Polysaccharides, one of three types of natural polymer, are used by living organisms for energy storage, structural support, and other vital applications. In particular, acidic polysaccharides such as alginic acid and hyaluronan play important roles in lubrication and water storage. Isolation of polysaccharides is complicated by the difficulty of purification and lack of batch-to-batch consistency. Polysaccharide synthesis has also proved challenging due to their stereochemical complexity and high density of functional groups with similar reactivity. One solution is the synthesis of mimics that possess many of the properties of natural polysaccharides, including a rigid pyranose or furanose backbone and numerous hydroxyl or carboxylic acid groups. Synthesized polysaccharide mimics include polymers with ether linkages not seen in nature, non-ether linked sugar monomers, and polymers created from non-carbohydrate sources. These mimics have been used in various applications, including biolubrication, membrane synthesis, and DNA delivery. As a first approach to a polysaccharide mimic, a polymer with a rigid cyclic backbone and several pendant water-soluble functional groups was sought. High molecular weight ester-functionalized norbornene polymers were synthesized by ring-opening metathesis polymerization of 5-norbornene-2-ethyl ester. The resulting polymers were saponified and hydroxylated along the polymer backbone without a reduction in chain length. The chemical, thermal, and mechanical properties of the various polymers were measured, indicating high thermal stability and strong solid-like character. Even in their saponified and hydroxylated form, the polymers possessed very limited water solubility. Poly-amido-saccharides, a new type of carbohydrate polymer mimetic, were synthesized by the controlled anionic ring opening polymerization of a beta-lactam glucose monomer. The primary alcohol was oxidized to investigate the effects of an ionizable carboxylic acid group, such as those found in natural polysaccharides containing glucuronic acid. Circular dichroism revealed an ordered helical secondary structure in solution that was lost following ring opening. The oxidized poly-amido-saccharides were shown to stabilize lysozyme towards freezing and dehydration stresses better than currently used methods. Glycopolymers containing the poly-amido-saccharides on a poly(acrylamide) backbone were also synthesized and characterized as a model for more complex systems.

Rapid depletion of fossil fuel stock with a simultaneous rise in greenhouse gas emissions has led to an increase in the need for alternative energy. Cellulose based biofuels, especially bioethanol is a form of alternative energy that has the potential to replace petrol. The first step in cellulosic bioethanol production is the release of fermentable sugars via pre-treatment. Conventionally, physico-chemical and biological pre-treatment methods are energy intensive, environmentally unfavourable and expensive. This study, however reports on the use of a less energy consuming, cheap and environmental friendly alternative; photocatalysis, to produce fermentable sugars from cellulose. To achieve this, a range of photocatalysts were first screened based on their OH radical production rates using coumarin as a probe. TiO2 P25 was the photocatalyst that was found to have the highest OH radical production rate of 35.6 μM/hr, followed by Pt-C3N4 (0.88 μM/hr) and WO3 (0.28 μM/hr). LaCr-SrTiO3, Cr-SrTiO3 and yellow TiO2 did not produce any OH radicals due to their unsuitable electronic structure. P25 was further used for photocatalytic fermentable sugar production from cellulose. Photocatalytic cellulose I breakdown produced 0.04 % fermentable sugars whereas, with cellulose II feedstock the yield increased to 0.2 %. To further improve the yield, membrane bags were deployed which improved the sugar yields to 0.43 % and 0.71 % respectively from cellulose and cellulose II feedstocks. Photonic efficiencies followed the same trends as the sugar yields. Engineering design was further opted to enhance the sugar yields and hence a stacked frame photocatalytic reactor (SFPR) was designed. Various mixer configurations were designed and their mixing regime was determined using COMSOL Multiphysics 5.1 simulations. Amongst the mixers simulated, an 8-blade Rushton impeller was found to be the best configuration due its superior radial mixing profile and higher fluid velocity. The SFPR was then fabricated and operated with the impeller or a plus shaped magnetic bar as the mixer and the sugar yields were determined. Highest sugar yield and photonic efficiency was obtained from the cellulose II-impeller setup and was calculated to be 2.61 % and 9.45 % respectively. Respective lowest yields were obtained with cellulose I-stirrer bar setup and calculated to be 1.71 % and 5.64 %. Furthermore, the effect of H2O2 on fermentable sugar production was also tested. The cellulose II-stirrer bar configuration yielded 3.15 % fermentable sugars with the addition of 0.01 wt% H2O2 to the reaction mixture. The yield improved significantly to 14.1 % when the concentration of H2O2 was increased to 0.1 wt%.

