Made available in DSpace on 2014-06-11T19:23:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-11Bitstream added on 2014-06-13T20:29:35Z : No. of bitstreams: 1 martins_ap_me_araiq_parcial.pdf: 803021 bytes, checksum: 804ec0f53b60292a8f9532a0179cf5e2 (MD5) Bitstreams deleted on 2015-06-30T11:22:10Z: martins_ap_me_araiq_parcial.pdf,. Added 1 bitstream(s) on 2015-06-30T11:23:06Z : No. of bitstreams: 1 000719251_20171231.pdf: 670436 bytes, checksum: 5568579de711dae552f537b78e54f563 (MD5) Bitstreams deleted on 2018-01-02T17:04:40Z: 000719251_20171231.pdf,. Added 1 bitstream(s) on 2018-01-02T17:05:46Z : No. of bitstreams: 1 000719251.pdf: 1345177 bytes, checksum: f8b7d8e1b6f813b3d43740594a3e7002 (MD5) / O maracujá amarelo azedo (Passiflora edulis f. flavicarpa Degener) pode ser consumido in natura ou industrializado. Sua importância é dada pelo valor medicinal, popularmente usado no tratamento da ansiedade, insônia e irritabilidade; alimentício, na forma de polpa congelada e suco, doces, geleia e sorvete; e nutracêutico ou alimento funcional, apresentando elevados teores de íons fosfato e potássio, vitamina A, B1 (tiamina), B2 (riboflavina) e C (ácido ascórbico). Algumas alterações podem ocorrer durante o processamento e armazenamento do suco interferindo na cor e sabor do produto final, o que pode implicar em não aceitação por parte dos consumidores. Isso pode ocorrer principalmente devido a reações bioquímicas de escurecimento e alterações bioquímicas moleculares que resultam em flavors indesejáveis e perda de nutrientes. Por esse motivo o controle desses efeitos indesejáveis durante o processamento de frutos é muito importante para a preservação da aparência natural dos mesmos. Deste modo as enzimas Pectinametilesterase (PME; EC: 3.1.1.11), Peroxidase (POD; EC: 1.11.1.7), Polifenoloxidase (PPO; EC: 1.10.3.1) e Ascorbato Oxidase (AO; EC: 1.10.3.3) podem ser responsáveis pelo escurecimento enzimático e outras reações que alteram o produto durante e ao final do processamento. Visto isso, com o objetivo de agregar valores nutricionais e mercadológicos ao maracujá vem sendo desenvolvida e usada a cultura híbrida, que, em síntese, significa o uso de sementes modificadas e com manejo adequado, com vistas à racionalização do uso de defensivos agrícolas e aumento de produtividade. O objetivo desse trabalho é estudar o comportamento cinético das enzimas já citadas e avaliar os teores de compostos bioativos como vitamina C, compostos fenólicos, flavonóides, e atividade antioxidante em cinco... / The yellow passion fruit (Passiflora edulis f. flavicarpa Degener) can be eaten in natura or industrialized. Its importance is given by medicinal value, commonly used for treating anxiety, insomnia and irritability; food in the form of frozen pulp and juice, candy, jelly and ice cream, and nutraceutical or functional food, with high levels of potassium and phosphate ions, Vitamin A, B1 (thiamine), B2 (riboflavin) and C (ascorbic acid). Some changes may occur during processing and storage of the juice interfere the color and flavor of the final product, which can result in non-acceptance by the consumers. This can occur mainly due to biochemical browning and reactions molecular biochemical changes that result in undesirable flavors and nutrient loss. Therefore the control of these undesirable effects during processing of fruits is very important for preserving the natural appearance. Thus, enzymes pectinmethilesterase (PME, EC: 3.1.1.11), peroxidase (POD, EC: 1.11.1.7), Polyphenoloxidase (PPO, EC: 1.10.3.1) and ascorbate oxidase (AO, EC: 1.10.3.3) can be responsible for enzymatic browning and other reactions that alter the product during and after processing. Seen it, with the goal of adding nutritional value and market the passion fruit has been developed and used a hybrid culture, which, in summary, means the use of modified seeds and with appropriate management, with a view to rationalizing the use of pesticides and increase productivity. The aim of this work is to study the kinetic behavior of the enzymes already mentioned and evaluate the contents of bioactive compounds such as vitamin C, phenolic compounds, flavonoids and antioxidant activity of five hybrid the yellow passion fruit tart cultivar. The main results of this study was to visualize distinct kinetic behaviors of the same enzyme in hybrids studied and higher levels... (Complete abstract click electronic access below)

