Antiplasmodial activity of (I-3,II-3)-biflavonoids and other constituents from Ormocarpum kirkii.
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.
Dhooghe
Liene
L
Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium. liene.dhooghe@ua.ac.be
Maregesi
Sheila
S
Mincheva
Irena
I
Ferreira
Daneel
D
Marais
Jannie P J
JP
Lemière
Filip
F
Matheeussen
An
A
Cos
Paul
P
Maes
Louis
L
Vlietinck
Arnold
A
Apers
Sandra
S
Pieters
Luc
L
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*
D000962:Antimalarials; D044946:Biflavonoids