This study has investigated the gene expression of ubiquitin¡B20S proteasome beta subunit type 1 (20s£]1)¡Bubiquitin-conjugating enzyme e2 (ucee2)¡BATP-dependent caseinolytic protease regulatory subunit (clpC) in the marine macroalga Ulva fasciata Delile in relation to the hypersalinity-induced oxidative stress and protein oxidation. During the early stage (0-1 h), the water contents and TTC (2,3,5-tripheny tetrazolium chloride) reduction ability maintained unchanged but recovery ability and photosynthetic ability (PS II activity as indicated by Fv/Fm) were decreased along with accumulated H2O2, suggesting the occurrence of oxidative stress. Only ubiquitin expressed at this stage. During 1-3 h, water lost (approximately 33% of the control) with a further decrease in recovery ability, TTC reduction ability¡BPS II activity but more H2O2 accumulation and protein carbonyl compound. The transcripts of 20s£]1 and clpC and caseinolytic protease activity increased at this stage with the maximum of clpC at hour 3. In the 6-48 h, water lost seriously with high accumulated free amino acid at 6-12 h but low recovery ability. The transcript amounts of ubiquitin¡B20s£]1 and ucee2 increased marked during this stage, in which these might be related to programmed cell death caused by long-term exposure to hypersalinity. Reactive oxygen species (ROS) scavengers inhibited H2O2 accumulation, caseinolytic proteolytic activity increase, carbonyl compound formation and gene expression of ubiquitin¡B20s£]1¡Bucee2¡BclpC, indicating a role of ROS in the regulation of protease genes. A role of polyamines in the regulation of protease gene expression was tested. Spermidine and spermine inhibited the gene expression of ubiquitin¡B20s£]1 and ucee2, the oxidation of proteins (carbonyl groups) and the induction of caseinolytic protease activity in 90‰-treated thalli, whereas putrescine inhibited clpC expression, the oxidation of proteins and caseinolytic protease activity but enhanced the gene expression of ubiquitin¡B20s£]1 and ucee2. In conclusion, the results of the present investigation show that the degradation of oxidatively damaged proteins under hypersalinity conditions by increased caseinolytic protease activity is driven by the up-regulation of clpC gene expression via ROS and polyamines. It seems likely that the induction of ubiquitin¡B20s£]1 and ucee2 gene expression might be associated with the hypersalinity-mediated programmed cell death.

The effects of copper on growth and phosphorus (P) utilization were investigated in the marine chlorophyte Ulva fasciata Delile. Both the daily specific growth rate and tissue P contents decreased as increasing CuSO4 concentrations, while the contents of total tissue, intracellular and cell-wall Cu increased. Based on the relationship between daily specific growth rate and external CuSO4 concentrations, the upper limit of U. fasciata is 100 uM CuSO4. After 4-day exposure to varying CuSO4 concentrations, Pi uptake was inhibited. Analysis of P fraction in U. fasciata exposed to 100 uM CuSO4 shows that the Cu-induced decline in total tissue P contents is mainly due to a decrease in both soluble reactive P (i.e. Pi). Exposure to 100 uM of Cu caused the accumulation of total tissue Cu contents to a plateau and then rose again at day 3, and tissue P contents and daily specific growth rate decreased at day 4. IC50 (concentration of 50 % inhibition) of daily specific growth rate and tissue P contents are 9.8 and 37.8 uM of Cu concentration in the medium, respectively, and 0.76 and 1.44 mg¡Dg-1 DW for total tissue Cu contents, respectively. Overall, Cu causes Cu accumulation in intracellular space and cell wall and decrease of growth and P contents of U. fasciata partly via Pi uptake inhibition.

