Insight into reduction of obacunone, and their ester derivatives as insecticidal agents against Mythimna separata Walker

摘要

Here we have prepared a series of ester compounds of obacunone, a naturally occurring limonoid, isolated from plants such as Citrus and Dictamnus angustifolius. Their insecticidal activity was evaluated at 1 mg/mL against the pre-third-instar larvae of oriental armyworm (Mythimna separata Walker), a typical lepidopteran pest. When obacunone reacted with NaBH4, the ratio of two reduction products, C7 alpha-hydroxyobacunone (2) and C7 beta-hydroxyobacunone(3), was related to the reaction mixing solvents. C7 alpha-Propionyloxybacunone (4b) and C7 beta-(n) heptanoyloxybacunone (5g) exhibited the more promising insecticidal activity than their precursor obacunone and toosendanin. (C) 2014 Elsevier Ltd. All rights reserved.