A biogenetically interesting ring-C seco limonoid, salannal, and a potent insect antifeedant, meliacarpinin E, were isolated from the root bark of Chinese Melia azedarach, along with four known seco limonoids, salannin, deacetylsalannin, nimbolinin B and nimbolidin B. Their structures were elucidated by spectroscopic studies and their antifeedant properties were examined with the larvae of Spodoptera eridania.