Bioactivity of essential oils from fruits of Bursera species.
The essential oil composition of fruits from six Mexican species of Bursera (B. copallifera, B. glabrifolia, B. fagaroides, B. submoniliformis, B. vejarvazquezii, and B. lancifolia) was analyzed using GC-MS. A total of forty-seven compounds, mainly monoterpenes, were detected. Limonene was found in all species and was the major constituent in B. vejarvazquezii, B. lancifolia, B. fagaroides and B. copallifera. Sesquiterpenoids were exclusively found in B. fagaroides, B. copallifera and B. submoniliformis; the latter was the only species having a sesquiterpene, caryophyllene, as a major constituent. Bursera copallifera showed the highest number of components (twenty-nine) while B. lancifolia the lowest (three), a high number of compounds did not implied more activity. Bioactivity was tested on larvae of Spodoptera frugiperda by the choice leaf disc, and artificial diet assays. The IC50 values were between 0.39 and 32.82 ppm. The biological activity followed a similar pattern to the limonene amount in the oils, suggesting an association between the antifeedant activity and the compound concentration.