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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Pharmaceutical and chemical analysis of the components carrying the antiplatelet activity of extracts from allium ursinum and allium sativum

Sabha, Dina Talat Tawfiq 09 January 2012 (has links) (PDF)
Allium sativum has a long tradition in medicine. While much is known about its potential healthy effects, nearly nothing is known about wild garlic (allium sativum, ramson), which is very common in the area of Leipzig and has been used as a herbal remedy since centuries. The goal of the present study was to assess a potential anti-platelet activity of these two allium species and to try to identify the chemical active principle. For that purpose various extracts (hydrophilic and lipophilic) were prepared from Allium sativum and Allium ursinum, and analysed using thin layer chromatography and HPLC. After identifying an active, i.e. antiaggregatory extract (see below), this was fractionated and the active fraction was further sub-fractionated for subsequent chemical analysis by mass spectroscopy, ESI (Electrospray ionization), and COSY (Correlation effect spectroscopy), and functional testing. Anti-platelet activity was assessed in human platelets (platelet rich plasma) using a classical turbidimetric method. Platelets were stimulated with various agonists (arachidonic acid, ADP, epinephrine, collagen, A23187) with and without the addition of the extracts or the fractions /sub-fractions. Both Allium Ursinum and Allium sativum extracts exert antiaggregatory effects with EC50 values around 0.1 mg/ml. The garlic extracts are acting by inhibition of the ADP pathway comparable as known from the clinically used drug clopidegrol.The pharmacological active antiaggregatory component of the extracts appears to be lipophilic rather than hydrophilic. This is the first report on an antiplatelet activity of Allium Ursinum. One final structure determined by HPLC, MS, ESI and COSY which exerts the antiplatelets inhibitory effect is β-sitosterol-3-O-β-D-glucoside of the fraction 7-14 crystals. It is considered that about three up to five grams of dried leaves might be enough to exert antiaggregatory effects (comment: in pharmacy normally dried plant material is used in therapy). The second compound with antiaggregatory activity was identified as 1-β-D-galactopyranoside-2, 3-bis-linolenic glycerate. The problem of loosing the active volatile oily components by drying the leaves in future studies looking for the clinical use may be solved by looking for a raw or a refined extract which would be the form of a real phytomedical drug; for example capsules about 120 to 200 micrograms of an alcoholic or better an heptane / oily extract gained from wood garlic leaves would be an useful drug formulation to reach respective concentrations in blood. However, we have to admit that since our investigations were in-vitro, the in-vivo situation is somewhat different due to the metabolism, which is nearly unknown. Nevertheless, this study shows for the first time that allium ursinum does exert anti-platelet activity and that both allium species can unfold antiaggregatory effects which are worth to be investigated in subsequent in-vivo studies. β-sitosterol-3-O-β-D-glucoside and 1-β-D-galactopyranoside-2, 3-bis-linolenic glycerate could be identified as active antiaggregatory principals.
12

Indutores de germinação de escleródios e uso de fungicidas no manejo de Sclerotium cepivorum / Germination inducers of sclerotia and fungicides on the management of Sclerotium cepivorum

