title: Cycloartane triterpenes from the leaves of Neoboutonia macrocalyx L.
abstract: Neoboutonia macrocalyx is used by people in south western Uganda around Kibale National Park in the treatment of malaria. Phytochemical investigation on the leaves of this plant led to the isolation of nine cycloartane triterpenes (1-9) and one phenanthrene; 7-methoxy-2,8 dimethyl-9,10-dihydrophenantherene-3,6 diol (10) along with three known compounds which included 22-de-O-acetyl-26-deoxyneoboutomellerone (11), mellerin B (12) and 6-hydroxystigmast-4-en-3-one (13). The chemical structures of the compounds were established mainly through a combination of spectroscopic techniques. The isolated compounds were evaluated for antiplasmodial activity against the chloroquine-resistant FcB1/Colombia strain of Plasmodium falciparum and for cytotoxicity against the KB (nasopharyngeal epidermoid carcinoma) and MRC-5 (human diploid embryonic lung) cells. Seven out of 13 compounds exhibited good antiplasmodial activity with IC50 of ⩽5μg/ml with two compounds exhibiting low cytotoxicity and five compounds having significant cytotoxicity.
authors.affiliation: Department of Chemistry, Makerere University, P.O. Box 7062, Kampala, Uganda.
authors.forename: Jane
authors.initials: J
authors.lastname: Namukobe
authors.affiliation: Department of Chemistry, Makerere University, P.O. Box 7062, Kampala, Uganda. Electronic address: kiremire@chemistry.mak.ac.ug.
authors.forename: Bernard T
authors.initials: BT
authors.lastname: Kiremire
authors.affiliation: Department of Chemistry, Makerere University, P.O. Box 7062, Kampala, Uganda.
authors.forename: Robert
authors.initials: R
authors.lastname: Byamukama
authors.affiliation: Mountain of the Moon University, P.O. Box 837, Fort Portal, Uganda.
authors.forename: John M
authors.initials: JM
authors.lastname: Kasenene
authors.affiliation: Institut de Chimie des Substances Naturelles, CNRS - Avenue de la Terresse, 91198 Gif-sur-Yvette, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Dumontet
authors.affiliation: Institut de Chimie des Substances Naturelles, CNRS - Avenue de la Terresse, 91198 Gif-sur-Yvette, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Guéritte
authors.affiliation: Eco-Anthropologie et Ethnobiologie, UMR 7206, MNHN, 43 rue Buffon, 75005 Paris, France; Sebitoli Chimpanzee Project, GACP UWA Camp, Kibale NP, Fort Portal, Uganda.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Krief
authors.affiliation: National Museum Natural History, UMR 7245, CNRS, CP 52, 61 rue Buffon, 75231 Paris Cedex 05, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Florent
authors.affiliation: College of Veterinary Medicine, Animal Resources and Biosecurity, P.O. Box 7062, Kampala, Uganda.
authors.forename: John D
authors.initials: JD
authors.lastname: Kabasa
mesh_terms: D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D019665:Euphorbiaceae / Q000737:chemistry*; D006801:Humans; D007624:KB Cells; D008826:Microbial Sensitivity Tests; D008968:Molecular Conformation; D018515:Plant Leaves / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000962:Antimalarials; D014315:Triterpenes; C085352:cycloartane
keywords: Antiplasmodial activity; Cycloartane triterpenoids; Cytotoxicity; Euphorbaceae; Neoboutonia macrocalyx; Phenanthrene; Steroid