Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 270-288). Also available on the World Wide Web.

The Asteraceae family is frequently used to describe several medicinal plants which contain various phytochemical compounds including phenols, flavonoids and terpenoids. Among the Asteraceae family German chamomile (Matricaria chamomilla L.) and yarrow (Achillea millefolium L.) plants are extant species used in contemporary medicine. These phytochemical compounds have been traditionally used since ancient times in health care systems worldwide as a source of medicines. The use of micropropagation is essential to improve and increase these active compounds via plant tissue culture within a short period of time using the application of key plant growth regulators (PGRs). Furthermore, quantitative and qualitative analysis using high performance liquid chromatography- ultraviolet detector (HPLC-UV) and gas chromatography- flame ionisation detector (GC-FID) of potential medicinal compounds expressed by both chamomile and yarrow are important points. The protocol of in vitro shoots, roots and callus formation of chamomile and yarrow seeds culture were investigated using Murashige and Skoog (MS) medium supplemented with different concentrations of plant growth regulators (PGRs). MS culture medium containing 0.5 mgL-1 IAA and 1.0 mgL-1 of GA3 were found to be the best culture medium for chamomile and yarrow seeds. In this project in vitro and in vivo growth rates of selected plant species were also investigated. In the earlier growth stages yarrow plants were found to grow much quicker than chamomile, while the yield of chamomile flowers was significantly (p ≤ 0.001) more than yarrow flowers. The phenolic, flavonoid and terpenoid compounds content of leaves and flowers of plants produced from both cultures were also studied. HPLC-UV analysis showed that chlorogenic acid, apigenin-7-O-glucoside and luteolin dominated as the main phenol and flavonoid compounds recovered in both in vitro and in vivo chamomile and yarrow cultures. However, GC-FID analysis indicated that farnesene and nerolidol were detected as the main terpenoid compounds present in the two culture conditions used to grow chamomile and yarrow plants. Moreover, this research examines how chamomile and yarrow plants can produce and improve their phytochemical compounds content not only under well-watered conditions but also under drought stress conditions. The main phenol and flavonoid compounds of chlorogenic acid, caffeic acid, apig-7-glucoside, umbelliferon and luteolin were found in chamomile and yarrow varieties grown under both well-watered and drought stress conditions using (HPLC-UV), however farnesene, nerolidol, chamazulene, α-(-)- bisabol and bisabolol oxide A were observed in the plant essential oils (EOs) using Soxhlet extraction and GC-FID analysis. The antibacterial activity of plant EOs was also investigated using disc diffusion and 96 well plates. In vivo chamomile EO showed the highest antibacterial activity against gram-positive and gram-negative bacteria strains. In addition, in vitro yarrow EO showed the greatest effect on the death of bacteria strains.

Made available in DSpace on 2015-08-20T17:10:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-27. Added 1 bitstream(s) on 2015-08-20T17:25:53Z : No. of bitstreams: 1 000840367_20160601.pdf: 108814 bytes, checksum: 71703ce0ff9e91fa2739e86d0b3b6a4b (MD5) Bitstreams deleted on 2016-06-02T14:22:25Z: 000840367_20160601.pdf,. Added 1 bitstream(s) on 2016-06-02T14:23:08Z : No. of bitstreams: 1 000840367.pdf: 636107 bytes, checksum: 8ac9a4b0c7f07da9a4cd86bede060d5a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / 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... / 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 ...

The oxidation kinetics of m-substituted phenols by TiO2/UV were investigated. An attempt was made to correlate Swain-Lupton parameters (R) for aromatic substituents with the oxidation kinetic constants, based upon molecular structure and reactivity theory. Irradiation experiments were carried out with suspended aqueous TiO 2 powder and substrate mixture in a Rayonet Photochemical Reactor. Langmuir-Hinshelwood model was applied to obtain apparent kinetic rate constants. A linear correlation is observed between Langmuir-Hinshelwood kinetic parameters and Hammett constants for m-chloro, m-bromo and m-fluoro phenols. The changes in p values of Hammett plots at pH 3 suggest that the main degradation pathway may involve a positively charged intermediate, such as a radical cation formed by direct electron transfer to the positive holes at low pH. At high pH levels, however, substrate speciation, surface charge of the semiconductor, and bandgap shift appear to lead to a change in the degradation mechanism.