This research has investigated the gene expression of protein disulfide isomerase (PDI; EC 5.3.4.1) and thioredoxin (Trx) in the marine macroalga Ulva fasciata Delile in response to hypersaline (90‰) for 1 h. 90‰ induced H2O2 accumulation, reflecting the occurrence of oxidative stress. The contents of free and protein-bound SH were increased by 90‰. Trx transcripts increased in response to 90‰. PDI transcripts and enzyme activities increased in response to 90‰. H2O2 accumulation under 90‰ condition was increased by putrescine (Put) but decreased by spermidine (Spd) and spermine (Spm). By treatment of spermidine and spermine, the contents of free SH was increased and the contents of protein-bound SH decreased, showing that spermidine and spermine can increase free SH against oxidative stress. The gene expression and activity of PDI were further increased by Spd and Spm. Overall, the gene expression of PDI and Trx were responded to 90‰ for 1 hour and were adjusted protein¡VSH in polyamines treatment.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-graduação em Recursos Genéticos Vegetais, Florianópolis, 2010 / Made available in DSpace on 2012-10-24T23:50:58Z (GMT). No. of bitstreams: 1 274964.pdf: 1041847 bytes, checksum: 78f57ef1cf2c57cdff4ea5a802c1bb57 (MD5) / Este trabalho teve como objetivo avaliar e comparar os mecanismos de defesa inata e induzida pela aplicação de ulvana à infecção de Colletotrichum gloeosporioides em macieira. Para tanto, plântulas resistentes foram tratadas com água destilada aos 6 dias antes da inoculação (DAI), enquanto que suscetíveis foram pulverizadas com ulvana (10mg/mL). Plântulas foram inoculadas com C. gloeosporioides e a severidade da Mancha Foliar de Glomerella (MFG) foi avaliada diariamente de 4 a 10 dias pós-inoculação (DPI), baseada na estimativa visual da porcentagem de tecido necrosado. Aos 10 DPI, todas as folhas foram destacadas e escaneadas para determinar a área foliar necrosada usando o Software Quant. A germinação dos conídios e a formação de apressórios de C. gloeosporioides foi avaliada às 24, 48 e 72 horas após a inoculação (HAI) na 2a e 3a folha expandida de plântulas. Discos foliares foram coletados, clareados e conservados em lactoglicerol até o exame em microscópio óptico. As atividades de peroxidases e glucanases foram determinadas em tecidos remanescentes da 2a e 3a folha expandida de plântulas de macieira às 24, 48 e 72 HAI. Plântulas com resistência inata nunca apresentaram sintomas da MFG. A ulvana pulverizada aos 6 DAI reduziu significativamente a severidade da MFG em plântulas. A germinação de conídios de C. gloeosporiodes não foi alterada pela resistência inata ou induzida por ulvana. O desenvolvimento de estruturas de infecção em plântulas resistentes foi semelhante às testemunhas, no entanto a pulverização com ulvana inibiu a formação de apressórios e elongamento do tubo germinativo do fungo. A resistência inata e induzida por ulvana aumentou a atividade de POX em plântulas de macieira, mas a atividade de GLU não foi alterada. Em suma, a resistência inata da macieira a MFG parece estar relacionada ao rápido reconhecimento do C. gloeosporioides com maior atividade de POX às 24 HAI. A redução da MFG por ulvana foi associada à menor formação de apressórios e elongamento do tubo germinativo de C. gloeosporioides, além do aumento da atividade de POX em plântulas às 72 HAI. / This study aimed to evaluate and compare the innate defense mechanisms and induced by the application of ulvan by infection of Colletotrichum gloeosporioides in apple. The resistance seedlings were treated with distillated water (control) 6 days before inoculation (DBI), while susceptible was sprayed with ulvan (10 mg/mL). Seedlings were inoculated with C. gloeosporioides and severity Glomerella Leaf Spot (GLS) was assessed daily from 4 to 10 days post-inoculation (DPI), based on visual estimation of the percentage of necrotic