A amiodarona é um dos fármacos mais usados para o tratamento de arritmias cardíacas, tanto ventriculares como supraventriculares. Apesar de sua eficácia, o uso da amiodarona está associado a vários efeitos adversos, incluindo a toxicidade pulmonar. O mecanismo pelo qual a amiodarona causa lesão nas células pulmonares humanas não é inteiramente conhecido, mas estudos em cultura de células hepáticas humanas e pulmonares de ratos têm sugerido que a disfunção mitocondrial e o estresse oxidativo têm um papel importante na citotoxicidade da amiodarona. Os compostos fenólicos, incluindo catequina e epicatequina são amplamente distribuídos na natureza e conhecidos por sua capacidade de reduzir o estresse oxidativo. Além disso, alguns compostos fenólicos são capazes de modular a atividade mitocondrial. Em vista disso, o objetivo deste trabalho foi avaliar a capacidade dos compostos fenólicos catequina e epicatequina em a disfunção mitocondrial e os danos oxidativos causados pela amiodarona em células de fibroblasto de pulmão humano (MRC-5). Para atingir os objetivos as células MRC-5 foram tratadas com diferentes concentrações de catequina e epicatequina e após foram expostas a amiodarona 100 μM. A disfunção mitocondrial foi determinada através da atividade do complexo I da cadeia de transporte de elétrons e a biossíntese de ATP usando kits específicos. A viabilidade celular foi avaliada através do ensaio de 3-[4,5- dimetiltiazol 2-il]-2,5 difenil brometo de tetrazolina. A atividade das enzimas superóxido dismutase e catalase foram determinadas espectrofotometricamente. Os danos oxidativos a lipídeos e proteínas foram verificados através dos ensaios de substâncias reativas ao acido tiobarbitúrico e a proteínas carboniladas, respectivamente, e os níveis de óxido nítrico foram avaliados usando o método de Griess. Os resultados mostraram que a amiodarona inibiu a atividade do complexo I da cadeia de transporte de elétrons em 53% e a biossíntese de ATP em 9,5% e tanto a catequina como a epicatequina foram capazes de evitar estes efeitos em todas as concentrações (5, 10, 20 μM) testadas. Verificou-se que a amiodarona reduziu a atividade das enzimas superóxido dismutase e catalase (indicando produção de superóxido e peróxido de hidrogênio) e aumentou os danos oxidativos a lipídeos e proteínas. Os compostos fenólicos catequina e epicatequina foram capazes de minimizar as alterações no metabolismo redox induzidos pela amiodarona e aumentar a viabilidade nas células MRC-5. Catequina e epicatequina reduziram a depleção de óxido nítrico causada pela amiodarona. Este trabalho mostrou, pela primeira vez, que o mecanismo de toxicidade da amiodarona em células MRC-5 está associado à disfunção mitocondrial, principal causa de geração de dano oxidativo celular e que estes efeitos tóxicos são em parte reduzidos pela catequina e epicatequina. Embora outros estudos sejam necessários, estes dados abrem novas perspectivas para estudos visando o desenvolvimento de medicamentos que minimizem os efeitos tóxicos da amiodarona. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES. / Amiodarone is among the most widely used drugs for the treatment of ventricular and supraventricular cardiac arrhythmias. However, the use of amiodarone is associated with several side effects including pulmonary toxicity. The mechanism of amiodarone toxicity is not well known, but studies in human liver cells and rats lung cells have been suggested that mitochondrial dysfunction and oxidative stress play important role in the amiodarone cytotoxicity. Phenolic compounds, including catechin and epicatechin are widespread in nature and known for their ability to reduce oxidative stress. In addition, some phenolic compounds are able to modulate mitochondrial activity. Therefore, the objective of this study was to evaluate the ability of phenolic compounds catechin and epicatechin to minimize the mitochondrial dysfunction and oxidative damage induced by amiodarone in human lung fibroblast cells (MRC-5). To achieve the objectives, MRC-5 cells were treated with different concentrations of catechin and epicatechin and then amiodarone 100 μM. Mitochondrial dysfunction was determined by the activity of complex I of the electron transport chain and ATP biosynthesis using specific kits. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The activity of the enzymes superoxide dismutase and catalase were determined spectrophotometrically. The oxidative damage to lipids and proteins have been verified through the test substances reactive to the thiobarbituric acid and carbonyl protein, respectively, and nitric oxide levels were evaluated using the Griess method. The results showed that amiodarone inhibit 53% of the activity of complex I of the electron transport chain and 9.5% of ATP biosynthesis and both catechin and epicatechin were able to avoid these effects in all concentrations (5 10, 20 mM) tested. It was found that amiodarone reduced the superoxide dismutase and catalase activities (indicating the production of radicals superoxide and hydrogen peroxide) and increased oxidative damage to lipids and proteins. Phenolic compounds catechin and epicatechin were able to minimize alterations in the redox metabolism and increase in viability of MRC-5 cells. Furthermore, catechin and epicatechin reduced nitric oxide depletion caused by amiodarone. This study showed, for the first time, that toxicity of amiodarone in human lung cultured cells is associated, at least, in part, with mitochondrial dysfunction which was avoided by catechin and epicatechin. Although further studies are needed, these data open new perspectives for studies aiming the development of drugs that minimize the toxic effects of amiodarone.

