LIMONOIDS FROM TOONA-CILIATA AND SPECULATIONS ON THEIR CHEMOSYSTEMATIC AND ECOLOGICAL SIGNIFICANCE

Evolution of limonoids in the Meliaceae appears to be consistent with the resistance of Melloideae against the shoot borer Hypsipyla. The li monoid chemistry of Toona, which has shown absence of attacks of H. gr andella, is reminiscent of Melioideae. An investigation of T ciliata, has led to the identification of two novel meliacin butenolides, 21-hy droxycedrelonelide and 23-hydroxycedrelonelide, two known limonoids, c edrelone and 23-hydroxytoonacilide, and sitosterol, alpha-amyrin and b eta-amyrin acylated with fatty acids. Three known coumarins, siderin, scopoletin and isofraxidin were also isolated. All structures were est ablished from spectral data. Some C-13 NMR signals for cedrelone are r eassigned.