132 resultados para Annona


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Background The recent emergence of extensively multidrug-resistant Mycobacterium tuberculosis strains has further complicated the control of tuberculosis. There is an urgent need for the development of new molecular candidates antitubercular drugs. Medicinal plants have been an excellent source of leads for the development of drugs. The aim of this study was to evaluate the in vitro activity of 28 alcoholic extracts and essential oils of native and exotic Brazilian plants against Mycobacterium tuberculosis and to further study these extracts through chemical fractionation, the isolation of their constituents, and an evaluation of the in vivo acute toxicity of the active extracts. To the best of our knowledge this is the first chemical characterization, antituberculosis activity and acute toxicity evaluation of Annona sylvatica. Methods The anti-mycobacterial activity of these extracts and their constituent compounds was evaluated using the resazurin reduction microtiter assay (REMA). To investigate the acute toxicity of these extracts in vivo, female Swiss mice were treated with the extracts at doses of 500, 1000 and 2000 mg · kg-1 of body weight. The extracts were characterized by LC-MS, and the constituents were isolated and identified by chromatographic analysis of spectroscopic data. Results Of the 28 extracts, the methanol extract obtained from the leaves of Annona sylvatica showed anti-mycobacterial activity with an minimal inhibitory concentration (MIC) of 184.33 μg/mL, and the ethyl acetate fraction (EAF) resulting from liquid-liquid partitioning of the A. sylvatica extract showed an MIC of 115.2 μg/mL. The characterization of this extract by LC-MS identified flavonoids and acetogenins as its main constituents. The phytochemical study of the A. sylvatica EAF resulted in the isolation of quercetin, luteolin, and almunequin. Conclusions Among the compounds isolated from the EAF, luteolin and almunequin were the most promising, with MICs of 236.8 μg/mL (827.28 μM) and 209.9 μg/mL (328.48 μM), respectively. The acute administration of the EAF fraction in doses of 500, 1000, and 2000 mg · kg-1 of body weight did not cause signs of toxicity in the treated animals.

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There is a growing call for inventories that evaluate geographic patterns in diversity of plant genetic resources maintained on farm and in species' natural populations in order to enhance their use and conservation. Such evaluations are relevant for useful tropical and subtropical tree species, as many of these species are still undomesticated, or in incipient stages of domestication and local populations can offer yet-unknown traits of high value to further domestication. For many outcrossing species, such as most trees, inbreeding depression can be an issue, and genetic diversity is important to sustain local production. Diversity is also crucial for species to adapt to environmental changes. This paper explores the possibilities of incorporating molecular marker data into Geographic Information Systems (GIS) to allow visualization and better understanding of spatial patterns of genetic diversity as a key input to optimize conservation and use of plant genetic resources, based on a case study of cherimoya (Annona cherimola Mill.), a Neotropical fruit tree species. We present spatial analyses to (1) improve the understanding of spatial distribution of genetic diversity of cherimoya natural stands and cultivated trees in Ecuador, Bolivia and Peru based on microsatellite molecular markers (SSRs); and (2) formulate optimal conservation strategies by revealing priority areas for in situ conservation, and identifying existing diversity gaps in ex situ collections. We found high levels of allelic richness, locally common alleles and expected heterozygosity in cherimoya's putative centre of origin, southern Ecuador and northern Peru, whereas levels of diversity in southern Peru and especially in Bolivia were significantly lower. The application of GIS on a large microsatellite dataset allows a more detailed prioritization of areas for in situ conservation and targeted collection across the Andean distribution range of cherimoya than previous studies could do, i.e. at province and department level in Ecuador and Peru, respectively.

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In Scrittori classici italiani di economia politica. Milano, 1805. 22 cm. [v. 47] Parte moderna, v. 40, p. [7]-202.

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A família Annonaceae possui 112 gêneros, dentre os quais encontra-se Annona, cuja espécie mais comum é a Annona muricata, conhecida popularmente como graviola. Possui fruto comestível de valor comercial e é rica em compostos bioativos que apresentam atividades antitumorais, antifúngicas, entre outros, tanto nos frutos como nas sementes, folhas e caule. Dentre os principais metabólitos encontrados estão os compostos fenólicos, óleos essenciais e as acetogeninas, citada como uma alternativa para o desenvolvimento de drogas antitumorais. Este trabalho visou à caracterização de aspectos morfoanatômicos das folhas de Annona muricata, a fim de investigar caracteres de secreção e ou armazenamento de substâncias lipídicas indicadas como uma das responsáveis pela ação farmacológica da espécie empiricamente. As amostras foram coletadas na área de plantio da Embrapa Amazônia Oriental, Belém-Pará. As folhas foram divididas em ápice, meio e base e confeccionados cortes histológicos semipermanentes, a mão livre, seguindo metodologia específica para detecção de substâncias lipídicas. Os testes deram positivos nos tecidos das células-guardas e subsidiárias dos estômatos, nos tricomas, epiderme abaxial, parênquima paliçádico e nervura central. Considerando que as acetogeninas são derivadas de ácidos graxos, pode-se inferir que estão presentes na maioria dos tecidos foliares de A. muricata. A análise qualitativa pode orientar a determinação de novas metodologias de extração do princípio ativo

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Através de analise gravimétrica de alcaloides e cromatografia comparativa de extratos de caule e folha de Annona cacans Warming coletados em 4 diferentes estações do ano observou-se alteração acentuada no teor das diversas substancias isoladas deste vegetal. No inverno o teor de alcaloides básicos do caule cai a nível muito baixo, elevando-se ao máximo na primavera. Os alcaloides lactamícos e a oxoaporfina liriodenina estão presentes no verão e ausentes na primavera, quando o teor de alcaloides e o maior possível. Pode ser observado, também, diminuição do teor de estefarina, considerado precursor biossintético dos alcaloides asimilobina e michelalbina, quando estas ultimas aparecem. Salienta-se a importância do estudo fitoquímico em diversas épocas do ano, para evitar conclusões equivocadas a respeito da presença ou ausência de determinadas substâncias.