O suco de uva é uma bebida rica em compostos fenólicos, os quais são importantes antioxidantes associados à redução na incidência de doenças relacionadas ao estresse oxidativo, incluindo as cardiovasculares. Estudos sobre os efeitos da suplementação com suco de uva tinto já foram realizados, no entanto, até o momento, não há dados sobre os efeitos da suplementação com de suco de uva branco. Em vista disso, o objetivo deste estudo foi avaliar os efeitos da suplementação de suco de uva branco sobre índice de massa corporal (IMC), circunferência da cintura (CC) e abdominal (CA), pressão arterial, glicemia, níveis de insulina, danos oxidativos e perfil lipídico em mulheres. Paralelamente avaliou-se a capacidade antioxidante da dieta destas mulheres. Participaram deste estudo 25 mulheres com idade entre 50 a 67 anos. As voluntárias foram instruídas a consumir 7ml/Kg peso/dia de suco de uva branco (Vitis labrusca) sem nenhuma outra alteração no consumo calórico ou no estilo de vida. A suplementação ocorreu durante 30 dias. Dados antropométricos e amostras de sangue foram colhidos antes e no final da intervenção. A maior parte das mulheres amostradas apresentou curso universitário completo, declarando praticar atividade física e fazer uso de medicação. Quarenta e quatro por cento das voluntárias eram eutróficas e quarenta por cento apresentaram sobrepeso. As participantes apresentaram uma ingestão de macronutrientes adequadas as recomendações nutricionais (IDR). Já os micronutrientes cálcio, iodo, folato, selênio vitamina B6, E e D foram ingeridos em menor quantidade do que as estipuladas, sendo que o sódio foi ingerido em quantidade maior do que à recomendada pela IDR. A capacidade antioxidante dietética das voluntárias foi superior à obtida em indivíduos saudáveis americanos. A suplementação com suco de uva branco reduziu o IMC, a CC e a CA (p<0,001). Não foi verificada diferença na pressão arterial antes e depois do consumo de suco de uva branco. Além disso, não houve alteração da glicemia, insulina e dos níveis de danos oxidativos. As mulheres suplementadas 2 apresentaram aumento de 16% do colesterol HDL, sem alteração nos demais parâmetros do perfil lipídico. Demostrando o potencial do suco de uva branco como um importante aliado na redução dos riscos para doenças cardiovasculares (sic). / Grape juice is a drink rich in phenolic compounds, which are important antioxidants associated with reduction in the incidence of diseases related to oxidative stress, including cardiovascular diseases. Studies about the effects of red grape juice supplementation have already been performed; however, there are no data on the effects of consumption of white grape juice until now. In view of this, the objective of this study was to evaluate the effects of white grape juice supplementation on body mass index (BMI), waist (WC) and abdominal (AC) circumference, blood pressure, glucose, insulin, oxidative damage and lipid profile in women. At the same time, the diet antioxidant capacity of these women was also evaluated. Twenty-five women aged 50-67 years participated of this study. The volunteers were instructed to consume 7ml/kg weight/day of white grape juice (Vitis labrusca) without any other change in diet energy consumption or habitual lifestyle. The supplementation occurred during 30 days. Anthropometric data and blood samples were collected before and after intervention. Most of the participants had university degrees, declaring practice physical activity and take medication. Forty-four percent of the volunteers were eutrophic and 40% were overweight. The participants presented intake of macronutrients adequate to nutritional recommendations (DRI). The micronutrients calcium, iodine, folate, selenium, vitamin B1 and D were consumed in smaller quantity than recommended; sodium was ingested in greater amount than those recommended by DRI. The dietary antioxidant capacity of volunteers was higher than obtained in healthy American individuals. Supplementation with white grape juice reduced BMI, WC and AC (p<0.001). There was no difference in blood pressure before and after white grape juice consumption. In addition, there was no change in glycemia, insulin and oxidative damage levels. Supplemented women presented a 16% increase in HDL-cholesterol, without altering other parameters on lipid profile, showing the potential of white grape juice as an important ally in reducing the risk of cardiovascular diseases (sic).

