Recebido em 29/6/11; aceito em 14/1/12; publicado na web em 15/5/12In the search for new larvicides from plants, we have investigated the potential activity of the rotenoids deguelin (1), 12a-hydroxy-α-toxicarol (2) and tephrosin (3), isolated from the bioactive ethanol extract of roots of Tephrosia toxicaria Pers., against Aedes aegypti, the main vector of dengue. The absolute configuration of these compounds was determined by circular dichroism (CD) spectra. The LC 50 values of the compounds evaluated justify the potential of T. toxicaria as a new natural larvicide.

T. toxicaria did not produce any signs of toxicity and effectively decreased zymosan-induced TMJ inflammatory hypernociception dependent, at least in part, upon the HO-1 pathway integrity.

No abstract

(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.

Recebido em 27/3/08; aceito em 23/9/08; publicado na web em 2/2/09 CHEMICAL AND BIOLOGICAL STUDY OF THE Tephrosia toxicaria Pers. The ethanol extracts from leaves, stems, pods and roots were assayed against the 3 rd instar Aedes aegypti larvae and the highest activity was observed in the roots extracts (LC 50 47.86 ppm). This extract was submitted to partition with hexane, chloroform, ethyl acetate and methanol. The respective fractions were bioassayed and the best larvicidal activities were identified in the hexane (LC 50 23.99 ppm) and chloroform (LC 50 13.80 ppm) fractions. Antioxidant activity (DDPH method) was observed in the ethanol extract (IC 50 276 µg/mL) from roots of T. toxicaria. Fractions from this extract were also tested and the highest antioxidant activity (IC 50 89 µg/mL) was found in the methanol fraction. The flavonoids iso-obovatin (1), obovatin (2), 6a,12a-dehydro-β-toxicarol (3), 6a,12a-dehydro-α-toxicarol (4) and α-toxicarol (5) were isolated and bioassayed against A. aegypti. The flavonoid 5 showed the best larvicidal activity (LC 50 24.55 ppm). The antioxidant activity of 2 was investigated and showed IC 50 3.370 µg/mL. The antioxidant and larvicidal activities of Tephrosia toxicaria are reported for the first time.Keywords: Tephrosia toxicaria; flavonoids; biological activity. iNtRoduÇÃoO gênero Tephrosia, família Leguminoseae Papilionoideae (Fabaceae), possui aproximadamente trezentas espécies, distribuídas em regiões tropicais e subtropicais.1 Espécies deste gênero apresentam capacidade biogenética para produzir substâncias com grande diversidade estrutural, tais como esteróides, aminoácidos e flavonóides, incluindo os isoflavonóides rotenóides.2 Estes últimos são conhecidos por apresentarem as atividades ictiotóxica 3 e larvicida. 4 Outras atividades biológicas importantes, como anti-tumoral e antiviral, aparecem também descritas na literatura. 5,6Tephrosia toxicaria Pers., popularmente conhecida por "timbó de caiena" ou "anil", é utilizada para capturar peixes 7 e o extrato aquoso de suas raízes é aplicado como defensivo agrícola em hortas orgânicas na localidade de Guaraciaba do Norte -CE. A literatura relata o isolamento e atividade anticâncer de compostos isolados de T. toxicaria, 8,9 bem como a composição química e atividade larvicida de seu óleo essencial. 10A busca por substitutos para os inseticidas sintéticos tem produzido muitos trabalhos científicos, contemplando inclusive a utilização de extratos ou constituintes ativos provenientes de plantas.10-15 Esta procura pode ser justificada pela fácil degradação destes constituintes, menor toxicidade ao homem e, conseqüen-temente, representa uma alternativa mais segura para o meio ambiente.15 Estas observações, aliadas à crescente incidência da febre dengue -endêmica nas Américas, 16 sendo diagnosticados de 50 a 100 milhões de casos por ano 17 -nos estimularam adicionalmente para uma prospecção química em T. toxicaria, com o objetivo de encontrar compostos sucedâneos aos larvicidas sintéticos utilizados no combate ao Aedes aegypt...

The present work describes the isolation of dehydrodiscretamine, discretamine, liriodenine, lichexanthone, molvizarin, rolliniastatin-1, annonacin and bullatacin from roots of Rollinia leptopetala R E Fries. The structures were established after analysis of their NMR spectral data including 2D NMR experiments. With the exception of discretamine, the presence of these compounds in R. leptopetala and the NMR data of dehydrodiscretamine are reported for the first time. The CH 2 Cl 2 extract of the roots demonstrated high larvicidal activity against Aedes aegypti, with an LC 50 value of 1.44±2.0 ppm.

Indigofera suffruticosa Mill. (Fabaceae), popularly known as "anil," is an endemic shrub, which is distributed in tropical America [1]. This plant species is used as a source of indigo dye, and its leaves and roots are popularly used against urinary tract disease, disorders of the nervous system, joint pain and neuralgic, epilepsy, spasm, fever, nose bleeding, acute inflammation of the skin, hepatitis, scabies, and gonococcal urethritis [2]. The literature points to studies on its several biological activities [3][4][5][6][7][8], and chemical investigations have been made previously [9-11] on this species; nevertheless, to the best of our knowledge, only one report has appeared concerning the volatile chemistry of this genus [12].Restrictions on the use of synthetic antioxidants are being imposed because of their potential carcinogenicity [13]. Therefore, the purpose of this study was to assess the antioxidant activity (Table 1) and the chemical composition of its pods. The presence of gallic acid, which is known to be a powerful antioxidant [14], seems to be responsible for its radical scavenging activity (1.55·10 -2 r 3.0·10 -4 mg/mL), as shown by the ethanol extract of pods of I. suffruticosa.Successive chromatographic treatments of the ethanol extract of the air-dried pods of I. suffruticosa afforded sitosterol and gallic acid. The structures of these compounds were established based on the comparison of 1 H and 13 C NMR data with the literature [15,16].The essential oil from the leaves of I. suffruticosa was analyzed by CG/MS to determine their constituents. Thirteen constituents were identified in the oil of I. suffruticosa leaves representing 96.8% of the total oil fraction, and the major constituents were phytol (75.8%) and methyl linoleate (9.1%) ( Table 2).The results indicated that I. suffruticosa essential oil was characterized mainly by a large amount of a linear diterpene (78.5%), the esters of fatty acids (12.8%) and aliphatic compounds (8.2%), and by the lack of mono-and sesquiterpenes.To the best of our knowledge, the only study on the essential oil of Indigofera genus in the literature is on I. microcarpa [12] and shows no similarities between the oils. The oil of I. microcarpa has the sesquiterpenes E-caryophyllene and D-humulene as the main constituents but no diterpenes and fatty acids. This fact suggests the chemical variability among the oils of the genus Indigofera.

The essential oils obtained by hydrodistillation of the leaves, stems, and shoots of Tephrosia toxicaria Pers (Papilionaceae) were analyzed using GC and GC/MS. Germacrene D was the major component (20.7-33.3 %) of the oils of leaves and shoots, whereas spathulenol was the main constituent (42.3%) of the stem oil. The essential oils from the leaves and stems, when tested for activity against mosquito larvae (Aedes aegypti), gave LC 50 values of 81.3 ± 2.9 and 63.1 ± 1.0 ppm, respectively.