A consensus ethnobotany of the Q’eqchi’ Maya of Southern Belize

An ethnobotany study in collaboration with Q’eqchi’ Maya healers of Southern Belize led to a collection of 169 medicinal plant species, belonging to 67 different families. The data show the use of a majority of species from primary or secondary semi-evergreen rainforests of Southern Belize, rather than weedy species. The medicinal uses of the plants were grouped into 17 usage categories. The frequency of use for each plant and the informant consensus factor for each usage category reveals a consensus among the healers on the use of plant species as well as on the diseases treated. These results suggest a well-defined medicinal tradition.     

Efficient production of isomelezitose by a glucosyltransferase activity in Metschnikowia reukaufii cell extracts

Metschnikowia reukaufii is a widespread yeast able to grow in the plants’ floral nectaries, an environment of extreme conditions with sucrose concentrations exceeding 400 g l⁻¹, which led us into the search for enzymatic activities involved in this sugar use/transformation. New oligosaccharides were produced by transglucosylation processes employing M. reukaufii cell extracts in overload-sucrose reactions. These products were purified and structurally characterized by MS-ESI and NMR techniques. The reaction mixture included new sugars showing a great variety of glycosidic bonds including α-(1→1), α-(1→3) and α-(1→6) linkages. The main product synthesized was the trisaccharide isomelezitose, whose maximum concentration reached 81 g l⁻¹, the highest amount reported for any unmodified enzyme or microbial extract. In addition, 51 g l⁻¹ of the disaccharide trehalulose was also produced. Both sugars show potential nutraceutical and prebiotic properties. Interestingly, the sugar mixture obtained in the biosynthetic reactions also contained oligosaccharides such as esculose, a rare trisaccharide with no previous NMR structure elucidation, as well as erlose, melezitose and theanderose. All the sugars produced are naturally found in honey. These compounds are of biotechnological interest due to their potential food, cosmeceutical and pharmaceutical applications.     

Overcompensating plants: their expression of resistance traits and effects on herbivore preference and performance

Overcompensation is a plant tolerance response in which plants have higher fitness after herbivory than without damage. Although it has been demonstrated that plants are able to simultaneously express resistance and tolerance traits, it remains unclear whether overcompensating plants are also inducing resistance‐mediating secondary metabolite production and how herbivores perform on plants that overcompensate. Our previous work has shown that a potato variety [Solanum tuberosum L. cv. Pastusa Suprema (Solanaceae)] from Colombia can express overcompensatory responses to damage by larvae of the Guatemalan potato moth, Tecia solanivora Povolny (Lepidoptera: Gelechiidae). Here we investigated (1) whether potatoes that express overcompensatory responses also induce resistance traits and (2) how the previous damage affects Guatemalan potato moth preference and performance. Our results show that larval feeding not only systemically induces higher tuber biomass but also an increased production of resistance‐related compounds, such as phenolics and proteinase inhibitors. Pupal mass increased with increasing tuber size, whereas changes in tuber secondary metabolism did not correlate with any metric of larval performance. Oviposition preference did not change between induced and undamaged plants. Our data show that potato plants expressing overcompensatory responses also induce secondary compounds known to increase resistance against herbivores. However, the induced response was relatively small, reducing the opportunities for a negative effect on the herbivore. Hypotheses for why larvae perform better in larger tubers and are not affected by the secondary metabolism are discussed. From an ecological and agricultural point of view, our results suggest that the expression of overcompensatory traits could have positive effects on herbivore performance.     

Partial trisomy-5p

Summary Two sibs with partial trisomy-5p are reported. Their father is the carrier of a balanced translocation 46,XY,t(4q+;5p-). Twelve cases of partial trisomy-5p—including our two patients—have been reported. The most common abnormalities found were mental retardation, short stature, dolichocephaly, prominent nasal bridge, prognathism, seizures, hypotonia, ear abnormalities, increased ulnar loops on the fingertips, and cryptorchidism in affected males.     