Orientador: Ellen Silva Lago Vanzela / Coorientador: Roberto da Silva / Coorientador: Isidro Hermosín Gutiérrez / Banca: Natália Soares Janzantti / Banca: Paulo César Stringheta / Resumo: A composição qualitativa e quantitativa dos compostos fenólicos (CF) presentes nas partes comestíveis das uvas BRS Carmem e BRS Magna foi determinada utilizando cromatografia líquida de alta eficiência com detector de arranjo de diodo acoplada à espectrometria de massas com sistema de ionização por eletronebulização e analisador de armadilha de íons (CLAE-DAD-IES-EM/EM). Com base nos resultados obtidos e, com auxílio de análise multivariada de componentes principais (ACP), foi possível identificar os CF que mais se destacam, devido serem majoritários ou minoritários: as antocianinas monoglicosiladas acetiladas derivadas da petunidina e malvidina foram os compostos marcadores da BRS Carmem inteira enquanto na BRS Magna foi a delfinidina diglicosilada cafeilada; no caso dos flavonóis, para ambas cultivares, os derivados da miricetina foram majoritários; para os derivados do ácido hidroxicinâmico (DAHC) verificou-se que a BRS Carmem inteira apresenta maior concentração do isômero do tipo p-cumárico enquanto que na BRS Magna, há maior concentração de ácido cutárico; há presença de estilbenos do tipo trans- e cis-piceido em ambas cultivares, porém, estas não mostraram ser ricas fontes destes compostos; e, os marcadores para os flavan-3-óis monômeros nas sementes da BRS Carmem e da BRS Magna foram os do tipo epicatequina e catequina, respectivamente. Quantitativamente, as cascas acumularam a maior parte dos CF, com diferenças nos perfis fenólicos encontrados entre as frutas inteiras, sementes e suas respectivas cascas. Pode-se observar que a BRS Carmem inteira apresentou concentração de CF, significativamente, maior quando comparado a BRS Magna, sendo que as antocianinas e os DAHC foram as classes de compostos que mais se destacaram / Abstract: The qualitative and quantitative composition of phenolic compounds (FC) present in the edible parts of BRS Carmen and BRS Magna grapes, determined using high-performance liquid chromatography with diode array detector coupled to mass spectrometry system electrospray ionization and ion trap analyzer (HPLC-DAD-ESI-MS/MS). Based on the results and using the method of principal component multivariate analysis (PCA), was possible identify the FC that stand out because they are majority or minority: acetylated monoglucosides anthocyanins derived from petunidin and malvidin were the main markers of BRS Carmem hole fruit while in BRS Magna was caffeoylated diglucoside of delphinidin; in the case of flavonoids for both varieties, the majority were derived from myricetin; for the hydroxycinnamic acid derivatives (HCAD) the BRS Carmen hole fruit showed higher concentration of the isomer p-coumaric type while the BRS Magna showed higher concentration of cutaric acid; It was also noted the occurrence of stilbene type trans- and cis-piceid, although this cultivars have not showed to be rich in these compounds; and the markers of flavan-3-ols monomers in the seeds of BRS Carmen and BRS Magna were the epicatechin and catechin types, respectively. Quantitatively, the seeds accumulated most of the CF, with differences in the phenolic profiles found for hole fruits, seeds and their respective seeds. It can be seen that the BRS Carmen hole fruit showed concentration of CF, significantly higher, compared with BRS Magna, thus anthocyanins and DAHC were the classes of compounds that stood out / Mestre