Domingos, Luisa Bastos 18 September 2015 (has links)
Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-06-03T09:02:33Z No. of bitstreams: 1 texto completo.pdf: 1143803 bytes, checksum: 0c14d3843edd0185ace5121513e595e2 (MD5) / Made available in DSpace on 2016-06-03T09:02:34Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1143803 bytes, checksum: 0c14d3843edd0185ace5121513e595e2 (MD5) Previous issue date: 2015-09-18 / A podridão branca, causada pelo fungo Sclerotium cepivorum, é uma das principais doenças, que ocorre em todo o mundo, que pode causar graves perdas nos cultivos de alho (Allium sativum L.) e cebola (Allium cepa L.). Escleródios de S. cepivorum são capazes de sobreviver por até 30 anos no campo. A gama de hospedeiros do fungo compreende plantas do gênero Allium e a germinação dos escleródios é induzida pela presença de exsudatos Allium, especialmente em solos úmidos e sob condições de temperatura entre 13 – 18 ° C. A erradicação do patógeno de áreas infestadas é muito difícil e a densidade de escleródios viáveis deve ser reduzida por meio de estratégias diferentes, tais como indutores de germinação e fungicidas. A aplicação de extratos de alho em campos de pousio pode induzir escleródios a germinarem e diminuir o número de estruturas de sobrevivência viáveis. Fungicidas podem inibir a germinação de escleródios e crescimento micelial. Assim, o efeito do extrato de alho e dialil dissulfeto (DADS) sobre a germinação de esclerócios de S. cepivorum e o potencial de fungicida sobre a inibição do crescimento micelial foi avaliado neste trabalho. Extrato aquoso e etanólico de alho preparados em laboratório (20 % m:v), as águas residuais de agroindústria de alho e extrato aquoso produzido por Shimada Agronegócios (20 %, m:m) foram utilizados como indutores de germinação aos 17 e 27 °C em laboratório. Além disso, o efeito de DADS em estimular a germinação de escleródios foi avaliada usando tubos plásticos com solo e contendo escleródios enterrados a 10, 20 e 30 cm de profundidade. Todos os extratos de alho induziram a germinação dos escleródios, independentemente da temperatura avaliada. DADS induziu a germinação de escleródios de 10 a 30 cm de profundidade, embora o efeito tenha sido maior sobre escleródios localizados a 10 cm. Em outro experimento, o fungicidas tebuconazol + trifloxystrobina, trifloxistrobina + protioconazol, tebuconazol, triadimenol, tiofanato metílico e fluazinam foram adicionados a meio batata dextrose agar (BDA) + extrato aquoso de alho (20 % m:m) em volumes equivalentes a 200 e 20.000 L/ha. Discos de micélio de 5 mm de diâmetro de S. cepivorum foram removidos da borda de culturas do fungo com 15 dias de idade em BDA e colocadas no centro de placas de Petri contendo BDA + extrato de alho, com ou sem fungicidas. O fungo foi incubado a 17 ± 2 oC por 30 dias, quando o crescimento mycelial foi avaliado. Todos fungicidas reduziram o crescimento do fungo em mais de 90 %. Os fungicidas triadimenol e fluazinam inibiram completamente o crescimento de S. cepivorum, independemente do volume da solução fungicida. A eficácia de tebuconazol e tebuconazol + trifloxistrobina foi reduzida quando o volume da solução foi aumentada de 200 para 20.000 L. Extratos de alho, residuo de agroindústria de alho e DADS induzem a germinação de escleródios de S. cepivorum. Triadimenol, fluazinam, tebuconazol e tebuconazol + trifloxistrobina suprimem o crescimento de S. cepivorum in vitro, especialmente em volume de soluçãofungicida equivalente a 200 L.ha -1 . Estudos adicionais em campo são necessários para avaliar o uso integrado de extratos de alho, DADS e os fungicidas triadimenol, fluazinam, tebuconazol e tebuconazol + trifloxistrobina no manejo da podridão branca. / White rot, caused by the fungus Sclerotium cepivorum, is a major disease worldwide that can cause severe losses in garlic (Allium sativum L.) and onion (Allium cepa L.). Sclerotia of S. cepivorum are able to survive for up to 30 years in the field. The host range of the fungus comprises plants from the genera Allium and the sclerotia germination is induced by the presence of Allium exsudates, especially in moist soils and at 13 – 18 °C. Since eradication of the pathogen from infested areas is very difficult, the density of viable sclerotia must to be reduced by using different strategies, such as germination inducers and fungicides. The application of garlic extracts at fallow fields may induce sclerotia germination and decrease the number of viable resting propagules. Fungicides may inhibit sclerotia germination and mycelial growth. Thus, the effect of garlic extract and diallyl disulfide (DADS) on the germination of sclerotia of S. cepivorum and the potential of fungicides on the inhibition of mycelial growth were evaluated in this work. Aqueous and ethanolic extracts of garlic prepared in laboratory (20 % m:v), wastewater of garlic agroindustry and aqueous extract produced by Shimada Agronegócios (20 % m:m) were used as germination inducers at 17 and 27 °C in laboratory. In addition, the effect of DADS in stimulating germination of sclerotia was assessed using plastic tubes filled with soil and containing sclerotia buried at 10, 20 and 30 cm depth. All extracts stimulated sclerotia germination, regardless the temperature. DADS induced germination of sclerotia at 10 to 30 cm depth, although the effect was higher at 10 cm. In other experiment, the fungicides tebuconazole + trifloxystrobin, trifloxystrobin + protioconazole, tebuconazole, triadimenol, thiophanate methyl and fluazinam were added into potato dextrose agar (PDA) + garlic aqueous extract (20 % m:m) broth at dosages equivalent to 200 and 20.000 L.ha -1 . Mycelial discs (5 mm in diameter) of S. cepivorum were removed from the border of 15 day cultures in PDA cultures and placed on the center of Petri dishes with PDA+garlic aqueous extract, amended or not with fungicides. The fungus was incubated at 17 ± 2 oC for 30 days, when the mycelial growth was assessed. All fungicides reduced the growth of the fungus by more than 90 %. The fungicides triadimenol and fluazinam inhibited completely the growth of S. cepivorum, regardless the volume of the solution. The efficacy of tebuconazole and tebuconazole + trifloxystrobin was reduced when the volume of the soultion was increased from 200 to 20.000 L. Garlic extracts, wastewater of garlic agroindustry and DADS induce germination of sclerotia of S. cepivorum. Triadimenol, fluazinam, tebuconazole and tebuconazole+trifloxystrobin suppress the growth of S. cepivorum in vitro, especially at the volume of fungicide solution equivalent to 200 L.ha -1 . Further studies under field conditions are needed to evaluate the integrated use of garlic extracts, DADS and the fungicides triadimenole, fluazinam, tebuconazole and tebuconazole + trifloxystrobin on the management of the white rot. / Ficha catalográfica com ano de aprovação diferente.
13