Orientador: Maria Lúcia Gonsales da Costa Araújo / Banca: Álvaro de Baptista Neto / Banca: Rosineide Gomes da Silva Cruz / Resumo: Streptomyces clavuligerus produz importantes Compostos -lactâmicos como: a holomicina (Hol), importante membro da classe pirrotina de antibióticos; cefamicina C (CefC), utilizada como matéria prima para a produção de antibióticos semi-sintéticos de amplo espectro, aplicados na prevenção de infecções pós-operatórias graves; além do ácido clavulânico (AC), inibidor de β-lactamases produzido por bactérias resistentes a penicilinas. A elevada instabilidade genética de S. clavuligerus resulta, com frequência, em deleções de trechos do DNA cromossomal que são, em sua maioria, associados à capacidade de esporulação e a produção de metabolitos secundários. Tais estados mutadores indesejáveis normalmente são potencializados por condições limite, como a mudanças bruscas de temperatura e pH, a presença de certos compostos, entre outros fatores, que podem ocorrer em qualquer etapa de manuseio/cultivo do microrganismo. Por outro lado, certas condições adversas ao crescimento durante a fermentação favorecem a produção de metabólitos secundários. Assim, a indústria da fermentação tem investido na busca de condições favoráveis de crescimento celular que permitam favorecer a produção. Para isto, é necessário dispor de estoque de células estáveis e produtivas, cuja integridade genética permita obter dados reprodutíveis e confiáveis. Deste modo, o presente trabalho teve por objetivo melhorar as condições de cultivo de S. clavuligerus, definindo-se um meio padrão de cultivo em batelada contendo nutrientes cuja presença favoreceu a produção de um determinado bioativo (CefC, AC ou Hol), tanto pela linhagem selvagem quanto pelas mutantes. Ainda, comparou-se a produção de Hol pelos mutantes utilizando-se como inóculo esporos estocados em criotubos (-80ºC) e suspensão fresca de esporos. / Abstract: Streptomyces clavuligerus produces important β-lactam compounds such as: holomycin (Hol), pirrotina an important member of the class of antibiotics; cephamycin C (CefC), used as raw material for the production of semi-synthetic broad-spectrum antibiotics, applied in the prevention of severe postoperative infections; lastly, clavulanic acid (AC) inhibitor, β-lactamases produced by bacteria resistant to penicillins. The high genetic instability of S. clavuligerus often results in chromosomal deletions of stretches of DNA that are mostly associated with the sporulation capacity and production of secondary metabolites. Mutators such undesirable states are usually exacerbated by boundary conditions, such as sudden changes in temperature and pH, the presence of certain compounds, among other factors, which may occur at any stage of handling/cultivation of the microorganism. On the other hand, certain adverse conditions promote growth during fermentation production of secondary metabolites. Thus, the present study aimed to improve the cultivation of S. clavuligerus, defining a means cropping pattern batch containing nutrients whose presence favored the production of a bioactive determined (CEFC, AC or Hol), both by wild type as well as the mutant strain. Still, compared to the production of Hol mutants using inoculum spores stored in cryotubes (-80 ° C) and fresh spore suspension. / Mestre

