Obesity is a public health concern and cardiometabolic consequences are severe when obesity develops during youth and continues into adulthood. Treatment prior to adulthood confers health benefits, but adolescent obesity rates have continually increased, reaching 20.6% in 2013-2014. Quality and quantity of dietary intake contribute to the development of obesity, but limitations of self-reported dietary intake are evident in overweight or obese adolescents, who frequently misreport nutrients of concern. Added sugar, sodium, and protein intake may indicate diet quality in this population. The 2015-2020 Dietary Guidelines recommend decreasing consumption of added sugars, sodium, and processed protein due to their known contributions to overweight and obesity. Objective dietary intake assessment measures are necessary for investigating the association between dietary intake and health outcomes. Added sugar, sodium, and protein intake could be assessed objectively with a panel of urinary biomarkers. Prior research indicates the potential of these urinary biomarkers to reflect dietary intake, but to date, no controlled feeding study has been conducted in adolescents. Using a controlled feeding design, the current study aims to evaluate the validity of urinary sucrose, fructose, sodium, and nitrogen as objective indicators of dietary intake. It is hypothesized that urinary sucrose and fructose will reflect dietary added sugar intake, while urinary sodium and nitrogen will correspond to dietary sodium and protein intake, respectively, in a healthy adolescent population. These biomarkers, if valid, could be used in clinical and epidemiological research to improve understanding of the associations between dietary intake and health outcomes. / Master of Science / An increasing percentage of adolescents are becoming overweight or obese as a result of lifestyle changes that have decreased physical activity and increased access to foods with more calories and less nutrients. Overweight or obese adolescents are typically less heatlhy than their normal weight peers, and they are more likely to become overweight or obese adults, increasing the liklihood that they will develop diabetes and heart disease. It is important to prevent adolescents from becoming overweight or obese to preserve their health, and to treat adolescents who are overweight or obese to improve their health. Eating certain foods in excess contributes to negative health outcomes, including increased weight gain, so dietary change is an important aspect of overweight and obesity prevention and treatment. Current dietary guidelines recommend eating less added sugars, sodium, and processed protein. Quantifying dietary intake of these food components is essential for fully understanding their impact on health. However, self-reporting food intake is a flawed measure, because individuals may not accurately report all of the foods they consume. An objective method is needed to determine dietary intake of specific food components. Fortunately, urinary biomarkers can objectively assess dietary intake of added sugar, sodium, and protein. Controlling consumption of each food component and measuring urinary excretion of each biomarker is necessary to establish how intake corresponds to excretion, but this type of study has not been conducted in adolescents. The current study aims to use a controlled feeding approach to establish relationships between dietary intake of added sugars, sodium, and protein, and urinary excretion of sucrose/fructose, sodium, and nitrogen, in an adolescent population. These biomarkers could be used in future research to advance understanding of the relationships between food intake and overall health.

Seven-membered cyclic sugars, namely, septanoses and septanosides, are less commonly known sugar homologues. Synthesis of septanoses arise an interest due to their configurational and conformational features and the attendant possibilities to explore their chemical and biological properties. Septanosides derivatives, mostly, deoxy-septanosides were synthesized, by many synthetic methodologies, such as, Knoevengal condensation, ring-closing metathesis, Bayer-Villeger oxidation and ring-expansion of 1,2-cyclopropanted glycals as key steps. Apart from septanosyl monosaccharides, septanoside containing di- and tri-saccharides were also performed using glycosylation and ring expansions. Another area of sustained interest is the studies of the stabilities of glycosidic bonds. Acid- and enzyme-catalyzed hydrolysis of glycosidic bond were investigated intensely in the case of pyranosides and furanosides. The explanation of the hydrolysis of such stereomeric sugars were rationalized on the basis of stereoelectronic effects, such as, (i) antiperiplanarity; (ii) synperiplanarity of lone-pair of electrons involed in the hydrolysis process; (iii) steric effects; (iv) field and hyperconjugative effects; (v) conformational effects; (vi) disarming torsional effects and (vii) substituent effects. Chapter 1 of the thesis describes a survey of (i) synthesis of deoxy-septanosides and septanoside-containing di-and tri-saccharides and (ii) acid-catalyzed hydrolysis of glycopyranosides. In a programme, it was desired to identify a new methodology for the synthesis of 2-deoxy-2-C-septanosides. Synthesis of various septanosides from 2-hydroxy glycals, namely, oxyglycals, involves intermediates, such as, vinyl halide (III) and diketone (IV) (Scheme 1). These intermediates were identified as precursors for the synthesis of desired 2-deoxy-2-C-septanosides. Scheme 1 reactions, namely, Heck, Suzuki and Sonogashira reaction for the formation of hither-to unknown septanoside, branching out at C-2. Heck