ISOLATION AND CHARACTERIZATION OF LARVICIDAL COMPONENTS AGAINST MOSQUITO LARVAE (AEDES AEGYPTI LINN.) FROM CALODENDRUM CAPENSE THUNB

Abstract

Chromatographic analysis of air-dried root barks and seeds of Calodendrum capense Thunb led to the isolation of calodendrolide (1), limonin (2) and limonin diosphenol (3) whose structures were elucidated using physical and spectroscopic techniques. The compounds and the crude extract were then tested against mosquito 2^nd instar larvae of the species Aedes aegypti Linn senso stricto, a yellow fever vector at concentrations of 25, 50, 75, and 100 ppm. Calodendrolide (1) was the most toxic as it killed all the larvae even at the lower concentration of 25 ppm. In addition, concentrations of 15, 10, 5 and 1 ppm of this compound retained moderate efficacy. Calodendrolide (1), C. capense root bark crude, limonin (2), and limonin diosphenol (3) had LC₅₀ values of 13.1, 29.2, 71.6 and 217.1 ppm, respectively.



KEY WORDS: Aedes aegypti, Limonoids, Calodendrum capense, 2^nd instar larvae, Limonin, Limonin diosphenol


Bull. Chem. Soc. Ethiop. 2005, 19(1), 145-148.