Orientador: Ellen Silva Lago Vanzela / Coorientador: Roberto da Silva / Coorientador: Isidro Hermosín Gutiérrez / Banca: Natália Soares Jazantti / Banca: Afonso Mota Ramos / Resumo: O processo de desidratação de uvas BRS Morena, pré-tratadas ou não com azeite extra-virgem (AV), para obtenção de passas, resultou em alterações na composição quantitativa e qualitativa dos compostos fenólicos identificados e quantificados utilizando cromatografia líquida de alta eficiência com detector de arranjo de diodo acoplada à sistema de ionização por eletronebulização e espectrômetro de massas de armadilha de íons (CLAE-DAD-IES-EM/EM). Resultado este evidenciado pela análise de componentes principais (ACP). Nas passas obtidas das uvas sem pré-tratamento, as antocianinas foram degradadas devido ao elevado tempo de exposição ao tratamento térmico. Com o pré-tratamento das uvas com AV, observou-se aceleração do processo de secagem para a obtenção das uvas passas (40% menor que o das uvas não pré-tratadas). Associado a maior permeabilidade de água nas bagas, houve uma maior difusão do oxigênio do ar exterior para dentro da uva, o que promoveu o desencadeamento de processos oxidativos de origem química e enzimática, que resultaram em retenções de flavonóis, derivados do ácido hidroxicinâmico e estilbenos menores quando comparadas as retenções para os mesmos compostos presentes nas passas sem pré-tratamento. Porém, grande concentração de antocianinas e proantocianidinas foram determinadas nestes produtos. Desse modo, pode-se inferir que o processamento com a adição de AV se mostrou eficiente do ponto de vista industrial, uma vez que promoveu redução do tempo total de secagem. Assim como, torna-se um processo alternativo interessante também do ponto de vista da saúde, já que preservou concentrações altas de flavonoides com importantes alegações de atividades biológicas / Abstract: The dehydration process of BRS Morena grapes, pretreated or not with extra virgin olive oil (AV), to obtain raisins, resulted in changes in the qualitative and quantitative composition of identified and quantified phenolic compounds using high-performance liquid chromatography with detector diode arrangement coupled to the ionization system eletronebulização and spectrometer ion trap mass (HPLC-DAD-ESI-MS / MS). Result evidenced by principal component analysis (PCA). In raisin obtained without pretreatment, anthocyanins have been extensively degraded due to the high time of exposure to heat treatment. With the pretreatment with AV of grapes, there was a significant acceleration of the drying process for obtaining the raisins (40% lower than non-pretreated grapes). Associated with increased permeability of water in the grapes, there was a greater spread of outside air oxygen into the grape, which promoted oxidative processes of chemical and enzymatic origin, resulting in retention of flavonols, hydroxycinnamic acid derivatives and stilbene, lower when compared to retention values for the same compounds in raisins without pretreatment. Thus, it can inferred that the processing with the addition of AV was efficient from the industrial point of view, since it promoted reduction in total drying time. As become an interesting alternative process also from a health point of view, since high concentrations of flavonoids preserved with important biological activities claims / Mestre

CNPQ; Fundação Araucária / O Brasil, devido à sua grande produção agrícola, é um dos países que mais produz resíduos agroindustriais no mundo e observa-se um interesse crescente na busca de alternativas para a utilização da matéria orgânica gerada, que atualmente tem sido fonte de poluição do meio ambiente. A indústria vinícola tem gerado um grande volume de resíduos que podem constituir um material de baixo custo e boa rentabilidade em aplicações tecnológicas, além de conter substâncias bioativas de alto valor comercial. Neste estudo; foi avaliado o bagaço de três variedades de uva. Ácidos graxos e compostos fenólicos foram identificados por cromatografia líquida e gasosa, respectivamente. A capacidade antioxidante dos extratos fenólicos foi avaliada pelos métodos DPPH, ABTS+ e íon ferroso. O bagaço da uva Cabernet Sauvignon apresentou os valores mais elevados de compostos fenólicos totais (5.101,82 ± 119,03 mg -1 -1 EAG 100 g), flavonoides (2.983,91 ± 51,76 mg ECT 100 g ) e antocianinas monomérica totais -1 (2.092,93 ± 71,57 mg mal-3-gli.100 g ). Além disso, o bagaço de Cabernet Sauvignon apresentou os menores valores de EC50 nos testes de DPPH e ABTS, apresentando alta atividade antioxidante. / Brazil, due to its large agricultural production, is one of the largest