Chemical compositions and bioefficacy against Spodoptera litura of essential oil and ethyl acetate fraction from Myoporum bontioides leaves

Abstract

Essential oil of fresh leaves from Myoporum bontioides A. Gray was analyzed by GC–MS. A total of nine components were identified in this volatile oil with epingaione (81.52 %) as a main constituent. Three flavonoids named isorhamnetin (1), 3,4’-dimethoxy-3’,5,7-trihydroxyflavone (2) and luteolin (3) were isolated from the ethyl acetate fraction of Myoporum bontioides A. Gray leaves. Their structures were elucidated on the basis of spectroscopic data and by comparison with their spectral data reported in literature. The essential oil and ethyl acetate fraction from the leaves of this species expressed the toxicity to Spodoptera litura. In the antifeedant bioassay more than 50 % insects were killed after 48 h at 1.6 % and 4.0 % concentrations of the essential oil and ethyl acetate fraction, respectively.