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1994

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Dispersal is a significant determinant of the pattern and process of invasions; however, weed dispersal distances are rarely described and descriptions of dispersal kernels are completely lacking for vertebrate-dispersed weeds. Here, we describe dispersal kernels generated by a native disperser, the endangered southern cassowary (Casuarius casuarius, L.) for an invasive, tropical rainforest plant, pond apple (Annona glabra, L.). Pond apple is primarily water-dispersed and is managed as such. We consider whether cassowary dispersal, as a numerically subordinate dispersal mode, provides an additional dispersal service that may modify the invasion process. In infested areas, pond apple seed was common in cassowary dung. Gut passage had no effect on the probability of single seed germination but deposition in clumps or as whole fruits reduced the probability of germination below that of single seeds. Gut passage times ranged from 65 to 1675 min. Combined with cassowary movement data, this resulted in estimated dispersal distances of 12.5-5212 m, with a median distance of 387 m (quartile range 112-787 m). Native frugivores can be effective dispersers of weeds in rainforest and even terrestrial dispersers can provide long-distance dispersal. Importantly, though pond apple might be expected to be almost entirely dispersed downstream and along the margins of aquatic and marine habitats, cassowaries provide dispersal upstream and between drainages, leading to novel dispersal outcomes. Even through the provision of small quantities of novel dispersal outcomes, subordinate dispersal modes can play a significant role in determining invasion pattern and influence the ultimate success of control programs by providing dispersal to locations unattainable via the primary mode.

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The EZ-Ject herbicide system was evaluated as a stem injection method for controlling woody weeds in a range of situations where traditional chemical application methods have limited scope. The equipment was trialled on three Queensland weed species; pond apple (Annona glabra), velvety tree pear (Opuntia tomentosa) and yellow oleander (Cascabela thevetia); at five different cartridge densities (0, 1, 2, 3 and 4) and with two herbicides (glyphosate and imazapyr). Cartridges filled with imazapyr were significantly more effective at controlling the three woody weed species than those filled with glyphosate. Injecting plants with three imazapyr cartridges resulted in plant kills ranging from 93 to 100%, compared with glyphosate kills of 17 to 100%. Pond apple was the most susceptible species, requiring one imazapyr cartridge or two glyphosate cartridges to kill 97 and 92% of the treated plants. Plant mortality increased as the number of cartridges injected increased. Mortality did not differ significantly for treatments receiving three and four imazapyr cartridges, as these cartridge densities met the criterion of injecting one cartridge per 10-cm basal circumference, a criterion recommended by the manufacturers for treating large plants (>6.35 cm in diameter at breast height). The cost of treating a weed infestation of 1500 plants ha–1 with three cartridges per tree is $1070 ha–1, with labour costs accounting for 16% of the total. The high chemical costs would preclude this technique from broad-scale use, but the method could have application for treating woody weeds in sensitive, high conservation areas.

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En las localidades Los Encuentros y Chacocente, en el departamento de Carazo, se realizó un estudio sobre la composición florísticas de las especies arbóreas en el bosque de galería. Los resultados corresponden a un inventario completo de los árboles de 1 O cm de diámetro a la altura del pecho (Dap) y regeneración natural en parcelas con área neta de muestreo de 1 hectárea en cada sitio, con sub-parcelas de 100 m2 para el muestreo de regeneración. Los bosques estudiados son Chacocente (360 msnm) y Los Encuentros (180 msnm). Ambos bosques son de galería y pertenecen a la zona de Vida Bosque Tropical Seco con transición a subtropical. , según el sistema de clasificación de Holdridge. En ambos bosques se encontraron un total 65 especies, pertenecientes a 39 familias y 53 géneros. En el bosque localizado en Los Encuentros, se encontraron 24 especies, siendo las mas frecuentes el Papaturro (Coccoloba caracasana), anona (Annona glabra) y Chaperno blanco (Lonchocarpus minimiflorus). En Chacocente se encontraron 41 especies, siendo las mas frecuentes Palo de piojo (Trichilia hirta), Naranjillo (Capparis odoratisima) y Melero (Thoudinium decandrum). La abundancia de árboles con Dap mayor de 10 cm fue de 333 en Chacocente y 379 en Los Encuentros. Los cocientes de mezcla obtenidos fueron 1:8 para el bosque del Refugio de Vida Silvestre, Chacocente y 1:15 para el de los Encuentros. En ambas comunidades difieren las familias mayormente representadas. Los valores de los coeficientes de Jaccard (4.4 %) y Sorensen (8.4 %) revelan poca similitud florística entre ambos sitios. La regeneración natural presentó en algunos aspectos el mismo comportamiento de la vegetación con Dap mayor o igual a los 10 cm, siendo la única diferencia los valores del coeficiente de mezcla que presentan al bosque de la comunidad Los Encuentros con mayor diversidad florística (l :50 en comparación con 1:16 de Chacocente). La abundancia de individuos de la regeneración natural fue de 242 individuos por hectárea en Los Encuentros y de 860 individuos por hectarea en Chacocente.