Lee Wai Hang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 71-76). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract --- p.ii / Table of Contents --- p.v / Abbreviations --- p.viii / List of Figures --- p.ix / List of Tables --- p.xiv / Chapter / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- The French Paradox --- p.1 / Chapter 1.2 --- Flavonoids --- p.2 / Chapter 1.3 --- Grape seed extract --- p.4 / Chapter 1.4 --- Instrunmental analysis --- p.7 / Chapter 1.4.1 --- High Performance Liquid Chromatography --- p.7 / Chapter 1.4.2 --- Colorimetry --- p.9 / Chapter 1.5 --- Capillary Electrophoresis --- p.10 / Chapter 1.5.1 --- Instrunmentation --- p.10 / Chapter 1.5.2 --- Electroosmotic Flow --- p.11 / Chapter 1.5.3 --- Electrophoretic mobility --- p.13 / Chapter 1.6 --- Objective of the study --- p.15 / Chapter 2. --- Experimental --- p.18 / Chapter 2.1 --- Reagents and material --- p.18 / Chapter 2.1.1 --- Reagents --- p.18 / Chapter 2.1.2 --- Instrunmentation --- p.18 / Chapter 2.1.3 --- Reference compounds --- p.19 / Chapter 2.1.4 --- Samples --- p.19 / Chapter 2.2 --- Selection of solvent for sample preparation --- p.20 / Chapter 2.3 --- Procedures --- p.21 / Chapter 2.3.1 --- Preparation of running buffer solution --- p.21 / Chapter 2.3.2 --- Preparation of standard solution --- p.21 / Chapter 2.3.3 --- Preparation of sample solution --- p.22 / Chapter 2.3.4 --- Flushing procedures --- p.22 / Chapter 3. --- Results and Discussion --- p.24 / Chapter 3.1 --- Preliminary experiments --- p.24 / Chapter 3.2 --- Effect of pH --- p.27 / Chapter 3.3 --- Addition of surfactant --- p.30 / Chapter 3.4 --- Effect of SDS concentration --- p.35 / Chapter 3.5 --- Addition of cyclodextrins --- p.39 / Chapter 3.6 --- Urea --- p.46 / Chapter 3.7 --- Addition of organic modifier --- p.47 / Chapter 3.8 --- Effect of borate concentration --- p.49 / Chapter 3.9 --- Effect of cyclodextrin concentration --- p.53 / Chapter 3.10 --- Optimized condition --- p.58 / Chapter 3.11 --- Reproducibility of the method --- p.58 / Chapter 3.12 --- Quantitative analysis of reference compounds --- p.60 / Chapter 3.13 --- Application of the CE method in grape seed products --- p.62 / Chapter 4. --- Conclusion --- p.69 / References --- p.71

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

African Americans (AA) are at great risk of cardiovascular diseases (CVD) which can lead to brain damage, dementia, and endothelial dysfunction. Decreased nitric oxide (NO) bioavailability contributes cardiovascular disease in AA population. Flavonols of the subclass known as flavonoids that have several beneficial effects on cerebral blood flow and cerebral vasomotor reactivity (CVMR). This study investigated the effects of the acute consumption of a flavanol-rich cocoa drink on CVMR. Ten non-smoking African American (6 males and 3 females) participants were randomly recruited. The subjects participated in two experimental sessions which were separated before and after the consumption of cocoa drink. For the pre-session, baseline CVMR was measured by the hypercapnia rebreathing (CVMR test) prior to the consumption of the cocoa drink and the again at 2h after consumption of one serving of the cocoa drink (45g of cocoa mixed with 8oz of cold water). Cerebral vascular conductance (CVC) was significantly increased in the post-study during hypercapnia rebreathing compared with the pre-study(post-study: 3.649 ± 1.833 CVC % of baseline/mmHg, pre-study: 2.483 ± 1.418 CVC % of baseline/mmHg vs. P < 0.05) Thus, CVMR was significantly increased in the post-study after the acute consumption of a flavonol-rich cocoa drink compared to the pre-study in AA. / text

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No description available.

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No description available.

In the present study the acetone extract of the heartwood of two trees, Virgilia oroboides and Chlorophora excelsa, were investigated. The heartwood of Virgilia oroboides afforded a variety of known flavonoids, as well as a new pterocarpene and a new α-hydroxydihydrochalcone, viz.; 3-hydroxy-8, 9-methylenedioxy-6a,11a-dihydropterocarpan (αS), 2' ,4'-trihydroxy-4-methoxydihydrochalcone. A series comprising substituted hydroxygeranylstilbenes, substituted benzenoid compounds and quercitin-type flavones were isolated from the acetone extract of the heartwood of Chlorophora excelsa. The new compounds isolated from this tree are: 3,5-dihydroxy-4-geranylbenzaldehyde; 3' ,4,5'-trihydroxy-4'-geranylstilbene; 2'-methoxy-3, 4',7-tri-O-methylquercitin. A combination of solvent extraction, Craig countercurrent, column (LH 20 and silica gel) and thin layer chromatography procedures were used to isolate and purify the compounds mentioned. Structures were elucidated by high resolution (300 MHz) ¹HNMR spectroscopy (including NOE and spin-spin decoupling experiments) and mass spectrometry. The proposed structural assignments of the following compounds were confirmed by synthesis: 3, 5-dihydroxy-4-geranylbenzaldehyde; 3' ,4 ,5'-trihydroxy-4' -geranylstilbene; 2 ,3' ,4 ,5'-tetrahydroxy-4' -geranylstilbene (chlorophorin). The modified Wittig reation was used to synthesize 3' ,4 ,5' trihydroxystilbene. U.V. irradiation experiments were performed on chlorophorin in an attempt to synthesize the cis-isomer and a phenanthrene-type compound. Biosynthetic pathways showing the structural relationships of the identified compounds in Virgilia oroboides and Chlorophora excelsa were proposed. An attempt to synthesize (+)-catechin lignoid involved the coupling of (+)-catechin to sinapyl alcohol, with the latter synthesized from 2 ,6-dimethoxyphenol via vinyl quinone methide. Further investigations on lignoid currently in progress. / Thesis (M.Sc.)-University of Durban-Westville, 1989.

A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master in Pharmacy. Johannesburg, South Africa, 2006 / The aqueous extract of rooibos has been used for more than three hundred years since its discovery by the indigenous people. Currently, rooibos is gaining popularity in the cosmetic industry and incorporation of rooibos extracts in topical cosmetic formulations has become a fashionable trend. Both topical and intestinal absorption of rooibos tea were investigated. The transport of aspalathin in the unfennented (green) rooibos aqueous extracts and aqueous solution of pure aspalathin were studied. / IT2018