RESUMO
The antioxidant and larvicidal activities of Tephrosia egregia extracts and its major component, dehydrorotenone, were studied. High antioxidant activity was found for dehydrorotenone and methanol and ethyl acetate extracts from roots and stems, respectively. Among the tested extracts, the hexane extract from stems showed potent larvicidal activity (LC50 12.88 +/- 0.64) while low activity was found for dehydrorotenone.
Assuntos
Aedes , Inseticidas/química , Tephrosia/química , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Inseticidas/isolamento & purificação , Dose Letal Mediana , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Caules de Planta/químicaRESUMO
(1)H and (13)C NMR chemical shifts of praecansone B, pongaflavone and dehydrorotenone isolated from Tephrosia egregia Sandw and obovatin from T. toxicaria Pers. were unambiguously assigned by 1D and 2D NMR experiments including (1)H, (1)H COSY, gHMQC and gHMBC, allowing the correction of literature assignments.
Assuntos
Flavonas/química , Flavonoides/química , Prótons , Tephrosia/química , Isótopos de Carbono , Flavonoides/isolamento & purificação , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Padrões de Referência , EstereoisomerismoRESUMO
One- and two-dimensional NMR experiments were used for the unambiguous assignment of the (1)H and (13)C NMR chemical shifts of the furoquinoline alkaloid maculine (1) and the new furanocoumarin 3,8-dimethoxyfuro[3,2-g]coumarin (2).
Assuntos
Cumarínicos/química , Dioxóis/química , Furanos/química , Espectroscopia de Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/normas , Quinolinas/química , Rutaceae/química , Isótopos de Carbono , Conformação Molecular , Prótons , Padrões de ReferênciaRESUMO
One- and two-dimensional NMR experiments were used for the unambiguous assignment of the 1H and 13C NMR chemical shifts of 3,3-diisopentenyl-N-methyl-2,4-quinoldione and five novel reaction derivatives.
Assuntos
Alcaloides/química , Isoquinolinas/química , Sapindus/química , Espectroscopia de Ressonância Magnética/métodos , Conformação Molecular , MadeiraRESUMO
The structure of the glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) from Trypanosoma cruzi complexed with chalepin, a natural product from Pilocarpus spicatus, has been determined by X-ray crystallography to 1.95 A resolution. The structure is in the apo form without cofactors in the subunits of the tetrameric gGAPDH in the asymmetric unit. Unequivocal density corresponding to the inhibitor was clearly identified in one monomer. The final refined model of the complex shows extensive conformational changes when compared with the native structure. The mode of binding of chalepin to gGAPDH and its implications for inhibitor design are discussed.
Assuntos
Furocumarinas/química , Gliceraldeído-3-Fosfato Desidrogenases/química , Microcorpos/enzimologia , Trypanosoma cruzi/enzimologia , Animais , Cristalização , Cristalografia por Raios X , Furocumarinas/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/genética , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Substâncias Macromoleculares , Estrutura Molecular , Ligação Proteica , Relação Estrutura-Atividade , Trypanosoma cruzi/genéticaRESUMO
The activity of crude plant extracts of nine species of Rutaceae against the trypomastigote form of Trypanosoma cruzi was evaluated at 4 mg/ml. Thirty-two crude extracts were tested and eight of them showed significant activity (>80%). The most active extract was obtained from the stems of Pilocarpus spicatus (97.3%). Fractionation of the active crude extracts provided 25 fractions which were tested against the trypomastigote form of T. cruzi at 2 mg/ml. Of these six showed significant activity (>80%). The most active fractions (100%) were obtained from the leaves of Almeidea coerulea (butanol fraction) and Conchocarpus inopinatus (dichloromethane fraction).