Made available in DSpace on 2015-04-22T22:02:03Z (GMT). No. of bitstreams: 1 DISSERTACAO LUZ PIEDAD VIILLAREAL.pdf: 1064710 bytes, checksum: c2a90c98dd31ff419482cc3156edb69b (MD5) Previous issue date: 2009-12-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Stingless bees have gained attention because their importance as pollinators of a wide range of native plant species and because they represent an important income source for meliponicultors. In order to contribute to the knowledge of the chemical composition and antioxidant activity of pollen collected by the stingless bee Melipona seminigra Cockerell, 1919 (uruçú-boca-de-renda), an economical specie in the Amazon region, two samples were collected during two distinguished weather season in the Brazilian Amazon, dry (august 2008, 50 mm) and rainy (april 2008, 300 mm) season. The centesimal composition analysis showed that both samples have a similar nutritional value and all values are in accord to the recommended by the Brazilian Ministery of Agriculture, but carbohydrate contents, which were ca 10 % above. In both samples of pollen, the main botanical source was Miconia dispar (Melastomataceae) (rainy season: 53.19% and dry season: 95.60%) followed by pollen of different Myrtaceae species (rainy: 25.64% and dry 0.96%) and Mimosa pudica pollen (Fabaceae; rainy: 16.81% and dry: 3.44%). Aqueous and ethanolic extracts from samples collected in the two different seasons were prepared and the ethanolic extracts were fractionated by liquid-liquid partition into hexanes, ethyl acetate and hydroalcoholic fractions. The antioxidant activity of the extracts and fractions was determined by two different methods: DPPH· radical scavenging assay and the ferric reducing antioxidant power assay. In both cases, the ethanolic extracts were more active than the aqueous ones. The fractions were also assayed and the ethyl acetate fractions were the most active ones. The total phenolics contents as determined by the Folin-Ciocalteu assay have confirmed that the phenolic compounds were concentrated into these fractions. Fingerprinting analysis by RPHPLC of purified fractions obtained by solid phase extraction (RP-SPE) of ethanolic extracts of each characteristic seasonal period showed similar compositions. The phenylpropanoid, p-coumaric, and the flavonoids myricetin, quercetin and naringenin could be identified with the help of coelution method with authentic commercial standards. The main component of the fraction obtained by RP-SPE was purified by semi-preparative RP-HPLC and was identified by 1H NMR data as quercitrin (quercetin 3-O-rhamnopyranoside). / As abelhas sem ferrão vêm ganhando atenção devido à sua importância como polinizadoras de espécies vegetais nativas e por representarem uma importante fonte de renda para os meliponicultores. Com o propósito de contribuir ao conhecimento da composição química e atividade antioxidante do pólen coletado pela abelha sem ferrão Melipona seminigra Cockerell, 1919 (uruçú-boca-de-renda), espécie muito procurada na região, duas amostras de pólen foram coletadas durante dois períodos característicos da região Amazônica, o chuvoso (abril de 2008, pluviosidade de 300 mm) e o seco (agosto de 2008, pluviosidade de 50 mm). A composição centesimal indicou que as duas amostras apresentam um valor nutricional similar e dentro dos parâmetros recomendados pelo Ministério da Agricultura, com exceção do teor de carboidratos que foi 10 % superior ao valor de referência. Nas duas amostras de pólen, Miconia dispar (Melastomataceae) foi o pólen predominante (periodo chuvoso: 53,19 % e seco: 95,60 %). Outros tipos de pólen identificados foram da família Myrtaceae (período chuvoso 25,64% e seco 0,96%) e da espécie Mimosa pudica (Fabaceae; período chuvoso 16,81% e período seco 3,44%). A partir dessas amostras foram preparados extratos aquosos e etanólicos. Estes últimos foram fracionados por partição líquido-líquido, resultando nas frações hexânica, acetato de etila e hidroalcoólica. A atividade antioxidante dos extratos e das frações foi determinada por dois ensaios: capacidade de seqüestro do radical livre difenilpicrilhidrazilo (DPPH·) e capacidade redutora de Fe(III). Em ambos os ensaios, observou-se que os extratos etanólicos foram os mais ativos, quando comparado aos aquosos. Das frações analisadas, as frações acetato de etila apresentaram a maior atividade antioxidante. O teor de fenólicos totais determinado pelo método de Folin-Ciocalteau confirmou que os compostos fenólicos se concentraram nessas frações. Perfis cromatográficos das frações purificadas por extração em fase sólida a partir dos extratos etanólicos de cada periodo foram obtidos por CLAE em fase reversa e mostraram-se bastante similares. Com o auxílio de padrões comerciais e utilizando o método da coeluição foi possível identificar a presença do fenilpropanoide, ácido p-cumárico e dos flavonóides: miricetina, quercetina e naringenina. O componente principal da fração obtida por extração em fase sólida do extrato etanólico da época de chuva foi ainda purificado por CLAE em fase reversa em escala semi-preparativa. Os dados espectroscópicos (RMN de 1H) dessa substância indicaram tratar-se da quercetina-3-O-ramnosídeo (quercetrina).