EXTRATOS Vegetais Associados Ou Não a Biofilme no Controle de Rhipicephalus (boophilus) Microplus (canestrini, 1887)

LUNS, D. A. R. 25 February 2015 (has links)
Made available in DSpace on 2018-08-01T22:56:59Z (GMT). No. of bitstreams: 1 tese_9382_Darcy Adriann.pdf: 1067264 bytes, checksum: 04c6250a2beb7cde0fdce121daa52a0f (MD5) Previous issue date: 2015-02-25 / O carrapato bovino tem sido responsável por grandes perdas econômicas na pecuária pela transmissão de doenças e redução da produção de carne e leite. Neste contexto, os produtos naturais constituem uma alternativa potencial aos carrapaticidas comerciais quepodem gerar acúmulo no meio ambiente e resíduos nos alimentos. Sendo assim, objetivou-se determinar o teor de fenóis totais e flavonoides totais e avaliar a eficácia carrapaticida de extratos vegetaisassociados ou não a biofilme sobre Rhipicephalus (Boophilus) microplus (CANESTRINI, 1887). As soluções extrativas deCapsicum chinense, Nicotiana tabacum, Chenopoide ambrosioides, Melia azedarach e Allium sativumforam testadas a 15%. A eficácia carrapaticida foi avaliada pela imersão de teleóginas nas soluções extrativas segundo Drummond (1973). O teste foi realizado em triplicata com 10 carrapatos por repetição. As soluções extrativas que apresentaram a maior eficiência carrapaticida foram incorporadas a 5% em soluções filmogênicas e avaliadas no controle, in vitro, de R. microplus utilizando a metodologia supracitada.Os maiores teores de fenóis totais e flavonóides totais foram encontrados nas soluções extrativas preparadas a partir da casca de cinamomo e das folhas de erva-de-santa-maria. As soluções extrativas a 15%com maior eficácia carrapaticida foram as de fumo (89,02%), casca de cinamomo (85,33%) e alho orgânico (58,36%). O biofilme incorporado com extrato de cinamomo a 5% apresentou o maior efeito carrapaticida (76,41%) quando comparado ao biofilme associado aos extratos de fumo (58,31 %), alho (34,16 %) e biofilme não associado (60,86%). Estudos futuros são importantes para determinar o efeito residual do extrato de cinamomo associado ao biofilme para avaliar seu potencial em assegurar a liberação controlada dos princípios ativos desse extrato.
14

Patogenicidade à cebola (Allium cepa L.) e análise da diversidade genética de isolados de Colletotrichum gloeosporióides do Estado de Pernambuco, Brasil, por RAPD e região ITS do rDNA

