published_or_final_version / abstract / toc / Chemistry / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 195).

Universiẗat, Diss.--Paderborn, 2000.

Thesis (Ph. D.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 213-224).

Universiẗat, Diss., 2001--Kiel.

Magister Scientiae - MSc (Chemistry) / Global climate change and geographical differences are two major parameters known to have, either, direct or indirect influence on the production of secondary metabolites in plants, which in-turn may affect the quality and/or quantity of the overall metabolites. The primary purpose of this thesis was to evaluate the phytochemistry of the whole leaf of Aloe succotrina Lam. spp. - a South African native plant - through a chromatographic spectroscopic approach-against available data accumulated for the cultivated population. Preliminary screening of the crude extracts i.e. HEX, DCM and EtOAc on TLC aluminium plates precoated with silica gel 60 F254 followed by various chromatographic separation, led to the isolation of five known compounds: ?-sitosterol (1) and two anthrone-C-glycosides (2 and 5), including two coumarin derivatives-the aglycone (3) and glycoside derivative (4). Notably, apart from 5 and 2, the accumulation of 1, 3 and 4 in A. succotrina Lam. spp. is reported for the first time. Structural elucidation of the individual compounds was achieved by extensive spectroscopic analysis i.e. MS, IR, 1H and 13C-NMR spectroscopy and in some cases comparison to the literature. A comparative HPLC chromatogram of the crude MeOH extract of the leaves of A. succotrina Lam. was developed for qualitative (and quantitative) identification of the active metabolites, which could be realized by VWD with detection at 290 nm.

>Magister Scientiae - MSc / Ethylene and propylene are greatly used for their importance as feedstocks for producing useful materials. Due to rise in prices and the demand of ethylene and propylene, the need to increase the selective production of these light olefins is necessary. To achieve this, zeolites, specifically ZSM-5 has been used to investigate catalytic cracking of several types of hydrocarbons for the production of these light olefins. This study focuses on developing hierarchical macro and/or mesoporous ZSM-5 zeolites with variable Si/Al ratios. The synthesized materials were then evaluated on their performance via catalytic cracking of hexane, dodecane and tyre derived oil [TDO] to produce light olefins, particularly ethylene and propylene.

This thesis examines the reactions of hydrocarbons exposed to chlorosulfonic acid in order to establish the reaction rate and associated molecular structure of each compound.

This thesis describes an experiment to chorinate neohexane, and the resulting compounds.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Vita. / Includes bibliographical references. / by Timothy George Peter Gutowski. / Ph.D.