title: Prenylated xanthone derivatives with antiplasmodial activity from Allanblackia monticola STANER L.C.
abstract: Further study of the methanol extract of the stem bark of Allanblackia monticola STANER L.C. resulted in the isolation of a new prenylated xanthenedione, designated allanxanthone C, together with the five known xanthones, garciniafuran, tovophyllin A, rubraxanthone, norcowanin and mangostin and one saponin, stigmasterol-3-O-beta-D-glucopyranoside. The structure of the new compound was established by detailed spectroscopic analysis to be 1,2-dihydro-3,6,8-trihydroxy-1,1,7-tri(3-methylbut-2-enyl)xanthen-2,9-dione (3-hydroxyapetalinone C). The methanol extract and pure compounds were tested on two strains of Plasmodium falciparum, F32 (chloroquine sensitive) and FcM29 (chloroquine resistant). The IC50 values obtained ranged from 0.6 to 8.9 microg/ml. Their cytotoxicity was estimated on human melanoma cells (A375) and the cytotoxicity/antiplasmodial ratio was found to be between 15.45 and 30.46. The antimicrobial activities against a range of microorganisms of the crude extract and some of these compounds are also reported.
authors.affiliation: Department of Chemistry, Faculty of Science, University of Douala, Cameroon. azebaze@yahoo.com
authors.forename: Anatole Guy Blaise
authors.initials: AG
authors.lastname: Azebaze
authors.forename: Michèle
authors.initials: M
authors.lastname: Meyer
authors.forename: Alexis
authors.initials: A
authors.lastname: Valentin
authors.forename: Edwige Laure
authors.initials: EL
authors.lastname: Nguemfo
authors.forename: Zacharias Tanee
authors.initials: ZT
authors.lastname: Fomum
authors.forename: Augustin Ephrem
authors.initials: AE
authors.lastname: Nkengfack
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology; D000962:Antimalarials / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D041022:Candida tropicalis / Q000187:drug effects; D045744:Cell Line, Tumor; D028084:Clusiaceae / Q000737:chemistry*; D004351:Drug Resistance; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008545:Melanoma / Q000188:drug therapy; D008826:Microbial Sensitivity Tests; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D010963:Plasmodium falciparum / Q000187:drug effects; D017368:Protein Prenylation; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013211:Staphylococcus aureus / Q000187:drug effects; D014970:Xanthines / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D044004:Xanthones / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D000962:Antimalarials; D014970:Xanthines; D044004:Xanthones; C508597:allanxanthone C