Navegando por Assunto "Mimosa pudica"

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Acesso aberto (Open Access)
Atividade alelopática de substâncias químicas isoladas da Acacia mangium e suas variações em função do PH
(2010) LUZ, Sylmara de Melo; SOUZA FILHO, Antonio Pedro da Silva; GUILHON, Giselle Maria Skelding Pinheiro; VILHENA, Karyme do Socorro de Souza
The aim of this study was to isolate, identify and characterize the allelopathic activity of the substances produced by Acacia mangium and to determine the variations of this activity according to the pH variation of the solution. The allelopathic activity was evaluated in germination bioassays (at 25 oC and under 12-12 h light-dark cycle) and radicle and hypocotyl development (at 25 oC and under 24-24 h light-dark cycle) of the weed species malicia (Mimosa pudica) and mata-pasto (Senna obtusifolia). The influence of the pH (3.0 and 9.0) of the solution in the allelopathic activity of the substances on seed germination of the same species was evaluated. The triterpenoids Lupenone (3 oxolup-20(29)-ene) and Lupeol (3β-hydroxylup-20(29)-ene), obtained from fallen leaves of the donor plant, separately and in pair, showed low allelopathic effects on seed germination and hypocotyl growth, especially on the former, with effects showing values lower than 2%. The effects on radicle growth were higher than the other two, reaching values above 40%, especially inhibition promoted by the substance Lupenone. Separately, each substance showed higher effects than those observed when tested in pair, indicating the existence of antagonism. The pH of the solution influenced the allelopathic activity of the substances; for Lupenone, the effects were more intense at acidic pH, while for Lupeol, best results were observed under alkaline conditions, showing that this is an important factor to be considered in field works.
Acesso aberto (Open Access)
Bioensaios de atividade alelopática dos esteroides espinasterol, espinasterona e glicopiranosil espinasterol
(2012-12) RIPARDO FILHO, Haroldo da Silva; PACHECO, Luidi Cardoso; SOUZA FILHO, Antonio Pedro da Silva; GUILHON, Giselle Maria Skelding Pinheiro; ARRUDA, Mara Silvia Pinheiro; SANTOS, Lourivaldo da Silva
Three steroids (spinasterol, spinasterone, and spinasterol glucopyranosyl) were isolated from the stem of the Amazonian plant Moutabea guianensis. Their structures were determined on the basis of NMR analysis and by comparison with spectroscopic data found in the literature. The allelopathic activities of the three substances were evaluated against two common weeds of the Amazon region, Mimosa pudica ('malicia') and Senna obtusifolia ('mata-pasto'). The substance spinasterol glucopyranosyl was the most active in the radicle growth bioassay, inhibiting Senna obtusifolia in 75%; spinasterol inhibited the development of hypocotyl of Senna obtusifolia in 22%, and spinasterone and spinasterol inhibited 10% of the seed germination of the species Mimosa pudica. These results showed that the difference of substitutes at the C-3 position of the steroids can influence allelopathic activity: the glicosyl group at the C-3 position enhanced the inhibition of hypocotyl growth of the species Mimosa pudica, compared to the hydroxilated and carbonylated steroid. This is the first chemical and allelopathic study with Moutabea guianensis.
Acesso aberto (Open Access)
Isolation of Fonsecaea pedrosoi from thorns of Mimosa pudica, a probable natural source of chromoblastomycosis
(2004-02) SALGADO, Claudio Guedes; SILVA, Jorge Pereira da; DINIZ JUNIOR, José Antônio Picanço; SILVA, Moisés Batista da; COSTA, Patricia Fagundes da; TEIXEIRA, Cláudio Eduardo Corrêa; SALGADO, Ubirajara Imbiriba
We report the isolation of Fonsecaea pedrosoi from thorns of the plant Mimosa pudica L. at the place of infection identified by one of our patients. Clinical diagnosis of chromoblastomycosis was established by direct microscopic examination and cultures from the patient's lesion. The same species was isolated from the patient and from the plant. Scanning electron microscopy of the surface of the thorns showed the characteristic conidial arrangement of F. pedrosoi. These data indicate that M. pudica could be a natural source of infection for the fungus F. pedrosoi.