coupling and Suzuki coupling reaction of bromo-oxepine was performed using activated alkenes, acrylates and substituted boronic acid, respectively, in presence of Pd(OAc)2, to furnish 2-deoxy-2-C-alkyl/aryl septanoside derivatives (Scheme 2). Scheme 2 2-deoxy-2-C-alkynyl septanoside derivatives (Scheme 3). Scheme 3 BnO OOMe BnO OOMePd(PPh3)2Cl2,CuIBr BnO R BnO DMF:THF:Et3N(3:2:1)BnO OBn 98 oC, 72 h BnO OBn R=Ph,SiMe3,C6H13 One of the 2-deoxy-2-C-alkyl septanoside derivative was converted to the corresponding protecting-group free 2-deoxy-2-C-alkyl septanoside, using hydrogenolysis (Pd/C, H2) and NaBH4-mediated reduction. Chapter 2 presents details of the synthesis of 2-deoxy-2-C-alkyl/aryl/alkynyl septanoside derivatives from a bromo-oxepine. Continuing the efforts to extend the ring-opening of oxyglycal derived gem-dihalo-1,2¬cyclopropanted sugar, a Lewis acid-catalyzed ring-opening was considered important. The presence of an additional substituent in C-2 of oxyglycal switches reactivity as compared to glycals. For example, ring-opening of glycal derived gem-dihalo-1,2-cyclopropane generates 2-C-branched pyranoside, whereas corresponding oxyglycal generates oxepines even when both the reactions were performed under a mild basic condition, illustrating a sufficient reactivity difference between a glycal and an oxyglycal. Thus, ring-opening reaction of gem-dichloro-1,2-cyclopropanted oxyglycal in the presence of a Lewis acid, hither-to unknown, was examined. In this event, it was found that ring-opening reaction led to chloro-oxepine derivatives in the presence of AgOAc, using alcohol as nucleophiles. Primary, secondary, unsaturated and aromatic alcohols were used in the ring-opening reaction. The ring-opening reaction was stereoselective and only α-anomer was obtained in a good yield in each case (Scheme 5). The counter-anion also reacted in an instance, so as to furnish O-acetyl chloro-oxepine during the ring-opening reaction. Scheme 5 The course of the reaction in the absence of alcohol led to afford only the O-acetyl chloro-oxepine (Scheme 6). Scheme 6 It became pertinent to compare the result this work with that of AgOAc-catalyzed ring-opening of glycal derived gem-dihalo-1,2-cyclopropanated sugar, which led to C-furanoside derivative, as reported by Harvey and co-workers. The sequence of reactions involved were protonation of the endo-cyclic oxygen, followed by ring-opening to generate resonance stabilized allylic ion, which rearranged to C-furanoside. In contrast, oxyglycal derived gem-dihalo-1,2-cyclopropane studied herein led to chloro-oxepine exclusively, without subsequent rearrangement. Ring-opening of glucal derived gem-dihalo-1,2-cyclopropanated sugars, followed by cyclization to C-furanoside were likely to have occurred, due to isomerisation of less-substituted endo-cyclic double bond at C2-C3 of oxepine to C1-C2 unsaturated vinyl ether. Such a reaction was related closely to the acid-catalyzed rearrangement in less-substituted oxepine systems. On the other hand, gem-dichloro-1,2¬cyclopropanated oxyglycal derived chloro-oxepine did not undergo such an isomerisation, possibly due to unsaturation being present at highly substituted C2-C3 carbons (Scheme 7). Thus, the presence of an additional oxy-substituent at C-2 in oxyglycal derived cyclopropane derivative plays a major role to control the reactivity, as compared to glycal derived cyclopropane derivatives. Scheme 7 without undergoing further reactions, was confirmed further by the following reactions: (i) RuCl3¬NaIO4 mediated oxidation; (ii) NaBH4 reduction and (iii) Pd/C mediated hydrogenolysis (Scheme 8). Scheme 8 1,2-cyclopropane to exclusive formation of chloro-oxepine in the presence of AgOAc. It was planned further to synthesize a 1,7-linked-α-D-diseptanoside, through the oxyglycal route. Ring-opening of oxyglycal derived gem-dihalo-1,2-cyclopropanated derivative with 6¬hydroxy glycal led to 1,7-α-linked disaccharide unit. The following reactions were performed in order to synthesize 1,7-linked-α-diseptanoside 2: (i) cyclopropanation of the glycal double bond; (ii) ring opening of the gem-dihalo cyclopropane; (iii) RuO4 mediated oxidation; (iv) NaBH4 reduction and (v) hydrogenolysis using Pd/C, H2 (Scheme 9). Similar methodology was used for the synthesis of monoseptanoside, namely, n-pentyl-D-glycero-D-galacto-septanoside. Scheme 9 1 Oxyglycal route was also used for the synthesis of 2-chloro-2-deoxy septanoside 3, using hydrogenolysis (Pd/C, H2) and NaBH4 mediated reduction of chloro-oxepine (Scheme 10). Scheme 10 A kinetic study of the hydrolytic stabilities of mono-and diseptanoside was undertaken using an acid-catalysis, in a subsequent investigation. In the course of studies, it was observed that glycosidic bond in the reducing-end hydrolyzed twice faster than that at the non-reducing end, whereas glycosidic bond in monosaccharide 1 hydrolyzed 1.5 times faster than of reducing-end glycosidic bond in diseptanoside 2. Further, it was found that the replacement of the C-2 hydroxyl group by a chloride group reduced the rate of hydrolysis (Table 1). Table 1. First order rate constants and thermodynamic parameters for the acid-catalyzed hydrolysis of glycosidic bond in septanosides 1, 2 and 3. Compound Rate of hydrolysis ΔH# ΔS# ΔG# (kobs) (104 s-1) (kcal/mol) (cal/mol K) (kcal/mol) 35 oC 45 oC 85 oC 90 oC a non-reducing end of 2. A computational study was conducted, in order to gain further insight into the hydrolysis, using B3LYP/6-311G* level theory in the Gaussian 09 program packages. Calculations using the PCM solvent model with water as the solvent showed that the orientation of hydroxylmethyl group plays an important role. In the case of 1, the gg