Orientador: Glaucia Maria Pastore / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-27T14:34:07Z (GMT). No. of bitstreams: 1 Santos_MichelleTeixeira_M.pdf: 1463009 bytes, checksum: 0c5abfd78d15e4538a9e205ff81e3046 (MD5) Previous issue date: 2015 / Resumo: Cresce o número de consumidores que optam por hábitos mais saudáveis e melhor qualidade de vida, incluindo em sua dieta alimentos que exerçam funções essenciais para a promoção da saúde e prevenção de doenças. O Brasil possui uma das maiores biodiversidades do planeta, com fontes inexploráveis de alimentos, como frutas exóticas ricas em compostos bioativos com funções diversas e complementares. Neste sentido, o presente trabalho buscou investigar o potencial prebiótico e a presença de compostos antioxidante em frutas exóticas da Mata Atlântica como o Cambuí Roxo (Eugenia candolleana), Araçá Una (Psidium eugeniaefolia) e Araçá Morango (Psidium guianensis). A extração etanólica apresentou melhor performance em relação à analise dos oligossacarídeos nas frutas. A concentração de oligossacarídeos totais nestes extratos foi em media de 44; 14 e 46 mg/100g de fruta para Cambuí roxo, Araçá una e Araçá morango, respectivamente, sendo verificada através de cromatografia de íons acoplada a detector amperiométrico pulsado. Os oligossacarídeos que se destacaram na composição das frutas foram os fruto-oligossacarídeos GF2, a estaquiose e a maltotriose. Foi observado ao microscópio a formação de aglomerados e formações celulares do tipo rede nos cultivos indicando a formação de exopolissacarídeo por Lactobacilos acidophilus em meio enriquecido com os extratos da frutas analisadas. A produção máxima de EPS foi verificada em 24h de cultivo sendo de 45,39; 41,90 e 17,16 mg/100g de meio para o Cambuí roxo, Araçá una e Araçá morango, respectivamente. A concentração de fenólicos para as extrações alcoólicas foi em média de 685; 395 e 361 mg de ácido gálico/100g de fruta, respectivamente para o Cambuí roxo, Araçá una e Araçá morango. Os extratos das frutas exóticas da Mata Atlântica foram avaliados, ainda quanto à capacidade antioxidante in vitro através do método Oxygen Radical Absorbance Capacity (ORAC) apresentando teores médios de 3.212; 2.065 e 2.641µM Trolox equivalente/100g de fruta para Cambuí roxo, Araçá una e Araçá morango, nesta ordem. A importância da pesquisa de compostos bioquímicos em frutas exóticas tem como objetivo, além de populariza-las, promover uma maior variedade de alimentos, novos sabores, aliado a componentes funcionais que exercem benefícios, tais como atividade prebiótica no intestino humano e atividade antioxidante, principal causa de envelhecimento celular. Os resultados desta pesquisa mostram a riqueza de componentes que podem ser explorados destas frutas / Abstract: A growing number of consumers who choose for good health and better quality of life, including in your diet foods that acts essential functions for health promotion and disease prevention. Brazil has one of the greatest biodiversity on the planet with unusable food sources, such as exotic fruits rich in bioactive compounds with different and complementary functions. In this sense, the present study investigated the prebiotic potential and the presence of antioxidant compounds in exotic fruits of the Atlantic Forest as Cambuí roxo (Eugenia candolleana), Araçá una (Psidium eugeniaefolia) and Araçá morango (Psidium guianensis). The ethanol extract showed better performance in relation to the analysis of oligosaccharides in fruits. The concentration of total oligosaccharides in these extracts was an average of 44; 14:46 mg/100g of fruit to Cambuí roxo, Araçá una and Araçá roxo, respectively, and verified by ion chromatography coupled with pulsed amperiométrico detector. Oligosaccharides that stood out in the composition of fruit were the fructo-oligosaccharides GF2, stachyose and maltotriose. It was observed under the microscope the formation of agglomerates and mobile network type formations on crops indicating the formation of exopolysaccharide by Lactobacillus acidophilus amid enriched with extracts of fruit analyzed. The maximum production of EPS was observed in 24 hours of cultivation being 45.39; 41.90 and 17.16 mg/100g medium for purple Cambuí roxo, Araçá una and Araçá morango respectively. The concentration of phenolic for alcoholic extractions averaged 685; 395 and 361 mg of AG/100 g of fruit, respectively for purple Cambuí roxo, Araçá una and Araçá morango. The extracts of exotic fruits of the Atlantic Forest were evaluated, even as the antioxidant capacity in vitro through the Oxygen Radical Absorbance Capacity method (ORAC) having average levels of 3,212; 2065 and 2.641?M Trolox equivalent/100 g of fruit to purple Cambuí roxo, Araçá una and Araçá morango, in that order. The importance of research biochemicals in exotic fruits, aims, and popularized them, promote greater variety of foods, new flavors, combined with functional components that exercise benefits such as prebiotic activity in the human gut and antioxidant activity, leading cause of cellular aging. The results of this research show the richness of components that can be exploited these fruits / Mestrado / Ciência de Alimentos / Mestra em Ciência de Alimentos

