamin were identified as the major constituents in Z. heitzii bark. Pellitorine was toxic to both adult insects (LD50 50 ng/mg insect) and larvae (LD50 13 μg/ml). None of the other compounds were toxic to adults, but caryophyllene oxide and sesamin exhibited moderate larvicidal effects (LD50 > 150 μg/ml). A mixture of the four compounds in the same ratio as in the hexane extract showed higher toxicity (LD50 34 ng/mg insect) towards adult insects than the pure compounds.
  
  
  CONCLUSIONS
  The toxicity of Z. heitzii bark hexane extract to An. gambiae is mostly due to pellitorine, although interactions between pellitorine and other, inactive constituents may enhance the activity of the extract.
authors.affiliation: School of Pharmacy, Department of Pharmaceutical Chemistry, Section Pharmacognosy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway. nastaranmoussavi@gmail.com.
authors.forename: Nastaran
authors.initials: N
authors.lastname: Moussavi
authors.affiliation: School of Pharmacy, Department of Pharmaceutical Chemistry, Section Pharmacognosy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway. k.e.malterud@farmasi.uio.no.
authors.forename: Karl Egil
authors.initials: KE
authors.lastname: Malterud
authors.affiliation: National Polytechnic High School, Marien Ngouabi University, BP 69, Brazzaville, Republic of Congo. mikolobertin@yahoo.fr.
authors.forename: Bertin
authors.initials: B
authors.lastname: Mikolo
authors.affiliation: School of Pharmacy, Department of Pharmaceutical Chemistry, Section Pharmacognosy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway. dawes@online.no.
authors.forename: Dag
authors.initials: D
authors.lastname: Dawes
authors.affiliation: Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (IRD 224-CNRS 5290 UM1-UM2), Montpellier, Cedex 5, France. Fabrice.chandre@ird.fr.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Chandre
authors.affiliation: Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (IRD 224-CNRS 5290 UM1-UM2), Montpellier, Cedex 5, France. vincent.corbel@ird.fr.
authors.forename: Vincent
authors.initials: V
authors.lastname: Corbel
authors.affiliation: National Polytechnic High School, Marien Ngouabi University, BP 69, Brazzaville, Republic of Congo. danielmassamba@yahoo.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Massamba
authors.affiliation: Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle (IRD 224-CNRS 5290 UM1-UM2), Montpellier, Cedex 5, France. hans.overgaard@nmbu.no.|Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, P.O. Box 5003, Ås, Norway. hans.overgaard@nmbu.no.|Department of Entomology, Kasetsart University, Bangkok, Thailand. hans.overgaard@nmbu.no.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Overgaard
authors.affiliation: School of Pharmacy, Department of Pharmaceutical Chemistry, Section Pharmacognosy, University of Oslo, P.O. Box 1068 Blindern, 0316, Oslo, Norway. helle.wangensteen@farmasi.uio.no.
authors.forename: Helle
authors.initials: H
authors.lastname: Wangensteen
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects*; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018547:Plant Stems / Q000737:chemistry*; D053284:Polyunsaturated Alkamides / Q000737:chemistry / Q000494:pharmacology; D032106:Zanthoxylum / Q000737:chemistry*
chemical_list: D005231:Fatty Acids, Unsaturated; D007306:Insecticides; D010936:Plant Extracts; D053284:Polyunsaturated Alkamides; C008778:pellitorine