10 research outputs found
Influences de la sylviculture sur le risque de dégâts biotiques et abiotiques dans les peuplements forestiers
New Antibacterial Germacrene from Verbesina negrensis
Several health benefits have been attributed to members of the Verbesina genus, including promotion of urinary and gastrointestinal health. Verbesina species are also reported to exhibit antibacterial, antiparasitic, and antioxidant activities. Although members of the Verbesina genus produce various pharmacologically relevant chemicals as secondary metabolites, including eudesmanes, flavonoids, guanidine alkaloids, acetylenic compounds, and germacrenes, the active compounds required for these benefits remain unknown. To investigate potential antimicrobial activities of Verbesina negrensis, crude extracts from plant aerial structures were evaluated. Following chemical fractionation, the chloroformic extract from Verbesina negrensis was subjected to bioassay-guided isolation using disk diffusion assays to determine antimicrobial activity. The active compound was characterized as 6 beta-cinnamoyloxy-1 beta-hydroxy-10 alpha-metoxy-3-oxo-germacra-4,5Z-ene (1). Fractions containing 1 inhibited both Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 29213). The MIC for 1 was determined by microbroth dilution assay to be 64 mu g/mL for both E. faecalis and S. aureus
Notes on the lesser white-lined bat, Saccopteryx leptura (Schreber) (Chiroptera, Emballonuridae), from southeastern Brazil
Saccopteryx leptura (Schreber, 1774) is reported from two new localities in southeastern Brazil, both in Atlantic forest remains in the state of Rio de Janeiro. Analysisof food material showed that individuals from both localities had preyedon insects in the order Hymenoptera. Cheek contents were available from one specimen, and in this case identification of the food item (flying ants) achieved generic level (Pheidole Westwood, 1841). Aspects in the social behavior observed in a colony suggest that the same traits documented in Central American populations (small colonies, monogamic mating system, and retention of young for up to a year in the parental unit) may also characterize this species in the southern most part of its range. In both external and craniodental selected measurements, specimens from Rio de Janeiro were close to the upper limits of the ranges known for the species