Plant estrogens have long been associated with health benefits. The potential of tissue culture techniques for the production of several secondary metabolites has been known for many years. Tissue cultures stimulate the production or induce the biosynthesis of novel compounds not found in the mature plant. Tissue culture of Morus alba, family Moraceae, is known to contain phytoestrogens, was established on plant-hormone supplemented Murashige and Skoog (MS) medium. Petiole and the stem tissue from mature trees were the best explants for initiation and proliferation of calli. The best callus proliferation was obtained on MS medium containing 1-napthalene acetic acid (1mg/ml) and benzylaminopurine (0.5mg/ml) for M. alba. Comparison of phytoestrogens of Moraceae species from in vivo and in vitro tissue isolation were carried out. The estrogenic activities of callus extracts were assayed in an estrogen-responsive yeast system expressing the human estrogen receptor alpha. Male callus extracts had higher estrogenic activity than male and female extracts from in vivo and in vitro tissues. Isolation and characterization of phytoestrogens from above tissues were carried out using solid phase extraction, high perfomance liquid chromatography and mass spectrometry techniques. Biochanin A, an isoflavonoid, was isolated as one of the compounds in male callus extracts. Biochanin A has been known to have an antiestrogenic acitivity in mammals. Isoflavonoid compounds have been characterized as strong protein tyrosine kinase inhibitors in variety of animal cells. Isoflavones are structurally similar to estradiol, and display agonistic and antagonistic interactions with the estrogen receptor. Isoflavones possess therapeutic and preventive properties such as being used for postmenopausal osteoporosis, breast cancer, and inhibition of tumors.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-08-04T13:34:48Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE - Waleska de Araújo Siqueira Bento - Versão final.pdf: 3392903 bytes, checksum: 633a749c72e4eb3f1d0e4f6b0f0c0b83 (MD5) / Made available in DSpace on 2017-08-04T13:34:48Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE - Waleska de Araújo Siqueira Bento - Versão final.pdf: 3392903 bytes, checksum: 633a749c72e4eb3f1d0e4f6b0f0c0b83 (MD5) Previous issue date: 2016-03-11 / O desenvolvimento de métodos de preparo de amostras é de suma importância para a análise química. Ao longo dos anos, cada vez mais os cientistas buscam técnicas para aprimorar metodologias e ferramentas matemáticas para a validação dos métodos desenvolvidos. No presente trabalho foram desenvolvidos dois diferentes métodos de preparo de amostras: um para a análise de corantes artificiais em iogurtes e posterior análise por HPLC-PAD e outro método utilizando a técnica de CE-UV/Vis para separar e fracionar amostras padrões de misturas de proteínas, seguido de um método para digestão destas e análise por LC-ESI-MS para posterior mapeamento dos peptídeos. O primeiro trabalho foi realizado para determinar a concentração de corantes artificiais em iogurtes e bebidas lácteas que são alimentos produzidos a partir da fermentação do leite sendo um alimento importante e indispensável a dieta de adultos e crianças. Para tanto foi desenvolvido um método de extração e determinação de corantes artificiais em iogurtes e bebidas lácteas por HPLC-PAD. O método foi devidamente validado e as amostras comerciais analisadas estavam de acordo com a legislação. Já o segundo trabalho visa o estudo da proteômica através do mapeamento de peptídeos. A eletroforese capilar (CE) por ser uma técnica de separação muito eficiente para a análise de proteínas e peptídeos foi utilizada na etapa inicial de preparo da amostra. A separação inicial foi seguida do fracionamento da amostra que é uma etapa muito importante e que a CE pode proporcionar, minimizando a complexidade da amostra. Posteriormente foi desenvolvido um método para a digestão das proteínas contidas em cada fração e o mapeamento dos peptídeos foi realizado com auxílio do LC-ESI-MS. Os resultados obtidos são animadores, visto que foi possível digerir as proteínas com quimotripsina em até duas horas. O que é um tempo curto se comparado a trabalhos da literatura que necessitaram de 12 a 24 horas para digestão de proteínas quando utilizadas enzimas livres em solução. / The development of sample preparation methods is of paramount importance for analytical chemistry. Over the years, more and more scientists are seeking techniques to improve methodologies and mathematical tools for the validation of the methods they have developed. In this study two different methods of sample preparation were developed: one for analysis of artificial colorants in yogurts and subsequent analysis by HPLC-PAD; and another method using the CE-UV/Vis technique to separate and fractionate standard samples of protein mixtures, followed by a digestion method for these and analysis by LCESI-MS for subsequent peptides mapping. The first study was conducted to determine the concentration of artificial colorant in yoghurts and milk drinks, foods produced from the fermentation of milk that are an important and indispensable part of the food diet for adults and children. To this end, a method was developed for the extraction and determination of artificial colorant in HPLC-PAD yoghurts and milk drinks. The method was validated and commercial samples were analyzed according to the legislation. The second work is aimed at the study of proteomics by peptide mapping. Capillary electrophoresis (CE) as an effective separation technique was used in the initial stage of sample preparation for the anaysis of proteins and peptides. The initial separation was followed by fractionation of the sample which is a very important step enabled by CE, thus minimizing sample complexity. Then, a method was developed to digest the proteins contained in each fraction and the mapping of the peptides was carried out with the aid of LC-ESI-MS. The results obtained are encouraging, since the study showed that it was possible to digest proteins with free chymotrypsin within two hours. This is a short time compared to that found in the published papers requiring 12 to 24 hours for protein digestion when free enzymes in solution are used.