Made available in DSpace on 2015-04-22T22:02:15Z (GMT). No. of bitstreams: 1 Edinilze Souza Coelho Oliveira.pdf: 4961035 bytes, checksum: f6de1b94d1c9a5c50a72d78882119b88 (MD5) Previous issue date: 2012-09-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Leishmaniasis is considered by the World Health Organization as one of the most severe infections, due to have high capacity to produce deformities. The existing drugs are highly toxic and the parasites have been showed resistance to these drugs. Scientific researches have been proven the antiparasitic potential of extracts and compounds isolated from plant species. The subject of this work is to obtain essential oils from leaves of three species of from Myrtaceae: Eugenia patrisii, Marlierea umbraticola and Myrciaria floribunda, two species from Myristicaceae: Virola mollissima and V. theiodora, one specie from Annonaceae: Bocageopsis multiflora and one specie from Lauraceae: Endlicheria bracteolata, collected at the Adolpho Ducke Forest Reserve, Manaus, AM. The collections were performed in two periods: winter (April) and summer (September). The analysis of essential oils of E. patrisii, M. floribunda, B. multiflora and V. mollissima by GC-MS showed a high percentageof sesquiterpenes, while oils M. umbraticola and V. theiodora presented the monoterpenes as main constituents. The essential oil of the fresh leaves from E. bracteolata presented a differential when extracted in the month of April. There was observed the precipitate during the extraction and when analyzed by GC-MS showed a chromatographic profile of about 73.7% oxygenated sesquiterpenes. However, the oil of the dry season showed the hydrocarbons sesquiterpene as major constituents. The solid material obtained from E. bracteolata was purified, and guaiol was identified by MS, NMR and comparison with the literature data. The study with the heartwood from V. mollissima led to obtain a precipitate of the hexane extract and isolation of neolignans carinatin and dehydrodieugenol. Concerning the pharmacological tests, essential oils and extracts of low polarity were tested on the promastigotes of Leishmania amazonensis. In this context, the oil V. mollissima showed highr activity (IC50 of 19.7g/mL). The neolignan carinatina showed lower activity with value IC50 of 53.9g/mL. The essential oils from B. multiflora and M. umbraticola were the most active with IC50 of 14.8 and 21.1g/mL, respectively. The extracts that showed highest activity on promastigotes from L. amazonensis were subjected to the cytotoxicity analysis in non-infected macrophages, and oil from V. mollissima was the most toxic with IC50 of 17.16g/mL 10 compared to standard pentamidine (IC50 = 24.40 g/mL), while the oil from B. multiflora showed less toxicity with IC50 = 42.71g/mL. When evaluated against brine shrimp Artemia salina, all the oils exhibited high toxicity compared to standard lapachol (LC50 = 10.47g/mL), being the essential oil from E. bracteolata the most toxic with LC50 of 0.53g/mL. The antioxidant activity evaluation against the radical free DPPH below 28% of activity to the essential oils. In contrast, the neolignan deidrodieugenol and precipitate obtained from V. mollissima, exhibit high antioxidant activity with IC50=10.68 and IC50=6.87g/mL, respectively. / A leishmaniose é considerada pela Organização Mundial de Saúde como uma das mais graves infecções existentes, por causa da sua alta capacidade de produzir deformidades. Os medicamentos existentes são de elevada toxicidade e o parasita tem apresentado resistência a esses medicamentos. Pesquisas científicas tem comprovado o potencial antiparasitário de extratos e substâncias isoladas de espécies vegetais. Este trabalho teve como objetivo principal a obtenção de óleos essenciais das folhas de três espécies da família Myrtaceae: Eugenia patrisii, Marlierea umbraticola