Trichilia americana

Plant parts other than seeds have been less well studied and little attention has been placed on insecticidal modes of action of the defenses of the neotropical Meliaceae. Our study of the insect growth-reducing activity of 50 extracts of bark, leaf and wood of Central American Meliaceae showed the potent effect of these extracts against lepidopteran larvae and the potential for isolation of bioactive compounds from alarge number of these species. Extracts from the genera Trichilia and Cedrela (Xie etal., 1994 Ewete etal., 1996a Wheeler etal., 2001) show exceptional activity. Trichilia americana extracts have strong antifeedant activity to Spodoptera... 

Wheeler DA, Isman MB (2000) Effect of Trichilia americana extract on feeding behavior of Asian armyworm, Spodoptera litura. J Chem Ecol 26 2791-2800... 

Fig. 6.2 Larval weight gain and leaf area eaten by 4 instar Spodoptera litura on cabbage plants sprayed with a crude twig extract from Trichilia americana. Adapted from reference 21.

Trichilia americana Crude MeOH extract of twigs Unknown (limonoids )... 

WHEELER, D.A., ISMAN, M.B., Antifeedant and toxic activity of Trichilia americana extract against the larvae of Spodoptera litura, Entomol. Exp. Appl, 2001, 98, 9-16. 

Other studies show the presence of a diversity of compounds other than limonoids as defenses in the tissues of Meliaceae. Woody tissues of Trichilia trifolia afforded three novel dolabellanes with flexible Curing structures. These substances were very active antifeedants in the Sitophilus bioassay (Ramirez et al., 2000). T. martiana seeds yielded large amounts of 2-((Z,Z)-6,9-heptadecadienyl)furan. T. hirta and T. americana bark have yielded novel steroids by insect bioassay-guided isolation and application of a nanoprobe nuclear magnetic resonance (NMR) technique for structure elucidation (Chaurest etal.,1996). Compounds isolated included hydroxyandrosta-l,4-diene-3,16-dione (Fig. 1.4) and derivatives. However, studies by Wheeler et al. (2001) suggest that other unidentified compounds may also be... 

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