No description available.

Over the past decades, electrospray ionization for mass spectrometry (ESI-MS) has become one of the most commonly employed techniques in analytical chemistry, mainly due to its broad applicability to polar and semipolar compounds and the superior selectivity which is achieved in combination with high resolution separation techniques. However, responsiveness of an analytical method also determines its suitability for the quantitation of chemical compounds; and in electrospray ionization for mass spectrometry, it can vary significantly among different analytes with identical solution concentrations. Therefore, we investigated the ESI-response behavior of 56 nitrogen-containing compounds including aromatic amines and pyridines, two compound classes of high importance to both, synthetic organic chemistry as well as to pharmaceutical sciences. These compounds are increasingly analyzed employing ESI mass spectrometry detection due to their polar, basic character. Signal intensities of the peaks from the protonated molecular ion (MH+) were acquired under different conditions and related to compound properties such as basicity, polarity, volatility and molecular size exploring their quantitative impact on ionization efficiency. As a result, we found that though solution basicity of a compound is the main factor initially determining the ESI response of the protonated molecular ion, other factors such as polarity and vaporability become more important under acidic solvent conditions and may nearly outweigh the importance of basicity under these conditions. Moreover, we show that different molecular descriptors may become important when using different types of instruments for such investigations, a fact not detailed so far in the available literature.

No description available.

