Isolationandinsecticidalactivityofaliphaticchainamidesisolatedfrom<italic>Piperhancei</italic>

Six aliphatic chain amides, including chingchengenamide A( C1 ), N-isobutyldeca-trans-2-trans-4-dienamide( C2 ), retrofractamide A( C3 ), piperlonguminine( C4 ), N-p-coumaroyltyramine( C5 ) and N-trans-feruloyltyramine( C6 ) were isolated from petroleum ether and chloroform extraction phase of the methanol extract of the whole plant of Piper hancei. The compound C1 was isolated from P. hancei for the first time. The insecticidal activities of these compounds had been tested by larval immersion method. The bioassay results showed that C1 had significant insecticidal activity with the corrected mortality rate (after 12 h) of 100% at the mass concentrations of 20 mg/L and LC₅₀ value (after 12 h) of 5.37 mg/L against 4^th instar larvae of Aedes albopictus. The compound C1 , C2 , C3 and C4 also exhibited high activities against 4^th instar larvae of Culex pipiens quinquefasciatus with the corrected mortality rates of 100%, 88.5%, 100% and 100%, respectively, and LC₅₀ values of 1.03, 9.68, 3.08 and 2.87 mg/L, respectively.