A comunidade de insetos visitantes de flores de clones do eucalipto urograndis (Eucalyptus grandis x E. urophylla) foi estudada em um plantio localizado na Fazenda Areão, em Piracicaba, SP (22° 41 41 S e 47° 38 5 3 W ) por meio de levantamentos semanais com rede entomológica, durante os florescimentos de 2007 e de 2008 com a finalidade de caracterizar seu potencial apícola com a determinação de sua apifauna associada, e das características de néctar produzidos por suas flores. A comunidade antófila nos dois anos do levantamento foi representada por 29.492 indivíduos pertencentes a 6 ordens, 21 famílias, 43 gêneros e 52 espécies. A apidofauna foi representada por 24.882 indivíduos pertencentes a 11 gêneros e 10 espécies. A abelha africanizada Apis mellifera, o visitante mais efetivo em todo o levantamento (80,96%), seguida do sirfídeo Ornidia obesa (5,29%) e do mantispídeo Zeugomantispa virescens (4,26%). Os índices de diversidade (H) e equitabilidade (E); foram distintos nos dois levantamentos indicando distribuição de espécies mais uniforme na coleta de 2007 em relação à de 2008. Dentre as demais espécies predominantes, destacaram-se as abelhas Trigona spinipes (irapuá), Tetragonisca angustula (jataí), e Nannotrigona testaceicornis (iraí). As concentrações médias encontradas por clones foram inferiores ao relatado na literatura, sendo os valores máximos variando entre 13 e 14%. As diferenças encontradas entre alguns clones possivelmente foram influenciadas pela altura de algumas plantas. / The community of insect flower visitors of eucalyptus urograndis clones (Eucalyptus grandis x E. urophylla) was studied in an plantation located at Areão farm, in Piracicaba, São Paulo state, Brazil (22° 41 41 S e 47° 38 53 W ). Weekly collections were conducted using hand net during the bloom periods of 2007 and 2008 in order to characterize the potential for beekeeping by determining the associated apifauna and the nectar characteristics produced by the flowers.The anthophilous community in the two-year survey was represented by 29,492 individuals belonging to 6 orders, 21 families, 43 genera and 52 species. The apidofauna was represented by 24,882 individuals belonging to 11 genera and 10 species. The Africanized honey bee Apis mellifera. This species was the most effective visitor throughout the survey (80.96%) followed by the syrphid Ornidia obesa (5.29%) and the mantispid Zeugomantispa virescens (4.26%). The diversity (H\') and equitability (E) indices were different between the two surveys showing that species distribution was more uniform in the collecting of 2007 when compared to the 2008. Among the other dominant species, the bees Trigona spinipes (Irapuá bee), Tetragonisca angustula (jataí bee), and Nannotrigona testaceicornis (Iraí bee) were the main ones. The differences found between some clones were possibly influenced by the height of some plants.

The purpose of this study is to show that the method just proposed can be used for the synthesis of 2-halo benzyl glycosides. And these derivatives can be used to synthesize biologically interesting compounds which were not previously attainable using the 2-halo-2-deoxy methyl glycosides which are currently available.

Due to the importance of carbohydrates in biological systems, many efforts have been made to develop a quantitative method for analysis of carbohydrates in natural waters. The low concentrations of dissolved sugars in natural waters require a sensitive analytical method. In this study, gas chromatography of alditol acetate derivatives of sugars was investigated for quantitative and qualitative analysis of individual dissolved sugars in natural waters. The alditol acetate derivatives of sugars give only one derivative for each sugar, yielding qualitative and quantitative results. The detection limit was 25 nM for each sugar. Because of this very low detection limit, only 100 ml of sample was required for analysis. From measurements of the alditol acetate derivatives, qualitative and quantitative analysis of pentoses (arabinose and xylose) and hexoses (mannose, galactose, and glucose) were obtained from The Williamson River and its tributaries, which are located near Klamath Falls, Oregon. Total organic carbon concentrations vary greatly in this river system as a result of the river passing through Klamath Marsh, which introduces very high amounts of humic substances into the river system. The range of total concentrations of dissolved sugars is 0.07 to 7.3 μM; the lowest occurring in the spring waters, and the highest in humic-rich waters. Monosaccharide, polysaccharide, and humic-bonded saccharide concentrations, which were obtained from three sample sites, showed very low concentrations of monosaccharides, moderate concentrations of polysaccharides, and moderately high concentrations of humic-bonded saccharides.

