- Lois Muiva-Mutisya, Bernard Macharia MHAKHASDLOAMK. "6α-Hydroxy-α-toxicarol and (+)-tephrodin with antiplasmodial activities from Tephrosia species." Phytochemistry Letters. 2014;10:179-183.
6α-Hydroxy-α-toxicarol and (+)-tephrodin with antiplasmodial activities from Tephrosia species
Lois Muiva-Mutisyaa, Bernard Machariaa, Matthias Heydenreichb, Andreas Kochb, Hoseah M. Akalac, Solomon Deresea, Leonidah K. Omosaa, Amir O. Yusufa, Edwin Kamauc, Abiy Yenesew
Phytochemistry Letters, Volume 10, December 2014, Pages 179–183
The CH2Cl2/MeOH (1:1) extract of the roots of Tephrosia villosa showed good antiplasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 3.1 ± 0.4 and 1.3 ± 0.3 μg/mL, respectively. Chromatographic separation of the extract yielded a new rotenoid, 6α-hydroxy-α-toxicarol, along with five known rotenoids, (rotenone, deguelin, sumatrol, 12a-hydroxy-α-toxicarol and villosinol). Similar treatment of the extract of the stem of Tephrosia purpurea (IC50 = 4.1 ± 0.4 and 1.9 ± 0.2 μg/mL against D6 and W2 strains of P. falciparum, respectively) yielded a new flavone having a unique substituent at C-7/C-8 [trivial name (+)-tephrodin], along with the known flavonoids tachrosin, obovatin methyl ether and derrone. The relative configuration and the most stable conformation in (+)-tephrodin was determined by NMR and theoretical energy calculations. The rotenoids and flavones tested showed good to moderate antiplasmodial activities (IC50 = 9 − 23 μМ). Whereas the cytotoxicity of rotenoids is known, the flavones (+)-tephrodin and tachrosin did not show significant cytotoxicity (IC50 > 100 μМ) against mammalian African monkey kidney (vero) and human larynx carcinoma (HEp2) cell lines.