conformer was calculated stable by 2.12 kcal/mol, as compared, to tg-conformer. In the gg conformation, the optimal positioning of the dipole C7-O7 stabilized the oxo-carbonium ion in the transition state (Figure 1). Also, hydroxyl group at C4 stabilized the transition state, through non-covalent interaction (Figure 1). The transition state for the hydrolysis of 1 was found to present activation barrier (∆G#) of 19.9 kcal/mol, which was in good agreement with value for 1 (∆G# = 23.26 kcal/mol), as calculated from Erying plot (Table 1). On the other hand, inductive effect of the chloride group, as well as, the tg-orientation of the hydroxymethyl group appeared to contribute to the slower rate of the hydrolysis. Figure 1. gg- and tg-conformations in the ground state of 1. Chapter 4 describes synthesis of 1,7-linked-α-D-diseptanoside, 2-chloro-2-deoxy septanoside and their acid-catalyzed hydrolysis studies. Solid-state and solution phase conformation of septanosides are rare at present even when solid-state structures of pyranoside and furanosides are known commonly, that provide rich information of covalent and non-covalent interactions. In this context, single crystal X-ray structural analysis of septanosides, namely, n-pentyl-2-chloro-2-deoxy-α-D-manno-sept-3-uloside 4 and p-bromo phenyl 4,5,7-tri-O-benzyl-β-D-glycero-D-talo-septanoside 5 were analyzed. It was observed that the solid-state structure of 4 adopted twist-chair conformation, namely, 5,6TC3,4, whereas 5 adopted O,1TC2,3 conformation (Figure 2). An analysis of non-covalent interactions revealed that a dense network of O−H···O and C−H···O stabilized the crystal lattice of 4, whereas O−H···O and C−H···π stabilized the crystal lattice of 5. Chapter 5 describes the detailed analysis of X-ray crystal structure of two septanoside derivatives including non-covalent interactions responsible for the stabilization of crystal lattice. Figure 2. ORTEP of 4 and 5 with displacement ellipsoids, at a 10 % and 50 % probability level. In summary, the thesis established the following major results: (i) synthesis of 2-deoxy-2-C¬alkyl/aryl septanoside from a bromo-oxepine, using organometallic C-C bond forming reactions; (ii) the ring-opening reaction of oxyglycal derived gem-dihalo-1,2-cyclopropane in the presence of AgOAc and the effect of additional C-2 oxy-substituent in the reactivity, in comparison to glycal; (iii) an oxyglycal route for the synthesis of 1,7-linked-α-D-diseptanoside, 2-chloro-2-deoxy septanoside and their acid-catalyzed hydrolysis studies and (iv) solid-state X-ray crystal structural analysis and computational analysis of the conformation and non-covalent interactions associated with the stabilization of crystal lattice. Overall, the studies presented in the thesis provide a new insight into the synthesis, acid-catalyzed hydrolysis and solid-state structural analysis of septanoside derivatives.

Branched chain sugars display a varied and valuable range of biological activities. This thesis concerns the synthesis of 3,5-di-C-methyl-D-glucose, a potential inhibitor of glycogen phosphorylase (GP), and therefore a proposed therapeutic agent for type 2 diabetes. Chapter 1 looks at the occurrence of branched sugars in the natural world and current therapies for type 2 diabetes. Inhibition of GP is explored, and the molecular modelling studies which led to the design of the project target. Chapter 1 also looks into the development of new foodstuffs, the chemistry and biochemistry of imino sugars and branched hydroxy proline analogues. In Chapter 2, a range of different approaches to 3,5-di-C-methyl-D-glucose are investigated. Most of the initial investigations were carried out on the L-enantiomer, a readily available test system deriving from 2-C-methyl-D-ribono lactone. 2-C-Methyl-D-ribono lactone is synthesised rapidly from D-glucose in a one-pot reaction; as the key starting material for this work, the scalability of this process was investigated. One of the attempted syntheses of di-C-methyl glucose lead to the development of a route towards 3,5-di-C-methyl fructose, a novel dibranched ketose sugar. It was envisaged that through an enzymatic transformation, it might be possible to produce 3,5-di-C-methyl glucose stereoselectively. Synthesis of both enantiomers of 3,5-di-C-methyl glucose and mannose are reported, alongside results of GPb inhibition studies. Analysis of the preferred ring size of a range of di-C-methyl branched sugars and sugar lactones generated in this work is also presented. Chapter 3 explores the chemistry of 2,4-di-C-methyl-L-arabinono lactone, a key intermediate in the synthesis of 3,5-di-C-methyl-L-glucose. From this lactone a novel deoxy sugar, 2-deoxy-2,4-di-C-methyl-L-arabinono lactone, was generated. Routes towards a selection of imino sugars were explored, resulting in the synthesis of a methyl branched isofagomine analogue. A substituted aziridine was synthesised, from which a route to a di-C-methyl branched piperidine was proposed, and a pyrrolidine. Also presented is a synthesis of a dihydroxy di-C-methyl branched proline analogue. Detailed NMR analysis of several of the sugars generated in this work was carried out by Dr M. Wormald, of the University of Oxford Biochemistry department. The results of these investigations are presented in the Appendix. Throughout this work, the presence of quaternary centres has posed a problem with the assignment of relative configuration. As a result, this work has been greatly supported by X-ray crystallography, and the structures shown herein were wholly generated by me. Several other crystals were run during the course of this work, not all pertaining to these projects, and are provided in the CD appendix.

