In this course of their work J. Risi and A. Labrie (1) found that guaiacol and vanillin were among the products derived from the sap of the sugar maple. By using a five percent sucrose solution and equal quantities of vanillin and guaiacol, a little calcium malate and manganese acetate, they obtained an amorphous powder possessing no odor of vanillin or guaiacol but having an odor greatly resembling the odor of the extracts of the sugar maple. This work is an investigation of the actual products of the reactions involved and the mechanism pertaining thereto. It is proposed to study this problem by carrying out the experiment of Risi and Labrie except that the constituents guaiacol, vanillin and sucrose will be used first one at a time, then two at a time and finally all together in an effort to determine the reaction and its mechanism. The following conclusions have been drawn from the work done: 1. The author has been unable to duplicate the work of Risi and Labrie by following their brief directions. 2. Several modifications of their procedure failed to produce the product described. 3. No change was found when each component was used alone in any of the modifications. 4. No change was found when the components were used two at a time in any of the modifications used. 5. No change was found using all three components in any of the modifications used. / M.S.

M.S.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1947. / Includes bibliographical references (p. 88-91).

La vanillyl alcool oxydase est un biocatalyseur prometteur d’un point de vue réactionnel en raison de sa faible sélectivité sur les composés phénoliques substitués en position para. Elle catalyse l’oxydation d’une large gamme de dérivés 4-hydroxybenzylique, des réactions de déméthylation oxydative, de désamination, de déshydrogénation et d’hydroxylation ; notamment celle de l’eugénol. L’hydroxylation de ce dernier conduit à la formation d’alcool coniférylique. Dans le but d’utiliser l’eugénol comme substrat de biosytnhèse de dérivés vanilliques, nous avons développé, au cours de ce travail de thèse, deux souches exprimant le biocatalyseur d’intérêt : une souche de levure et une souche bactérienne.La première partie de la thèse a donc consisté à mettre au point un système d’expression pour la production de VAO dans la levure de boulanger et un procédé d’hydroxylation de l’eugénol en fermenteur. Le principal apport réside dans la construction de la souche 93645, qui contient la cassette d’expression VAO et une activité oxydase propre permettant la bioconversion de l’alcool coniférylique formé en acide férulique. En fonction des conditions de fermentation, 20 g/l d’alcool coniférylique ou 27 g/l d’acide férulique sont produits par les cultures de S. cereviaise- VAO 93645. La reproductibilité des procédés, ainsi que leur faisabilité à l’échelle pilote, ont été démontrés.Dans la seconde partie de cette étude, le même travail de clonage a été réalisé dans la souche Amycetales Streptomyces setonii ATCC 39116. La bactérie, reclassifiée en 2009 sous le nom d’Amycolatopsis sp 39116, est connue pour sa capacité à bioconvertir l’acide férulique en vanilline ; d’où l’intérêt d’exprimer l’enzyme VAO dans cette souche. Plusieurs stratégies de clonage ont été expérimentées et une souche recombinante, exprimant une activité VAO active a été obtenue. Les conditions optimales pour l'utilisation de cette dernière dans le cadre de la production de vanilline et d’alcool coniférylique ont été identifiées. Elles conduisent à la biosynthèse de 0,4 g/l vanilline et de 15 g/l d’alcool coniférylique. Les résultats mettent en évidence une activité insuffisante des oxydases de Streptomyces sur l’alcool coniférylique formé. Ce type de production n’a encore jamais été réalisé chez S. setonii et ces premiers résultats demandent encore des mises au point avec, sans doute, le clonage d’oxydases hétérologues permettant la bioconversion de l’alcool coniférylique formé en acide férulique. / Our aim was to develop a process for the biosynthesis of vanillin derivatives from eugenol.Vanillyl alcohol oxidase isolated from Peniciiiium simplissicimum, catalyzes the hydroxylation of eugenolinto coniferyl alcohol. In this study, two strains expressing the biocatalyst were constructed: a yeast,Saccharomyces cerevisiae, and a bacteria; Streptomyces setonii.It has been demonstrated that the wild strain Saccharomyces cerevisiae can bioconvert coniferyl alcohol, most probably due to its dehydrogenase activity. Strain 93645, genetically modified to expressvanillyl-alcohol oxidase, enabled us to optimize an industrial scale process for the production of natural ferulic acid.Streptomyces setonii strain ATCC 39116 was also genetically engineered to over-express VAO. Abioconversion process was developed leading to a coniferyl alcohol concentration of 15 g/1 coniferyl alcohol. The impact of several parameters; such as temperature, substrate addition mode and pH, werealso explored to improve the bioconversion reaction of coniferyl alcohol to vanillin. The amounts of product resulting from bacterial biosynthesis were however too low for implementation of an industrial process.

