Two new insecticidal sesquiterpene esters from Euonymus japonicus

Two new insecticidal sesquiterpene esters with a beta-dihydroagarofuran sesquiterpene skeleton, ejaponine A (1) and ejaponine B (2), and two known compounds, 3 and 4, were isolated from the EtOAc extract of the root bark of Euonymus japonicus Thunb. by bioassay-guided fractionation. Their chemical structures were elucidated mainly by analysis of MS and NMR spectral data. The LD50 values of ejaponine A (1), ejaponine B (2), 3 and 4 showed against Mythimna separata were 89.2, 98.6, 181.4 and 109.2 microg g(-1), respectively.