producers of agro-industrial waste worldwide and there is a growing interest in finding alternatives to the use of organic material generated, which currently has been a source of environmental pollution. Wine industry has generated a large amount of waste that may be a low cost and good profitability in technological applications, besides containing bioactive compounds of high commercial value. Grape pomace of three varieties was evaluated in current study. Fatty acids and phenolic compounds were identified respectively by gas and liquid chromatography. Antioxidant capacity of the phenolic extracts was determined by three different methods, namely DPPH, ABTS+ and ferrous ion assays. Cabernet Sauvignon pomace revealed the higher rates of total phenolic -1 -1 compounds (5,101.82 ± 119.03 mg GAE 100 g ), flavonoids (2,983.91 ± 51.76 mg CTE 100g ) -1 and monomeric anthocyanin (2,092.93 ± 71.57 mg mal-3-glu.100 g), coupled to lowest EC50 rates in DPPH and ABTS assays, showing a high antioxidant activity.

Dissertação(mestrado)- Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia e Ciência de Alimentos, Escola de Química e Alimentos, 2008. / Submitted by Caroline Silva (krol_bilhar@hotmail.com) on 2012-09-17T14:46:33Z No. of bitstreams: 1 dissertaovnia.pdf: 754889 bytes, checksum: d24dfb5596ca30a0d5f0dacfb90ce785 (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2012-09-18T21:25:30Z (GMT) No. of bitstreams: 1 dissertaovnia.pdf: 754889 bytes, checksum: d24dfb5596ca30a0d5f0dacfb90ce785 (MD5) / Made available in DSpace on 2012-09-18T21:25:30Z (GMT). No. of bitstreams: 1 dissertaovnia.pdf: 754889 bytes, checksum: d24dfb5596ca30a0d5f0dacfb90ce785 (MD5) Previous issue date: 2008 / O trabalho tem como objetivo determinar propriedades funcionais de tecidos vegetal e microbiano visando fornecer subsídios para uma dieta saudável. O tecido vegetal escolhido para este estudo foi a cebola cultivada na região sul do Rio Grande do Sul e a microalga chlorella, que será avaliada como padrão de funcionalidade. As amostras de cebolas foram fornecidas e separadas em classes comerciais, conforme o Regulamento Técnico de Qualidade de Cebola, aprovado em 1995 pelo Ministério da Agricultura, do Abastecimento e da Reforma Agrária, pelos técnicos da EMATER - Rio Grande. A composição centesimal, pH e acidez (AOAC, 2000) e os compostos fenólicos da cebola que foram extraídos em três sistemas solventes sob condições padronizadas (etanólico, aquoso, acetato de etila) e quantificados colorimétricamente com reagente de Folin-Ciocalteau. Na microalga chlorella os fenóis foram extraídos em sistema solvente metanólico. O teor de lipídios foi determinado pelo método de Bligh & Dyer para ambas as matrizes, os açúcares redutores foram determinados conforme método do 3,5-DNS (MILLER) para as amostras de cebola e na microalga chlorella foi estimado por diferença. Nas cebolas foi estimada a atividade específica de catalase, peroxidase e polifenoloxidase. A estimativa do potencial funcional dos compostos fenólicos foi indicada pela capacidade de seqüestrar o radical livre (DPPH), inibição da ação de enzimas oxirredutases e inibição de produção de peróxidos e compostos oxidados em sistemas lipídicos. Nos extratos de cebola a média dos teores de fenóis em solvente metanol, água e acetato de etila foram respectivamente 2,3; 3 e 0,08 mg/g de cebola. Os valores para umidade variaram entre 88,3 e 88,6%, lipídios entre 0,16 e 0,19%, proteínas entre 0,86 e 1,04%, cinzas entre 0,73 e 0,76%, fibras entre 0,6 e 0,7%, açúcares redutores entre 3,73 e 5,2%, o pH entre 5,08 e 5,23, a acidez entre 0,29 e 0,38%. A microalga chlorella apresentou 56,9% de proteína, 4,1% de umidade, 6,3% de cinzas, 22,3% de açúcares redutores, 2,8% de fibra-bruta, 7,6% de lipídios, 0,2% de acidez e pH 5,7. A atividade específica da catalase nas diferentes classes de cebola variou entre 0,014 e 0,025 mg H2O2/min/mg proteínas, sendo os maiores valores encontrados nas classes 2 e 3. A polifenoloxidase não foi detectada nas diferentes classes enquanto que a atividade específica da peroxidase variou entre 0,003 e 0,031 