This thesis describes the synthesis, characterization and magnetic investigation of homometallic lanthanide complexes based on two different o-vanillin-derived Schiff base ligands: H2ovph and H2ovgrd. The studies were performed using single crystal X-ray diffractometry, Powder XRD and SQUID magnetometry. Chapter 2 focuses on dinuclear systems 1-8 coordinated to the ligand H2ovph and presents their structural and magnetic properties, mainly with respect to their intramolecular interactions. Chapter 3 describes two hexanuclear systems, 9 (DyIII) and 10 (GdIII), with trigonal prism-assembled core structures. A structural comparison to other similar complexes in the literature is performed. A series of dinuclear complexes, 11-15, based on the ligand H2ovgrd are described in Chapter 4, focusing on the synthetic strategy, crystal structures and magnetism. The presence of the lanthanide contraction is evident in this system of complexes and is consistent with the intrinsic lanthanide contraction property.

No description available.

In der vorliegenden Dissertationsarbeit wird auf die Thematik der Entwicklung von Polymerwerkstoffen, basierend auf vollständig natürlichen Resourcen, eingegangen. Die vorliegende Lösung beruht auf der Compoundierung von Polylactid mit unterschiedlich modifizierten Vanillin. Ziel war es, flammschutzwirkende Komponenten einzubringen und die Abhängigkeiten zwischen Zusammensetzung und Eigenschaften aufzuklären. Dem liegt die Absicht zugrunde, optimale Werkstoffe zur Verfügung zu stellen, die sich durch deutlich verbesserte flammhemmende und mechanische bzw. thermo-mechanische Eigenschaften auszeichnen. Die erzeugten modifizierten Vanillin-Derivate sowie deren Composite wurden hinsichtlich der physikalischen und chemischen Struktur mittels REM, EDX, FTIR, NMR, DSC, TGA, SEC und Zugversuch charakterisiert. Zur Bestimmung der flammwidrigen Eigenschaften wurden UL-94 V, LOI und CCT durchgeführt. Es hat sich gezeigt, dass System aus PLA und einem Vanillin-Phosphorsäure-Ester in Bezug auf werkstofflichen Eigenschaften insgesamt die optimale Leistung aufwies. Die Materialen ergaben eine verbesserte Zähigkeit und erheblich erhöht flammwidrige Eigenschaften. In einem weiteren Schritt wurden MMT und APP, zwei kommerzielle Flammschutzmittel, mit dem PLA/VP System kombiniert. Die daraus abgeleiteten Resultate bewiesen eine synergistische Wirkung zwischen VP und MMT bzw. APP und führten zu besseren Brandklassen bei LOI und UL-94 Brandtests. / The present work demonstrates the development of fully bio-based polymeric composites. It was realized by the compounding of poly(lactic acid) and differently modified vanillin. The aim of this work was to introduce flame retardant components into PLA and to study the flame retardant mechanism. The intention of this approach is the preparation of optimized PLA composites with significantly improved flame retardant, mechanical as well as thermo-mechanical properties. The modified vanillin and the PLA composites based on those vanillin derivatives were characterized by means of SEM, EDX, FTIR, NMR, DSC, TGA, SEC and tensile test for their physical and chemical structures. UL-94 V, LOI and CCT were carried out to determine the corresponding flame retardant properties. The results showed that, the PLA/VP system represented the best overall performance. The PLA/VP composite exhibited increased toughness and significantly improved flame retardancy. In addition, two commercialized flame retardants, MMT and APP, were introduced into the PLA/VP system, respectively. It was suggested that there were synergic effects between VP and MMT as well as APP. The combined used flame retardants resulted in an improved classification in UL-94 and LOI tests.

