Calliandra portoricensis is a medicinal plant growing freely in Nigeria. It is used traditionally to treat tuberculosis, as an anthelmintic and an abortifacient. Phytochemical fractionation and screening of its root extracts has yielded a... more
Calliandra portoricensis is a medicinal plant growing freely in Nigeria. It is used traditionally to treat tuberculosis, as an anthelmintic and an abortifacient. Phytochemical fractionation and screening of its root extracts has yielded a novel (5-hydroxy-7-methoxy-4-oxo-1-chromanyl)-4-methoxy-p-benzoquinone (breverin)-substituted cassane diterpene, which was designated bokkosin. It was obtained from column chromatography of the ethyl acetate extract of the roots. The compound was characterized using IR, NMR (1D and 2D) and mass spectral data. Promising antiparasitic activity was observed against the kinetoplastid parasite Trypanosoma brucei brucei, as well as moderate activity against Trypanosoma congolense and Leishmania mexicana and low toxicity in mammalian cells, with the best in vitro EC50 values against T. b. brucei (0.69 μg/mL against a standard laboratory strain, and its multi-drug resistant clone (0.33 μg/mL). The effect on T. b. brucei in culture was rapid and dose-depend...
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The stem bark of Cassia sieberiana was extracted with methanol and the methanol extract partitioned with chloroform. Column chromatography of the chloroform fraction over silica gel yielded a novel benzofurochromene... more
The stem bark of Cassia sieberiana was extracted with methanol and the methanol extract partitioned with chloroform. Column chromatography of the chloroform fraction over silica gel yielded a novel benzofurochromene [2-(4-hydroxylphenyl)-7'-1, 2-dihydroxy-1-phenylpropyl)-4', 6'-dihydroxy [1] phenylbenzofuro (2, 3-c)-7'-chromene], lupeol and epiafzelechin. Their structures determined by Nuclear Magnetic resonance and mass spectrometry.