tissue. At 10 DPI all the leaves were detached and scanned to determine leaf area necrosis using Software Quant. Conidial germination and appressoria formation of C. gloeosporioides was evaluated at 24, 48 and 72 hours after inoculation (HAI) in 2nd and 3rd expanded leaf of seedlings. For this, foliar discs (9mm) were collected, leached and maintained in lactoglicerol until microscopical examination. The peroxidases and glucanases activity was determined in tissue remaining of the 2nd and 3rd expanded leaf of seedlings apple at 24, 48 and 72 HAI. Seedlings with innate resistance never showed symptoms of GLS. Ulvan sprayed at 6 DBI significantly reduced the severity of the GLS in seedlings. Conidial germination of C. gloeosporioides was not changed by either innate resistance or induced by ulvan. The development of structures of infection in resistance seedlings was similar to controls, however the ulvan spraying inhibited appressorium formation and germ tube elongation of fungus. Both innate resistance and induced by ulvan increased the POX activity of apple seedlings, but the activity of GLU was not changed. In sum, the innate resistance of apple against GLS seems to be related to the rapid recognition of C. gloeosporioides with increased activity of POX at 24 HAI. Disease reduction by ulvan was associated with a lesser appressorium formation and germ tube elongation of C. gloeosporioides, as well as enhanced POX activity in seedlings at 72 HAI.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-graduação em Recursos Genéticos Vegetais, Florianópolis, 2010 / Made available in DSpace on 2012-10-25T00:28:43Z (GMT). No. of bitstreams: 1 274975.pdf: 809433 bytes, checksum: b63aa5f59469f013c937206b22f4bf42 (MD5) / O presente trabalho teve por objetivo avaliar os mecanismos de defesa bioquímicos e histológicos envolvidos na resistência inata do feijoeiro à antracnose, compará-los com aqueles induzidos pela aplicação foliar de ulvana e avaliar o efeito de inertes na armazenabilidade e eficiência da ulvana. Para a avaliação dos mecanismos de defesa, plantas resistentes e suscetíveis de P. vulgaris cv. Uirapuru foram tratadas, 6 e 3 dias antes da inoculação (DAI), com água (testemunha) ou ulvana (10mg/mL) e inoculadas com C. lindemuthianum no estádio fenológico V4. A severidade da antracnose foi avaliada em intervalos de 2 dias. As atividades de peroxidases e glucanases foram determinadas às 12, 24 e 48 horas após a inoculação (HAI) em folíolos do primeiro trifólio. A germinação de conídios, formação de apressórios de C. lindemuhianum e a reação de hipersensibilidade (RH) em plantas de P. vulgaris foram avaliadas às 12, 24 e 48 HAI em discos foliares retirados do primeiro trifólio. Para a avaliação do efeito de diferentes inertes, foram realizados quatro experimentos idênticos durante o período de 1 ano. Para tanto, plantas de P. vulgaris cv. Uirapuru foram tratadas, 6 e 3 DAI, com água destilada ou ulvana (10mg/mL) (testemunhas) ou com as formulações de ulvana com os inertes caulinita, sílica amorfa e atapulgita e inoculadas com C. lindemuthianum no estádio fenológico V4. Plantas resistentes não apresentaram sintomas da antracnose, sendo que, 4 DPI foram visualizados pequenos pontos necróticos caracterizando a RH. O efeito local da ulvana foi mais evidente que o sistêmico. A atividade de POX foi sempre maior em plantas resistentes, mas a atividade de GLU foi similar. A pulverização de ulvana elevou a atividade de POX e GLU tanto em plantas inoculadas quanto em não inoculadas. A germinação e a formação de apressórios do fungo não foram alteradas pela resistência inata ou pela aplicação de ulvana. O número de células hipersensitivas foi maior em plantas resistentes e menor em plantas tratadas com ulvana, quando comparadas com os respectivos controles. A eficiência da ulvana foi reduzida pela formulação contendo atapulgita, mas não pela que continha sílica amorfa ou caulinita.

