O gênero Croton possui aproximadamente 1300 espécies amplamente distribuídas em zonas tropicais e subtropicais do novo e velho mundo e é o segundo maior gênero de Euphorbiaceae. No presente trabalho, foram analisadas a composição e a morfologia das ceras foliares cuticulares de 13 espécies de Croton. Para a maioria das espécies, foram amostrados três indivíduos. A morfologia das ceras foi analisada por microscopia eletrônica de varredura. Diversos tipos de depósitos cerosos foram observados (amorfos, plaquetas, grânulos), principalmente na face adaxial e caracterizando grupos de espécies. A observação dos padrões de depósitos cerosos de várias espécies foi prejudicada na face abaxial, devido à alta densidade de tricomas. As ceras foram extraídas por três imersões consecutivas das folhas em diclorometano e a separação das classes dos constituintes foi feita por cromatografia em camada delgada preparativa. A análise da distribuição dos constituintes foi realizada por cromatografia a gás acoplada a espectrometria de massas. n-Alcanos e álcoois primários foram detectados em todos os indivíduos analisados. Triterpenos também são muito comuns, não tendo sido detectados em apenas uma espécie. Os esteroides são constituintes raros nas espécies analisadas. Os resultados da distribuição de n-alcanos, álcoois primários e triterpenos foram utilizados para o estabelecimento de afinidades químicas por meio de análises de agrupamento pelo método UPGMA, empregando-se distâncias euclidianas (n-alcanos e álcoois) e coeficiente de DICE (triterpenos), baseando-se na distribuição de cada classe de constituinte isoladamente e combinando-se as distribuições de n-alcanos e álcoois primários. Não se notou congruência entre as topologias dos dendrogramas de afinidades químicas e a filogenia molecular do gênero. Observou-se coerência entre algumas afinidades químicas e características morfológicas, como tipos de tricomas foliares e presença de glândulas peciolares. A distribuição de n-alcanos, álcoois primários e triterpenos mostraram-se úteis como caracteres da maioria das espécies analisadas. Entre os constituintes analisados, distribuição de álcoois primários revelou-se o melhor marcador para a caracterização de espécies. A variação intraespecífica, no entanto, impede que esses caracteres sejam úteis como marcadores taxonômicos de algumas espécies de Croton / Croton comprises nearly 1300 species distributed in tropical and subtropical areas of either the New or Old Worlds, making up the largest genus of Euphorbiaceae. In the present work, the chemical composition and the morphology of the foliar cuticular waxes of 13 species of Croton were analized. Three individuals were sampled for analyses of most species. The morphology of the waxes was analyzed by scanning electron microscopy. Several types of wax deposits were observed (amorph, platlets, granules), chiefly on the adaxial side, characterizing groups of species. The observation of wax deposits on the abaxial side was hampered in several species due to the high density of trichomes. The cuticular wax was extracted by three successive immersions of the leaves in dichloromethane, and the separation of the constituent classes was achieved by preparative thin layer chromatography. The analyses of the distribution of the constituents were performed by gas chromatography coupled to mass spectrometry. n-Alkanes and primary alcohols were detected in all analyzed individuals. Triterpenes were also very common, having not been detected in only one species. Steroids are rare constituents in the analyzed species. The results of the distribution of n-alkanes, primary alcohols and triterpenes were used for the establishment of chemical affinities using cluster analysis by the UPGMA method and Euclidean distances (n-alkanes and alcohols) and DICE coefficient, based on the distribution of each constituent class alone and combining the distribution of n-alkanes and primary alcohols. No congruence was noted between the topologies of the dendrograms of chemical affinity and the molecular phylogeny of the genus. Coherence was observed between chemical affinities and morphologic characteristics, such as types of foliar trichomes and petiolar glands. The distribution of n-alkanes, primary alcohols and triterpenes were shown to be useful as characters for most analyzed species. Among the constituents analyzed, the distribution of primary alcohols was the best marker for species characterization. Intraspecific variation, however, precludes the use of these characters as taxonomic markers of some Croton species

