Dang_2010_J.Asia.Pac.Entomol_13_51

The methanol extract of dried roots of Euphorbia kansui, known as Gan Sui in oriental medicine, showed pesticidal activity against brown plant hopper (Nilaparvata lugens Stal) and two-spotted spider mite (Tetranychus urticae Koch). Bioassay-guided fractionation led to the isolation of two active compounds from the dried roots of E. kansui. The substances were identified as 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoylingenol (1) and 3-O-(2'E,4'Z-decadienoyl)-ingenol (2) by MS and NMR spectral data. Both compounds exhibited insecticidal activity against the brown plant hopper and compound 1 was active against the two-spotted spider mite. Compared to anise oil and eugenol, the two ingenane diterpenes showed greater activity against brown plant hopper. The results suggest that 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoylingenol and 3-O-(2'E,4'Z-decadienoyl)-ingenol could be used directly as natural pesticides or as lead principles for the control of brown plant hopper and two-spotted spider mite.