CHEMICAL AND BIOLOGICAL STUDY OF THE Tephrosia toxicaria Pers

The ethanol extracts from leaves, stems, pods and roots were assayed against the 3(rd) instar Aedes aegypti larvae and the highest activity was observed in the roots extracts (LC50 47.86 ppm). This extract was submitted to partition with hexane, chloroform, ethyl acetate and methanol. The respective fractions were bioassayed and the best larvicidal activities were identified in the hexane (LC50 23.99 ppm) and chloroform (LC50 13.80 ppm) fractions. Antioxidant activity (DDPH method) was observed in the ethanol extract (IC50 276 mu g/mL) from roots of T. toxicaria. Fractions from this extract were also tested and the highest antioxidant activity (IC50 89 mu g/mL) was found in the methanol fraction. The flavonoids iso-obovatin (1), obovatin (2), 6a, 12a-dehydro-beta-toxicarol (3), 6a, 12a-dehydro-alpha-toxicarol (4) and alpha-toxicarol (5) were isolated and bioassayed against A. aegypti. The flavonoid 5 showed the best larvicidal activity (LC50 24.55 ppm). The antioxidant activity of 2 was investigated and showed IC50 3.370 mu g/mL. The antioxidant and larvicidal activities of Tephrosia toxicaria are reported for the first time.