Ce travail porte sur l'étude de liens entre les propriétés mécaniques de comprimés modèles composés de billes de verre et les caractéristiques physico-chimiques des liants, constitués de sucres et préparés sous forme de sirops. Le procédé de fabrication consiste en une méthode modifiée de compression humide. Deux paramètres de formulation ont été testés : le taux de saturation en sirop et sa concentration massique. Nous en avons tiré une variable unique qui est la fraction massique de sucre ajoutée aux billes de verre. Ces paramètres se sont avérés essentiels dans la maîtrise de la tenue mécanique des comprimés. Il en est de même pour leurs conditions de stockage. Une corrélation linéaire a été établie entre une activité de l'eau, définie comme critique, du fructose, du galactose, du glucose, du lactose et du saccharose et l'apparition du phénomène de transition vitreuse pour chacun de ces sucres, engendrant une chute brutale dans la résistance mécanique de leurs comprimés respectifs. Le taux de cristallisation des sucres et l'absence d'anomérie sont aussi des paramètres qui semblent être à l'origine d'une meilleure tenue mécanique des comprimés / This work focuses on the study of relationships between the mechanical properties of model compacts composed by glass beads and the physicochemical characteristics of binders consisting of sugars and prepared in the form of syrups. Fructose, galactose, glucose, lactose and sucrose were used in this study. The manufacturing process consists in a modified wet compression method. Two formulation parameters were tested: the saturation ratio and the mass concentration of the syrup. We deduced from them a single variable which is the mass fraction of sugar added to the glass beads. These parameters were essential in controlling the mechanical strength of the compacts. It has been shown that storage conditions also influence tablets properties. A linear correlation was established between a specific water activity value, defined as critical, and the glass transition temperature for each of sugars, resulting in a collapse in mechanical strength of the compacts. The rate of crystallization of sugar and the absence of anomeric forms are also parameters that seem to be targeted in order to increase compacts mechanical strength

A cana-de-açúcar apresenta acentuada variação genotípica relacionada à eficiência de uso dos nutrientes, sendo que a abordagem desse assunto em pesquisas científicas prioriza os estudos relacionados ao nitrogênio (N) e fósforo (P). Porém, devido a essencialidade do potássio (K) como nutriente pela função exercida nas relações hídricas das plantas e sua importância na economia brasileira, pesquisas relacionadas à eficiência de uso de K podem auxiliar no desenvolvimento de genótipos mais eficientes, com implicações diretas no processo de eficiência de uso de água. No primeiro experimento (Experimento I), objetivou-se avaliar as mudanças morfológicas e fisiológicas promovidas pela redução do suprimento de K, em dois genótipos de cana-de-açúcar (SP90-3414 e SP83-2847), por meio da quantificação da área foliar; aspectos morfológicos do sistema radicular (comprimento total e superfície total de raízes); produção de biomassa de raízes e parte aérea; concentração e acúmulo de K nos tecidos vegetais; partição de fotoassimilados (porcentagem de açúcares solúveis totais [AST] e redutores [AR]); atividade da enzima redutase do nitrato (RNO3-); potencial da água na folha (?a) e parâmetros de trocas gasosas (taxa de assimilação de CO2 [A], condutância estomática [gs] e transpiração [E]). As concentrações de K empregadas na solução nutritiva foram de 1 e 6 mmol L-1, distribuídas conforme delineamento experimental de blocos completos ao acaso, utilizando-se esquema fatorial 2 x 2 (duas doses de K x dois genótipos de cana-de-açúcar), com cinco repetições. As doses promoveram diferenças quanto à absorção e uso do K pelos cultivares, promovendo alterações significativas no acúmulo desse elemento nos tecidos vegetais, na quantidade de açúcares solúveis totais e redutores nos tecidos, nos parâmetros morfológicos e produtivos da parte aérea e do sistema radicular, bem como nos atributos fisiológicos da fotossíntese e da redução do nitrato. No segundo experimento (Experimento II) objetivou-se avaliar a influência do déficit hídrico nos parâmetros morfológicos e fisiológicos das plantas, bem como estudar o comportamento desses parâmetros em função do aumento da concentração de K disponível no substrato. As análises tiveram como objetivo avaliar as relações hídricas das plantas e a interferência dessa condição hídrica nos processos de trocas gasosas, bem como relacionar os parâmetros de eficiência de uso de K (KUtE) com a eficiência de uso de água (EUA). O experimento foi conduzido em vasos contendo 8 dm3 de terra, o delineamento experimental também foi o de blocos completos ao acaso, utilizando esquema fatorial 2 x 2 x 2 (duas doses de K x dois regimes hídricos x dois cultivares), sendo utilizadas as doses de K de 1 e 6 mmolc dm-3 de terra, os regimes hídrico de 70% e 20% da capacidade máxima de armazenamento de água do solo e os genótipos SP90-3414 (suscetível) e SP83-2847 (tolerante ao estresse hídrico). Constataram-se incrementos nos parâmetros hídricos e de trocas gasosas dos cultivares desenvolvidos com adequado suprimento de K e submetidos ao déficit hídrico, indicando haver relação positiva entre a adubação potássica e a resistência das plantas de cana-de-açúcar submetidas a condição hídrica adversa. Ou seja, a eficiência de uso da água (EUA) no genótipo tolerante (SP83-2847) pode ser resultado direto da eficiência de uso de K (KUtE) / Sugarcane has marked genotypic variation related to nutrient use efficiency, which in turn the approach of this subject in scientific research prioritizes studies related to nitrogen (N) and phosphorus (P), but due to the essentiality of potassium (K) as a nutrient, and its importance in the Brazilian economy, researches related to K use efficiency can help the development of efficient genotypes, which, because the K water relation functions in plants may have a direct relation in the water use efficiency. In the first experiment were evaluate the changes in morphological and physiological sugarcane genotypes (SP90-3414 and SP83-2847) promotes by the reduction of K concentration, the parameters were quantifying the leaf area; root system morphology (total length and total surface area of roots); biomass of roots and shoots; K concentration and accumulation in plant tissues; total soluble and reduced sugars percentage; activity of the enzyme nitrate reductase; leaf water potential and gas exchange parameters. The K concentrations used in the nutrient solution were 1 and 6 mmol L-1, distributed as experimental design of randomized complete block design, using a factorial 2 x 2 (two K rates x two sugarcane genotypes), with five replications. The rates caused differences in the K uptake efficiency by cultivars, triggering positive changes in their accumulation in plant tissues and the morphological and physiological parameters. The second experiment were to evaluated the influence of water deficit on morphological and physiological parameters of the plants and to study the behavior of these parameters according to the increase of the available K concentration. The analysis aimed to evaluate the water relations in plants and the water status interference in the gas exchange process, as well as relating the parameters of the K use efficiency with the efficiency of water use. The experiment was conducted in pots containing 8 dm3 of soil, the experiment was also conducted in a randomized block design, using a factorial 2 x 2 x 2 (two K rates x two water regimes x two sugarcane cultivars), and the K rates used was 1 and 6 mmolc dm-3 of soil, water regimes was 70% and 20% of field capacity and the genotypes were the same as the first experiment. The results shows improvements in water and gas exchange parameters of cultivars developed in high-level K and subjected to water deficit, showing a positive relationship between potassium fertilization and sugarcane plant resistance to adverse water condition. On average, the highest water use efficiency (WUE) of SP83-2847 tolerant genotype may result from potassium use ufficiency (KUtE)

A doença de Chagas e as leishmanioses são doenças endêmicas tropicais, que afetam milhões de pessoas, especialmente em países subdesenvolvidos, e são responsáveis por série de implicações médicas, sociais e econômicas. Seus agentes etiológicos são protozoários pertencentes à ordem Kinetoplastida, os quais provocam várias manifestações clínicas, dependendo do tipo de protozoário infectante, da imunidade do hospedeiro e da progressão destas infecções. Atualmente, os principais problemas relacionados a estas parasitoses são a carência de fármacos eficazes, a elevada toxicidade dos fármacos disponíveis na terapêutica, bem como o crescente número de casos de resistência. Neste contexto, a busca por novos e melhores quimioterápicos contra essas doenças é urgente. A latenciação é um dos processos que podem ser utilizados com vistas a esse objetivo. Por meio desse processo, o uso de micelas poliméricas como transportadoras de fármacos com a finalidade de prolongar a ação e, consequentemente, diminuir a toxicidade do fármaco, tem sido crescente. Ademais, é possível dirigir a ação dessas formas de transporte por meio de fármacos dirigidos. Face ao exposto, o presente trabalho teve por objetivo a síntese fármacos dirigidos formadores de micelas dos compostos bioativos helenalina e hidroximetilnitrofural, os quais apresentam atividade tripanomicida e leishmanicida. Pretende-se, assim, promover a liberação controlada e a consequente diminuição da toxicidade destes compostos, bem como melhorar suas características físico-químicas. A ação destes compostos será dirigida para macrófagos, no interior dos quais se encontram os parasitos, através da ligação do tiomanosídio como grupo diretor das micelas. / Chagas disease and leishmaniasis are endemic tropical diseases affecting millions of people, especially in underdeveloped countries, being responsible and they are responsible for relevant medical, social and economic matters. Etiological agents for both diseases are protozoa belonging to the Kinetoplastidae order, which cause various clinical manifestations depending on the type of protozoa infecting, the host immunity and the progression of the infection. Currently, the main problems with these parasitic diseases are the lack of effective drugs, the high toxicity of available drugs for their treatment and the growing number of cases of resistance. In this context, the search for new and better chemotherapeutic agents against those diseases is urgent. Latentiation is one of the molecular modification processes that can be used with the aim of achieving this objective. Through this process, the use of micelles as drug carriers with the objective of prolonging its action and, consequently, diminishing its toxicity has been increasing. Besides, it is possible to direct the action of those carriers thourhg the targetd drugs. This said, in this work we studied the synthesis of micelle-forming targeted drugs of the bioactive compounds helenaline and hydroxymethylnitrofurazone, which showed to be trypanomicide and leishmanicide. Thus, promoting the controlled release and the consequent decreasing of the toxicity of those compounds, besides improving their physic-chemical properties are our goal. The action of those compounds will be directed to macrophages, where the parasites, mainly leishmanias, live, by covalent binding of the directed group thiomanoside to the micelles.