Admixtures like reactants and byproducts are solublenon-crystallizing compounds that can be present in industrialsolutions and affect crystallization of the main substance.This thesis provides experimental and molecular modellingresults on the influence of admixtures on crystal nucleation ofvanillin (VAN). Seven admixtures: acetovanillone (AVA),ethylvanillin (EVA), guaiacol (GUA), guaethol (GUE), 4-hydroxy-acetophenone (HAP), 4-hydroxy-benzaldehyde (HBA), andvanillic acid (VAC) have been used in this study. Classicalnucleation theory is used as the basis to establish arelationship between experimental induction time andsupersaturation, nucleation temperature, and interfacialenergy. A novel multicell device is designed, constructed, andused to increase the experimental efficiency in thedetermination of induction times by using 15 nucleation cellsof small volumes simultaneously. In spite of the largevariation observed in the experiments, the solid-liquidinterfacial energy for each VAN-admixture system can beestimated with an acceptable statistical confidence. At 1 mole% admixture concentration, the interfacial energy is increasedin the presence of GUA, GUE, and HBA, while it becomes lower inthe presence of the other admixtures. As the admixtureconcentration increases from 1 to 10 mole %, the interfacialenergy also increases. The interfacial energies obtained are inthe range 7-10 mJ m-2. Influence of admixtures on metastable zone widthand crystal aspect ratio of VAN is also presented. Theexperimental results show that the admixtures studied arepotential modifiers of the nucleation of VAN. Molecularmodelling by the program Cerius2 is used to identify the likelycrystal growth faces. Two approaches, the surface adsorptionand the lattice integration method, are applied to estimatequantitatively the admixture-crystal interaction energy on thedominating crystal faces of VAN,i.e., {0 0 1} and {1 0 0}. However, a simple and clearcorrelation between the experimental values of interfacialenergy and the calculated interaction energies cannot beidentified. A qualitative structural analysis reveals a certainrelationship between the molecular structure of admixtures andtheir effect on nucleation. The determination of the influenceof admixtures on nucleation is still a challenge. However, themolecular and crystal structural approach used in this thesiscan lead to an improved fundamental understanding ofcrystallization processes. Keywords: Crystallization,nucleation, vanillin, admixtures, additives, impurities,induction time, interfacial energy, molecular modelling,interaction energy.

<p>Admixtures like reactants and byproducts are solublenon-crystallizing compounds that can be present in industrialsolutions and affect crystallization of the main substance.This thesis provides experimental and molecular modellingresults on the influence of admixtures on crystal nucleation ofvanillin (VAN). Seven admixtures: acetovanillone (AVA),ethylvanillin (EVA), guaiacol (GUA), guaethol (GUE), 4-hydroxy-acetophenone (HAP), 4-hydroxy-benzaldehyde (HBA), andvanillic acid (VAC) have been used in this study. Classicalnucleation theory is used as the basis to establish arelationship between experimental induction time andsupersaturation, nucleation temperature, and interfacialenergy. A novel multicell device is designed, constructed, andused to increase the experimental efficiency in thedetermination of induction times by using 15 nucleation cellsof small volumes simultaneously. In spite of the largevariation observed in the experiments, the solid-liquidinterfacial energy for each VAN-admixture system can beestimated with an acceptable statistical confidence. At 1 mole% admixture concentration, the interfacial energy is increasedin the presence of GUA, GUE, and HBA, while it becomes lower inthe presence of the other admixtures. As the admixtureconcentration increases from 1 to 10 mole %, the interfacialenergy also increases. The interfacial energies obtained are inthe range 7-10 mJ m^-2. Influence of admixtures on metastable zone widthand crystal aspect ratio of VAN is also presented. Theexperimental results show that the admixtures studied arepotential modifiers of the nucleation of VAN. Molecularmodelling by the program Cerius2 is used to identify the likelycrystal growth faces. Two approaches, the surface adsorptionand the lattice integration method, are applied to estimatequantitatively the admixture-crystal interaction energy on thedominating crystal faces of VAN,<i>i.e</i>., {0 0 1} and {1 0 0}. However, a simple and clearcorrelation between the experimental values of interfacialenergy and the calculated interaction energies cannot beidentified. A qualitative structural analysis reveals a certainrelationship between the molecular structure of admixtures andtheir effect on nucleation. The determination of the influenceof admixtures on nucleation is still a challenge. However, themolecular and crystal structural approach used in this thesiscan lead to an improved fundamental understanding ofcrystallization processes. Keywords: Crystallization,nucleation, vanillin, admixtures, additives, impurities,induction time, interfacial energy, molecular modelling,interaction energy.</p>

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 151-159). Also available on the Internet.