No description available.

<p> Undecynoic acid (UDA) attached to a silica hydride surface has been found to exhibit weak cationic exchange properties and an aqueous normal phase (ANP) type of retention. ANP is a mechanism similar to normal phase chromatographic retention, except for the use of a polar solvent such as water in the mobile phase. In ANP, the retention of a polar molecule is increased with a higher concentration of the non-polar mobile phase solvent (usually acetonitrile). Non-polar molecules exhibit retention behavior as in reverse phase (RP) chromatography. The goal of this research was to characterize the chromatographic retention pattern of an undecynoic based silica hydride column by studying various polar and nonpolar analytes. Also investigated were the effects of varying the buffer concentrations&mdash;formic acid and ammonium acetate and the effect of temperature on the retention of selected compounds. It has been established from the current work that a silica hydride based UDA column can be used for separation and analysis of nucleotides and nucleosides as well as phenolic acid components in pomegranate peel samples. A phenyl hydride column was additionally used to complete the study on the peel samples since the UDA column was not effective in separating isobaric compounds found in the peels. In conclusion, silica hydride based UDA column has been found to exhibit dual retention capabilities for polar and non-polar molecules.</p>

<p> Copper hydride (CuH) has been shown to enable a number of selective 1,2- and 1,4-reductions when complexed with the appropriate ligand, yet the allylic substitution chemistry of CuH has been much less studied. This dissertation describes the further study of CuH to perform sequential reductions on Morita-Baylis-Hillman (MBH) adducts. Specifically: I) Selectivity in the SN2&rsquo; reduction of MBH adducts was shown to be highly dependant on the nature of the ligand used. II) The reaction of MBH alcohols was shown to involve an initial dehydrogenative silylation with PMHS, where both the oligomeric nature and electronics of the initially formed trialkoxysilyl ether intermediate are important in determining both the observed stereoselectivity, and efficiency of the substitution. III) MBH ketones could be employed in tandem SN2&rsquo;/1,2-reduction sequences to arrive at stereodefined allylic alcohols with central chirality. </p><p> Vinylsilanes are versatile intermediates in organic synthesis owing to numerous methods for their transformation into other functional groups that proceed with high stereoretention. While there are numerous methods to synthesize stereodefined vinylsilanes from alkynes, many existing methods require the use of highly reactive moisture intolerant reagents and harsh reaction conditions, features that limit the functionality that can be accommodated. Even fewer of these existing methods are conducted under environmentally responsible conditions. The use of Suginome&rsquo;s reagent as a moisture tolerant source of nucleophilic silicon, small catalytic quantities of a simple copper(I) salt, and an aqueous solution of TPGS-750-M as an environmentally benign nonionic surfactant, is described herein as a highly effective combination of reagents that allows for the stereoselective silylcupration of conjugated alkynes giving access to a variety of (<i>E</i>)-&beta;-silyl-substituted carbonyl derivatives under environmentally responsible conditions. </p><p> This dissertation also describes the application of substituted allenoates as electrophilic butadienyl coupling partners under palladium catalysis in aqueous micellar media. The substituted allenoates could then be transformed by the methods developed herein into a variety of 2-substituted butadienes, where the methods were then extended to provide entry into a variety of substituted [3]-[6]dendralenes. Specifically: I) Application of an additive based screen allowed for evaluation of functional group tolerance in the Pd-catalyzed coupling of substituted allenoates with boronic acids. II) Curiosity driven investigations to identify boron based sp3 coupling reagents compatible with the conditions of micellar catalysis led to the identification of OBBD alkylborinate reagents as stable and isolable coupling reagents, which was the applied to the synthesis of 2-alkyl 1,3-butadienes. III) An analogous vinylallenyl coupling partner that functions formally as an electrophilic [3]dendralene synthon was proposed, and a number of synthetic routes were examined to access this molecule. Optimization of the synthetic route allowed for access to multigram quantities of this material, where it was applied to the synthesis of variously substituted [3]-[6]dendralenes. </p><p> Efforts to understand the marine mussels mechanism of strong wet adhesion has been a subject of intense scientific investigation. Analysis of the peptide sequence of mfp-5, a mussel foot protein most correlated with interactions at the interface, revealed a high proportion of charged, hydrophobic, and catechol containing residues. Described in this dissertation is the synthesis of small molecule underwater adhesives by incorporation of these key features of mfp-5. These newly designed molecules formed adhesive bilayers underwater, and were shown to replicate and even exceed mfp-5&rsquo;s strong wet adhesive energy, while also being orders of magnitude smaller than both the native mussel proteins or existing biomimetic adhesive platforms. By systematically varying key portions of these small molecular adhesives, the adhesive bilayers could be transformed into molecularly uniform monolayers which were applied to the nanofabrication of organic electronic devices.</p>

