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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Tephrosia toxicaria Pers. (Fabaceae) popularmente conhecida como âtimbà de caienaâ, à utilizada na lavoura como defensivo agrÃcola e na pesca para paralisar peixes, devido sua atividade ictiotÃxica. Este trabalho relata o estudo quÃmico de T. toxicaria e avaliaÃÃo das atividades antioxidante e larvicida sobre Aedes aegypti. O estudo quÃmico permitiu o isolamento de dez flavonoides (TTP-1 â luteolina, TTP-3 â 6a,12a-desidro- a-toxicarol, TTP-4 â a-toxicarol, TTP-5 â obovatina, TTP-6 â deguelina, TTP-8 â villosinol, TTP-9 â 12a-hidroxi-a-toxicarol, TTP-10 â sumatrol, TTP-11 â 12a-hidroxirotenona e TTP-12 â tephrosina) â sendo oito deles rotenoides â uma cromona (TTP-13 â 6,7-dimetoxicromona) e a mistura dos esteroides sitosterol e estigmasterol, nas suas formas simples e glicosiladas. Ensaios larvicidas e antioxidantes foram realizados com diversos extratos, partiÃÃes e com alguns dos metabÃlitos secundÃrios isolados. Devido à presenÃa de rotenoides, compostos que tÃm sido utilizados no controle de pragas agrÃcolas desde o sÃculo XIX, o estudo de T. toxicaria se mostrou bastante promissor, com diversas amostras ativas, apresentando atividade comparÃvel à da rotenona, composto utilizado como padrÃo positivo do ensaio larvicida. Os resultados dos ensaios antioxidantes sugerem T. toxicaria como uma fonte potencial desses agentes, provavelmente devido à presenÃa de flavonoides. As substÃncias isoladas foram identificadas por mÃtodos espectromÃtricos e espectroscÃpicos (IV, EM, RMN 1H e RMN 13C), incluindo RMN bidimensional (HMBC, HSQC e COSY) e por comparaÃÃo com dados da literatura. / Tephrosia toxicaria Pers. (Fabaceae) popularly known as "timbà de caiena" is used as pesticide and fishing poison, because its activity icthyotoxic. This work reports the chemical study of T. toxicaria and its larvicidal and antioxidant activities evaluation. Phytochemical investigation led to the isolation of ten flavonoids (TTP-1 â luteolin, TTP-3 â 6a,12a-dehydro-a-toxicarol, TTP-4 â a-toxicarol, TTP-5 â obovatin, TTP-6 â deguelin, TTP-8 â villosinol, TTP-9 â 12a-hydroxy-a-toxicarol, TTP-10 â sumatrol, TTP-11â12a-hydroxyrotenone and TTP-12 â tephrosin) â eight of them rotenoids â one cromone (TTP-13 â 6,7-dimethoxychromone) and the mixture of steroids sitosterol and stigmasterol, in their simple forms and glycosylated. Antioxidant and larvicidal assays were performed with several extracts, partitions and with some of the secondary metabolities isolated. Due to the presence of rotenoids, compounds have been used to control in agricultural pest since the XIX century, the study of T. toxicaria was quite promising, with several active extracts, with activity comparable to that of rotenone, compound used as a positive test. Its antioxidant activity tests shown T. toxicaria as a potential source of these agents, probably due to the presence of flavonoids, compounds characteristic for presenting various types of biological activities. The substances were isolated and its structures determined by spectroscopic and spectrometric methods (IR, EM, 1H NMR and 13C NMR), including two-dimensional NMR (HMBC, HSQC and COSY) and by comparison with literature data.