Avaliação da atividade antimicrobiana e citotóxica de extratos de Gochnatia polymorpha ssp floccosa

Neste estudo procedeu-se a avaliação da atividade antimicrobiana e citotóxica de extratos de Gochnatia polymorpha ssp floccosa, espécie empregada na medicina popular contra doenças respiratórias. Folhas, cascas do tronco e ramos foram extraídos com hexano, diclorometano e etanol, sucessivamente, sendo obtidos os respectivos extratos brutos. A atividade antimicrobiana foi determinada pelo método de difusão em ágar utilizando-se bactérias Gram-positivas, Gram-negativas e fungos. A avaliação da citotoxicidade foi realizada empregando-se o ensaio de letalidade contra Artemia salina. Nenhum dos extratos mostrou atividade citotóxica. Os extratos das folhas apresentaram uma fraca atividade antimicrobiana frente a algumas cepas de Staphylococcus aureus e Streptococcus mutans, enquanto o extrato em diclorometano dos ramos e o extrato em etanol das cascas foram ativos contra Micrococcus luteus, Staphylococcus aureus e S. epidermidis. A maior atividade antimicrobiana foi observada para o extrato em diclorometano das cascas, que inibiu o crescimento de Micrococcus luteus, Staphylococcus aureus, S. epidermidis, Streptococcus mutans, Enterococcus faecalis e Candida albicans. Esta atividade parece estar relacionada à presença de diterpenos no extrato. Nenhum dos extratos estudados (a 5,0 mg/mL) mostrou atividade frente a cepas de bactérias Gram-negativas. Esses resultados demonstram o potencial dessa planta como fonte de compostos antibacterianos e justificam, parcialmente, seu uso popular

Further chemical constituents from sinningia canescens and s. leucotricha (gesneriaceae)

Four new compounds were isolated from the tubers of Sinningia canescens and S. leucotricha: one naphthoquinone, 7-methoxy-8-hydroxy-α-dunnione (1); two arylbenzofurans, sinningial A (2) and B (3); and one sesquiterpene, 11-epi-subergorgiol (4). Seventeen additional known compounds were isolated and identified. The structures of all compounds were determined by spectroscopic and MS analysis22205209CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINA - FAPESC472-392/2011-5; 010087/2012-538.394/201

Chemical composition, seasonal variation and evaluation of antimicrobial activity of essential oils of talauma ovata A. St. Hil. (magnoliaceae)

The essential oils isolated by hydrodistillation from trunk bark and leaves of Talauma ovata A. St. Hil. (Magnoliaceae), collected in four seasons, were analyzed by capillary GC and GC/MS. Altogether 52 components were identified. The oils were characterized by predominance of cyclic sesquiterpenes. The main components were linalool, trans-β-guaiene, germacrene D, germacrene B, spathulenol, caryophyllene oxide, viridiflorol and α-eudesmol. The content of individual components was variable during the year. All oils were screened against several strains of bacteria and yeasts, using the agar well-diffusion technique. The antimicrobial activity of oils showed strong dependence with the season. Significant activity was found for oils obtained in the spring and summer206565569FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão te

Chemical composition and cytotoxic activity of the essential oils of Cantinoa stricta (Benth.) Harley & J.F.B. Pastore (Lamiaceae)

The essential oils from the leaves and flowers of Cantinoa stricta (Benth.) Harley & J.F.B. Pastore (Lamiaceae) were obtained by hydrodistillation and analyzed by GC/FID and GC/ MS. The major components of both oils were caryophyllene oxide (leaf – 31.6%; flower – 21.7%) and cis-pinane (leaf – 15.4%; flower – 9.7%). The flower oil also contained significant amounts of a -pinene (9.4%) and b -pinene (9.1%). The oils were tested in vitro against U251 (glioma), UACC-62 (melanoma), MCF-7 (breast), NCI-H460 (lung), PC-3 (prostate), K-562 (leukemia) human cancer cell lines and against HaCat (no cancer cell), using the sulforhodamine B method. Both oils showed antiproliferative activity against all tested cells lines (TGI < 50 m g/mL), with exception of K562 cells. The highest activity was observed against MCF-7 cell lines (TGI = 4.54-10.36 m g/mL).10225726