title: Antiplasmodial quinones from Pentas longiflora and Pentas lanceolata.
abstract: The dichloromethane/methanol (1:1) extracts of the roots of Pentas longiflora and Pentas lanceolata showed low micromolar (IC(50) = 0.9-3 µg/mL) IN VITRO antiplasmodial activity against chloroquine-resistant (W2) and chloroquine-sensitive (D6) strains of PLASMODIUM FALCIPARUM. Chromatographic separation of the extract of PENTAS LONGIFLORA led to the isolation of the pyranonaphthoquinones pentalongin (1) and psychorubrin (2) with IC(50) values below 1 µg/mL and the naphthalene derivative mollugin (3), which showed marginal activity. Similar treatment of Pentas lanceolata led to the isolation of eight anthraquinones ( 4-11, IC(50) = 5-31 µg/mL) of which one is new (5,6-dihydroxydamnacanthol, 11), while three--nordamnacanthal (7), lucidin-ω-methyl ether (9), and damnacanthol (10)--are reported here for the first time from the genus Pentas. The compounds were identified by NMR and mass spectroscopic techniques.
authors: Department of Chemistry, University of Nairobi, Nairobi, Kenya.
authors: Milkyas
authors: M
authors: Endale
authors: John Patrick
authors: JP
authors: Alao
authors: Hoseah M
authors: HM
authors: Akala
authors: Nelson K
authors: NK
authors: Rono
authors: Fredrick L
authors: FL
authors: Eyase
authors: Solomon
authors: S
authors: Derese
authors: Albert
authors: A
authors: Ndakala
authors: Martin
authors: M
authors: Mbugua
authors: Douglas S
authors: DS
authors: Walsh
authors: Per
authors: P
authors: Sunnerhagen
authors: Mate
authors: M
authors: Erdelyi
authors: Abiy
authors: A
authors: Yenesew
mesh_terms: D000880:Anthraquinones / Q000302:isolation & purification / Q000494:pharmacology; D000962:Antimalarials / Q000494:pharmacology*; D004351:Drug Resistance / Q000187:drug effects*; D020128:Inhibitory Concentration 50; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots; D010963:Plasmodium falciparum / Q000187:drug effects*; D011809:Quinones / Q000302:isolation & purification / Q000494:pharmacology*; D019666:Rubiaceae / Q000737:chemistry*
chemical_list: C572559:5,6-dihydroxydamnacanthol; D000880:Anthraquinones; D000962:Antimalarials; D010936:Plant Extracts; D011809:Quinones