Acesso aberto (Open Access)
Lesões traumáticas de pele causadas pelos espinhos de Mimosa pudica e Mimosa debilis em equídeos
(2011-09) REIS, Alessandra dos Santos Belo; DUARTE, Marcos Dutra; SOUSA, Melina Garcia Saraiva de; FREITAS, Nayra Fernanda de Queiroz Ramos; YAMASAKI, Elise Miyuki; SILVA, André Guimarães Maciel e; OLIVEIRA, Carlos Magno Chaves; BARBOSA NETO, José Diomedes
Studies on the nature and cause of skin lesions in horses on a farm in the county of Castanhal, northeastern Para, Brazil were conducted. These were visits to the farm, epidemiological studies, blood sample collections, skin biopsies, and inspection of the pasture. The study included 25 Equidae, 14 males and 11 females, six months to eight years old. The animals showed ulcerative lesions of irregular borders on the head (nose, muzzle, upper and lower lips), in the oral cavity (buccal vestibule and gum) and on the limbs (billets, metacarpals and metatarsals and scapular-humeral joint). The histopathological examination revealed foci of cutaneous erosions with epidermal necrosis, spongiosis and vesicular degeneration of the remaining epidermis, and mild inflammatory infiltrate in the underlying dermis, consisting predominantly of macrophages and, to a lesser degree, eosinophils. The inspection of the pasture, which consisted of Brachiaria humidicola, revealed a heavy invasion by two plants provided with spines, Mimosa pudica and Mimosa debilis, of the Leguminosae Mimosoideae family. It was concluded that the skin lesions were caused by traumatic action of the spines of Mimosa pudica and Mimosa debilis.
Acesso aberto (Open Access)
Lesões traumáticas na pele causadas pelos espinhos de Mimosa pudica e Mimosa debilis em equídeos
(Universidade Federal do Pará, 2012-02-24) REIS, Alessandra dos Santos Belo; BARBOSA NETO, José Diomedes; http://lattes.cnpq.br/1516707357889557
We studied traumatic injury of the skin in horses caused by traumatic plants, popularly known as "sleep-mary", "Poppy", "scraper", "malice" and "do not touch me". The study was conducted on a farm in the district of Castanhal, northeastern of the state of Para, where there were technical visits, epidemiological study, blood samples, biopsies of affected skin and collection of plants. The study included 25 horses, 14 males and 11 females, aged between six months and eight years. The pasture consisted of Brachiaria humidicola and was heavily invaded by traumatizing plants. The animals showed ulcerative lesions of irregular borders, on the head (nose, muzzle, upper and lower lips and chamfer), oral cavity (buccal vestibule and gum) and limbs (billets, metacarpals and metatarsals and scapular-humeral joint). The histopathological examination revealed foci of cutaneous erosions, characterized by loss and epidermal necrosis with spongiosis and vesicular degeneration of the remaining epidermis and mild inflammatory infiltrate in the underlying dermis, consisting predominantly of macrophages and, to a lesser degree, eosinophils. We identified two plants, Mimosa pudica and Mimosa debilis, both from the Leguminosae Mimosoideae family. Based on these results we can conclude that the skin lesions were caused by the traumatic action of Mimosa pudica and Mimosa debilis.
