ABSTRACT
Bioassay-guided fractionation of the fruit pericarp of Pentadesma butyracea, using the antiplasmodial test, led to the isolation of a new xanthone, named pentadexanthone (1), together with six known compounds: cratoxylone (2), α-mangostin (3), 1,3,5-trihydroxy-2-methoxyxanthone (4), garcinone E (5), (-)-epicathechin (6), and lupeol (7). The structure of 1 was elucidated by spectroscopic data analysis. An antiplasmodial assay was performed with the isolates, in which compounds 1- 3 and 5 exhibited potent activity in vitro against Plasmodium falciparum chloroquine-resistant strain W2, with IC50 values below 3 µM.
Subject(s)
Antimalarials/pharmacology , Clusiaceae/chemistry , Plant Extracts/pharmacology , Plasmodium falciparum/drug effects , Xanthones/pharmacology , Antimalarials/chemistry , Antimalarials/isolation & purification , Fruit/chemistry , Molecular Structure , Plant Extracts/chemistry , Xanthones/chemistry , Xanthones/isolation & purificationABSTRACT
Phytochemical investigation of the stem bark of Beilschmiedia zenkeri led to the isolation of four new methoxylated flavonoid derivatives, (2S,4R)-5,6,7-trimethoxyflavan-4-ol (1), (2S,4R)-4,5,6,7-tetramethoxyflavan (2), beilschmieflavonoid A (3), and beilschmieflavonoid B (4), together with seven known compounds. The structures of 1-4 were established by spectroscopic methods, and their relative configurations confirmed by X-ray crystallographic and CD analysis. The isolated compounds were evaluated in vitro for their antibacterial activity against three strains of bacteria, Pseudomonas agarici, Bacillus subtilis, and Streptococcus minor, and for their antiplasmodial activity against Plasmodium falciparum, chloroquine-resistant strain W2.
Subject(s)
Flavonoids/isolation & purification , Flavonoids/pharmacology , Lauraceae/chemistry , Plants, Medicinal/chemistry , Bacillus subtilis/drug effects , Cameroon , Chloroquine/pharmacology , Drug Resistance/drug effects , Flavonoids/chemistry , Microbial Sensitivity Tests , Molecular Structure , Parasitic Sensitivity Tests , Plant Bark/chemistry , Plant Stems/chemistry , Plasmodium falciparum/drug effects , Pseudomonas/drug effects , Streptococcus/drug effectsABSTRACT
Bazouanthrone (1), a new anthrone derivative, has been isolated from the root bark of Harungana madagascariensis, together with known compounds, feruginin A (2), harunganin (3), harunganol A (4), harunganol B (5), friedelan-3-one (6) and betulinic acid (7). The structure of the compound (1) was assigned as 3,5,8,9-tetrahydroxy-2,4,4-tri-(3,3-dimethylallyl)-6-methyl-1-(4H)-anthracenone, by means of spectroscopic analysis. The anti-plasmodial activity of the isolated compounds was evaluated in culture against W2 strain of Plasmodium falciparum. All the compounds were found to be active against the Plasmodium parasites with bazouanthrone (1) showing particular potency (IC50=1.80 microM).