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Programa de Pós-Graduação em Biotecnologia. / Made available in DSpace on 2013-07-15T23:25:42Z (GMT). No. of bitstreams: 1 224306.pdf: 1144206 bytes, checksum: 3851e6455c9e7fcbff5c43c79ee99f3c (MD5) / Compostos presentes em algas marinhas podem desempenhar importantes funções biológicas, entre elas: atividade antimicrobiana direta, influenciando as interações entre planta-patógeno ou ativando mecanismos de defesa das plantas tratadas. O polissacarídeo ulvana, os extratos solúvel e insolúvel em metanol, o extrato etanólico obtidos de Ulva fasciata e o polissacarídeo B obtido de Ulva sp. foram testados quanto a atividade antimicrobiana e o potencial desta macroalga marinha no controle da antracnose de feijoeiro comum, causada pelo fungo Colletotrichum lindemuthianum. Para a obtenção da ulvana, algas frescas foram autoclavadas com água destilada; a solução resultante foi filtrada e precipitada com etanol. O polissacarídeo foi identificado por RNM-1H e RNM-13C e I.V. como unidades repetitivas de ácido ulvanobiurônico-3-sulfato. Para a obtenção dos extratos metanólicos e do extrato etanólico, algas secas e moídas foram extraídas com metanol em sistema de soxhlet ou com etanol, respectivamente. A atividade antimicrobiana da ulvana e dos extratos metanólicos foi determinada pelo método de difusão em ágar frente a bactérias potencialmente patogênicas ao homem: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus cereus, Micrococcus luteus, a levedura Candida albicans e bactérias fitopatogênicas: Xanthomonas campestris e Erwinia carotovora. A concentração inibitória mínima, através do método de microdiluição em caldo, foi determinada contra os fungos: C. lindemuthianum (fitopatogênico), Trichophyton mentagrophytes e Microsporum canis (dermatófitos). Além disto, o efeito da ulvana e dos extratos metanólicos foi avaliado, in vitro, nos testes de inibição de crescimento miceliano e inibição da germinação de conídios de C. lindemuthianum. In vivo, foi avaliado o efeito do extrato etanólico, extratos metanólicos, ulvana e polissacarídeo B na proteção de plantas de feijão comum (Phaseolus vulgaris L.) contra antracnose em casa-de-vegetação. Os resultados demonstraram que os extratos metanólicos inibiram o crescimento de bactérias Gram-negativas: P. aeruginosa, X. campestris e E. carotovora. Além disso, o extrato insolúvel (2 mg/ml) em metanol inibiu o crescimento de T. mentagrophytes e o extrato solúvel em metanol (1 e 2 mg/ml) inibiu significativamente (p<0,05) o crescimento miceliano de C. lindemuthianum. Por outro lado, nenhum dos extratos testados inibiu a germinação dos conídios deste fungo e a ulvana não apresentou nenhuma atividade in vitro contra os microrganismos testados. Nos experimentos in vivo, observou-se que o extrato etanólico (10 mg de alga seca/ml) e a ulvana (10 mg/ml) de U. fasciata apresentaram uma possível indução de resistência quando pulverizados três dias e quatro dias antes da inoculação do fungo, respectivamente.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / As macroalgas marinhas sÃo consideradas fontes promissoras de compostos bioativos para estudos fitoquÃmicos. Tais compostos possuem diferentes propriedades biolÃgicas, funcionando como antibacterianos, antifÃngicos, antivirais, anti-inflamatÃrios, anti-helmÃnticos, antileishmaniose, antimalÃria, antioxidantes, antitumorais cuja utilizaÃÃo como fÃrmacos tem despertado o interesse de muitos pesquisadores. O objetivo deste trabalho foi realizar a investigaÃÃo fitoquÃmica do extrato etanÃlico da macroalga marinha verde Ulva fasciata. O material foi coletado em abril de 2008, na Praia do Pacheco, no municÃpio de Caucaia-CE. As macroalgas in natura foram desidratadas em estufa com recirculaÃÃo de ar a 40ÂC por 15 horas e, em seguida, trituradas, obtendo-se 500 g, os quais foram submetidos primeiramente a uma extraÃÃo a frio com hexano (UFH), e posteriormente com etanol a 70% (UFE). Para o isolamento e a purificaÃÃo dos constituintes fixos foi empregada uma combinaÃÃo de tÃcnicas cromatogrÃficas clÃssicas em que foram isolados UF-1, UF-2 e UF-3. Na amostra UF-1 foi observada a presenÃa de um constituinte majoritÃrio (86,17%) com tempo de retenÃÃo de 24,940 min, cujo espectro de massas o caracterizou por apresentar o Ãon molecular M+ 284. A sugestÃo fornecida pela anÃlise CG-EM e a comparaÃÃo visual do espectro do composto analisado com os da