Bioactivity and structure–activity relationship of natural methoxylated phenylpropenes and their derivatives against Aphis craccivora Koch (Hemiptera: Aphididae)

In the light of recent increased interest in developing plant based secondary chemistry into products suitable for integrated pest management, the objective of the present study was to investigate the bioactivity in field simulated conditions and structure–activity relationship of some natural phenylpropenes and their related analogues (1–6) against Aphis craccivora. The activities of different compounds varied depending on the substitution of the functional groups and the side chain attached to the aromatic ring of the phenylpropene. Dimethyleugenol (5) showed maximum activity among all tested phenylpropenes with LC₅₀ values 880 and 2,047 ppm against nymphs and adults respectively. Present study showed that phenylpropenes appear to be promising natural insecticides and may hold potential for identification of new lead structures against A. craccivora. The activity of the most active phenylpropene (5) was comparable with that of the chemical pesticide (dimethoate).