A new sesquiterpene lactone glucoside and other constituents from Inula salsoloides with insecticidal activities on striped flea beetle (Phyllotreta striolata Fabricius).

A new sesquiterpene, eupatolide 13-O-β-d-glucopyranoside (eupatolide-II, 1), lactone glucoside, along with 15 known compounds, were isolated from the whole plant of Inula salsoloides (Asteraceae). Dichloromethane extract and compounds 1-11 were used to investigate insecticidal activities against vegetable important pest, striped flea beetle (Phyllotreta striolata Fabricius). None of the samples show any toxicity under concentration of 500 times, while compound 1 and the extract had toxic effect when the concentration increased to 250 times. But the corrected mortality of compound 1 and the extract were only 44.83 and 13.80%, respectively. Compound 11 (inulasalene) showed repellency effect in the no-choice test, and the repellency rate was 70%. Compounds 1 and 3 (inulasalsolide) showed the antifeeding rates of 65.22 and 47.06%, respectively. Compound 10 (11β,13-dihydrogeneupatolide) showed strong attractive effects on the adults, while the difference of injured area between the treatment and control was also not significant.