Physical Sciences and Mathematics Commons^™

Titanium Dioxide Photocatalytic Degradation Of Aliphatic Ethers And Their Primary Oxidation Products, Vivian Cruz

FIU Electronic Theses and Dissertations

Two studies were performed to obtain fundamental mechanistic information on the TiO₂ catalyzed degradation of organic substrates irradiated at 350 nm in dilute aqueous solutions under oxygenated conditions: (a) The photodecomposition of methyl tert-butyl ether (MTBE) and its intermediate products from β - oxidation, 2-methoxy-2-methylpropanol and 2-methoxy-2-methylpropanal. (b) The photodecomposition of two haloethers, bis-(2-chloroethyl) ether, and bis-(2-chloroisopropyl) ether. Controls were carried out throughout the two studies in the absence of light, and without the semiconductor in order to evaluate the role of photolysis.

The syntheses of proposed intermediate products, 2-methoxy-2-methylpropanol, 2-methoxy-2-methylpropanal, 2-methoxy-2-methylpropanoic acid, 2-chloroethyl formate, and 1-chloro-2-propyl acetate, …

Oxidation Of Zeaxanthin And Characterization Of 3'-Alkyl Lutein Ethers, Jie Chi

FIU Electronic Theses and Dissertations

One purpose of this study was to understand the oxidation metabolites of zeaxanthin, another was to prepare, purify, and characterize a series of 3'-alkyl lutein ethers for use as internal standards.

Studies have proven that lutein and zeaxanthin are two of the principal carotenoids in human serum and the only carotenoids found in the retina, but their metabolism and transport in the human body are still only poorly understood. In vitro oxidation of zeaxanthin with MnO₂ produced three components. They were characterized by HPLC, UV/Vis, MS, NMR and identified as all-trans rhodoxanthin and its cis-isomers.

3'-alkyl lutein ethers have …

An Approach For Clarification Of The Mechanism Of Inactivation Of Ribonucleotide Reductases With 3'<¹⁷O>-Labeled 2'-Azido-2'-Deoxynucleotides, Saiful Mahmud Chowdhury

FIU Electronic Theses and Dissertations

Inactivation of ribonucleotide reductases by 2'-azido-2'-deoxynucleotides is accompanied by appearance of new EPR signals for a nitrogen-centered radical. The structure of this elusive nitrogen-centered radical has been studied extensively and shown to be derived from azide moiety. Synthesis of 3'[¹⁷ O]-labeled 2'-azido-2'-deoxyuridine-5'- diphosphate was targeted in this research. Such a labeled analogue should perturb the EPR spectrum in predictable fashion, and the hyperfine interaction between the free electron and the ¹⁷O nucleus should allow the choice between the recently proposed structures of this elusive radical (Van Der Donk, W. A. et al. J Am. Chem. Soc. 1995 …