Bioassay directed fractionation of the methyl ethyl ketone extract of Crescentia cujete resulted in the isolation of nine bioactive compounds, and detailed spectroscopic interpretation led to the assignment of their structures as (2S,3S)-3-hydroxy-5,6-dimethoxy dehydroiso-α-Iapachone [2.10], (2R)-5,6- dimethoxydehydroiso-α-Iapachone [2.11], (2R)-5-methoxy dehydroiso-alapachone [2.12], 5-hydroxy-2-(1'-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.13], 2-(1 '-hydroxyethyl)naphtho[2,3-b ]furan-4,9-dione [2.14]' 2-isopropenylnaphtho[ 2,3-b ]furan-4,9-dione [2.15], 5-hydroxydehydro-iso-a-Iapachone [2.16], 3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.17], and 9- hydroxy-3-hydroxymethylfuro[3,2-b ]naphtho[2,3-d]furan-5,10-dione [2.18]. Compounds 2.10-2.12 are new, showing selective activity towards DNA repair-deficient yeast mutants. The selective DNA damaging activity of known compounds 2.13-2.16 is reported herein for the first time. Compounds 2.17 and 2.18 also show DNA damaging activity, and possess a novel fused ring system. The bioactive sterols ergosta-5-24(28)-diene-3β,7α-diol [3.1] and 24,28- epoxyergost-5-ene-3β,7α-diol [3.2], originally isolated from <i>Pseudobersama mossambicensis</i>, have been synthesized from stigmasterol. In addition to these sterols, some of their analogs were prepared, and the bioactivity of all compounds were assessed. / Ph. D.

This dissertation is concerned with the metabolic bioactivation of several amines which are either known or suspected to be neurotoxic and with the exploration of bioactivation processes in order to generate metabolites with therapeutic potential. The following three programs were pursued in this work: (1) Theoretical considerations and recent experimental data have prompted an investigation of the neurotoxicological properties of the 6-hydroxydopamine analog 2-methylamino-1-(2,4,5-trihydroxyphenyl) propane and its possible precursor intermediate 1-(2-hydroxy-4,5-methylenedioxyphenyl)-2-methylaminopropane, potential metabolites of the serotonergic neurotoxin 2-methylamino- 1-(4,5-methylenedioxyphenyl)propane, (Methylenedioxymethamphetamine, MDMA). The syntheses and serotonergic neurotoxic properties of the potential metabolites are discussed. (2) The further biotransformation of the 1-(1-phenylcyclohexy!)- 3,4,5,6-tetrahydropyridinium metabolite derived from_ the psychosis inducing agent phencyclidine [1-(1-phenylcyclohexy]l)- piperidine, PCP] has been examined in rat liver and brain subcellular fractions. In the presence of brain mitochondria this tetrahydropyridinium compound was converted to 1-(phenylcyclohexyl)- 1,2,3,4-tetrahydropyridine-5-carboxaldehyde. The same product was identified in the corresponding liver mitochondrial and microsomal incubation mixtures and in liver microsomal incubations of phencyclidine. The chemical conversion of the synthetic tetra hydropyridinium perchlorate to this product by N⁵-formyltetrahydrofolic acid (folinic acid) suggests that the metabolic reaction is mediated by a transformylation process involving this or the corresponding N¹⁰-formyltetrahydrofolic acid. (3) Extensive substrate-activity studies have established that only those 1,2,3,6-tetrahydropyridine derivatives bearing a lipophilic C-4 substituent and an N-methyl group are likely to be good monoamine oxidase B substrates. The design and synthesis of potential prodrugs based on this enzyme-substrate selectivity has been pursued with model compounds. / Ph. D.

Thesis (M.Phil.) - University of Queensland, 2006. / Includes bibliography.

