Abstract
A new series of 1-substituted-5-[(E)-2, 6-dimethyl-1, 5-heptadienyl]imidazoles were prepared and bioassayed for anti-juvenile hormone activity on the silkworm, Bombyx mori. The compounds induced unequivocal precocious metamorphosis in the 3rd and 4th instar larvae by topical application. Of the compounds tested, l-benzyl-5-[(E)-2, 6-dimethyl-1, 5-heptadienyl] imidazole (KK-42) proved to be the most active compound eliciting 100% of precocious pupation at 2 μg/larva on the 4th instar larvae. The E isomer showed considerably higher activity than the corresponding Z isomer. The anti-juvenile hormone effect of KK-42 was counteracted by simultaneous application of JH I or methoprene.