Xavier Vila Nova, Meiriana January 2004 (has links)
Made available in DSpace on 2014-06-12T15:04:56Z (GMT). No. of bitstreams: 2 arquivo4513_1.pdf: 733474 bytes, checksum: 96d9ff147d1527b544a0ce02910e2af1 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2004 / A antracnose foliar ou mal-das-sete-voltas na cebola, causada pelo fungo Colletotrichum gloeosporioides, destaca-se como uma das principais doenças em locais de produção da cebola no estado de Pernambuco. O presente trabalho objetivou estudar a patogenicidade na cebola de isolados de C. gloeosporioides e analisar a variabilidade genética pelo uso dos marcadores moleculares RAPD e a região ITS do rDNA. No trabalho foram utilizados 11 isolados do fungo, obtidos de diferentes substratos e hospedeiros e 5 isolados obtidos de cebola de diferentes regiões de Pernambuco e um do Amazonas. O teste de patogenicidade foi realizado em mudas e bulbos da cebola Os isolados mais agressivos foram quatro provenientes de cebola nos dois testes. Nas análises de RAPD foram utilizados sete primers de seqüências arbitrárias. Os produtos de amplificação foram separados em gel de agarose a 1,4%. e mostraram bandas polimórficas que permitiram avaliar a distância genética entre os 15 isolados. Estes foram classificados em quatro grupos distintos. Os produtos de amplificação dos lócus ITS1-5.8S-ITS2 do rDNA com primer ITS1 e ITS4 também apresentaram polimorfismo e foram digeridos com três enzimas de restrição, Dra I, Hae III e Msp I. Apenas as duas últimas foram eficientes em mostrar variações genéticas entre os isolados. Os dois marcadores utilizados foram capazes de diferenciar o isolado do Amazonas dos demais de Pernambuco. Os resultados obtidos com os marcadores moleculares não mostraram relação com o grau de patogenicidade dos mesmos à cebola
15

Analysis of selected ions in Allium cratericola growing on serpentine and non-serpentine soil

McIntyre, Todd Ian 01 January 1991 (has links)
The primary problems which plants growing on serpentine soil must overcome are high magnesium concentrations and calcium deficiency. The ability of Allium cratericola to successfully exploit both serpentine and non-serpentine habitats may be due to physiological adaptations which compensate for unusual mineral composition of the soil. Although the Table Mountain soil is described as non serpentine, it bears ionic similarities to the three serpentine soils studied in this investigation. With the advent of modern biochemical techniques in plant physiology, there are ample opportunities to expand on past work concerning plant growth on serpentine soil. Investigations into the biochemical nature of tolerance mechanisms, especially those involving the mechanics of ion transport and translocation, could further elucidate the nature of plant growth on this soil type.
16

Pharmaceutical and chemical analysis of the components carrying the antiplatelet activity of extracts from allium ursinum and allium sativum

Sabha, Dina Talat Tawfiq 15 November 2011 (has links)
Allium sativum has a long tradition in medicine. While much is known about its potential healthy effects, nearly nothing is known about wild garlic (allium sativum, ramson), which is very common in the area of Leipzig and has been used as a herbal remedy since centuries. The goal of the present study was to assess a potential anti-platelet activity of these two allium species and to try to identify the chemical active principle. For that purpose various extracts (hydrophilic and lipophilic) were prepared from Allium sativum and Allium ursinum, and analysed using thin layer chromatography and HPLC. After identifying an active, i.e. antiaggregatory extract (see below), this was fractionated and the active fraction was further sub-fractionated for subsequent chemical analysis by mass spectroscopy, ESI (Electrospray ionization), and COSY (Correlation effect spectroscopy), and functional testing. Anti-platelet activity was assessed in human platelets (platelet rich plasma) using a classical turbidimetric method. Platelets were stimulated with various agonists (arachidonic acid, ADP, epinephrine, collagen, A23187) with and without the addition of the extracts or the fractions /sub-fractions. Both Allium Ursinum and Allium sativum extracts exert antiaggregatory effects with EC50 values around 0.1 mg/ml. The garlic extracts are acting by inhibition of the ADP pathway comparable as known from the clinically used drug clopidegrol.The pharmacological active antiaggregatory component of the extracts appears to be lipophilic rather than hydrophilic. This is the first report on an antiplatelet activity of Allium Ursinum. One final structure determined by HPLC, MS, ESI and COSY which exerts the antiplatelets inhibitory effect is β-sitosterol-3-O-β-D-glucoside of the fraction 7-14 crystals. It is considered that about three up to five grams of dried leaves might be enough to exert antiaggregatory effects (comment: in pharmacy normally dried plant material is used in therapy). The second compound with antiaggregatory activity was identified as 1-β-D-galactopyranoside-2, 3-bis-linolenic glycerate. The problem of loosing the active volatile oily components by drying the leaves in future studies looking for the clinical use may be solved by looking for a raw or a refined extract which would be the form of a real phytomedical drug; for example capsules about 120 to 200 micrograms of an alcoholic or better an heptane / oily extract gained from wood garlic leaves would be an useful drug formulation to reach respective concentrations in blood. However, we have to admit that since our investigations were in-vitro, the in-vivo situation is somewhat different due to the metabolism, which is nearly unknown. Nevertheless, this study shows for the first time that allium ursinum does exert anti-platelet activity and that both allium species can unfold antiaggregatory effects which are worth to be investigated in subsequent in-vivo studies. β-sitosterol-3-O-β-D-glucoside and 1-β-D-galactopyranoside-2, 3-bis-linolenic glycerate could be identified as active antiaggregatory principals.
17