e Myrciaria floribunda, duas espécies da família Myristicaceae: Virola mollissima e V. theiodora, uma espécie da família Annonaceae: Bocageopsis multiflora e uma espécie da família Lauraceae: Endlicheria bracteolata, ocorrentes na Reserva Florestal Adolpho Ducke, Manaus, AM. As coletas foram realizadas em dois períodos correspondentes ao inverno (abril) e verão (setembro). As análises dos óleos essenciais de E. patrisii, M. floribunda, B. multiflora e V. mollissima por CG-EM evidenciaram alta porcentagem de sesquiterpenos, enquanto que os óleos de M. umbraticola e V. theiodora apresentaram monoterpenos como constituintes majoritários. Já o óleo essencial das folhas frescas de E. bracteolata apresentou um diferencial quando extraído no mês de abril. Um precipitado foi observado durante a extração e quando analisado por CG-EM apresentou um perfil cromatográfico com cerca de 73,7% de sesquiterpenos oxigenados. Entretanto, o óleo da estação seca apresentou sesquiterpenos hidrocarbonetos como constituintes principais. O material sólido obtido de E. bracteolata foi purificado, e o guaiol foi identificado por EM, RMN e comparação com dados descritos da literatura. O estudo com o cerne de V. mollissima levou a obtenção de um precipitado do extrato hexano e ao isolamento das neolignanas carinatina e deidrodieugenol. Concernente aos ensaios farmacológicos, os óleos essenciais e extratos de baixa polaridade foram testados frente às formas promastigotas de Leishmania amazonensis. Nesse contexto, o óleo de V. mollissima exibe maior atividade (CI50 de 19,7 g/mL) e a neolignana carinatina apresenta menor atividade com valor de CI50 de 53,9 g/mL. Em relação aos óleos das demais espécies, os 8 óleos essenciais de B. multiflora e de M. umbraticola foram os mais ativos com CI50 de 14,8 e 21,1 g/mL, respectivamente. Os extratos que demonstraram maior atividade sobre as formas promastigotas de L. amazonensis foram submetidos ao ensaio de citotoxicidade em macrófagos não parasitados, sendo o óleo de V. mollissima o mais tóxico com CI50 de 17,16 g/mL em comparação ao padrão pentamidina (CI50 = 24,40 g/mL), enquanto que o óleo de B. multiflora apresentou menos toxicidade com CI50 de 42,71g/mL. Quando avaliados frente ao microcrustáceo Artemia salina, todos os óleos apresentaram elevada toxicidade em relação ao padrão lapachol (CL50 =10,47g/mL), sendo o óleo essencial de E. bracteolata o mais tóxico com CL50 de 0,53g/mL. A avaliação da atividade antioxidante frente ao radical livre DPPH demonstrou que os óleos apresentaram atividade abaixo de 28%. Em contrapartida, a neolignana deidrodieugenol e o precipitado obtido de V. mollissima, apresentam atividade bastante pronunciada com CI50=10,68 e CI50=6,87 g/mL, respectivamente. Palavras-chave: Óleos essenciais, análise cromatográfica, leishmaniose,

O objetivo deste trabalho de pesquisa foi de fazer a modelagem por meio de sistemas de inferência Fuzzy da análise da concentração dos gases dissolvidos no óleo mineral isolante e desta forma diagnosticar defeitos elétricos internos em transformadores de Potência. Assim sendo o sistema proposto deve fornecer respostas que auxiliem no diagnóstico de falhas e avarias nos interiores dos transformadores e no processo de tomada de decisões no acompanhamento da evolução destas falhas de forma a aumentar a confiabilidade em relação à utilização dos métodos individualmente. O sistema desenvolvido baseou-se na pesquisa acadêmica de normas e técnicas mais utilizadas na literatura que relacionam o gás dissolvido no óleo mineral isolante com a falha. O sistema proposto foi validado por meio de dados reais de dois transformadores pilotos e vários sistemas Fuzzy foram construídos, cada um especialista em um determinado método. Os resultados encontrados mostraram-se compatíveis com aqueles obtidos pelos métodos convencionais comprovando que a ferramenta pode