title: In vitro antimalarial activity of biflavonoids from Wikstroemia indica.
abstract: In our investigation of in vitro antimalarial screening of medicinal herbal extracts, the n-BuOH extract from the root of Wikstroemia indica showed a potent inhibitory effect. Fractionation of the active extract led to the isolation of two biflavonoids, sikokianin B ( 1) and sikokianin C ( 2) with IC (50) values 0.54 microg/mL and 0.56 microg/mL, respectively, against the chloroquine-resistant strain of Plasmodium falciparum. This is the first report of the biological activity of 1 and 2. As the structure of l has remained unsettled, we confirmed the conformation by (1)H- and (13)C-NMR.
authors.affiliation: The Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan.
authors.forename: Shinyu
authors.initials: S
authors.lastname: Nunome
authors.forename: Aki
authors.initials: A
authors.lastname: Ishiyama
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Otoguro
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kiyohara
authors.forename: Haruki
authors.initials: H
authors.lastname: Yamada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Omura
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000494:pharmacology*; D044946:Biflavonoids / Q000737:chemistry / Q000494:pharmacology*; D002738:Chloroquine / Q000494:pharmacology; D004351:Drug Resistance; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D021261:Parasitic Sensitivity Tests; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010963:Plasmodium falciparum / Q000187:drug effects*; D032365:Wikstroemia
chemical_list: D000962:Antimalarials; D044946:Biflavonoids; D010936:Plant Extracts; D002738:Chloroquine