| Nature is a rich source of products with interesting and useful biological activity, natural insecticide is one of the important ways to develop new pesticides at present, and novel natural products with high intrinsic activity can be used as lead structures for an economical synthesis of highly active analogues.In our previous work, the insecticidal properties of 1, 5-diphenyl-1-pentanone(A), 1, 5-diphenyl-2-penten-1-one (B) and 1,5-diphenyl-3-hydroxy-1-pentanone(C) had been extracted from Stellera chamaejasme L. Laboratory bioassay showed that these compounds, 1, 5-diphenyl-1-pentanone and 1, 5-diphenyl-2-penten-1-one, have strong contact activity and very good anti-feedant activity against Aphis gossypii and Schizaphis graminum . Moreover, products A and B at a dose of 2 g kg-1 per os did not cause any toxic effects in mice, rats or rabbits. The compound 1,5-diphenyl-3-Hydroxy-1-pentanone has strong contact activity against Peries Rapae L. aging 3 (LC50 =0.48 g/L). These products are similar in structure to daphneolone (the nematicidal substance extracted from Daphne odora Thunb), chalcones, dihydrochalcones and flavonoids. Most of these compounds contain a C6-Cn-C6 skeleton, indicating that this may be important for insecticidal activity. In searching for novel environmentally benign insecticides with high activity, a novel series of substitutions on the phenyl ring of diphenylones derivatives were prepared based on C6-C5-C6 skeleton and the principle of molecule similitude. Their structures were established on the basis of 1H NMR and GC-MS detector. Insecticidal activities of these compounds were evaluated against Aphis gossypii Glov. Insecticidal assays indicated the substitution of phenyl ring for heteroaromatic ring was favorable. Thus, the modification of compound 3-Phenylpropyl furan-2-carboxylate, which showed excellent activity (LC50 = 0.85 g liter-1), offers a promising prospect. |
