Insecticidal activity of extracts isolated from Syzygium Aromaticum

Abstract

This study separated the crude extract (70% ethanol) of and its three fractions (hexane, chloroform and ethyl acetate extracts) on the basis of polarity indexes, and examined for their insecticidal activities against aphid (Uroleucon lactucicola). For crude extraction, the 70% ethanol extract showed the best extract yield (58.0%) and insecticidal activity (69.0%) among the various concentrations tested (water. 30% ethanol, 50% ethanol, 70% ethanol and 95% ethanol). The major chemical compounds of different fractions (hexane. chloroform and ethyl acetate extracts) were identified as eugenol by head space-GC-MS analysis. The hexane extract showed the highest eugenol content (43.7%) and insecticidal activity (80.0%). The insecticidal activity is accordingly believed to be attributable to the eugenol component. This may provide a useful starting point for the development of bio-pesticides.