literatura, bem como pela proposta mecanÃstica de formaÃÃo dos principais fragmentos reforÃaram sua identificaÃÃo como hexadecanoato de etila com um Ãndice de similaridade de 96%. Os compostos UF-2 e UF-3 foram encaminhados para o Centro Nordestino de AplicaÃÃo e Uso da RessonÃncia MagnÃtica Nuclear (CENAUREMN) da Universidade Federal do CearÃ, para a determinaÃÃo sua estrutura quÃmica atravÃs de tÃcnicas espectroscÃpicas de RMN 1H e 13C uni- e bidimensionais (1H, 1H-COSY, gs-HMQC, gs-HMBC, ROESY, NOESY e TOCSY), bem como por espectrometria de massa (EM). / Marine macroalgae have been considered promising sources of bioactive compounds. These compounds exhibit different biological properties, such as antibacterial, antifungal, antiviral, anti-inflammatory, antihelminthic, antileshmaniose, antimalaria, antioxidants, and antitumor. Their use as medicine has spurred the interest of many researches. The objective of this work was to carry out a phytochemistry investigation of the ethanolic extract of green marine macroalga Ulva fasciata. The plant material was collected in April 2008 at Pacheco Beach, Caucaia-CE. Macroalgae in natura were dehydrated in an air-circulation oven at 40ÂC for 15 hours. After the drying process, the material was cut into small pieces. 500 grams were submitted to a cold extraction with hexane (UFH) followed by an extraction with 70% ethanol (UFE). Both isolation and purification from fixed constituents were performed using a combination of classic chromatographic techniques. Three samples were isolated and named UF-1, UF-2 and UF-3. The presence of a major constituent (86.17%) with retention time of 24.940 min was observed in the first sample (UF-1), and its mass spectrum was characterized by the molecular ion M+ 284. The GC-MS analysis suggestion and the comparison of its spectrum with literature reinforce its identification as ethyl hexadecanoate with a similarity index of 96%. Compounds UF-2 and UF-3 have been taken to the Northeastern Center of Application and Use of Nuclear Magnetic Resonance (CENAUREMN) of Federal University of Ceara, to determine the chemical structure by spectroscopy techniques such as uni- and bidimensional (1H, 1H-COSY, gs-HMQC, gs-HMBC, ROESY, NOESY and TOCSY) 1H-NMR and 13C-NMR, as well as mass spectrometry (MS).

This study has investigated the involvement of photosynthetic electron transport chain on the regulation of gene expression of methionine sulfoxide reductase (UfMSR) in the marine macroalga Ulva fasciata Delile.UfMSRA is from copper stress and UfMSRB ir from hypersalinity stress. UfMSRA is similar to Arabidopsis AtMSRA4 and UfMSRB is similar to AtMSRB1. UfMSRA is specific to the MetSO S-enantiomer and UfMSRB catalytically reduces the MetSO R-enantiomer. Both enzymes are required, since in the cell oxidation of Met residues at the sulfur atom results in a racemic mixture of the two stereoisomers. UfMSRA and UfMSRB transcripts were increased by white light, blue light and red light with the maximum at 1 h following a decline, but kept constant in the dark. The magnitude of UfMSRA and UfMSRB transcript increase showed a positive linear correlation to increasing light intensity from 0-1200 u mole¡Pm-2¡Ps-1. The treatment with linear electron transport chain inhibitors, hydroxylamine, 3-(3,4-dichlorophenyl) -1,1-dimethylurea (DCMU), 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) and stigmatellin, effectively inhibited PS II activity under 300 u mole¡Pm-2¡Ps-1 irradiance. DBMIB and stigmatellin can increase UfMSRA transcript that was reversed by 2,6-dichlorophenolindophenol (DCPIP), a PS I electron donor. It indicates that the block of electron transport of the downstream of cytochrome b6f indeuces UfMSRA gene expression. Hydroxylamine, DCMU and DBMIB decreased UfMSRB transcript that was not reversed by DCPIP while stigmatellin increased UfMSRB mRNA level, reflecting a role of reduced state with Qo site located at cytochrome b6f on the induction of UfMSRB gene expression. The cyclic electron transport chain inhibitors, antimycin A that inhibited photosynthetic electron transport, can inhibit the increase of UfMSRA and UfMSRB transcripts by irradiance. UfMSRA and UfMSRB gene expression were both modulated by cyclic electron transport chain and linear electron transport chain. These results reveal that photosynthetic electron transport chain modulates UfMSRA and UfMSRB gene expression by change its redox state.