No description available.

Production and consumption of edible berries are increasing rapidly in the United States, mostly due to their superior flavor profile, and popular diet-related value with their human health relevant bioactives and nutritional benefits. However, bioactive and nutritional qualities, especially human health protective phenolic antioxidants and associated non-communicable chronic disease (NCD) relevant health benefits of berries vary widely among accessions/cultivars and due to different production practices (organic vs conventional). Therefore, the aim of this thesis was to screen and select high phenolic and high antioxidant serviceberry and blackberry accessions/cultivars and to investigate the effect of different weed management and fertilization (organic vs. conventional) practices on phenolic bioactive linked antioxidant and anti-diabetic properties of blackberry using in vitro assay models. Overall, high phenolic-bioactive linked antioxidant and anti-hyperglycemic properties were observed in both serviceberry and blackberry accessions/cultivars and further for blackberry it was significantly higher under organic weed management and fertilization practices.

Orientador: Cláudio Cabello / Banca: Rogério Lopes Vieites / Banca: Luis Fernando Barbisan / Resumo: A farinha de mandioca é consumida intensamente na culinária brasileira, participando como fonte importante de carboidratos na dieta. Em algumas regiões onde condições sócio econômicas impõe restrições a uma dieta balanceada, esta fonte de carboidrato se apresenta talvez como a única fonte de nutrientes para o consumo. A mandioca possui baixas concentrações de proteínas e matérias graxas quando comparada a outras fontes de alimento concorrentes nestes nichos, tais como o feijão e o milho e, portanto esta característica não a recomenda como constituinte principal nas dietas. Aproveitar materiais residuários descartados na colheita significa aproveitamento mais racional do custo de produção. As pesquisas sempre focaram a presença de proteínas nas folhas de mandioca, bem como a importância dessa fonte alternativa de nutrientes, disponível para o consumo humano, onde normalmente são consumidos na forma desidratada e crua, adicionado aos alimentos em diferentes proporções. No entanto, não foi encontrado nenhum trabalho onde a utilização desse alimento não se apresentasse na forma crua, e que fosse submetido ao processo de cocção em temperatura suficiente para diminuir a presença de compostos fenólicos, haja visto que estes compostos são sensíveis à exposição de temperatura elevada, onde supõe-se a possibilidade do processo de degradação parcial dos mesmos compostos, considerando, as condições de tempo de cocção, umidade do material, concentração de fibras presentes na variedade, concentração de ácidos orgânicos, entre outros, onde essa farinha fosse preparada, adicionando proporções dessa folha, antes do processo de cocção e na seqüência submetidos a fornos abertos em temperatura em torno de 150 a 200ºC. O processo de fabricação da farinha pode afetar positivamente ao provocar a redução dos compostos considerados antinutricionais... (Resumo completo, clicar acesso eletrôncio abaixo) / Abstract: The cassava flour is largest consumed in Brazil and is an important carbohydrate source. Due the social and economic situation of some Brazilian regions, this product shows it the main nutrient source. The cassava has low protein and lipids when compared with other important foods as bean and corn. Because of nutrient deficiency, cassava is not recommended as principal food in diets. The use of harvest residues means a rational production with low cost for industries. In the same way, the addition of plant parts without additives with low alterations in process is other argument for cost reduction with low nutrition risk. The research always aiming the protein presence in cassava leaves, as well as the importance of leaves as alternative source of nutrients, available for the human consumption. The cassava leaves are normally consumed in the dehydrated and raw form and are added in different percentage in food preparations. However, is difficult to observe researches that objective to use temperature aiming to reduce