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / Orthopaedics and Traumatology / Doctoral / Doctor of Philosophy

Submitted in complete fulfillment for the degree of Doctor of Philosophy (Food Science and Technology), Durban University of Technology, Durban, South Africa, 2016. / Bambara groundnut (Vigna substerranea) is an indigenous legume of African origin which is currently experiencing a low level utilisation. It is tolerant to drought and can grow under poor soil conditions in which other lucrative crops such as groundnut cannot grow. Bambara is a good source of protein comparable to that of cowpea and slightly lower than soya bean. In order to assess the potential use of bambara protein as a functional ingredient in food systems and as an important ingredient for the formulation of therapeutic product, the knowledge of its protein composition, structure and functionality becomes important. The main goal of this thesis was to determine the composition and bioactive properties of bambara protein and its hydrolysates. Specifically, a comparative study was carried out on the protein content, yield and functional properties of protein concentrates prepared from three different bambara landraces using different extraction methods (Salt solubilisation and Acid precipitation). There was no significant difference in protein content, yield and functional properties of the landraces. However, the method of extraction had an influence on their physicochemical and functional properties. Acid precipitation produced bambara protein concentrates with high protein content and yield (79% and 52% respectively) when compared to salt solubilisation (protein content - 57% and yield - 25%). Protein concentrates prepared through salt solubilisation method exhibited better functional properties in terms of water absorption capacity, oil absorption capacity, foaming capacity, foaming stability and emulsion activities when compared to concentrates obtained through acid precipitation. Furthermore, the composition of bambara proteins produced through isoelectric precipitation was determined. SDS PAGE revealed four major bands; a broad band at 55 kDa which was analysed to be vicilin, two medium bands at 62 kDa and 80 kDa and a high molecular weight (HMW) protein at 141 kDa. Further investigation of bambara protein revealed vicilin (55 kDa) with two sub units as the major protein in bambara and this was also confirmed by the proteomic map. The proteomic map revealed acidic amino acids as the major protein of bambara which is characteristic of vicilin, the map also showed that there were differences in the number of spots across the landraces with 77 spots matching each other. Circular dichroism spectroscopy exhibited reductions in α-helix, and β-pleated sheet conformations as pH varies. In addition, the tertiary structures as observed from the near-UV CD spectra were also influenced by shifts in pH conditions. Differential scanning calorimetry thermograms showed two endothermic peaks at around 67 and 81oC respectively. These can be attributed to thermal denaturation of vicilin and the HMW protein. Subsequent studies used isolates from red bambara since the composition of the landraces were similar. Bambara protein isolate was subjected to enzymatic hydrolysis using three proteases (alcalase, pepsin and trypsin) to produce various bambara protein hydrolysates (BPHs). BPHs were investigated for antioxidant and antihypertensive activities. The in vitro structural and functional characteristics of bambara protein and its enzymatic protein hydrolysate revealed that bambara groundnut possessed antioxidant properties against a variety of physiologically relevant free radicals. High surface hydrophobicity and the molecular size of the peptide seem to be important for scavenging of hydroxyl radicals, ferric reducing power and metal chelation. BPHs and peptide fractions were able to scavenge DPPH radicals with greater affinity for smaller size. Less than 1 and 1-3 kDa pepsin fraction was able to scavenge DPPH radical more than glutathione, BPHs and its fractions scavenge ABTS•+ three folds than the isolate. Scavenging of superoxide radicals was generally weak except for 5-10 kDa peptide fractions. All BPHs inhibited linolenic acid oxidation with greater affinity for the lower molecular size peptide. BPHs showed potential antihypertensive properties because of the in vitro inhibition of activities of angiotensin converting enzyme (ACE) and renin inhibition. The molecular size had significant effect on the ACE inhibitory properties with low molecular weight peptide (<1 kDa) fractions exhibiting significantly higher (p<0.05) inhibitory activities. However, enzyme type had synergistic effects on renin inhibition with alcalase hydrolysate showing highest inhibition at 59% when compared to other hydrolysates and their membrane fractions. The fractions with <1 and 1-3 kDa peptides showed a higher potential as antihypertensive and antioxidant peptides. Based on this study, incorporation of bambara protein isolate as an ingredient may be useful for the manufacture of high quality food products. Likewise, the bambara protein hydrolysates, especially the <1 kDa and 1-3 kDa fraction represent a potential source of bioactive peptides in formulating functional foods and nutraceuticals. / D