A major challenge in organic apple production in Vermont is the available fungicide options for apple scab management. The standard lime sulfur/sulfur fungicide program used can be injurious to the applicator, the apple ecosystem, and the apple tree itself. Because of these drawbacks of the standard program it is necessary to evaluate potential alternative fungicides for organic apple production. The objectives of this study were to: (i) compare the efficiency of potassium bicarbonate, neem oil, and Bacillus subtilis to a standard organic lime sulfur/sulfur fungicide program and a non-sprayed treatment for control of apple scab and other fungal diseases; (ii) evaluate potential non-target impacts of these fungicides on pest and beneficial insect populations; and (iii) conduct a preliminary experiment evaluating the potential of raw milk as a fungicide in organic apple production in Vermont. Five treatments (potassium bicarbonate, neem oil, Bacillus subtilis, lime sulfur/sulfur, and a non-sprayed treatment) were applied to „Empire‟ trees arranged in a completely randomized design with five single-tree replications at the University of Vermont Horticultural Research Center in South Burlington, VT. Fungicides were applied with a handgun to drip, using maximum label rates. Applications began on 26 April 2007 and 23 April 2008 and continued on approximately a weekly schedule through the end of June and then every two weeks through 23 July 2007 and 17 July 2008, respectively. Data obtained were analyzed by analysis of variance and significance between means was determined by Fisher‟s Protected LSD Test (P ≤ 0.05). None of the alternatives managed disease as well as the standard lime sulfur/sulfur fungicide program. The neem oil treatment showed more activity against apple diseases than the other alternative fungicides. Both the lime sulfur/sulfur and neem oil treatments had disadvantages, including phytotoxic burning and/or significantly more russetting on the fruit at harvest. The neem oil treatment had significantly more fruit clean of insect damage than the other alternatives and the non-sprayed treatment in 2007 and more than all treatments in 2008, which is attributable to its insecticidal properties. However, the insect management from the neem oil treatment was not commercially acceptable. The overall quality of the fruit was not at commercially acceptable levels. No treatment had above 40% of the harvested fruit placed in marketable grades. This research shows that potassium bicarbonate, Bacillus subtilis, and neem oil do not offer substantial advantages over the standard lime sulfur/sulfur fungicide program in organic apple production in Vermont. In a preliminary study at the University of Vermont Horticultural Research Center, the efficiency of a 30% v/v raw milk dilution was compared to a non-sprayed treatment. Treatments were applied to „McIntosh‟ trees in a completely randomized design with three single-tree replications. Milk applications were made on approximately a weekly schedule from 26 Apr 2007 to the end of June and every two weeks through 23 Jul 2007. Overall, milk did not provide management of disease and caused premature leaf yellowing and defoliation of the apple trees.

No description available.

No description available.

<p> Chemical identity is a foundational crosscutting concept in chemistry and encompasses the knowledge, reasoning, and practices relevant for the classification and differentiation of substances. Substances are found everywhere &ndash; from the chemistry classroom to the kitchen at home &ndash; so classification and differentiation of substances is important for everyday decisions as well as challenges that are solved using chemistry. An understanding of chemical identity, then, is essential for scientifically literate citizens in addition to students training to be chemists. A better understanding of how chemical identity thinking develops could be used to inform instruction and education research, with the intent of producing students and citizens who can use their chemical knowledge to reason with in order to practice chemical identity thinking. </p><p> This thesis characterizes chemical identity thinking from the perspective of chemical identity knowledge and chemical identity practices, both of which contribute to chemical identity thinking. First, the literature is examined for existing research on how students perceive substances and chemical identity, and a hypothetical learning progression for chemical identity thinking is proposed. This is followed by the design of a qualitative instrument, the CSI Survey, to capture the chemical identity practices exhibited by students at a range of education levels (8th grade &ndash; 4th year university). The data collected using the CSI Survey are analyzed using content analysis. Eight unique themes corresponding to chemical identity practices (the application of chemical identity knowledge and reasoning) are revealed by this analysis (<i>change, class, composition and structure, function, organism effect, sensory information, source, tests and experimental values</i>). The application of chemical identity knowledge in biochemical contexts by both expert biochemists and biochemistry students is investigated in the final chapter, and the chemical identity knowledge observed in the biochemical contexts is characterized using the eight themes of chemical identity practices. Suggestions are offered on how the products of the research on chemical identity thinking can be used to inform decisions in both instruction and research.</p>