the phenolic components in cassava leaves. The phenolic composites are high temperature sensible and in this conditions occur the partial degradation of these components. It is important to consider the time of exposition, humidity of material, fiber percentage, organic acids concentration, process of flour preparation, percentage of leaves and dryer temperature in opened oven (150ºC to 200ºC) in this process. The cassava flour processing can affect positively due the decrease of anti-nutritional components, increase of digestibility and protein absorption, and the use of the enriched flour can be an alternative to recoup the nutritional state of individuals group with alimentary deficiency. The objective of this work was to evaluate the composition and nutritional value of cassava flour added of leaves aiming to analyze the viability as alimentary source, as well as the... (Complete abstract click electronic access below) / Mestre

Les travaux décrits dans ce manuscrit concernent l’élaboration de conservateurs naturels et hydrosolubles à base de polysaccharides greffés par des molécules actives d’origine végétale de type phénoliques (peu solubles dans l’eau). L’objectif est de développer de nouveaux systèmes présentant des propriétés antioxydantes et/ou antibactériennes, voire rhéologiques et principalement destinés aux domaines des formulations aqueuses cosmétiques et/ou alimentaires. Pour ce faire, le composé aminogaïacol (dérivé du gaïacol) a été greffé chimiquement sur un polysaccharide (carboxyméthylpullulane) selon des proportions variées (comprises entre 5 et 58 %). Les études physico-chimiques en milieux salins dilué et semi-dilué mettent en avant un caractère associatif (de type polysavon) des dérivés les plus greffés, avec des interactions intramoléculaires hydrophobes prédominantes qui limitent les propriétés rhéologiques. Tous les produits synthétisés ont par contre démontré des propriétés antioxydantes et antibactériennes. Le caractère associatif (i.e. la présence de microdomaines hydrophobes) s’est avéré être favorable à l’activité antioxydante, avec les meilleures activités observées pour le dérivé le plus fortement greffé en aminogaïacol (58%). Au contraire, le comportement associatif a limité l’activité biologique, dans ce cas, c’est le dérivé le moins greffé (5%) qui a démontré la meilleure activité antibactérienne, en raison d’une meilleure disponibilité des greffons. Afin d’améliorer les propriétés biologiques et/ou rhéologiques, cette approche de greffage de l’aminogaïacol a été étendue sur un autre polysaccharide anionique (l’alginate), plus rigide que le carboxyméthylpullulane avec des résultats prometteurs notamment en rhéologie. / The works described in this manuscript concern the development of natural and water soluble preservatives based on polysaccharides grafted with molecules of plant origin (from phenolic structure). The aim consists in developing new systems with antioxidant and/or antibacterial properties together with rheological ones for cosmetic and/or food application fields. For this purpose, aminoguaiacol (derived from guaiacol) was chemically grafted onto a polysaccharide (carboxymethylpullulan) in various proportions (between 5 and 58 %). The physicochemical studies in dilute and semi-dilute saline media put forward an associative character (of polysoap type) of the most grafted derivatives, with predominant hydrophobic intramolecular interactions which are limiting for rheology. All synthesized products have demonstrated antioxidant and antibacterial properties. The associative character (i.e., the presence of hydrophobic microdomains) was found to be favorable to the antioxidant activity, with the best activity for the most grafted aminoguaiacol derivative (58%). On the contrary, the associative behavior limited the antibacterial activity, in this case, the least grafted derivative (5%) demonstrated the best antibacterial activity, due to best availability of the grafted moieties. In order to improve the biological and/or rheological properties, this grafting approach of aminoguaiacol has been extended to another anionic polysaccharide (alginate), more rigid than carboxymethylpullulan with promising results notably as concerns rheology.

