Trichilia hirta

Chaurest, D., Durst, T., Arnason, J. T. et al. (1996). Novel steroids from Trichilia hirta identified by nanoprobe. Tetrahedron Letters 37 7875-7878. 

The capabilities of the Nano-probe were challenged in a completely different fashion in 1996 by a study reporting the characterization of novel steroids from Trichilia hirta through the acquisition of INADEQUATE spectra.192 Using samples of 11 and 9 mg, respectively, INADEQUATE spectra were recorded to establish the structures of 99 and 100. Data were acquired in 62 h for each sample and the interpretation of the data was facilitated through the use of FRED software.84 86... 

Hirtin (25), from Trichilia hirta 47), has been known since 1966, but the stereochemistry at C-4 is unknown. The methyl shifts agree with those calculated for a C-28 carbomethoxy structure using the Turrea compounds and cedrelone as references, so it is likely this is the configuration. 

Hirtin 3-0X0, A , llp-OAc, 12a-propionyloxy-29-oic acid methyl ester Trichilia hirta (47)... 

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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