Thesis (Doctor of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018. / Lignocellulosic biomass (agro-waste) has been recommended as the most promising feedstock for the production of bioalcohols, in the biofuel industry. Furthermore, agro-waste is well-known as the most abundant organic matter in the agricultural and forestry product processing industry. However, the challenge with utilizing agro-waste as a feedstock is its highly recalcitrant structure, which limits hydrolysis to convert the holocelluloses into fermentable sugars. Conventional pre-treatment methods such as dilute acid, alkaline, thermal, hot water and enzymatic, have been used in previous studies. The challenge with these conventional methods is the generation of residual toxicants during the pretreatment process, which inhibits a high bioalcohol yield, by reducing the microbial populations’ (fermenter) ability to be metabolically proficient during fermentation. Numerous studies have been developed to improve the engineered strains, which have shown to have an ability to reduce the inhibition and toxicity of the bioalcohols produced or by-products produced during pre-treatment, while enhancing the bioalcohol production. In the present study (chapter 5), evaluation of common conventional methods for the pretreatment of the mixed agro-waste, i.e. (˃45µm to <100µm) constituted by Citrus sinensis, Malus domestica peels, corn cobs from Zea mays and Quercus robur (oak) yard waste without a pre-rinsing step at a ratio of 1:1 at 25% (w/w) for each waste material, was undertaken, focusing on hot water pre treatment followed by dilute acid (H2SO4) pre-treatment. To further pretreat the mixed agro-waste residue, cellulases were used to further hydrolyse the pre-treated agro-waste in a single pot (batch) multi-reaction process. The TRS concentration of 0.12, 1.43 and 3.22 g/L was achieved with hot water, dilute acid and cellulases hydrolysis as sequential pretreatment steps, respectively, in a single pot multi-reaction system. Furthermore, a commercial strain was used to ascertain low (C1 to C3) and high carbon content (C4+) bioalcohol production under aerobic conditions. Multiple bioproducts were obtained within 48 to 72 h, including bioethanol and 1-Butanol, 3-methyl, which were major products for this study. However, undesirable bio-compounds such as phenolics, were detected post fermentation. Since multiple process units characterised by chemical usage and high energy intensivity have been utilized to overcome delignification and cellulolysis, a sustainable, environmental benign pretreatment process was proposed using N. mirabilis “monkey cup” fluids (extracts) to also reduce fermenter inhibitors from the delignification of mixed agrowaste; a process with minimal thermo physical chemical inputs for which a single pot multi-reaction system strategy was used. Nepenthes mirabilis extracts shown to have ligninolytic, cellulolytic and xylanolytic activities, were used as an enzyme cocktail to pretreat mixed agro-waste, subsequent to the furtherance of TRS production from the agro-waste, by further using cellulase for further hydrolysis. N. mirabilis pod extracts were determined to contained carboxylesterases (529.41±30.50 U/L), β-glucosidases (251.94±11.48 U/L) and xylanases (36.09±18.04 U/L), constituting an enzymatic cocktail with a significant potential for the reduction in total residual phenolic compounds (TRPCs). Furthermore, the results indicated that maximum concentration of TRS obtainable was 310±5.19 mg/L within 168 h, while the TRPCs were reduced from 6.25±0.18 to 4.26 ±0.09 mg/L, which was lower than that observed when conventional methods were used. Overall N. mirabilis extracts were demonstrated to have an ability to support biocatalytic processes for the conversion of agro-waste to produce fermentable TRS in a single unit facilitating multiple reactions with minimised interference with cellulase hydrolysis. Therefore, the digestive enzymes in N. mirabilis pods can be used in an integrated system for a second generation biorefinery.