Aeruginosins are a family of marine natural products containing mostly non-proteogenic amino acids. These compounds contain a common 2-carboxy-6-hydroxy-octaindole (Choi) rigid bicyclic structure. Many aeruginosins are inhibitors for enzymes involved in the blood coagulation cascade, such as thrombin and Factor VIIa. In order to understand the structure activity relationship (SAR) of the aeruginosins and to discover novel anticoagulants with potentially improved inhibitory and pharmacokinetic properties, in the first part of my thesis I have discussed, synthesis of a series of novel analogs of aeruginosin 298-A, in which the Choi will be replaced with L-proline and oxygenated Choi analogs, and the Argol is replaced with various other functionalities. The preparation of oxygenated Choi analogs starting from glucose using a new method has been discussed. In the second part of my dissertation, I have discussed the design, synthesis and self–assembly of glucosamine based hydro and organogelators. Carbohydrate-based low molecular weight gelators are an interesting class of molecules with many potential applications. A series of amides and ureas were prepared from the protected D-glucosamine from the corresponding acid chloride and isocyanates. The self-assembling properties of these compounds were studied in several solvents, including water and aqueous solutions. Most of these compounds were found to be efficient low molecular weight hydrogelators (LMHGs) for aqueous solutions. The preparation and characterization of these compounds will be elaborated.

N-Ethoxycarbonyl-5'-hydroxynorreticuline (1) was oxidized with vanadium oxytrichloride (VOCl(,3)) to give the para-ortho coupled N-ethoxycarbonyl-2-hydroxynorsalutaridine (2) in 55% yield. / Dienone 2 was converted into N-ethoxycarbonyl-2-hydroxynorthebaine (3) in 47% yield. Hydrolysis of 3 gave an 85% yield of N-ethoxycarbonyl-2-hydroxynorcodeinone (4) which upon reduction produced ((+OR-))-2-hydroxycodeine (5). / Reaction of the protected thebaine analogue 6 with singlet oxygen generated the protected 2,14-dihydroxynorcodeinone derivative 7. Selective dehydroxylation with concurrent double bond reduction gave the known N-ethoxycarbonylnoroxycodone (8); subsequent hydrolysis of 8 then concluded the total synthesis of ((+OR-))-noroxycodone (9). / Source: Dissertation Abstracts International, Volume: 42-01, Section: B, page: 0225. / Thesis (Ph.D.)--The Florida State University, 1981.

This thesis describes the work performed by the author during PhD studies at FSU. The first two chapters present the summary of the studies done trying to accomplish the first total synthesis of aldingenin B - a natural product first isolated in 2003. While our studies were ongoing, some additional information on the structure of the natural product emerged, therefore our studies and their relationship with the literature available up to 2015 are discussed in detail. Chapters 3 through 6 represent the main topic of the thesis. They focus on the studies directed towards the development of the efficient synthesis of ent-progesterone - a potential drug candidate for the treatment of traumatic brain injury. Chapter 3 introduces the problem and the necessity for such synthesis and reviews the literature relevant to the topic. Chapter 4 presents an improved synthesis of rac-progesterone - an important step in the synthesis of ent-progesterone. Chapter 5 compares the efficiency of the two approaches: an old one and the improved route. / A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the Doctor of Philosophy. / Spring Semester 2015. / April 29, 2015. / aldingenin B, benzylation, ent-progesterone, process improvement, progesterone, total synthesis / Includes bibliographical references. / Gregory B. Dudley, Professor Directing Dissertation; John Telotte, University Representative; Tyler McQuade, Committee Member; Sourav Saha, Committee Member; Michael Shatruk, Committee Member.