Acesso aberto (Open Access)
Potencial alelopático de duas neolignanas isoladas de folhas de Virola surinamensis (Myristicaceae)
(2007-03) BORGES, Fábio Cardoso; SANTOS, Lourivaldo da Silva; CORRÊA, Marivaldo José Costa; OLIVEIRA, Marilene Nunes; SOUZA FILHO, Antonio Pedro da Silva
The objective of this research was to isolate, identify and characterize the allelopathic activity of chemical compounds in Virola surinamensis leaves. The process of isolation and identification of chemicals compounds involved the use of organic solvents and Magnetic Nuclear Resonance (MNR 1H, MNR 13C and MNR 13C-DPT), HETCOR and COSY specter. Allelopathic activity was evaluated by bioassays, under constant temperature of 25 ºC and 12-h photoperiod for seed germination and 25 ºC of constant temperature and 24-hour photoperiod for radicle and hypocotyl elongation, at concentrations ranging from 1.0 mg L-1 to 8.0 mg L-1. The receiving plants used were the weeds Mimosa pudica, Senna obtusifolia and Senna occidentalis. Two neolignans were isolated and identified: surinamensin and virolin. The general trend observed was a positive relation between allelopathic effects and the concentration of the compounds, with maximum inhibition obtained at the concentration of 8.0 mg L-1. Surinamensin presented greater potential to inhibit seed germination and radicle/hypocotyl elongation than virolin, regardless of the receiving species or plant parameter. Radicle and hypocotyl elongation were more intensely inhibited than seed germination by the two compounds. Except for the effects promoted on hypocotyl elongation, the species M. pudicawas the most sensitive to the allelopathic effects caused by the two neolignans.
Acesso aberto (Open Access)
Potencial alelopático de Myrcia guianensis
(2006-12) SOUZA FILHO, Antonio Pedro da Silva; SANTOS, Reinaldo Araujo dos; SANTOS, Lourivaldo da Silva; GUILHON, Giselle Maria Skelding Pinheiro; SANTOS, Alberdan Silva; ARRUDA, Mara Silvia Pinheiro; MÜLLER, Adolfo Henrique; ARRUDA, Alberto Cardoso
The use of fire and mowing as weed methods have proved inefficient. Although more efficient, synthetic chemical herbicides are usually related to environmental problems. Thus, the search for natural herbicides has become a priority matter. Based on these facts, research was conducted on Myrcia guianensis (pedra-ume-caá) including the isolation and identification of chemical substances with allelophatic activity. The allelophatic effects of extracts, fractions, essential oils, and isolated chemical substances (gallic acid and protocatechuic acid) on germination and radicle and hypocotyl growth of weed species Mimosa pudica (malícia) and Senna obtusifolia (mata-pasto) were analyzed. Extracts and fractions were analyzed at a concentration of 1%, essential oils at 15, 30, 45, 60 ppm and the isolated chemical substances at 15, 30, 45, 60 ppm. Malicia showed more sensitivity to the allelophatic effects of extracts and fractions. The essential oil inhibited the germination of M. pudica but stimulated that of S. obtusifolia. The allelophatic effects of the chemical substances were concentration dependent and the strongest activity was observed at 60 ppm.
Acesso aberto (Open Access)
Substâncias químicas com atividades alelopáticas presentes nas folhas de Parkia pendula (Leguminosae)
(2005-12) SOUZA FILHO, Antonio Pedro da Silva; FONSECA, Marcelo Lobato; ARRUDA, Mara Silvia Pinheiro
The objective of this paper was to isolate, identify and characterize the allelopathic activity of chemical compounds produced by Parkia pendula. The allelopathic effects were evaluated on seed germination and radicle elongation of the weeds Mimosa pudica and Senna obtusifolia. The isolation process of the compounds involved the use of solvent in an increasing polarity order for extraction and the structural elucidation was carried out by Nuclear Magnetic Resonance, COPSY's and HETCOR's spectrum. The bioassays were carried out under controlled conditions of 25 ºC of temperature and 12-hour photoperiod for seed germination and 24-hour photoperiod for radicle elongation. The following allelochemicals were isolated and identified in P. pendula's leaves: 3,4,5-trimethoxybenzoic acid (S1), 3,4-dimethoxybenzoic acid (S2) and Blumenol A (S3). Comparatively, S1 and S2 showed greater allelopathic activity. The effects on radicle elongation were greater than those observed on seed germination. The isolated substances showed low inhibition potential on seed germination, especially on S. obtusifolia seeds. The allopathic inhibition effects were positively related to the concentration of the substances, although in some cases, these effects have not corresponded to the statistical differences.