Abstract: A new compound named melianoninol I, along with five known cornpounds melianol II, melianone III, meliandiol IV, vanillin V and vanillic acid VI was isolated from the fruits of Melia azedarach L.. Their structures were elucidated by IR, MS, ¹H NMR, ¹³C NMR, and other spectral evidence. Compounds II, III, IV possess different insecticidal effects. and I exhibits a certain antifeeding property against the cabbage worm. Pieris rapae L..

Key words: Melia azedarach L., Melianoninol, Melianol, Meliandiol, Melianone