Thesis (M.S.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 64-66).

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (p. 74-81).

Příbram uranium and base-metal district is the most important vein uranium district in the Czech Republic. The main ore was represented by uraninite there and the occurrences of selenium mineralization are directly connected to it. The presence of selenides was not confirmed during the mining activities. Major development of the uranium-carbonate mineralization was found in the Bytíz deposit in the central part of the uranium district. All known occurrences of selenides have been found from this area only so far. Antimonselite, athabascaite, bellidoite (?), berzelianite, brodtkorbite, bukovite, clausthalite, dzharkenite, eskebornite, eucairite, giraudite, hakite, cadmoselite, klockmannite, naumannite, permingeatite, sabatierite, tiemannite and umangite, as well as the new unnamed selenium analogue of chalcostibite were newly identified from the dump material from the shafts No. 16 and 11A. The extremely Hg-rich hakite, which contains up to 30 wt.% of Hg, is the most remarkable mineral from the tetrahedrite group of minerals. The pertinence of the Hg-hakite was verified by means of the transmission electron microscopy. Uncommon recently formed supergene selenium association is represented by molybdomenite, munakataite and piretite. A large scale of associated minerals was found in association with...

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A primeira parte desta tese consiste na preparação de compostos aromáticos contendo átomos de selênio e de telúrio. Quatro metodologias foram utilizadas para essa finalidade, a saber: orto-metalação de compostos contendo oxigênio, troca metal-halogênio em haletos aromáticos substituídos, reação de substituição eletrofílica aromática entre tetracloreto de telúrio e compostos aromáticos ativados e reação de sais de diazônio com disselenetos e diteluretos orgânicos. Alguns dos teluretos preparados foram usados em reações de acoplamento com alcinos terminais catalisada por Paládio, em reações de troca telúrio-lítio e em reações de oxidação de Te (II) a Te(IV). A segunda parte da tese consiste no uso de calcogenetos de arila em reações biocatalisadas. Inicialmente foram estudadas biotransformações em substratos não contendo átomo de selênio e de telúrio. Reações de redução de carbonila e de desracemização de álcoois foram observadas por ação de fungos e de raízes de plantas. Meta e para organosseleno acetofenonas foram reduzidas aos organosseleno feniletanóis correspondentes por ação de fermento de pão, células íntegras de fungos e por Daucus carota com conversões e excessos enantioméricos que chegaram a >99%. Orto organosseleno e metiltio feniletanóis foram resolvidos em seus isômeros R e S por ação de lipase imobilizada (Novozyme 435) em presença de acetato de vinila com excessos enantioméricos acima de 99% . / The first part of this thesis shows the preparation of organic compounds containing selenium or tellurium. For this purpose, four methodologies were applied: ortho-metallation of 1-phenylethanol, metal-halogen exchange involving aromatic halides, electrophilic aromatic substitution using tellurium tetrachloride and reactions with aryldiazonium salts and diselenides or ditellurides. Next, the aryl tellurides were applied in Palladium catalyzed coupling reactions with terminal alkynes, tellurium-lithium exchange reactions and oxidation of Te(II) to Te(IV). The second part of this thesis consists in the inverstigation of biocatalyzed reactions. Biotransformations of substrates without Se or Te atoms were initially investigated. Carbonyl reduction reactions and deracemization of secondary alcohols were observed by means of whole fungal cells and plants. Meta and para organoseleno acetophenones were then reduced with baker´s yeast, whole fungal cells and Daucus carota, yielding the corresponding organoseleno phenylethanols optically pure with enantiomeric excess up to >99%. Ortho organoseleno e methylthio phenylethanols were resolved in both enantiomeric forms by reacting them with immobilized lipase (Novozyme 435) and vinyl acetate in hexane. High values of enantiomeric excess (>99%) were obtained.

The overproduction of reactive oxygen species (ROS) have been linked to diseases and other pathologies. As therapeutic agents, antioxidants have been tested and some shown to attenuate these diseases by relieving oxidative stress. The May laboratory has previously developed a family of phenylaminoalkyl selenides and has demonstrated the antihypertensive and antioxidant properties of these compounds. To further understand the antioxidant property of these selenide compounds, the two step mechanism of the reaction between the selenoxide form and glutathione was investigated by stopped-flow and mass spectrometry, leading to the detection and characterization of a novel thioselenurane intermediate. Mass spectrometry studies supported the redox cycle of the selenide compounds as a straightforward cycle with no byproducts or side reactions and was the first evidence reported of a thioselenurane intermediate present in a reduction reaction of a selenoxide. The therapeutic potential of these compounds was further supported by cell and histological studies demonstrating their ability to alleviate the cardiotoxic effect of anthracyclines without affecting the anti-cancer property of the drugs. Codosage of a phenylaminoethyl selenide with Doxorubicin decreased the infiltration of inflammation cells in the myocardium of mice. Phenylaminoethyl selenides were also able to maintain the body weight of mice treated with Doxorubicin, compared to mice treated with Doxorubicin alone. In order to make the possibility of using Phenylaminoalkyl selenides as therapeutic agents or supplements with other agents, delivery of the compounds was investigated. N acetyl phenylaminoethyl selenides were successfully encapsulated into poly(lactic-co-glycolic) (PLGA) nanoparticles using the nanoprecipitation technique. An attempt was made to demonstrate the ability of these selenide- nanoparticles to reduce cellular oxidative stress caused by incubation with LPS. Future studies are needed to optimize the loading of the selenide compounds into nanocarriers and to demonstrate the ability of the encapsulated drug to work as the free drug. The long term goal of this research is to fully understand the potential of phenylaminoalkyl selenides as an efficient therapeutic agent for ailments derived from increased levels of ROS and a state of oxidative stress. As a supplemental project funded by the National Science Foundation, the Center for Innovative Biomaterial Education and Research (CIBER) was created. Enzymatically catalyzed reaction and polymerizations were investigated using Candida antarctica Lipase B (CALB). Several CALB catalyzed Michael addition reactions were successful and yielded compounds that could be used as future reactants and monomers. As an education requirement of the project a website was created in order to educate the public of the importance, sources and uses of biomaterials. The website provides information for all levels of students and educators. This center has allowed The Georgia Institute of Technology to form relationships and exchange programs with leading universities around the world allowing the exchange of knowledge and research in biomaterials.