Khayanolides, rearranged phragmalin limonoid antifeedants from Khaya senegalensis

Three new rearranged phragmalin-type limonoids, named khayanolides A, B and C, were isolated as insect antifeedant together with four known rings B,D- seco compounds, seneganolide, methyl angolensate and its 6-hydroxy and 6-ac etoxy derivatives from the ether extract of the stem bark of Khaya sencgale nsis. The structure of new compounds was elucidated by spectroscopic means and the absolute structure of khayanolide A was established by X-ray analys is and CD study. The antifeedant activity of the isolated compounds was als o reported. (C) 2000 Elsevier Science Ltd. All rights reserved.