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The new ryanodane diterpenes cinnzeylanone, ryanodol 14-monoacetate, and epi-cinnzeylanol have been isolated from Persea indica (Lauraceae). The structure of cinnzeylanone has been determined by X-ray analysis. These compounds proved to be antifeedants against Spodoptera litura. Cinnzeylanol and ryanodol were the most active antifeedants of this plant, with a range of activity close to that of ryanodine. This is the first report on the antifeedant effects of this class of diterpenes. Their structure-activity relationships and possible mode of action are discussed.

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Four new phenalenone-type phytoalexins (2 -5) have been isolated from rhizomes of Musa acumituzta (AAA) infected with the fungus Fusurium oxysporum. The structures of the new phytoalexins were elucidated using spectroscopic evidence, chemical correlation, synthesis, and X-ray diffraction analysis. The major compound 2, has been previously described as a natural product, named anigorufone, but never as a phytoalexin. The chemical shift for all of the hydrogen and carbon atoms in the substances were unanibiguously established by mono-and bidimensional, homo-and heteronuclear NMR experiments ('HNMR, ''CNMR, COSY, HMQC and HMBC). In preliminary in virro assays, all of the four new phytoalexins have shown inhibitory activity on the growth of the germinative tube of Fusurium oxysporum f. sp. cubense race 4.