Submitted by Leticia Schettini (leticia@ufrrj.br) on 2016-09-19T15:16:21Z No. of bitstreams: 1 2010 - Juarez Vicente.pdf: 1012625 bytes, checksum: 30ce03687174fc4cf4226e455adde13a (MD5) / Made available in DSpace on 2016-09-19T15:16:21Z (GMT). No. of bitstreams: 1 2010 - Juarez Vicente.pdf: 1012625 bytes, checksum: 30ce03687174fc4cf4226e455adde13a (MD5) Previous issue date: 2010-05-07 / From the scientific viewpoint, the word ?uncertainty? expresses doubt about an analytic result. The implementation of the concept of uncertainty of measurement is a crucial step that the Brazilian laboratories must take in the process for obtaining the certification of the ability to perform essays in accordance with the Brazilian technical norm ABNT NBR ISO/IEC 17025. Regardless the technical area of application, the determination of the uncertainty of measurement associated with the result of an analysis is extremely important, especially in the food industry. The expanded uncertainty is related with the degree of reliability of an analytical result, and by means of this information it is possible to evaluate if the result of an analysis is consistent, i.e., if the uncertainty associated to the measurement remains inside an acceptable range. When the percentage of uncertainty exceeds a threshold, it is necessary to find the process variables that more intensely contribute to increasing the uncertainty and, in the sequence, to take corrective actions in order to minimize the impact caused for those variables over the uncertainty of measurement. The aim of this study was to detect the uncertainty of measurement associated with the analysis of total reducing sugars (TRS) by the Lane-Eynon method. The equipments used were analytical and semi analytical balances, burettes with 10mL and 25mL, and the food matrix studied was wild honey. To perform the calculations of the standard uncertainty, u, information about the uncertainty of the laboratory materials used in the analysis ? obtained from the certificate of calibration. The combined uncertainty, uc, was obtained by deriving the influence factors and considering, if necessary, the effective degree of freedom, ?eff, as stated in the Welch-Satterthwaite equation. The expanded uncertainty, U, was obtained by multiplying uc by the appropriate coverage factor, k = 2 (at level of confidence of 95,45%). The results showed that the expanded uncertainty obtained for the analysis of TRS was less than 2,0% when the analytical balance was used. The process variable having the greatest impact was the volume (close to 80,0%), followed by the title (close to 20,0%). The analysis of the expanded uncertainty obtained for the analysis of TRS when the semi analytical balance, and 10mL as well as 25mL burettes were used provided reliable results. However, care must be taken in such a combination of equipments, especially when using the 25mL burettes, since the percentage of uncertainty was great than 3,5%, too close to the limit established by the Codex Alimentarius, 4,0%. It was observed that, in this case, the variable having the greatest impact on the uncertainty was the title, with 79,82% (10mL burettes), and 87,10% (25mL burettes). / Do ponto de vista t?cnico-cient?fico, a palavra ?incerteza? expressa a d?vida em rela??o a um resultado anal?tico. A aplica??o do conceito de incerteza de medi??o ? fundamental para os laborat?rios brasileiros que almejam obter o reconhecimento da capacidade de realiza??o de ensaios em conformidade com a norma ABNT NBR ISO/IEC 17025. Independentemente da ?rea de atua??o, ? de extrema import?ncia o estudo e o conhecimento da incerteza de medi??o associada a um resultado de an?lise, em particular quando aplicado ? ind?stria de alimentos. A incerteza expandida informa o grau de confiabilidade de um resultado anal?tico e, atrav?s dela, ? poss?vel avaliar, a um n?vel de abrang?ncia estabelecido, se o resultado de uma an?lise transmite credibilidade, ou seja, se o valor da incerteza est? em uma faixa de concentra??o aceit?vel ou n?o. Quando o percentual de incerteza ultrapassa o limite aceit?vel, ? necess?rio conhecer quais as vari?veis do m?todo que mais contribuem para a incerteza e executar as medidas corretivas a fim de minimizar este impacto e, consequentemente, reduzir a incerteza total. O objetivo geral deste trabalho foi determinar a incerteza expandida associada ? an?lise titulom?trica de a??cares redutores totais (ART) pelo m?todo de Lane-Eynon, tendo como matriz uma amostra de mel, utilizando balan?a anal?tica e semi anal?tica e buretas de 10mL e 25mL. Para o c?lculo da incerteza padr?o (u), utilizaram-se os dados obtidos nos certificados de calibra??o de equipamentos e vidrarias empregados na an?lise. A incerteza combinada ( ) foi obtida derivando os fatores de influ?ncia e considerando, quando necess?rio, o grau de liberdade efetivo (?eff), dado pela Equa??o de Welch-Satterthwaite. Obteve-se a incerteza expandida (U) multiplicando-se por 2 (dois) o valor de para um n?vel de confian?a de 95,45%. Os resultados obtidos mostraram que a incerteza expandida de ART utilizando balan?a anal?tica n?o foi significativa (<2%) e que a vari?vel que mais influenciou foi o volume de amostra gasto (~80%), seguido do T?tulo (~20%). A an?lise da incerteza expandida de ART obtida com balan?a semi anal?tica e buretas de 10mL e 25mL gerou resultados confi?veis. No entanto, deve haver cautela neste caso, especialmente ao se utilizar bureta de 25mL, visto que o valor percentual de incerteza superou 3,5%. Observa-se que a vari?vel que mais contribui para a incerteza foi o T?tulo com 79,82% (bureta de 10mL) e 87,10% (bureta de 25mL).