ser utilizada como suporte para uma análise rápida e confiável do estado do óleo isolante dos transformadores. / The objective of this research was to model by analyzing the fuzzy inference systems the concentration of gases dissolved in the insulating oil and diagnosing thereby internal defects in electrical power transformers. Therefore the proposed system should provide answers that help in the diagnosis of faults and malfunctions in the interiors of the transformers and in the decision-making process in monitoring the evolution of these failures in order to increase the reliability regarding the use of the methods individually. The system developed was based on academic research standards and techniques commonly used in the literature relating the gas dissolved in the insulating oil with failure. The proposed system was validated by real data of two pilots transformers and various Fuzzy systems were built, each an expert in a particular method. The results were compatible with those obtained by conventional methods proving that the tool can be used as support for quick and reliable analysis of the insulating oil condition of transformers.

Adsorption separation processes are extremely important to the chemical industry, especially in the manufacturing of food, pharmaceutical, and fine chemical products. This work addresses three main topics: first, systematic decision-making between rival gas phase adsorption processes for the same separation problem; second, process development for liquid phase simulated moving bed chromatography (SMB); third, accelerated startup for SMB units. All of the work in this thesis uses model-based optimization to answer complicated questions about process selection, process development, and control of transient operation. It is shown in this thesis that there is a trade-off between productivity and product recovery in the gaseous separation of enantiomers using SMB and pressure swing adsorption (PSA). These processes are considered as rivals for the same separation problem and it is found that each process has a particular advantage that may be exploited depending on the production goals and economics. The processes are compared on a fair basis of equal capitol investment and the same multi-objective optimization problem is solved with equal constraints on the operating parameters. Secondly, this thesis demonstrates by experiment a systematic algorithm for SMB process development that utilizes dynamic optimization, transient experimental data, and parameter estimation to arrive at optimal operating conditions for a new separation problem in a matter of hours. Comparatively, the conventional process development for SMB relies on careful system characterization using single-column experiments, and manual tuning of operating parameters, that may take days and weeks. The optimal operating conditions that are found by this new method ensure both high purity constraints and optimal productivity are satisfied. The proposed algorithm proceeds until the SMB process is optimized without manual tuning. In some case studies, it is shown with both linear and nonlinear isotherm systems that the optimal performance can be reached in only two changes of operating conditions following the proposed algorithm. Finally, it is shown experimentally that the startup time for a real SMB unit is significantly reduced by solving model-based startup optimization problems using the SMB model developed from the proposed algorithm. The startup acceleration with purity constraints is shown to be successful at reducing the startup time by about 44%, and it is confirmed that the product purities are maintained during the operation. Significant cost savings in terms of decreased processing time and increased average product concentration can be attained using a relatively simple startup acceleration strategy.