This is the first research by using suppression subtractive hybridization (SSH) to analysis the gene expression in marine macroalga Ulva fasciata Delile against excess copper toxicity, and it gives us a comprehensive understanding of the tolerant mechanism while macroalgae face to the excess copper. Suppression subtractive hybridization was used to identify genes differentially expressed following exposure to 50 £gM CuSO4 for 6- 12h in a marine macroalga Ulva fasciata Delile. In this work, 69 genes were identified, of which 55 were up-regulated and 14 were down-regulated. According to the database of Gene Ontology (GO), these genes were classified into 10 categories as follows: 1. Transcription; 2. Translation, ribosomal structure and biogenesis; 3. Posttranslational modification, protein turnover, chaperones; 4. Photosynthesis; 5. Cell redox homeostasis; 6. Stress; 7. Metabolism; 8. Energy production and conversion; 9. Transport; 10. Function unknown. According to the results, we suggest that the responses of U. fasciata against excess copper toxicity are mainly through increase of the energy production for providing sufficient energy to many metabolic pathways, and control of the Fe homeostasis and redox form of thiol groups for maintaining the cellular redox homeostasis, moreover, expression of photosynthetic genes for letting the photosynthesis work. In addition, to scavenge the ROS is by expression of stress-related genes, meanwhile, the proteins, DNA and lipids damaged by ROS (reactive oxygen species) and copper are repaired by expression of the other categorical genes. Over and above, the genes expressing in the metabolism category might maintain the amino acids homeostasis and increase the purine content, and subsequently increase the tolerant capacity of U. fasciata against excess copper toxicity. In addition, the concentrations of antioxidants and the activities and gene expression of antioxidant enzymes were determined in Ulva fasciata Delile by a 4-day exposure to 0, 5, 10, 20 and 50 £gM CuSO4. These results demonstrate that the maintenance of antioxidant homeostasis and the induction of activities of antioxidant enzymes via enhanced gene expression are used by U. fasciata to cope with the Cu-induced oxidative stress, but the defense capacity cannot sufficiently alleviate oxidative damage occurring under the condition of higher Cu concentrations. Moreover, according to the results from the expression of genes involved in the control of redox homeostasis and antioxidant defense was studied in macroalga Ulva fasciata Delile in response to CuSO4 (5 and 50 £gM) and ROS (H2O2 and O2£»-), we suggest that ROS involved in up-regulation of antioxidant defense-related genes and the expression of genes of antioxidant defense enzymes and UfMsrA (methionine sulfoxide reductase A) are associated with long-term adaptation of U. fasciata to Cu excess and transcription of redox- related genes and UfGr (glutathione reductase) is up-regulated for short-term acclimation. Promoters play a key role in regulating gene expression. Based on the analysis of cis-acting elements on UfMsr promoters, we suggested that the signal transduction pathway of copper stress in U. fasciata is related to that of other stresses and of defense-related plant hormones, however, Ca2+ and calmodulin might participate in it. To sum up, U. fasciata could resist oxidative damage caused by excessive copper through the regulation on the molecular level.

