Podophyllotoxin derivatives show activity against Brontispa longissima larvae.

In an attempt to find biorational insecticides, eleven podophyllotoxin analogues were tested for their insecticidal activity against the fifth-instar larvae of Brontispa longissima in vivo for the first time. Among all of the tested compounds, deoxypodophyllotoxin (3) and beta-apopicropodophyllin (4) showed more promising and pronounced insecticidal activity than toosendanin, a commercial insecticide derived from Melia toosendan, and important SAR information has been revealed. Together, these preliminary results may be useful in guiding further modification of podophyllotoxins in the development of potential new insecticides.