a b s t r a c t
Four alkaloids, 10-O-demethyl-17-O-methylisoarnottianamide 1, 6-acetonyl-N-methyl-dihydrodecarine
2, nitidine 3, and chelerythrine 4 were isolated from the plant Zanthoxylum lemairei (Rutaceae) and evaluated
for mosquito larvicidal activity against the malaria vector Anopheles gambiae. The mortalities of the
larvae were determined after 24 h. The results of the larvicidal tests demonstrated that compounds 1 and
2 were the most potent with mortality rates of 96.7% and 98.3% at a concentration of 250 mg/L, respectively.
Compound 3 was less potent with a mortality of 28.3% at the same concentration. The percent
mortality of 100% was observed at a concentration of 500 mg/L. The least potent of the four alkaloids
was compound 4, which achieved 100% mortality at 1000 mg/L. These findings could be useful in the
research for newer more selective, biodegradable and natural larvicidal compounds or can be used as lead
compounds for the development of larvicides.