Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Chemistry in the Faculty of Applied Science at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2014 / Crystal engineering based upon acid: base compounds have been studied in this thesis. Selected phenolic acids such as: vanillic acid (VA), phenylacetic acid (PAA), 4-hydroxyphenylacetic acid (HPAA), 3-chloro-4-hydroxyphenylacetic acid (CHPAA), caffeic acid (CFA), p-coumaric acid (pCA), trans-ferulic acid (tFER), 2-phenylpropionic acid (PPA) and 2-phenylbutyric acid (PBA) were the main compounds investigated. These phenolic acids have formed co-crystals/co-crystal hydrates, salts/salt hydrates and hybrid salt-co-crystals with acridine (ACRI), caffeine (CAF), cinchonidine (CIND), isonicotinamide (INM), isonicotinic acid (INA), nicotinamide (NAM), quinidine (QUID), quinine (QUIN), theobromine (THBR), theophylline (THPH) and urea (U). The two racemic compounds 2-phenylpropionic acid (PPA) and 2-phenylbutyric acid (PBA) were used to study chiral discrimination leading to the understanding of separation enantiomers. Compounds were prepared in different solvents (alcohols, ketone and distilled water) to investigate the relationship between solvents used and the crystalline product obtained. (If there is any effect on the crystalline compound obtained by changing the solvent). The structures were elucidated using single crystal X-ray diffraction. Ground products of obtained compounds were characterized by powder X-ray diffraction (PXRD). Thermal analyses like thermogravimetry (TG), differential scanning calorimetry (DSC) and hot stage microscopy (HSM) were used for the determination of thermal character of the new compounds. IR was also performed to characterize the new compounds. Non-isothermal TG was utilised to obtain kinetic parameters for the water and the methanol release in (pCA−)(QUIN+)•pCA•MeOH•H2O. A selective experiment was done in which quinidine and quinine were used to compete between selected phenolic acids (PAA and HPAA). viii The comparison of the crystal structures determined showed that, changing the phenolic acid while using the same co-crystal former has a significant effect on the type of compounds obtained. The obtained crystal structures were either co-crystal/co-crystal hydrates, salts/salt hydrates or hybrid salt-co-crystals which formed network via means of supramolecular interactions.

Orientador: Célia Maria de Sylos / Banca: Patricia Maria Vieira / Banca: Luis Vitor Silva do Sacramento / Resumo: O consumo regular de frutas, hortaliças e grãos com altos teores de substâncias antioxidantes, como os compostos fenólicos, vitamina C e Carotenoides, tem sido associado a diversos benefícios à saúde humana. Sua presença na alimentação pode auxiliar na proteção do organismo contra o estresse oxidativo, evitando e prevenindo assim, uma série de distúrbios crônico-degenerativos. Em vegetais pode ocorrer variação no conteúdo de compostos bioativos, dependendo da variedade genética, condições de cultivo, clima, estádio de maturação e fatores de pós-colheita. O objetivo deste trabalho foi avaliar três cultivares de alface (Lactuca sativa L.), sendo elas a alface americana, crespa e lisa, e também três variedades de condimentos, sendo eles o coentro (Coriandrum sativum L.), a salsa (Petroselinum crispum, (Mill.) Nym.) e a cebolinha (Allium fistulosum L.) cultivados em dois períodos quanto ao conteúdo de compostos fenólicos totais (CFT), capacidade antioxidante total (CAT), ácidos fenólicos e flavonoides, clorofilas e Carotenoides. Três lotes de cada amostra foram adquiridos no comércio local de Araraquara-SP em dois períodos de cultivo: agosto de 2013 [1º período]; e janeiro/fevereiro de 2014 [2º período] e suas folhas (partes comestíveis) foram secas para as determinações. As análises foram realizadas individualmente em triplicata e os resultados expressos em média ± desvio padrão. O coentro, a alface lisa e a alface crespa apresentaram teores elevados de CFT e CAT. Poucas hortaliças apresentaram diferença entre o período de cultivo nas análises realizadas, com destaque para o coentro. O teor de clorofila total dos condimentos foi maior nas amostras analisadas no 2º período. Entre as três variedades de alface, a alface crespa apresentou os maiores teores de CFT e CAT enquanto que a alface americana apresentou os menores. Conclui-se que é de grande importância o conhecimento dos diferentes... / Abstract: Regular consumption of fruits, vegetables and grains rich in antioxidants, such as phenolic compounds, vitamin C and carotenoids, has been associated with many benefits to human health. His presence in the diet can help in protecting the body against oxidative stress, avoiding and preventing so, a number of chronic degenerative disorders. In plants there can be variations in the content of bioactive compounds, depending on the genetic variety, growing conditions, climate, maturity stage and postharvest factors. The objective of this study was to evaluate three lettuce cultivars (Lactuca sativa L.), which were the lettuce american, curly and smooth, and also three varieties of condiments, coriander (Coriandrum sativum L.), parsley (Petroselinum crispum (Mill.) Nym.) and spring onion (Allium fistulosum L.) cultivation in two periods on the content of phenolic compounds (TPC), total antioxidant capacity (TAC), phenolic acids and flavonoids, chlorophyll and carotenoids. Three lots of each sample were acquired in the local market of Araraquara-SP in two cultivation periods: August 2013 [1º period]; and January/February 2014 [2º period] and its leaves (edible parts) were dried for determination. Analyses were performed individually in triplicate and the results expressed as mean ± standard deviation. Coriander, Smooth lettuce and Curly lettuce showed high levels of and TAC. Few vegetables showed differences between the cultivation period in the analyzes, especially coriander. The total chlorophyll content of condiments was higher in the samples analyzed in the 2º period. Among the three varieties of lettuce, the curly lettuce showed the highest TPC and TAC levels while the cabbage lettuce had the lowest. It follows that it is of great importance to know the different bioactive compounds present in the vegetables and the variation of their content in the analyzed cultivation ... / Mestre