abs/min/mg proteínas. Todos os extratos apresentaram atividade seqüestradora do radical livre DPPH, porém o extrato de cebola extraído com acetato de etila foi o que apresentou maior inibição específica (53%) em relação aos demais. As velocidades máximas da reação de escurecimento enzimático diminuíram em presença dos extratos de cebola e chlorella, o que caracteriza o efeito de inibição da oxidação do guaiacol catalisado pela peroxidase. O extrato mais promissor para evitar a oxidação ocasionada pela catálise metálica em sistema lipídico foi o extrato de cebola extraído com acetato de etila com uma inibição percentual de 53% acompanhado pela menor formação de peróxido (até três vezes menor) e de malonaldeído (1,5 vezes menor) ao longo do tempo do experimento. / The work has as objective to determine functional properties in vegetal and microbian tissues aiming at to supply subsidies a healthful diet. The tissue vegetal chosen for this study was the onion cultivated in the southern region of the Rio Grande do Sul and the microalgae chlorella, that it will be evaluated as functionality standard. The samples of onions had been supplied and separate in commercial classrooms, as the Regulation Technician of Quality of Onion, approved in 1995 for the Ministry of Agriculture, the Supplying and the Agrarian Reformation, for the technician of the EMATER – Rio Grande. The centesimal composition, pH and acidity (AOAC, 2000) and the phenolic composites of the onion that had been extracted in three solvent systems under conditions standardized (ethanolic, watery, acetate of etila) and quantified colorimetrically with reagent of Folin-Ciocalteau. In the microalgae chlorella the phenols had been extracted in methanolic solvent system. The content of lipids was determined by the method of Bligh & Dyer for both the matrices, the reducing sugars had been determined in agreement method of 3,5-DNS (MILLER) for the samples of onion and in the microalgae chlorella was esteem by difference. In the onions the specific activity of catalase was esteem, peroxidase and poliphenoloxidase. The estimate of the functional potential of phenolic composites was indicated by the capacity to scavenging the radical (DPPH), inhibition of the enzyme action oxirredutases and inhibition of production of peroxides and composites oxidated in lipídicos systems free. In onion extracts the average of phenol texts in solvent methanol, water and acetate of etila had been respectively 2,3; 3 and 0,08 mg/g of onion. The values for humidity had varied between 88,3 and 88,6%, reducing lipids between 0,16 and 0,19%, proteins between 0,86 and 1,04%, leached ashes between 0,73 and 0,76%, staple fibers between 0,6 and 0,7%, sugars between 3,73 and 5,2%, pH between 5,08 and 5,23, the acidity between 0,29 and 0,38%. The microalgae chlorella presented 56.9% of protein, 4.1% of humidity, 6.3% of leached ashes, 22.3% of reducing sugars, 2.8% of fiber-rude, 7.6% of lipids, 0.2% of acidity and pH 5,7. The specific activity of catalase in the different classrooms of onion varied between 0,014 and 0,025 mg H2O2/min/mg proteins, being the biggest values found in classrooms 2 and 3. Poliphenoloxidase w as not detected in the different classrooms while that the specific activity of peroxidase varied between 0,003 and 0,031 abs/min/mg proteins. All the extracts had presented scavenging activity of free radical DPPH, however the extract of onion extracted with acetate of etila was what it presented greater specific inhibition (53%) in relation to excessively. The maximum speeds of the reaction of enzymatic blackout had diminished in presence of extracts of onion and chlorella, what it characterizes the effect of inhibition of the oxidation of guaiacol catalyzed by peroxidase. The extract most promising to prevent the oxidation caused for the metallic catalysis in lipídico system was the extract of onion extracted with ethyl acetate with a percentile inhibition of 53% followed by the lesser peroxide formation (up to three times lesser) and of malonaldeído (1,5 lesser times) to the long one of the time of the experiment.

