Antimalarial prenylated chalcones from the twigs of Dorstenia barteri var. subtriangularis

Abstract

The ever widening level of Plasmodium falciparum resistance to antimalarials has led to the search of alternative therapies. In this context, any resources that can help alleviate the burden of the deadly malaria; including the search for new plant-derived biologically active ingredients are worthy of investigation. Amongst these, naturally occurring and synthetic chalcones have demonstrated promising potencies. In the present study, two diprenylated chalcones Bartericin A 1 and B 2, and four known natural products, stipulin 3, 4-hydroxylonchocarpin 4, isobavachalcone 5 and kanzonol B 6 were isolated from the twigs of Dorstenia barteri var. subtriangularis (Moraceae) by means of chromatographic methods. The structures of the purified compounds were elucidated by spectroscopic methods, mainly 1D and 2D-NMR spectroscopy. These compounds (1-6) were evaluated in culture against the W2 strain of P. falciparum. The evaluated compounds were found to be active in vitro against P. falciparum, 1, 3 and 4 demonstrating particular potencies with relatively low IC 50 values (2.15 µM, 5.13 µM and 3.36 µM respectively). The observed activities confirmed the chalcones as potential leads for the development of antimalarials.

Virtualizing the p-ANAPL Library: A Step towards Drug Discovery from African Medicinal Plants

“…The antiplasmodial activity of knipholone is IC 50 = 0.38 μM compared to Chloroquine 0.09 μM [68] . The chalcones bartericin A ( 23 ), stipulin ( 24 ), kanzonol B ( 26 ) and 4-hydroxylonchocarpin ( 27 ) have also shown anti-malarial activities [69] . while caffein ( 25 ) is a common psychostimulant.…”

Cytotoxic, Antimutagenic, and Antioxidant Activities of Methanolic Extract and Chalcone Dimers (Lophirones B and C) Derived From Lophira alata (Van Tiegh. Ex Keay) Stem Bark

“…21,22 The presence of a,bconjugated double bonds, the hydroxyl groups at C2 0 and C4 0 in ring A, and at C4 of ring B, in chalcones (eg, lophirones B and C) appear to be important for enhanced cytotoxic activity. 23,24 Antimutagenic Activity…”

The potential of anti-malarial compounds derived from African medicinal plants, part II: a pharmacological evaluation of non-alkaloids and non-terpenoids

“…The chalcones bartericin A ( 16 ), and 4-hydroxylonchocarpin ( 17 ), stipulin ( 18 ) and kanzonol B ( 19 ) were isolated from the twigs of Dorstenia barteri (Moraceae) from Cameroon by Ngameni et al . [ 63 ]. These compounds were evaluated in culture against the W2 strain of P. falciparum .…”