Le noyau benzofuro[2,3-b]indoline est une structure complexe que l’on retrouve dans différentes substances naturelles telles que l’azonazine, la voacalgine A, la bipleiophylline ou encore le diazonamide A. Ces produits naturels possèdent une activité biologique intéressante et plus particulièrement le diazonamide A avec un IC50 inférieur à 15ng/mL sur plusieurs lignées cellulaires cancéreuses. De plus, certaines de ces substances n’ont jamais été synthétisées à ce jour. Lors de la biogénèse de ces composés, il est supposé que le motif benzofuroindoline est créé par un couplage oxydant entre un indole et un phénol. Nous avons ainsi entrepris de développer différentes méthodologies de synthèse biomimétiques du motif benzofuroindoline. Inspiré par les biosynthèses de l’azonazine et du diazonamide A, nous avons développé une arylation diastéréodivergente du tryptophane par la tyrosine. Les diverses méthodologies de synthèse de benzofuroindolines existantes effectuant ce couplage ne permettent pas un contrôle stéréosélectif. Nous avons remédiés à ce problème en réalisant une réaction de Friedel-Crafts entre une tyrosine protégée et des exo- et endo-bromopyrroloindolines issues stéréosélectivement du tryptophane. Cette réaction procède avec rétention de configuration et nous permettent une synthèse diastéréodivergente de précurseurs potentiels du diazonamide et de l’azonazine. Une méthodologie générale de synthèse de benzofuroindolines par un couplage oxydant direct entre des indoles 2,3-disubstitués et des phénols a été développée. Cette réaction implique l’oxydation de l’indole par du N-iodosuccinimide. L’iodoindolénine intermédiaire réagit par action d’un sel d’argent, via une réaction de Friedel-Crafts avec le phénol pour donner la benzofuroindoline en une étape. Une bibliothèque de diverses benzofuroindolines a pu être obtenue par cette stratégie.Cette dernière méthodologie a été appliquée à la synthèse de modèles hexacycliques complexes de la voacalgine A et de la bipleiophylline à partir d’indoles apparentées à la pleiocarpamine que nous avons synthétisés. Une autre stratégie de synthèse du motif benzofuroindoline de la voacalgine A et de la bipleiophylline impliquant l’oxydation d’un catéchol en orthoquinone a également été étudiée. / The benzofuro[2,3-b]indoline core is a complex structure present in several natural products such as azonazine, voacalgine A, bipleiophylline and diazonamide A. These products possess an interesting biological activity and especially diazonamide A with an IC50 below 15ng/mL on different cancer cells lines. Some of these compounds have never been synthesize. It is postulated that the biogenesis of the benzofuroindolines natural products implies an oxidative coupling between indoles and phenols. Therefore, we wished to develop a bioinspired synthesis of benzofuroindoline core.Inspired by the biosynthesis of azonazine and diazonamide A, we developed an diastereodivergent arylation of tryptophan by tyrosine. The existing synthetic methodology of benzofuroindoline involving an oxidative coupling do not allow a stereoselective control. We solved this problem by doing a Friedel-Crafts reaction between a protected tyrosine and the exo-, and endo-bromopyrroloindolines obtained stereoselectively from tryptophan. This reaction witch proceeds with a retention of configuration allowed us to access selectively azonazine and diazonamide A precursors. A general methodology of benzofuroindoline synthesis by an oxidative coupling between 2,3-disubstituted indoles and phenols has then been developed. This reaction proceeds by oxidation of the indole with N-iodosuccinimide. The resulting iodoindoline was then engaged in a Friedel-Crafts reaction with a phenol in presence of a silver salt to form the desired benzofuroindoline in a one-pot operation. Through this method, a library of several benzofuroindolines has been created.This last methodology has been applied to the synthesis of complex hexacyclic voacalgine A and bipleiophylline analogs from pleiocarpamine-like indoles. Another strategy towards the voacalgine A and bipleiophylline benzofuroindoline core has also been studied and involves the oxidation of a catechol into an orthoquinone which can react with an indole.