No description available.

Lignocellulosic ethanol production currently uses expensive and harsh methods to extract wood sugars from small-diameter hardwood trees that otherwise would have little or no marketability. A byproduct that adds no value to the conversion process results, thus alternative methods are needed to make this fuel source cost-effective. This dissertation proposes only partially hydrolyzing southern hardwoods, extracting some polysaccharides for ethanol fermentation while leaving behind a modified wood material which could be used as furnish for manufacturing strand-based wood composites. Three treating solutions, 1% sulfuric acid, water, and 1% sodium hydroxide, along with untreated controls, were utilized in a partial hydrolysis at 150°C for 30 minutes. The treatments’ effects were measured by testing the mechanical, physical, surface, and durability properties of red oak, sweetgum, and yellow-poplar miniature beams (3 mm x 15 mm x 150 mm, t x r x l). These properties were then correlated to the polysaccharide content of the modified woods following treatment. All treatments provided a significant mass loss, with sweetgum’s mass loss being significantly greater than the other species. The initial effect of the partial hydrolysis on modulus of elasticity (MOE) showed water reduced MOE the least for each species. Sweetgum produced a higher reduction in MOE in all three solutions. Specific modulus was calculated to eliminate the density effect between the treatment combinations for measuring bending properties at oven-dry conditions. Sweetgum produced a lower SM in all treatments, and only the water treatment consistently reduced SM across all species. Wettablility was measured by dynamic contact angle analysis via the Wilhelmy plate technique in four probe liquids. Surface energies were then calculated by the geometric mean procedure. Acid and water treatments improved the wettability for all species. Alkaline treatment effects were species-specific. All treatments improved the surface energy of red oak. The AWPA E1-09 no-choice termite test determined mass loss due to Reticulitermes flavipes Kollar. Yellow-poplar averaged a significantly higher mass loss while wood treated in water or NaOH showed a higher degree of termite degradation compared to the controls. Polysaccharide content significantly correlated with mass loss due to treatment and specific modulus.

No description available.

Amongst the very many different kinds of amino sugars, theones that have aroused the most interest are the 2-amino 2-deoxy hexoses which are found in such well known antibiotics as streptomycin and neomycine (2). There are so far about forty-three antibiotics which are known to contain different aminosugars (6). Aminosugars exhibit the same properties as other reducing aldohexoses, e. g. reduction of silver and cupric salts, oxidation to hexonic acids, reduction to alcohols and formation of glycosides. The object of this project is to synthesize methyl N-acetyl α-D-talosaminide which has previously been prepared by Jeanloz (3) following a different route. The path that jeanloz, Jeanloz, and Glazer (3) followed involved the preparation of methyl 2-acetamide 4, 6-benzylidene 2-deoxy α-D-idospyradoside by ammonolysis of methyl 2,3-anhydro 4,6-benzylidene α-D-idospyranoside which was converted to methyl 2-acetamido 4,6-benzylidene talopyranoaide by treatment with sodium acetate in aqueous 2-methoxyethanol. This compound was debenzylidenated with aqueous acetic acid and acetylated to obtain methyl 2-acetamido 3,4,6-tri-0-acetyl talosaminide. In short, the above route involved essentially a direct conversion from the idose series into the talose series which is illustrated in Scheme I.

Hydrolysis of cellulosic biomass is an important and ongoing subject of research due to generating precursors for biofuel synthesis. This work involves hydrolysis of microcrystalline cellulose and Arundo donax to glucose. Methods for acid hydrolysis include the use of sulfuric acid, phosphomolybdic acid, blue molybdenum using low concentrations at 40-100 °C. For comparison purposes, enzymatic hydrolysis was also carried out using cellulase. Products were quantified by measuring total organic carbon and reducible sugars using dinitrosalicylic acid. Use of phosphomolybdic acid, blue molybdenum and sulfuric acid even at 6.0 M did not increase the amount of glucose compared to using water only. Interestingly, enzymatic hydrolysis of powdered Arundo donax without pretreatment was successful and resulted in statistically similar amounts of glucose compared to using microcrystalline cellulose. Efforts are ongoing to understand the enzyme kinetics in the hydrolysis of Arundo donax and potentially increase the yield of glucose using chemical and microbiological pretreatment.