title: Antiplasmodial activity of (I-3,II-3)-biflavonoids and other constituents from Ormocarpum kirkii.
abstract: Preliminary screening of a series of medicinal plants, traditionally used in Tanzania, showed an IC(50) of 15.6-31.2 microg/ml for the crude extract of the root of Ormocarpum kirkii S. Moore (Papilionaceae) against Plasmodium falciparum. A bioguided isolation was performed in order to isolate the active constituents. Twelve constituents were obtained and identified using NMR and MS data, and optical rotation measurements. The compounds comprised seven (I-3,II-3)-biflavonoids, three (I-3,II-3)-bi-4-phenyldihydrocoumarins, an isoflavanone and a C-glucosylated flavone. Six compounds, liquiritigeninyl-(I-3,II-3)-naringenin, apigeninyl-(I-3,II-3)-naringenin, 7-O-beta-D-glucopyranosylchamaejasmin, (3R,4S,3''R,4''S)-5,5''-di-O-methyldiphysin, 7-O-beta-D-glucopyranosyldiphysin, and 4''-hydroxydiphysolone, were isolated in addition to six known components. The compounds were evaluated for antimicrobial activity in a broad screening panel, including P. falciparum. Seven of these showed antiplasmodial activity; isochamaejasmin being the most active with an IC(50) of 7.3+/-3.8 microM, but the selectivity was rather limited. Thus, these constituents may contribute, at least in part, to the antimalarial use of O. kirkii in traditional medicine.
authors.affiliation: Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium. liene.dhooghe@ua.ac.be
authors.forename: Liene
authors.initials: L
authors.lastname: Dhooghe
authors.forename: Sheila
authors.initials: S
authors.lastname: Maregesi
authors.forename: Irena
authors.initials: I
authors.lastname: Mincheva
authors.forename: Daneel
authors.initials: D
authors.lastname: Ferreira
authors.forename: Jannie P J
authors.initials: JP
authors.lastname: Marais
authors.forename: Filip
authors.initials: F
authors.lastname: Lemière
authors.forename: An
authors.initials: A
authors.lastname: Matheeussen
authors.forename: Paul
authors.initials: P
authors.lastname: Cos
authors.forename: Louis
authors.initials: L
authors.lastname: Maes
authors.forename: Arnold
authors.initials: A
authors.lastname: Vlietinck
authors.forename: Sandra
authors.initials: S
authors.lastname: Apers
authors.forename: Luc
authors.initials: L
authors.lastname: Pieters
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000737:chemistry / Q000494:pharmacology*; D044946:Biflavonoids / Q000737:chemistry / Q000494:pharmacology*; D007887:Fabaceae / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010963:Plasmodium falciparum / Q000187:drug effects*
chemical_list: D000962:Antimalarials; D044946:Biflavonoids