Abstract:
The toxicity of six periplocoside compounds against 3
th M. separata larvae was measured by toxic carrying leaf disc method, the activities of aminopeptidase, alkaline phosphatase and V-ATPase in BBMV were determined using six periplocoside compounds on the basis of preparing brush border membrane vesicles (BBMV) of oriental armyworm midgut cells by MgCl
2 precipitation and differential centrifugation. The results showed that PSP and PST had obvious insecticidal activity with LC
50 value of 1.60 and 1.23 mg/mL at 24 h, respectively. PSA, PSD and PSF revealed weak insecticidal activity (LC
50 > 20 mg/mL) while PSE had no insecticidal activity. Six periplocosides had no significant inhibitory effect on aminopeptidase and alkaline phosphatase. The activity of V-ATPase was significantly inhibited by PSP and PST with a concentration dependence manner. Therefore, we preliminarily speculated that the initial binding site of insecticidal periplocoside compounds was located on the V-ATPase.