Jacket plum [ Pappea capensis ( Eckl.&Zeyh)] belongs to the Sapindaceae or Litchi family. It is well adapted to different climatic conditions. It has been used for medicinal purposes for both animals and human beings. Due to the richness of seeds in oil, it has great potential to be selected for production of biodiesel in South Africa. Suitable vegetative propagation methods for Pappea capensis trees have not yet been investigated and sexual propagation does not produce true-to-type plants, which take many years to bear fruits. Therefore, research was carried out to identify alternative methods for vegetative propagation of Pappea capensis which could be used for rapid multiplication. Several vegetative propagation experiments were carried out with stem cuttings and air layers. Stem cuttings were collected from two mature Pappea capensis trees grown at the Experimental Farm of the University of Pretoria in the spring and autumn seasons. The cuttings were placed for rooting on the mist bed for rooting with and without Seradix® No. 2 [active ingredient, indolebutyric acid (IBA)] treatment. Other experiments followed in which the branches were girdled before making stem cutting to improve the level of any carbohydrates or available carbohydrates. Trials to investigate the rooting potential of Pappea capensis coppices, using different stem lengths, were also conducted. Rooting of Pappea capensis stem cuttings was unsuccessful. Air layers were made on the same trees where cuttings were collected. The trials were conducted in the spring and autumn seasons from 2006, 2007 and 2008. Some air layers were treated with Seradix® No. 2 and others were not treated with the auxin. High rooting percentages (100% in spring, 60% in autumn) were achieved with untreated air layers of Tree No. 1 and Tree No. 2 (80% in spring, 40% in autumn). Regardless of season, IBA and tree treatments, rooting was successful when the air layering method was used. Due to inconsistency in rooting from both vegetative methods, total phenolic compounds were extracted. The Folin-Ciaocalteau reagents method was used to extract phenolic compounds and the results were detected with Elisa reader instrument. The stem cuttings and air layers were further analysed for carbohydrates (starch and soluble sugars) with ó-toluidine reagent and ethanol and read with Spectrophotometer and high performance liquid chromatography (HPLC). Higher levels of total phenol compounds were observed from callused (27.13 mg/g) and non rooted untreated (26.41 mg/g) stem cuttings from Tree No. 2, compared to IBA treated stem cuttings (19.90 mg/g) of callused and non rooted IBA treated stem cuttings (20.25 mg/g) of Tree No. 2. High total phenols (34.55 mg/g) in untreated air layers were also found in callused air layers of Tree No. 2 and lower amounts (22.85 mg/g) in treated air layers of the same tree. No soluble sugars were detected in stem cuttings or air layers with HPLC. Regarding starch, higher amounts were observed in stem cuttings of Tree No. 1 (18.45 mg/g) of the control and Tree No. 2 (19.82 mg/g) of IBA treated cuttings. Most of the air layers made on Tree No. 1 had higher percentages of starch, with the exception of the callused (7.41 mg/g) air layers of the control. Tree No. 2 air layers had very low amounts of starch when compared with those of Tree No. 1. The variation in rooting potential of stem cuttings and air layers led to the consideration of tree gender as a factor influencing success rates, where inflorescences were collected from the two Pappea capensis trees for two years (2007 and 2008). The microscopic investigations showed that Pappea capensis trees (Tree No. 1 and Tree No. 2) were monoecious, however, Tree No. 2 switched from monoecious to male by producing only male flowers. Based on the results of the above investigations, air layering in the spring season can be used as a (alternative) vegetative propagation method for Pappea capensis tree, but on specifically monoecious tree to obtain higher rooting percentage. However, these are preliminary trials which require further investigation. / Dissertation (MSc(Agric))--University of Pretoria, 2010. / Plant Production and Soil Science / unrestricted