The phenolic resin chemistry is an old chemistry that started in the late 1800’s. A lot of research work to gain understanding of phenolic resins has been done and reported in literature. However, most of the studies are based on phenol novolac resins. It was necessary to acquire more knowledge on specifically o-cresol novolac (OCN) resins because of the interest in the production of these resins. The chemistry in question was new to Sasol and one of the major objectives of doing this work was to build in-house competency in this field. This was achieved by first investigating whether the available feed materials containing certain impurities can be used to synthesise o-cresol novolacs with set specifications of purity and physical characteristics. The suitability of the Sasol o-cresol in terms of its contamination with sulfur (which is sometimes found in relatively higher amounts due to operating conditions) was investigated. The results showed that the sulfur in o-cresol did not have a significant contribution in the sulfur of the OCN. Another contaminant, formic acid, an auto-oxidation product found in formalin solutions was also investigated. It was also observed that, at formic acid levels of up to 4000 ppm, there was no effect on the softening point of the OCN. Secondly, it was important to study and understand the effect of different reaction variables on the quality of the OCN resins. The effect of formaldehyde: o-cresol molar ratio was investigated, the softening point increased with the increase in the molar ratio. The effects of other reaction variables (catalyst, reaction time, temperature and formaldehyde feed rate) on the softening point of the OCN were also investigated using p-toluenesulfonic acid and oxalic acid as catalysts. With p-toluenesulfonic acid as a catalyst, the temperature had no effect on the softening point, while all the other variables showed an effect on this parameter. A softening point model was formulated, which predicted the softening point with 98% accuracy. With oxalic acid, only the amount of catalyst had an effect. In addition, the chemical structures of these compounds were studied using 13C-NMR spectroscopy. The focus was on the isomer distribution of the methylene linkages. / Prof. D.B.G. Williams

This research was initiated to determine the mechanism(s) of action that could explain increased weight gain and decreased milk production i n dairy cattle fed corn silage containing residues of certain organophosphate pesticides. It was proposed that the mode of action involved and alteration of thyroid physiology by the metabolites of the pesticides, namely halogenated phenols. Studies were carried out to determine the effect of tri-halogenated phenols and pyridinols upon T4-binding to bovine serum albumin (BSA) and to liver mitochondria isolated from male rats. Using the rat as a model, feeding trials were performed to determine the effect of halogenated phenols and pyridinols on rate of gain, relative thyroid weight, thyroid histology, and serum- T 4 levels. In vitro results with BSA indicated that the mechanism could have involved competition between T4 and the phenol for the T4 -binding site(s) of serum proteins, thus possibly lowering the serum-T4 level. This was not well substantiated by in vivo measurements of serum-T4 levels from rats fed varying concentrations of halogenated phenols. The methods employed to determine the effect of halophenols upon r4 binding to mitochondria indicated that these compounds are poor competitors for the T4 -binding site on mitochondria. At the dose levels employed, there appeared to be no uniform dose response relationship between the various halogenated phenols and pyridinols and thyroid histology, relative thyroid weight and feed efficiency.