Sphingolipids are found in essentially all animals, plants and fungi, and some prokaryotic organisms and viruses. Sphingolipids function as structural components of membranes, lipoproteins, and as cell signaling modulators and mediators. To complicate matters further, sphingolipids often vary in type in different regions of tissues, and even in single cells, the subcellular localization of sphingolipids and their metabolic enzymes, transport proteins and targets may influence their functions. It is important to study sphingolipids spatial distribution within living organisms to understand how sphingolipids are involved in complex biochemical processes. As part of this thesis, procedures were optimized for the use of matrix assisted laser desorption/ionization (MALDI) tissue mass spectrometry (TIMS) to visualize the location of several types of lipids including sulfatides (ST), gangliosides and phosphoglycerolipids in brains from a mouse model for Tay-Sachs/Sandhoff disease. MALDI-TIMS was next applied to human ovarian carcinoma tissue to detect sulfatide location and established that ST are associated specifically with the regions of the ovarian tissue that bear the carcinoma. Electrospray ionization tandem mass spectrometry (ESI-MS-MS) was also used to confirm that ST and galactosylceramide (GalCer) are elevated in ovarian cancer. Gene expression data using tumor cells collected using laser capture microdissection revealed greater expression of mRNAs for GalCer synthase, GalCer sulfotransferase (Gal3ST1) and other enzymes of ST biosynthesis in epithelial ovarian carcinoma cells. This is a unique combination of two complementary, profiling technologies--mass spectrometry (metabolomic approach) with analysis of gene expression to study complex cancer pathology. The next study focused on the subcellular location of sphingolipids. In comparison with wild type Hek293 cells, a Hek293 cell line stably overexpressing serine palmitoyltransferase (SPT1/2 cells) was found to have elevated amounts of all subspecies of ceramide (Cer), but produces disproportionately higher amounts of C18-Cer and GalCer. Since Cer is known to inhibit protein ER/Golgi trafficking, these studies found that the higher production of Cer caused impairment of ER/Golgi trafficking of Ceramide synthase 1 (CerS1), thus increased C18-Cer. In addition, since GalCer is only synthesized in the lumen of the ER, this impairement of ER/Golgi trafficking also gave GalCer synthase access to its substrate and increased GalCer biosynthesis. These studies illustrate the complexity of sphingolipid biology and the usefulness of multiple tools to understand sphingolipid complex biological processes.

D. Tech. Chemistry. / Aims to isolate and characterise mesembrine-type alkaloids from S. tortuosum for use as reference standards ; develop and validate analytical methods for the accurate determination of mesembrine-type alkaloids in S. tortuosum samples and commercial products for quality control purposes ; investigate inter-species variation of alkaloids in endemic Sceletium species ; establish the variation of mesembrine-type alkaloids within and between different populations of S. tortuosum specimens and hence identify various chemotypes ; determine the variations of the target alkaloids in S. tortuosum commercial products purchased from various suppliers ; determine the mesembrine-type alkaloid content of the combustion products from S. tortuosum; and to evaluate the in vitro permeation of the alkaloids across oral and intestinal mucosa.

The investigation of the atmospheric fate and transport of semi-volatile organic compounds (SOCs) often requires the sampling of large volumes of air (>100 m3) in a relatively short period of time. Conventionally high-volume pumps are not suitable for remote areas without access to reliable network power. We have developed a flow through sampler for such situations. It consists of a horizontally-oriented flow-tube, that can collect gaseous and particle-bound SOCs from large volumes of air by turning into the wind and having the wind blow through a porous sampling medium such as polyurethane foam. Through both indoor and outdoor experiments, we quantified its air sampling rate (through battery operated anemometers inside and outside of the flow tube), its sampling efficiency (by theoretical plate number analysis of the break-though curves for PCBs, PAHs, OCPs and PBDEs), and its accuracy (by comparison of concentrations, time trends, temperature dependences and isomer ratios with those obtained by conventional high-volume sampling) under conditions of constant and variable meteorological conditions (wind speed, temperature). The flow-through sampler was deployed to monitor SOC concentrations at a remote Chinese research station located close to Nam Co Lake, Tibet. During the campaign, fifteen 1 month-long samples were taken, corresponding to sample volumes between 5,000 and 20,000 m3. Despite those large sample volumes, only HCB and HCHs experienced break-through, but application of frontal chromatograph theory allows the estimation of breakthrough-corrected air concentrations even for those relatively volatile SOCs. The pesticide levels at Nam Co are generally very low. Most pesticides had higher levels during summer, resulting in a strong temperature dependence. This is correlated with air mass origin across the Himalayas in the Gangetic plains of India and Bangladesh. The flow through sampler constitutes a feasible method for reliably and quantitatively collecting SOCs from large air volumes.