Molecular recognition, particularly as it applies to strong binding interactions between complementary ligand/receptor molecules in solution, is important in such varied areas as molecular biology, pharmacology, synthetic chemistry, and chemical detection. Strong binding is the additive result of a number of specific, weak, non-covalent interactions occurring between complementary molecules. This dissertation reports on the energetics of forming complexes between small molecules and model DNA constructs. Ligands included cationic and metallated cationic porphyrins and polyheterocyclic ruthenium compounds. DNA receptors included double stranded B-DNAs (hairpin and short linear sequences) as well G-quadruplex DNAs. Thermodynamic data were collected using isothermal titration calorimetry, circular dichroism spectropolarimetry, ultraviolet-visible spectroscopy, and mass spectrometry. The measured thermodynamic parameters included the changes in free energy, enthalpy and entropy for ligand/receptor complex formation as well as the stoichiometry of the stable complexes. The first section of this dissertation reports that the binding of cationic porphyrins to model G-quadruplex DNA may proceed through two pathways, end stacking and intercalation. Modulating the number of pyridinium groups on a pyridinium substituted porphyrin yielded differing binding thermodynamics leading to the understanding that a balance of surface area, charge, and geometry affect the ability of a porphyrin to bind to G-quadruplex DNA. Further investigations into the binding of metallated porphyrins developed the understanding that the geometry of the central metal ion affected not only the thermodynamics but could also inhibit the intercalative mode. It was previously shown that the high affinity binding for binuclear polyheterocyclic ruthenium compounds proceeds through an intercalative mode. To further understand the binding process and the structureunction relationship of the ligand components, the binding of smaller mononuclear complexes that were representative of portions of the binuclear complex was examined in this dissertation. While limiting the intercalative ability lowered the binding affinity, the mononuclear complex with the full intercalating bridge was able bind to DNA with a higher affinity than the binuclear complex. These studies have been successful in part in determining the contributions of numerous weak interactions including: charge (Coulombic interactions), H-bonding, hydrophobic interactions, and solvent structure (solvation changes), to the overall energetics of this molecular recognition process. The first section of this dissertation reports that the binding of cationic porphyrins to model G-quadruplex DNA may proceed through two pathways, end stacking and intercalation. Modulating the number of pyridinium groups on a pyridinium substituted porphyrin yielded differing binding thermodynamics leading to the understanding that a balance of surface area, charge, and geometry affect the ability of a porphyrin to bind to G-quadruplex DNA. Further investigations into the binding of metallated porphyrins developed the understanding that the geometry of the central metal ion affected not only the thermodynamics but could also inhibit the intercalative mode. It was previously shown that the high affinity binding for binuclear polyheterocyclic ruthenium compounds proceeds through intercalation. To further understand the binding process and the structureunction relationship of the ligand components, the binding of smaller mononuclear complexes that were representative of portions of the binuclear complex was examined in this dissertation. While limiting the intercalative ability lowered the binding affinity, the mononuclear complex with the full intercalating bridge was able bind to DNA with a higher affinity than the binuclear complex. These studies have been successful in part in determining the contributions of numerous weak interactions including: charge (Coulombic interactions), H-bonding, hydrophobic interactions, and solvent structure (solvation changes), to the overall energetics of this molecular recognition process.

Research was conducted on thirteen 100% cotton denim samples using an acid wash, established by Murray, to extract oligosaccharides from the cellulosic material. The oligosaccharide ion groups (+, +, and +) for molecules with degrees of polymerization between two and seven (DP2-DP7) were analyzed using liquid chromatography coupled to mass spectrometry with an electrospray ionization interface (LC-ESI-MS). The results were compared using the least-squares means in a Multivariate ANOVA (MANOVA) test followed by Univariate ANOVA and Tukey HSD tests and demonstrated that the method could correctly determine that two samples were statistically different 85.9% of the time when analyzing the amount (ng) of each of the oligosaccharide ion groups separately, and 82.0% when analyzing the total moles of monosaccharide units released. A dye extraction was performed on the denim materials and the extract analyzed using gas chromatography coupled with mass spectrometry (GC-MS). Indigo dye was present in all of the denim samples except one. When these results were combined with the two oligosaccharide statistical analyses, the discriminating power was increased to 88.5% and 85.9%, respectively. Additional cellulosic materials were also investigated including four white 100% cotton t-shirts as well as five raw cotton samples grown in Tajikistan, Uzbekistan, Egypt, Iran, and Benin West Africa. The analytical methodology gave results for the white cotton t-shirts and raw cotton samples that were inconsistent with those obtained from the denim samples.

The work in this thesis has demonstrated the chiral recognition through the adaptation of chromatographically derived chiral recognition systems by electrospray ionization mass spectrometry (ESI-MS). Mass-labeled, pseudoenantiomeric chiral selectors (where each pseudoenantiomer had the opposite stereochemistry, but was slightly different in mass due to labeling of one enantiomer) were prepared as soluble analogues of Pirkle type chiral stationary phases. When mixed with a chiral analyte, solutions containing these pseudoenantiomeric selectors afforded selector-analyte complexes in the ESI-MS, and the relative peak intensities of the complexes could be related back to the enantiomeric composition of the analyte. In each case of this study, the complex intensity fraction for either of the selector-analyte complexes in the ESI-MS varies linearly with the enantiomeric composition of the analyte. This linear relationship provides a measure of the extent of enantioselectivity and allows quantitative analysis of the enantiomeric composition of analyte.

No description available.

No description available.