Antiplasmodial and Antioxidant Isofuranonaphthoquinones from the Roots of Bulbine capitata

Abstract

The roots of B. capitata yielded the new compounds 5,8-dihydroxy-1-tigloylmethylnaphtho[2,3-c]furan-4,9-dione, 1-acetoxymethyl-8-hydroxynaphtho[2,3-c]furan-4,9-dione, and 1-acetoxymethyl-5,8-dihydroxynaphtho[2,3-c]furan-4,9-dione, in addition to the known compounds chrysophanol, 10,10'-chrysophanol bianthrone, 8-hydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione, 5,8-dihydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione, 5,8-dihydroxy-1-hydroxymethylnaphtho[2,3-c]furan-4,9-dione, and 8-hydroxy-5-methoxy-1-methylnaphtho[2,3-c]furan-4,9-dione, or 5-hydroxy-8-methoxy-1-methylnaphtho[2,3-c]furan-4,9-dione. The new as well as the known isofuranonaphthoquinones showed antioxidant and weak antiplasmodial activities.

Natural products as antiparasitic drugs

“…Quinones have been tested intensively in the past against different parasites including Plasmodium (Weiss et al 2000;Bezabih et al 2001), Leishmania (Kayser et al 2000;Teixeira et al 2001), Toxoplasma gondii (Khan et al, 1998) and Trypanosoma sp. (Lopes et al 1978;Pinto et al 2000).…”

Bulbine-Knipholone, a New, Axially Chiral Phenylanthraquinone fromBulbine abyssinica (Asphodelaceae): Isolation, Structural Elucidation, Synthesis, and Antiplasmodial Activity

“…[1] A milk decoction of the roots is applied to cure body rash and sexually transmitted diseases, while related Bulbine species are used for the treatment of various ailments such as bacterial and fungal infections, eczema, venereal diseases, and rheumatism. [2] Previous chemical investigations on the genus Bulbine have resulted in the isolation of antioxidant isofuranonaphthoquinones such as 1 (see Figure 1), [3] DNA-intercalating [4] and antileukemic [5] anthraquinones such as chrysophanol (2) and aloe-emodin (3), [6] and axially chiral phenylanthraquinones with good antiplasmodial activities, [7] among them knipholone (4) [8,9] and isoknipholone (5). [10] These promising bioactivities and the importance of Bulbine plants in traditional medicine make the search for, and synthetic availability of, further metabolites rewarding goals.…”

Modulation ofAnopheles gambiaeEpsilon glutathione transferase activity by plant natural productsin vitro

“…The following chemicals and biochemicals were obtained from Sigma-Aldrich Chemical Companies, (St. Louis MO, USA): 1-chloro-2, 4-dinitrobenzene (CDNB), glutathione (GSH), hexylglutathione, ethacrynic acid, EDTA, DDT, NaN 3 , BSA, tris-(hydroxymethyl) amino methane (Trizma base), yeast extract, glycerol, tryptone, ampicillin, isopropyl thiogalactoside (IPTG), chicken egg white lysozyme, molecular weight markers.. The isofuranonaphthoquinones (Mr13/4 and Mr11/2) were extracted from Bulbine species [18], 14-hydroxy, 8, 15-diacetoxy-1(10)4, 11(13)germacratrien-12,6-olide (Jb42c) was extracted from Dicoma anomala, knipholone anthrone, (12KA) was extracted from Knipholfia foliosa, prinoidin (2QG1) and geshoidin were extracted from Rhamnus prinoides [19], PE10 was extracted from Plumera rubra [20], DE6 was from Dorstenia elliptica [21], GGI, Tral-1 and Tral-4 were extracted from Garcinia species. The natural products GG1, JB42c, Tral1 and Tral-4 were extracted from the above mentioned plants using the following general protocol.…”