Advantages such as chemical, mechanical and thermal stability together with high selectivity for the templated analyte render molecularly imprinted polymers MIPs interesting alternatives to routinely applied separation materials or antibodies. Nevertheless, many factors such as the choice of functional monomer, cross-linker, and porogenic solvent, as well as the ratio between template, functional monomer, and cross-linker will affect the resulting imprinting efficiency and polymer particle size and morphology. The research described in this thesis contributes to the development of new synthetic strategies for the generation of imprinted micro- and nanospheres for 17beta-estradiol (E2) focusing on accurate control and optimization of the governing parameters for precipitation polymerization, including the polymerization temperature and the cross-linker, yielding a one-step synthetic approach with superior control on the bead diameter, shape, monodispersity and imprinting efficiency. Thus synthesized imprinting materials for E2 were successfully applied in HPLC separation, solid phase extraction and radioligand binding assays. As the optimization of imprinted materials is based on fundamental understanding of the binding site properties, the investigations is aimed at establishing a more rational basis for further tailoring imprinted materials to the desired analytical application. The relationships between the particle porosity and rebinding properties were detailed, providing useful guidelines for controlling the particle properties for the desired application including, SPE pre-concentration, HPLC separations, and biomimetic binding assays. Furthermore, analytical techniques (1H-NMR and IR, etc.) and molecular modeling were combined in this thesis to facilitate advanced understanding of the fundamental principles governing selective recognition of molecularly imprinted polymers at a molecular level. The molecular interactions involved in the templating process of molecularly imprinted polymers based on the self-assembly approach were simulated in molecular dynamic simulation model by building a modeling system include all the imprinting components with correct ratio, which has never been reported before. Molecular level interactions such as hydrogen bonding, π-π stacking interactions as well as the free energy governing complex formation of E2 with the functional monomers 4-vinylpyridine (4VP) and methacrylic acid (MAA), and the cross-linker divinylbenzene (DVB) were discussed.

This thesis describes the characterization of ceramide (Cer) biosynthesis by mammalian cells. The possibility that Cer undergo developmental changes was explored using mouse embryonic stem cells versus embryoid bodies by analysis of the Cer subspecies by liquid chromatography, electrospray ionization-tandem mass spectrometry (LC ESI-MS/MS) and of the transcript levels for enzymes involved in Cer biosynthesis by qRT-PCR. Cer of embroid bodies had higher proportions of very-long-chain fatty acids, which correlated with the relative expression of mRNA for the respective Cer synthases (CerS) and fatty acyl-CoA elongases, as well as changes in the fatty acyl-CoA's of the cells. Therefore, it is clear that Cer subspecies change during embryogenesis, possibly for functionally important reasons. One CerS isoform, CerS2, was studied further because it has the broadest tissue distribution and a remarkable fatty acyl-CoA specificity, utilizing longer acyl-chain CoAs (C20-C26) in vitro. The fatty acid chain selectivity was refined by analysis of the Cer from livers from CerS2 null mice, which displayed very little Cer with fatty acyl chains with 24 + 2 carbons. Another interesting structural variation was discovered in studies of cells treated with fumonisin B1 (FB1), which inhibits CerS. Under these conditions, cells in culture and animals accumulate substantial amounts of a novel sphingoid base that was identified as 1-deoxysphinganine. This compound arises from utilization of L-alanine instead of L-serine by serine palmitoyltransferase (SPT) based on the inability of LYB cells, which lack SPT, to make 1-deoxysphinganine. In the absence of FB1, 1-deoxysphinganine is primarily acylated to 1-deoxydihydroceramides. These are an underappreciated category of bioactive sphingoid bases and "ceramides" that might play important roles in cell regulation and disease. In summary, cells contain a wide variety of Cer subspecies that are determined by changes in expression of CerS, enzymes that produce co-substrates (such as fatty acyl-CoAs), and the types of amino acids utilized by SPT, the initial enzyme of de novo sphingolipid biosynthesis. One can envision how these changes might impact membranes structure as well as signaling by this family of highly bioactive compounds.

Thesis (Ph.D.) -- University of Western Sydney, Hawkesbury, 1998. / "A thesis presented to the University of Western Sydney for the degree of Doctor of Philosophy, September, 1998" Bibliography: leaves 193 - 219.