Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 137-145). / Also available by subscription via World Wide Web / xiv, 145 leaves, bound ill. (some col.) 29 cm

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 103-110). Also available on the Internet.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 137-145).

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 103-110). Also available on the Internet.

>Magister Scientiae - MSc / Crude extracts from Myrothamnus flabellifolius were fractionated through variouschromatography techniques in order to achieve satisfactory separations. Two compounds, arbutin and lupeol, were isolated from the butanol and ethyl acetate extracts, respectively. Structural elucidation of the compounds was carried out on the basis of 1H and 13C NMR spectroscopy. It was the first time that lupeol had been isolated from M. flabellifolius.The water extract was found to contain heterogeneous pectic polysaccharides. Three polysaccharide fractions were separated from the water extract, namely; MPS, MPS-I and MPS-II. The predominant fraction was found to be MPS, with a molecular weight distribution of 2 X 105 Da. The polysaccharides were made up the following monosaccharides; arabinose, rhamnose, xylose, mannose, galactose and glucose. Monosaccharide composition was determined through acid hydrolysis at high temperatures, followed by GC analysis. The linkage analysis was carried out by GC-MS, following partial methylation of the polysaccharides. The use of human serum albumin (HSA) following its anchoring on magnetic nanoparticles, in order to isolate targeted saponins from Sutherlandia frutescens led to successful isolation of four saponins, namely; sutherlandiosides A-D. The saponins showed great affinity to bind to the HSA.

Nanoparticles are currently used in a wide range of applications including industrially processes, consumer products, and as drug delivery vehicles. The potential toxicity of these nanoparticles in living organisms is concerning due to their ever-expanding applications and accumulation in the environment. The effects of properties of the human body on the potential harmful nature of these nanoparticles must be understood in order to ensure safety in workplaces and at-home products. In this thesis, the interactions between nanoparticles and the most abundant blood protein, serum albumin, were investigated. The effects of changing the aqueous environment was investigated over a range of different pH values and with different ionic salts dissolved in water. The effects of changing the nanoparticle substrate were investigated to determine if different nanoparticles affect proteins differently. Finally, the effects of changing the concentration of nanoparticles and the presence of protein were investigated in a model lung cell line in vitro. The studies over different pH values revealed that serum albumin was able to adsorb to the silica nanoparticle surface, and retained its secondary structure both as a function of pH and adsorption in a 2-hour time frame. However, adsorption was greater on the titanium dioxide nanoparticle surface and the protein lost secondary structure at acidic pH (pH 2.0). Studies with different ionic salts revealed a possible correlation between BSA adsorption and nanoparticle aggregation in that the attractive interactions between nanoparticles were least when the least amount of protein was adsorbed. To the nanoparticle surface. In vitro studies with A549 human adenocarcinoma lung cells were inconclusive in determining the potential toxicity of these nanoparticles, but preliminary results suggested that the addition of protein to the system decreased toxicity compared with nanoparticles alone. This research aims to inform the field of nanotechnology to investigate the safety and efficacy of nanoparticles before they reach the consumer.

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This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

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