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| Mehta,Angela; Rosato,Yoko B.. |
| Xanthomonas axonopodis pv. citri is a phytopathogenic bacterium responsible for citrus canker, a serious disease which causes severe losses in citriculture around the world. In this study we report the differential expression of X. axonopodis pv. citri in response to specific treatments by using Representational Difference Analysis of cDNA (cDNA RDA). cDNAs from X. axonopodis pv. citri cultured in the presence of leaf extract of the host plant (Citrus sinensis), in vivo, as well as in the complex medium were hybridized against cDNA of the bacterium grown in the minimal medium. Sequencing of the difference products obtained after the second and third hybridizations revealed a total of 37 distinct genes identified by homology searches in the genome of X.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Citrus canker; Differential expression; Leaf extract; In vivo. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000100024 |
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| Borghetti,Fabian; Lima,Elisa Coutinho de; Silva,Lucas de Carvalho Ramos. |
| Most studies conducted to test the allelopathic activity of plant parts have made use of water as solvent. However, the presence of polar, water-soluble substances, such as proteins and carbohydrates, tends to hamper the purification of active compounds. In this study, we present a simple purification procedure that separates the active fraction of the extract from the undesirable substances, thus facilitating the search for active molecules through standard chromatographic methods. Aqueous leaf extracts of three Cerrado species (Caryocar brasiliense, Qualea parviflora and Eugenia dysenterica) were prepared at 5% concentration (w/v) and stored at 4ºC (crude extracts). After 24 h, these solutions were filtered and freeze-dried. The powder obtained was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allelopathy; Cerrado; Freeze-drying; Leaf extract; Purification. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062013000100007 |
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| Yuldasheva,L.N.; Carvalho,E.B.; Catanho,M.-T.J.A.; Krasilnikov,O.V.. |
| Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Passiflora quadrangularis; Leaf extract; Liposomes; Bilayer permeation; Hemolysin; Membrane cholesterol. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000700009 |
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| Pagno,T.; Blind,L.Z.; Biavatti,M.W.; Kreuger,M.R.O.. |
| Vernonia scorpioides has been widely used in Brazil to treat skin problems and chronic wounds, such as ulcers of the lower limbs and diabetic lesions. In the present study, we investigated the effect of a dichloromethane (DCM) fraction of V. scorpioides leaf extract on Ehrlich ascitic and solid tumor-bearing mice. The animals were treated once a day with the DCM fraction at a concentration of 5 mg/kg, administered ip during and after the development of the tumor. The lifespan, weight, number and type of leukocytes, number of tumor cells, volume of solid and ascitic tumors were measured. The development of the tumor with pre-treated tumor cells in vitro with the DCM fraction (5 mg/kg) was analyzed and the animals were sacrificed after 7 days. The DCM... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vernonia scorpioides; Leaf extract; Antitumoral; Ehrlich ascitic tumor; Neutrophils. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006001100012 |
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