RESUMEN
The genus Bursera belongs to the family Burseraceae and has been used in traditional Mexican medicine for treating various pathophysiological disorders. The most representative phytochemicals isolated from this genus are terpenoids and lignans. Lignans are phenolic metabolites known for their antioxidant, apoptotic, anti-cancer, anti-inflammatory, anti-bacterial, anti-viral, anti-fungal, and anti-protozoal properties. Though the genus includes more than 100 species, we have attempted to summarize the biological activities of the 34 lignans isolated from selected Mexican Bursera plants.
Asunto(s)
Bursera/química , Etnofarmacología , Lignanos/farmacología , Fitoquímicos/farmacología , Lignanos/química , Fitoquímicos/químicaRESUMEN
Copal is the Spanish word used to describe aromatic resins from several genera of plants. Mexican copal derives from several Bursera spp., Protium copal, some Pinus spp. (e.g., P. pseudostrobus) and a few Fabaceae spp. It has been used for centuries as incense for religious ceremonies, as a food preservative, and as a treatment for several illnesses. The aim of this review is to analyze the chemical composition and biological activity of commercial Mexican Bursera copal.
Asunto(s)
Bursera/química , Resinas de Plantas/química , Resinas de Plantas/farmacología , Sulindac/química , Sulindac/farmacología , Fabaceae/química , Conservantes de Alimentos/química , Conservantes de Alimentos/farmacología , Humanos , MéxicoRESUMEN
The leaf volatile components of Mexican Bursera linanoe were identified as (R)-(-)-linalyl acetate (57.6%; 95.5% ee) and (S)-(-)-germacrene D (39.3%; 100% ee) by solvent extraction and GC-MS and chiral GC analyses. Linalool was previously reported as the major component from the leaves of B. linanoe. However, we believe that this is a decomposition product of linalyl acetate during steam distillation, a common method for extraction of essential oils. The chemically unique blend in the leaves of B. linanoe may act as a chemical barrier against its potential herbivores, Blepharida beetles that have a tendency for attacking chemically similar plants as hosts.
Asunto(s)
Bursera/química , Monoterpenos/química , Sesquiterpenos de Germacrano/química , Cromatografía de Gases y Espectrometría de Masas , Indicadores y Reactivos , México , Monoterpenos/aislamiento & purificación , Hojas de la Planta/química , Sesquiterpenos de Germacrano/aislamiento & purificaciónRESUMEN
Elucidating the geographical history of diversification is critical for inferring where future diversification may occur and thus could be a valuable aid in determining conservation priorities. However, it has been difficult to recognize areas with a higher likelihood of promoting diversification. We reconstructed centres of origin of lineages and identified areas in the Mexican tropical dry forest that have been important centres of diversification (sources) and areas where species are maintained but where diversification is less likely to occur (diversity sinks). We used a molecular phylogeny of the genus Bursera, a dominant member of the forest, along with information on current species distributions. Results indicate that vast areas of the forest have historically functioned as diversity sinks, generating few or no extant Bursera lineages. Only a few areas have functioned as major engines of diversification. Long-term preservation of biodiversity may be promoted by incorporation of such knowledge in decision-making.
Asunto(s)
Biodiversidad , Clima , Conservación de los Recursos Naturales , Árboles , Bursera/genética , Agricultura Forestal , México , FilogeniaRESUMEN
Coevolutionary theory proposes that the diversity of chemical structures found in plants is, in large part, the result of selection by herbivores. Because herbivores often feed on chemically similar plants, they should impose selective pressures on plants to diverge chemically or bias community assembly toward chemical divergence. Using a coevolved interaction between a group of chrysomelid beetles and their host plants, I tested whether coexisting plants of the Mexican tropical dry forest tend to be chemically more dissimilar than random. Results show that some of the communities are chemically overdispersed and that overdispersion is related to the tightness of the interaction between plants and herbivores and the spatial scale at which communities are measured. As coevolutionary specialization increases and spatial scale decreases, communities tend to be more chemically dissimilar. At fairly local scales and where herbivores have tight, one-to-one interactions with plants, communities have a strong pattern of chemical disparity.
Asunto(s)
Bursera/crecimiento & desarrollo , Bursera/genética , Escarabajos/crecimiento & desarrollo , Escarabajos/genética , Ecosistema , Filogenia , Animales , MéxicoRESUMEN
Macroevolution examines the temporal patterns of biological diversity in deep time. When combined with biogeography, it can provide unique information about the historical changes in the distribution of communities and biomes. Here I document temporal and spatial changes of diversity in the genus Bursera and relate them to the origin and expansion of the tropical dry forests of Mexico. Bursera is very old, highly adapted to warm dry conditions, and a dominant member of the Mexican tropical dry forest. These characteristics make it a useful indicator of the history of this vegetation. I used a time-calibrated phylogeny to estimate Bursera's diversification rate at different times over the last 60 million years. I also reconstructed the geographic center and time of origin of all species and nodes from information on current distributions. Results show that between 30 and 20 million years ago, Bursera began a relatively rapid diversification. This suggests that conditions were favorable for its radiation and thus, very probably for the establishment of the dry forest as well. The oldest lineages diverged mostly in Western Mexico, whereas the more recent lineages diverged in the south-central part of the country. This suggests that the tropical dry forest probably first established in the west and then expanded south and east. The timing of the radiations in these areas corresponds to that suggested for formations of the mountainous systems in Western and Central Mexico, which have been previously recognized as critical for the persistence of the Mexican dry forest.
Asunto(s)
Evolución Biológica , Bursera/genética , Ecosistema , Árboles , Bursera/clasificación , Variación Genética , México , Filogenia , Factores de Tiempo , Clima TropicalRESUMEN
I reconstructed a phylogeny of 66 species and varieties of Bursera and 9 outgroup species using sequences of the internal transcribed spacer region (ITS), the 5S non-transcribed region (5S-NTS), and the external transcribed region (ETS) of nuclear ribosomal DNA. This study extends a previously proposed parsimony-based phylogenetic study that used the ITS sequences of 57 Bursera species and five outgroups. Parsimony and maximum likelihood methods were used to infer the phylogeny in this new study. Analyses of the combined data sets largely confirmed the phylogenetic relationships proposed by the previous molecular study but generated a considerably more robust topology. The new phylogenies corroborate the monophyly of the genus, and its division into the two monophyletic subgenera or sections, Bursera and Bullockia. The current analyses also identify four main groups of species in section Bursera, and two in section Bullockia, confirming some of the previously proposed groups based on fruit, flower, and leaf morphology. One previously problematic species B. sarcopoda, which has sometimes been placed in Commiphora, is shown to belong in Bursera. Another controversial species, Commiphora leptophloeos, which was thought to belong to Bursera, falls within Commiphora.