It is generally accepted that biological membranes consist of a lipid bilayer matrix with proteins incorporated into the lipid bilayer. Typically, these membranes are negatively charged due to the presence of negatively charged lipids in the bilayer as well as negatively charged molecular groups on proteins. Biologically active molecules, such as environmental pollutants, enter the membrane from the aqueous phase by adsorption or partitioning into the lipid bilayer. The thesis consists of two parts. Part I is a computational study of spatial distribution of electric potential in the aqueous portion of the membrane-water interface using two models of charge distribution: (i) the discrete charge model, in which charges are located on a square lattice either on the surface or embedded in the membrane: (ii) the continuous charge density (smeared charge), Gouy-Chapman, model in which the charge is assumed to be evenly spread on the membrane surface. The computed distributions of electric potential are used to predict spatial distributions of positively charged hexavalent cation of Ruthenium Red (RuR) at the membranewater interface. It was found that anomalous behavior of RuR cannot be explained by this version of the discrete charge theory. Part II is concerned with the distribution of ionized and un-ionized species of 2,4,6-Trichlorophenol (2,4,6-TrCP) in octanol-water system, which is often used as an experimental model for predicting the distribution of toxic chemicals in the environment. In this experimental study we obtained the pH dependence of the total distribution coefficient of 2,4,6-TrCP from which the octanol water partition coefficients of the un-ionized and ionized species were determined. We compared the octanol-water partition coefficient of several chlorophenols with experimental data on adsorption of ionized chlorophenols to lipid membranes. It was found that the membrane-water partition coefficient of ionized 2,4,6-TrCP is about 240 greater than that predicted from the octanol-water system. This finding supports the hypothesis that octanol-water partition coefficients cannot be used for predicting concentrations of ionized species of chlorophenols in lipid membranes.

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"October 2002" / Includes bibliographical references (leaves 172-183) / x, 183 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 2002

Bibliography: leaves 195-209. / xxvi, 209 leaves : ill., ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study investigated seed development, phenolic composition of seeds and skins, and phenolic composition and sensory properties of wines made from berries of Vitis Vinifera L. cv. Shiraz that were developed and ripened under different levels of sunlight intensity at the bunch zone. The study also examined the relationships between seed and berry development, and the links between berry composition, wine composition and wine sensory properties. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Wine and Horticulture, 2004

Thesis (M.Sc.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 63-67.

Thesis (Ph.D.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 203-239.

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