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 limonoid chemistry of Toona, which has shown absence of attacks of H. grandella, is reminiscent of Melioideae. An investigation of T ciliata, has led to the identification of two novel meliacin butenolides, 21-hydroxycedrelonelide and 23-hydroxycedrelonelide, two known limonoids, cedrelone and 23-hydroxytoonacilide, and sitosterol, alpha-amyrin and beta-amyrin acylated with fatty acids. Three known coumarins, siderin, scopoletin and isofraxidin were also isolated. All structures were established from spectral data. Some C-13 NMR signals for cedrelone are reassigned.