A nêspera (Eriobotrya japonica Lindl.) é uma fruta do tipo pomo, que tem sido cultivada principalmente no estado de São Paulo. Cinco cultivares de nêspera foram selecionadas por se destacarem no sabor e na capacidade produtiva. Foi realizado o estudo das mudanças fisiológicas e físico-químicas dos frutos durante o desenvolvimento e o período pós-colheita. Amostras das cultivares (Centenária, Mizuho, Mizumo, Néctar de Cristal e Mizauto) foram colhidas semanalmente conforme o avanço do estádio de desenvolvimento (na planta), desde a fase verde dos frutos até se tornarem maduros. Os frutos maduros para estudo do período pós-colheita foram colhidos seguindo critérios adotados por produtores, através da cor dos frutos. As determinações físico-químicas realizadas nas nêsperas maduras foram umidade, fibra, ácido ascórbico, açúcares solúveis (glicose, frutose, sacarose e sorbitol), ácidos orgânicos e carotenóides. Durante o período de desenvolvimento das nêsperas, as curvas de respiração decresceram progressivamente, e houve um considerável aumento na produção de etileno, precedendo o aumento na concentração de açúcares e as mudanças de coloração dos frutos (verde a amarela ou alaranjada). A composição de açúcares e ácidos dos frutos maduros foi semelhante a encontrada nos frutos precocemente maduros durante o desenvolvimento na planta. Portanto, a observação visual da cor não foi apropriada para a definição do ponto ideal de colheita. Durante o período póscolheita, as curvas de respiração e de produção de etileno das cultivares tenderam a queda, mostrando comportamento típico de frutos não-climatéricos. O estudo fisiológico e físico-químico das cinco cultivares de nêspera permitiu conhecer melhor o padrão de amadurecimento de cada cultivar, e assim obter informações que auxiliem na definição do ponto ideal de colheita, e que permitam obter frutos de boa qualidade e apropriados para distribuição comercial. / Loquat (Eriobotrya japonica Lindl.) fruit is a pome fruit cultivated mainly in the state of São Paulo. Five loquat fruit cultivars were selected to analysis mainly by their high productivity and taste. Physiological and physico-chemical changes were analised during development and ripening fruit. Samples were harvest weekly according to progress in development stage (in the tree), since imature stage (green) until mature stage. Mature stage to harvest was defined by fruit color, like methods\' producer. The physico-chemical parameters analysed were moist value, fiber, ascorbic acid, soluble sugars (glucose, fructose, sucrose and sorbitol), organic acids and carotenoids. During development of loquat fruits, the respiration levels decreased, and show a increase in ethylene levels, which was associed with increase of sugar concentration in the pulp and the changes of fruit color (green to yellow or orange color). According to sugars and acids levels during development (in the tree) and in ripe stage, the composition in ripe fruits was similar to that early mature fruits analyzed during development in the tree. The visual determination of color was not appropriate to define the harvest point of fruits. During postharvest period of the cultivars, the levels in respiration and ethylene production decreased, which is a typical pattern of non-climacteric fruits. The study of physiological and physico-chemical characteristics of loquat cutivars contribute to know the ripening pattern of each cultivar and to auxiliary in the definition of best mature point to harvest and to comercial distribution.

Les cyanoglucosides non-cyanogènes se trouvent dans de nombreuses plantes en particulier médicinales, mais n'ont été qu'assez peu étudiés. En particulier la Ménisdaurine, dont la synthèse n'a jamais été réalisée, nous a paru un objectif intéressant. Le produit de départ, choisi en fonction de travaux antérieurs, est un dérivé de la 7-oxanorbornanone. La première voie étudiée avait comme étape-clé l'addition électrophile sur une double liaison mais n'a pas abouti. Nous avons ensuite envisagé l'ouverture d'un époxyde suivie de réduction. Ayant observé que le cycle époxy peut être ouvert par migration intramoléculaire d'un groupement méthoxy en présence d'iode, nous avons réalisé la même réaction avec un groupement phenylthio. L'ouverture de l'époxyde a ainsi été effectuée de façon totalement régio- et stéréo-sélective dans des conditions pratiquement neutres, ce qui n'avait jusque là pas été rapporté dans la littérature. Une étude mécanistique a confirmé que cette réaction se déroulait bien en deux étapes : formation d'un hémimercaptal sur la fonction cétone suivie d'une ouverture de l'époxyde par attaque exclusivement intramoléculaire. Le remplacement de l'iode par l'iodure de zinc conduit à des rendements encore supérieurs. Le groupement phenylthio étant facilement enlevé par réduction, cette voie est très efficace pour réduire sélectivement un époxyde en alcool. La suite de la synthèse conduit à l'aglycone protégée souhaitée puis la glycosidation a été réalisée avec un rendement de 80%. La(-)-Ménisdaurine naturelle a été obtenue (et caractérisée sous forme de son pentaacétate) en 10 étapes et 3% de rendement global. / Non-cyanogenic cyanoglucosides are found in many plants, specially in medicinal species but have been the subject of only few studies. Particularly, Menisdaurin seemed us an interesting target and we decided to work on its first total synthesis. The starting material, chosen by reference to previous work in the laboratory, is a derivative of 7- oxanorbornanone. The first synthetic route had as key-step an electrophilic addition on a double bond but, unfortunately, was unsuccessful. Then we chose as an alternative the nucleophilic opening of an epoxide ring followed by reduction. We noticed that this epoxide ring could be opened by the intramolecular migration of a methoxy group in the presence of iodine, and therefore we tried, successfully, to perform the same reaction with a phenylthio group. So the opening of the epoxide ring was carried out with total regio- and stereo-selectivity in almost neutral conditions, which had not been hitherto reported in literature. Mechanistic studies confirmed that this reaction consisted of two steps : the formation of an hemimercaptal on the ketone followed by the opening of the epoxide by an intramolecular attack. Replacement of iodine by zinc iodide afforded even better yields. The phenylthio group being easily removed by reduction, this procedure is very efficient to obtain selectively an alcohol from an epoxide. Then, the following synthetic steps afforded the desired protected aglycone which was glycosidated with a 80% yield. Natural (-)­-Menisdaurin was obtained (and characterized as its pentaacetate) in 10 steps with a global 3% yield.