Artigos Científicos - ICS
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/6317
Navegar
Navegando Artigos Científicos - ICS por Periódicos "Acta Amazonica"
Agora exibindo 1 - 2 de 2
- Resultados por página
- Opções de Ordenação
Item Acesso aberto (Open Access) Estudo fitoquímico biomonitorado pelos ensaios de toxicidade frente à Artemia salina e de atividade antiplasmódica do caule de aninga (Montrichardia linifera)(Instituto Nacional de Pesquisas da Amazônia, 2011) AMARANTE, Cristine Bastos do; MÜLLER, Adolfo Henrique; PÓVOA, Marinete Marins; DOLABELA, Maria FâniMontrichardia linifera is an aquatic plant widely use in Amazon folkmedicine. However, very little is known about the chemical composition and biological activity. In search of biologically active (s) substance (s) phytochemical bioassay-guided study was conducted evaluating hexane extract and ethanol extract obtained from stems of this species. Since only the ethanol extract presented toxicity against Artemia salina and activity against Plasmodium falciparum, this extract was selected for chromatographic fractionation. The biological activities were concentred in dichloromethane fraction which showed high toxicity against A. saline (LD50< μg mL-1) and high antiplasmodial activity (IC50 <10 μg mL-1), showing promising antimalarial activity. Of this fraction, the aromatic compound p-hydroxybenzaldehyde was isolated for the first time in this plant.Item Acesso aberto (Open Access) Natural gaps associated with oxidative stress in Willisornis poecilinotus (Aves: Thamnophilidae) in a tropical forest(Instituto Nacional de Pesquisas da Amazônia, 2014-06) GOMES, Andreza de Lourdes Souza; GONÇALVES, Andrey Felipe Gomes; VIEIRA, José Luiz Fernandes; MARCELIANO, Maria Luiza Videira; SILVA, José Maria Cardoso daNatural disturbances in tropical forests modify the availability and quality of resources and alter the patterns of bird distribution. These environmental changes increase the metabolic rate and disrupt the redox balance promoting oxidative stress. This study aimed to compare the abundance of Willisornis poecilinotus between gaps and the understory of a forest with undisturbed canopy at Caxiuanã National Forest. The abundance was correlated with vegetation heights. The oxidative stress and the stress promoting factors were determined in both sites of sampling. We captured 81 specimens of W. poecilinotus. The number of captures was high in gaps. The specimens sampled at gaps showed high levels of oxidative stress. The biomarkers of oxidative stress were significantly correlated in gaps. The variability of oxidative stress and oxidative damage were explained only by site of sampling. These results suggest that gaps are stressors sites to W. poecilinotus, which probably can be due to an increase of metabolic rate to deal with new flight strategies of foraging and avoid predation.