Protein-promoted membrane domains

The current notion of biological membranes encompasses a very complex structure, made of dynamically changing compartments or domains where different membrane components partition. These domains have been related to important cellular functions such as membrane sorting, signal transduction, membrane fusion, neuronal maturation, and protein activation. Many reviews have dealt with membrane domains where lipid-lipid interactions direct their formation, especially in the case of raft domains, so in this review we considered domains induced by integral membrane proteins. The nature of the interactions involved and the different mechanisms through which membrane proteins segregate lipid domains are presented, in particular with regard to those induced by the nAChR. It may be concluded that coupling of favourable lipid-lipid and lipid-protein interactions is a general condition for this phenomenon to occur.     

A regression analysis of q’eqchi’ Maya medicinal plants from southern Belize

A previous study provided a general quantitative analysis of 169 collected medicinal plants used by the Q’eqchi’ Maya healers of southern Belize. This paper is focused on a statistical analysis of this ethnobotanical information using the method developed by Moerman (1991). The residual values obtained from the regression analysis of the Q’eqchi’ medicinal plant species versus the species listed in the checklist of the vascular plants of Belize (Balick, Nee, and Atha, 2001) placed the Piperaceae, the Rubiaceae, and the Asteraceae in the first three ranks, and the Poaceae, the Cyperaceae, and the Orchidaceae in the last three ranks. The results were compared with three northern temperate regions (Kashmir, Korea, and North America) and three southern neotropical regions (Chiapas, Ecuador, and Veracruz). The coefficients of correlation between the checklist of vascular plants of Belize and the other six floras showed, as expected, high values for regions with similar climatic type. Thus, high correlations were determined between the tropical vegetation of Belize and those of Chiapas, Ecuador, and Veracruz. The coefficients were lower with the three temperate floras but still quite high. The same analysis was done with the medicinal plants only and led to much lower coefficients, but once again, the higher results were obtained for Chiapas and Veracruz. In this case, the last rank for Ecuador demonstrated that the selection of plants in traditional medicine by the indigenous people is a complex phenomenon which depends not only on the composition of the flora but also on culture-specific factors.

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Analyse par Regression des Plantes Médicinales des Mayas Q’eqchi'’ du Sud du Belize

Résumé  Une précédente étude a fourni une analyse quantitative générale de 169 plantes médicinales utilisées par les guérisseurs Maya Q’eqchi’ du sud du Belize. Ce document se concentre sur l’analyse statistique des informations ethnobotaniques selon la méthode développée par Moerman (1991). Les valeurs résiduelles obtenues à partir des analyses de régression des plantes médicinales Q’eqchi’ vis-à-vis des espèces mentionnées dans la liste des plantes vasculaires du Belize (Balick, Nee, et Atha, 2001) ont placé les Piperacées, les Rubiacées et les Asteracées aux trois premières places, et les Poacées, les Cyperacées et les Orchidacées aux trois dernières places. Les résultats ont été comparés avec ceux de trois régions tempérées du nord (Cachemire, Corée, et Amérique du Nord) et de trois régions néotropicales du sud (Chiapas, équateur, et Veracruz). Les coefficients de corrélation entre les plantes listées dans le manuel des plantes vasculaires du Belize et les six autres flores ont montré comme attendu de hautes valeurs pour les régions possédant un type climatique similaire. Ainsi, une haute corrélation a été démontrée entre la végétation tropicale du Belize et celles du Chiapas, de l’équateur, et du Veracruz. Les coefficients étaient plus bas avec les trois régions tempérées mais tout de même passablement élevés. La même analyse a été effectuée avec les plantes médicinales et a mené à des coefficients beaucoup plus bas, mais encore une fois, les résultats les plus élevés ont été obtenus pour le Chiapas et le Veracruz. Dans ce cas, la dernière position de l’équateur a souligné que la sélection des plantes par les indigènes dans la médecine traditionnelle est un phénomène complexe qui dépend non seulement de la composition de la flore mais aussi de facteurs spécifiques à la culture.