A biosystematic study of Allium amplectens Torr

Cain, Vickie Lynn 01 January 1974 (has links)
This investigation attempts to verify the identification of the anthocyanin in A. amplectens by spectral means. An attempt was also made to identify the sugars, and possibly their locations on the heterocyclic ring system, of the anthocyanins.
18

Studies on the anthocyanin pigments in Allium amplectens Torr

Chu, Chun-Mei 01 January 1972 (has links)
In this investigation, the basic pigment component, or anthocyanidin, of the ten most common spots was identified using paper and thin layer chromatographic techniques.
19

A taxonomic re-evaluation of the Allium sanbornii complex

Denison, Stella Sue 01 January 1986 (has links) (PDF)
Allium sanbornii is a member of the Sanbornii alliance which is characterized by prominent ovarian crests and a single terete leaf. Because of inadequate material, previous investigators have confused species limits and lumped together taxa that are not conspecific. This investigation included herbarium and field studies and determined that previously ignored characters, such as the relative lengths of the inner and outer perianth segments, general attitude of the perianth segments and texture of the outer bulb coat, were useful in delimiting relationships within the complex. Based on these findings Allium sahbornii consists of two geographic variants: A. sahbornii var. sanbornii and A. sanbornii var. congdonii. The two other currently recognized varieties are elevated to specific status as A. jepsonii and A. tuolumnense.
20

Engineering Allium White Rot Disease Resistance in Allium Species and Tobacco Model Species

Glue, Joshua Barnaby January 2009 (has links)
Allium white rot (AWR) is a soilborne disease that seriously damages commercial cultivation of onion (Allium cepa) and garlic (Allium sativum) crops. The disease has been found everywhere onions are cultivated and at present no system of control has been found that fully prevents the occurrence of the disease. The fungus responsible for the disease, Sclerotium cepivorum, uses oxalic acid to kill Allium bulb and root tissue in growing onion and garlic plants. Research suggests recombinant oxalate oxidase and oxalate decarboxylase enzymes may be able to degrade this acid and confer resistance against pathogens that rely on it, such as Sm. cepivorum or Sclerotinia sclerotiorum. To test the efficacy of these enzymes against white rot pathogens, three transgenes for wheat oxalate oxidase, barley oxalate oxidase and Flammulina oxalate decarboxylase were transformed into onions and garlic by Agrobacterium-mediated transformation. Allium species are highly recalcitrant to transformation, so these three transgenes were also transformed into tobacco to provide fast-recovering, easy to test transformants to assess the efficacy of the transgenes. Transformed garlic and tobacco lines were analysed to assess the integration and expression of the transgenes, then challenged with Sm. cepivorum or Sa. sclerotiorum, respectively, to assess the bioactivity of recombinant wheat oxalate oxidase, barley oxalate oxidase, and Flammulina oxalate decarboxylase against oxalic acid-dependent pathogens. Results show that one line of tobacco expressing the Flammulina oxalate decarboxylase enzyme was found to be consistently resistant to Sclerotinia sclerotiorum. Garlic lines transformed with this transgene failed to display stable transgene expression or disease resistance, possibly due to silencing of the transgene in recovered transformant tissue.

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