Thesis (DTech (Chemistry))--Cape Peninsula University of Technology, 2016. / The use of ozone as an advanced oxidation process is gathering wide spread attention with the major limitation to its application being its cost of operation and design considerations. While the general approach of most researches is to buttress the already known fact of the efficacy of the process, little attention is given to studying the by-products of ozone reactions with organics. The aims of this study were to investigate the efficacy of the ozonation process for removing recalcitrant phenolics: phenol, 2-chlorophenol (2CP), 4-chlorophenol (4CP) and 2,4-dichloropheno (2,4DCP) from aqueous medium with a view of understanding various reaction pathways of the process and identifying possible intermediates and residual compounds using liquid chromatography-mass spectrometry (LC-MS). The choice of the selected chlorophenols would also elucidate the role of the positioning of the chlorine atoms in determining reaction rates, pathways and subsequent mechanisms and by-products. Sequel to this, oxy-hydroxy iron in β-phase (β-FeOOH, akaganite) and various β-FeOOH bonded composites on support metal oxides (Al2O3, NiO and TiO2) were prepared via hetero-junction joining, and explored as a possible promoter to improve the efficiency of the ozonation process. Apparent first order reaction rates constants of tested phenolics was in the order 2,4-DCP > 2-CP > Phenol > 4-CP, irrespective of the tested pH. The individual rates however increased with increasing pH. The position 4 chlorine atom was found to be least susceptible to hydroxylative dechlorination. Catechol intermediate and pathway was identified as the major degradation pathway for phenol and 2-CP, while 4-chlorocatechol pathways were more important for 4-CP and 2,4-DCP. The formation of polymeric dimers and trimers by all compounds was pronounced at alkaline pH. Heterogeneous catalytic ozonation using β-FeOOH reduced ozonation time for 4-CP by 32%. Mechanism for β-FeOOH/ozone catalysis showed that the catalyst suffered reductive dissolution in acidic pH and the kinetics of 4-CP removal using the catalyst was best described using a two stage kinetic model. The first stage was attributed to heterogeneous catalysis of ozone breakdown on β-FeOOH surface generating faster reacting radicals, while the second stage was due to homogeneous catalysis by reduced Fe2+ ions in solution. β-FeOOH stabilized on NiO at a 5% ratio exhibited superior catalytic property compared to the other tested composites. Characterization by high-resolution transmission electron microscopy (HRTEM) affirmed a β-FeOOH-NiO bonded interfaced composite which was stable as a iv catalyst over four (4) recycle runs. The mechanism of operation of the composite was via an increased ozone breakdown to radicals as monitored via photoluminescence experiments. The composite material produced satisfactory results when tested on real wastewater samples. Results from this study contribute to the current understanding on reaction mechanisms for ozone with phenols and chlorophenols, for the first time monitoring time captured intermediates via liquid chromatography-mass spectrometric method, which preserves the integrity of reaction intermediates. Also this study proposes heterogeneous catalysts; β-FeOOH and β-FeOOH bonded composites as possible improvements for simple ozone based water purification systems.

Exposure to halogenated phenols and pyridinols is of increasing concern because of their wide use and distribution. This research was initiated to determine the distribution, accumulation, and depletion of a group of halogenated phenols and a pyridinol in selected tissues of male weanling rats at different time intervals following a single oral dose of 0.33 or 1.66 m moles per kg body weight. The halogenated phenols and pyridinol were distributed differently in every tissue sampled following their administration, even though the amount administered was the same in each case. The concentrations in tissue were found in the order: 2,4,5-trichloro-phenol > 4-bromo-2,5-dichlorophenol > 4-iodo-2,5-dichlorophenol > 3,5,6-trichloro-2-pyridonol in kidney and fat, whereas the series 3,5,6-trichloro-2-pyridinol > 4-iodo-2,5-dichlorophenol > 4-bromo-2,5-dichlorophenol > 3,5,6-trichlorophenol occurred in liver. No structurally significant series was observed for their concentrations in blood. All halogenated phenols and pyridinol concentrations in tissues declined rapidly with time but not always in an apparently log linear fashion. Rates were greatest for clearance from blood. The highest concentration of halogenated phenols was in kidney among the tissues studied, whereas the highest concentration of halogenated pyridinol was in liver. Relationships were found between the relative lipophilicity, as indicated by the chromatographic Rm value, and the concentrations of these compounds in tissues. The RH (i.e., relative lipophilicity) was generally very well correlated with the log concentration of compounds in tissues observed 24 h after dosing. The correlation coefficients ranged between .517 and .995 among tissues. Correlations were positive between the Rm values and 24 h concentrations in adipose tissue, and kidney, but negative for the relationship between the Rm and 24 h concentrations in blood and liver.