New insecticidal rocaglamide derivatives from the roots of Aglaia duperreana

Bioassay-guided fractionation of an extract obtained from roots of Aglaia d uperreana led to the isolation of 17 1H-cyclopenta[b]benzofurans of the roc aglamide type. Of the compounds isolated, four rocaglamide derivatives (2, 6, 11, and 16) were obtained as new natural products, and their structure e lucidation was conducted by spectral methods. For bioassay-guided fractiona tion and determination of LC50 and EC50 values, neonate larvae of Spodopter a littoralis were employed. The results of chronic feeding assays have show n new aspects of the structure-activity relationship of rocaglamide derivat ives. The substitution of a hydroxyl group at C-8b by a methoxyl substituen t leads to a loss of insecticidal activity in a manner not previously docum ented in this compound class.