Insecticidal rocaglamide derivatives from Aglaia spectabilis (Meliaceae)

Bark of Aglaia spectabilis collected on the island of Phu Quoc (Vietnam) yi elded 11 insecticidal cyclopentatetrahydrobenzofurans of the rocaglamide ty pe including four new natural products. Structure elucidation of the new co mpounds is described. All rocaglamide derivatives isolated exhibited strong insecticidal activity towards neonate larvae of the polyphagous pest insec t Spodoptera littoralis when incorporated into an artificial diet. LC50 val ues varied from 0.8 to 80 ppm. The most active compounds isolated, methylro caglate and C-3' hydroxylmethylrocaglate, were similar with regard to their insecticidal activity to the well-known natural insecticide azadirachtin. (C) 2000 Elsevier Science Ltd. All rights reserved.