ALENCAR, Daniel Barroso de. Prospecção química da macroalga marinha verde Ulva fasciata Delile. 2010. 68f. Dissertação (Mestrado em Engenharia de Pesca)-Centro de Ciências Agrária,Universidade Federal do Ceará, Fortaleza, 2010. / Submitted by Maria Naires Souza (marianaires@ufc.br) on 2011-11-11T19:22:22Z No. of bitstreams: 1 2010-dis-dbalencar.pdf: 1843830 bytes, checksum: d2be4a7f57929369252c5c735b5c6d2c (MD5) / Approved for entry into archive by Aline Nascimento(vieiraaline@yahoo.com.br) on 2011-11-16T15:00:44Z (GMT) No. of bitstreams: 1 2010-dis-dbalencar.pdf: 1843830 bytes, checksum: d2be4a7f57929369252c5c735b5c6d2c (MD5) / Made available in DSpace on 2011-11-16T15:00:44Z (GMT). No. of bitstreams: 1 2010-dis-dbalencar.pdf: 1843830 bytes, checksum: d2be4a7f57929369252c5c735b5c6d2c (MD5) Previous issue date: 2010-08-27 / Marine macroalgae have been considered promising sources of bioactive compounds. These compounds exhibit different biological properties, such as antibacterial, antifungal, antiviral, anti-inflammatory, antihelminthic, antileshmaniose, antimalaria, antioxidants, and antitumor. Their use as medicine has spurred the interest of many researches. The objective of this work was to carry out a phytochemistry investigation of the ethanolic extract of green marine macroalga Ulva fasciata. The plant material was collected in April 2008 at Pacheco Beach, Caucaia-CE. Macroalgae in natura were dehydrated in an air-circulation oven at 40°C for 15 hours. After the drying process, the material was cut into small pieces. 500 grams were submitted to a cold extraction with hexane (UFH) followed by an extraction with 70% ethanol (UFE). Both isolation and purification from fixed constituents were performed using a combination of classic chromatographic techniques. Three samples were isolated and named UF-1, UF-2 and UF-3. The presence of a major constituent (86.17%) with retention time of 24.940 min was observed in the first sample (UF-1), and its mass spectrum was characterized by the molecular ion M+ 284. The GC-MS analysis suggestion and the comparison of its spectrum with literature reinforce its identification as ethyl hexadecanoate with a similarity index of 96%. Compounds UF-2 and UF-3 have been taken to the Northeastern Center of Application and Use of Nuclear Magnetic Resonance (CENAUREMN) of Federal University of Ceara, to determine the chemical structure by spectroscopy techniques such as uni- and bidimensional (1H, 1H-COSY, gs-HMQC, gs-HMBC, ROESY, NOESY and TOCSY) 1H-NMR and 13C-NMR, as well as mass spectrometry (MS). / As macroalgas marinhas são consideradas fontes promissoras de compostos bioativos para estudos fitoquímicos. Tais compostos possuem diferentes propriedades biológicas, funcionando como antibacterianos, antifúngicos, antivirais, anti-inflamatórios, anti-helmínticos, antileishmaniose, antimalária, antioxidantes, antitumorais cuja utilização como fármacos tem despertado o interesse de muitos pesquisadores. O objetivo deste trabalho foi realizar a investigação fitoquímica do extrato etanólico da macroalga marinha verde Ulva fasciata. O material foi coletado em abril de 2008, na Praia do Pacheco, no município de Caucaia-CE. As macroalgas in natura foram desidratadas em estufa com recirculação de ar a 40°C por 15 horas e, em seguida, trituradas, obtendo-se 500 g, os quais foram submetidos primeiramente a uma extração a frio com hexano (UFH), e posteriormente com etanol a 70% (UFE). Para o isolamento e a purificação dos constituintes fixos foi empregada uma combinação de técnicas cromatográficas clássicas em que foram isolados UF-1, UF-2 e UF-3. Na amostra UF-1 foi observada a presença de um constituinte majoritário (86,17%) com tempo de retenção de 24,940 min, cujo espectro de massas o caracterizou por apresentar o íon molecular M+ 284. A sugestão fornecida pela análise CG-EM e a comparação visual do espectro do composto analisado com os da literatura, bem como pela proposta mecanística de formação dos principais fragmentos reforçaram sua identificação como hexadecanoato de etila com um índice de similaridade de 96%. Os compostos UF-2 e UF-3 foram encaminhados para o Centro Nordestino de Aplicação e Uso da Ressonância Magnética Nuclear (CENAUREMN) da Universidade Federal do Ceará, para a determinação sua estrutura química através de técnicas espectroscópicas de RMN 1H e 13C uni- e bidimensionais (1H, 1H-COSY, gs-HMQC, gs-HMBC, ROESY, NOESY e TOCSY), bem como por espectrometria de massa (EM).