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BACKGROUND: The arthropod-borne Mayaro virus (MAYV) causes 'Mayaro fever', a disease of medical significance, primarily affecting individuals in permanent contact with forested areas in tropical South America. Studies showed that the virus could also be transmitted by the mosquito Aedes aegypti. Recently, MAYV has attracted attention due to its likely urbanization. To date, there are no drugs that can treat this illness. METHODS: Fractions and compounds were obtained by chromatography from leaf extracts of C. australis and chemically identified as flavonoids and condensed tannins using spectroscopic and spectrometric techniques (UV, NMR, and ESI-FT-ICR MS). Cytotoxicity of EtOAc, n-BuOH and EtOAc-Pp fractions were measured by the dye-uptake assay while their antiviral activity was evaluated by a virus yield inhibition assay. Larvicidal activity was measured by the procedures recommended by the WHO expert committee for determining acute toxicity. RESULTS: The following group of substances was identified from EtOAc, n-BuOH and EtOAc-Pp fractions: flavones, flavonols, and their glycosides and condensed tannins. EtOAc and n-BuOH fractions inhibited MAYV production, respectively, by more than 70% and 85% at 25 µg/mL. EtOAc-Pp fraction inhibited MAYV production by more than 90% at 10 µg/mL, displaying a stronger antiviral effect than the licensed antiviral ribavirin. This fraction had an excellent antiviral effect (IC90 = 4.7 ± 0.3 µg/mL), while EtOAc and n-BuOH fractions were less active (IC90 = 89.1 ± 4.4 µg/mL and IC90 = 40.9 ± 5.7 µg/mL, respectively). CONCLUSIONS: C. australis can be used as a source of compounds with anti-Mayaro virus activity. This is the first report on the biological activity of C. australis.

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In this study, we investigated the leaf anatomy and the composition of volatiles in Myrrhinium atropurpureum var. atropurpureum endemic to Rio de Janeiro restingas. Particularly, leaf secretory structures were described using light microscopy, and histochemical tests were performed from fresh leaves to localize the secondary metabolites. To observe secretory cavities, fixed leaf samples were free-hand sectioned. To evaluate lipophilic compounds and terpenoids the following reagents were employed: Sudans III and IV, Red oil O and Nile blue. Leaf volatiles were characterized by gas chromatography after hydrodistillation (HD) or simultaneous distillation-extraction (SDE). Leaf analysis showed several cavities in mesophyll that are the main sites of lipophilic and terpenoid production. Monoterpenes, which represented more than 80% of the major volatiles, were characterized mainly by alpha- and beta-pinene and 1,8-cineole. In order to provide tools for M. atropurpureum identification, the following distinguishing characteristics were revealed by the following data: 1) adaxial face clear and densely punctuated by the presence of round or ellipsoidal secretory cavities randomly distributed in the mesophyll; 2) the presence of cells overlying the upper neck cells of secretory cavities; 3) the presence of numerous paracytic stomata distributed on the abaxial leaf surface, but absent in vein regions and leaf margin; and 4) non-glandular trichomes on both leaf surfaces. Our study of the compounds produced by the secretory cavities of M. atropurpureum led us to conclude that volatile terpenoid class are the main secretory compounds and that they consist of a high concentration of monoterpenes, which may indicate the phytotherapeutic importance of this plant.

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Eugenia rotundifolia Casar., Myrtaceae, occurs in the sandy coastal environments of Rio de Janeiro and Espírito Santo States. To the best of our knowledge, E. rotundifolia was not included in ethnobotanical and nor in pharmacological research, but its leaves are sold in a public market of Rio de Janeiro City as "abajurú", the common name for Chrysobalanus icaco L., Chrysobalanaceae. C. icaco, in contrast, has been studied and its medicinal effects reported. Since E. rotundifolia is often sold in the public market as "abajurú," this paper describes and compares the leaf anatomy and morphology of E. rotundifolia with C. icaco, previously described in the literature, in order to provide tools for the authentication of commercialized "abajurú." Phyllotaxy; texture; color; margin; midrib prominence; stomata type; type and shape of midrib and petiole vascular bundle; the presence of marginal vein, secretory cavities, which are seen as translucent dots, and overlying cells only in E. rotundifolia; and the presence of trichomes, periclinal divisions in adaxial face epidermis, hypodermis and vascular bundle extensions only in C. icaco were found to be the most distinguishable diagnostic characters.

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In vitro shoots of thyme (Thymus vulgaris L.) were established, and the effects of the auxin indole-3-acetic (IAA) acid and the cytokinins benzyladenine (BA), zeatin (ZEA), and kinetin (KIN) at 1.0, 5.0, and 10.0 microM on rooting, biomass production, and volatile compounds production by these plants were investigated. The volatiles were extracted by solid phase microextraction (SPME) and analyzed by gas chromatography. The highest biomass shoot growth was obtained with BA at 5.0 microM, while IAA at all concentrations tested achieved 100% rooting frequency. The three major compounds were gamma-terpinene (22.8-38.8%), p-cymene (13.8-27.9%), and thymol (6.5-29.0%). Quantitative changes of these compounds were observed in response to the effect of varying growth regulators concentrations in the culture medium. Growing Thymus vulgaris L. plants in media supplemented with IAA at 1.0 microM increased volatile compounds such as thymol by 315%. Nevertheless, the same major compounds were produced in all treatments and no qualitative changes were observed in the volatile profile of thyme plants.

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Culturas de tecidos de Alternanthera brasiliana (L.) Kuntze foram tratadas com diferentes reguladores de crescimento (Cinetina e 2,4-D), tirosina e com ultravioleta longo (UV-A; 320 -400 nm) adicional com o intuito de observar seus efeitos no desenvolvimento e produção de pigmentos. Segmentos nodais de plantas crescidas a partir de sementes foram inoculados nos meios de cultura testados e mantidos sob os diferentes tipos de iluminação. Após 8 semanas este material foi utilizado para avaliação da produção de biomassa, clorofilas e betacianinas. O meio de Murashige and Skoog (MS) + cinetina proporcionou plântulas com até 4 brotos/explante. Este meio iluminado com luz branca (tipo luz do dia) foi a combinação mais adequada para micropropagação, pois apresenta maior porcentagem de enraizamento e maior produção de betacianinas. Plântulas crescidas sob iluminação com ultravioleta adicional tiveram diminuídas tanto a produção de biomassa quanto a relação Clor a/ Clor b. A adição de 2,4-D ao meio de cultura resultou na inibição da produção de pigmentos e no crescimento das plântulas.