Inhibitory effects of schiff analogues of aniline on phenoloxidase from Pieris rapae (L.) and Plutella xylostella (L.).

To screen the insecticide with novel modes of action,the inhibitory effects of 9 aniline schiff analogues as inhibitors on PO from Pieris rapae was studied by using microtitration assay,then a bio-assay was conducted by the immersion method in lab.The results showed that the tested compounds 2-hydroxy-4-methoxybenzylidene-3-chloroaniline,2-hydroxy-3-methoxybenzylidene-aniline,2-hydroxy-3-methoxybenzylidene-3,4-dichloroaniline could inhibit PO activity obviously and the inhibitory concentration(IC50) was estimated to be 0.051 mmol/L,0.013 mmol/L and 0.059 mmol/L,respectively.The inhibitors were all found to be reversible competitive inhibitors.Bio-assay of the 3 inhibitors for controlling Plutella xylostella was carried out and the results showed that the killer effects on Plutella xylostella was not obvious.