Aims. The objectives of this study were (i) to isolate and characterize by conventional column chromatography, structurally diverse triterpenes from G. lucidum to serve as chemical markers; (ii) to develop a high performance liquid chromatography (HPLC) method for the quality control and/or standardization of Lingzhi-containing products; (iii) to utilize and optimize operating conditions for the newer extraction technology: supercritical fluid extraction (SFE), in order to maximize yields of bioactive triterpenes, and to reduce time and costs. / Background. The dried fruiting body of Ganoderma lucidum, commonly known as Lingzhi, has been used extensively as a traditional Chinese medicine (TCM) for many centuries not only in China, but also in other countries such as Japan and Korea. In recent years, Lingzhi has also become a popular health supplement in many Western countries. The chemical composition of Lingzhi is complex, but it has been well documented that the lipophilic triterpenoid class of compounds possess a range of biological effects that include antitumor, immunomodulatory, cardiovascular, respiratory and antihepatotoxic activity. A major drawback in TCM research has been the lack of authentic chemical standards, and efficient methods for the extraction and analysis of bioactive fractions and/or single components. Conventional extraction methods for G. lucidum are time-consuming and laborious, and often result in low yields of useful chemical constituents. / Conclusion. This study enabled the development of a method for the simultaneous analysis of structurally diverse triterpenes with remarkably different chromatographic profiles. The isolated triterpenes, as chemical markers, and the HPLC method can readily be used for quality control and/or standardization purposes in evaluating Lingzhi-containing products. Optimization of operating conditions for SFE facilitated the rapid and selective extraction of acidic triterpenes from raw G. lucidum in significantly higher yields. / Methods. Raw material of G. lucidum was extracted with 80% ethanol; subjected to repeated column chromatography to purify triterpenes; and characterized by NMR (1H and 13C) and mass spectroscopy. Isolated lipophilic triterpenes were qualitatively and quantitatively analyzed by reversed-phase HPLC using an ODS column (150 x 4.6 mm) and PDA detection at 256 nm. The assay was validated over appropriate concentration ranges and benzophenone was used as an internal standard. Supercritical fluid extraction of G. lucidum was carried out using a commercial supercritical fluid extractor system Thar, SFE-1000M. Briefly, the raw powder of G. lucidum was soaked in ethanol containing 10% aqueous ammonia for 30 minutes prior to extraction. Extractions were performed at temperatures of 40, 50 and 60°C; and pressures of 200, 250, 300 and 350 bar; 5% ethanol was used as the co-solvent; and the flow rate of CO 2 was set at 20 g/min. / Results. Eight compounds were isolated and identified from G. lucidum: four triterpenes; namely, lucidenic acid N, ganoderic acid B, ganodermanontriol, and ganodermadiol; two steroids; ergosterol-7, 22-dien-3beta-ol and ergosterol peroxide; and two fatty acids, oleic acid and tetracosanoic acid. The four triterpenes were utilized as chemical markers, and the developed HPLC method was able to simultaneously analyze the structurally diverse components with good resolution. The total analysis run time was 110 min, and retention times (tR) were 14.88, 18.96, 63.88 and 90.73 min respectively, and the eluting system was a mixture of three solvents, methanol (A), acetonitrile (B) and 2% acetic acid solution (C): 0-22 min, 5% A, 25% B and 70% C; 22-85 min, gradient elution, the ratio changed gradually to 5% A, 80% B and 15% C; 85-110 min, gradient elution, the ratio changed gradually to 5% A, 85% B and 10% C. The validated HPLC method and the isolated chemical markers were effectively applied to determine the triterpenoid contents in a variety of commercial Lingzhi products. Supercritical fluid extraction conditions of: pressure 300 bar and temperature 50°C, gave the highest yields of triterpene-containing extracts. HPLC analysis of the SFE extracts showed predominantly acidic triterpenes such as lucidenic acid N and ganoderic acid B. / Hong Xin. / "December 2006." / Advisers: Ho Yee Ping; Albert H. L. Chow. / Source: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 5968. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 149-175). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Yeung Chung Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 83-97). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract (Chinese) --- p.iv / Acknowledgements --- p.vii / Table of contents --- p.ix / List of figures --- p.xii / List of tables --- p.xiv / List of abbreviations --- p.xv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- Literature Review --- p.5 / Chapter 1.2.1 --- Cancer and melanoma --- p.5 / Chapter 1.2.2 --- Anticancer drugs from natural products --- p.6 / Chapter 1.2.3 --- Challenges in treatment of melanoma --- p.9 / Chapter 1.2.4 --- TCM - New source of natural products for cancer therapy --- p.10 / Chapter 1.2.6 --- The genus Schefflera --- p.11 / Chapter 1.2.7 --- Anticancer activities of triterpenoids --- p.16 / Chapter 1.2.8 --- Cancer and apoptosis --- p.17 / Chapter 1.2.8.1 --- The Apoptosis Pathways --- p.20 / Chapter 1.2.9 --- Studies of anticancer molecules against melanoma --- p.26 / Chapter 1.2.9.1 --- In vitro models for studying anticancer molecules --- p.26 / Chapter 1.2.9.2 --- In vivo models for studying anticancer molecules --- p.30 / Chapter Chapter 2 --- Materials and Methods --- p.34 / Chapter 2.1 --- Phytochemicals --- p.34 / Chapter 2.2 --- "Chemicals, Cell Lines and Culture Conditions" --- p.34 / Chapter 2.3 --- Determination of in vitro antiproliferative effects of HLDA and the ethyl acetate fraction from S. heptaphylla on human cancer cells --- p.36 / Chapter 2.3.1 --- MTT assay --- p.36 / Chapter 2.4 --- Determination of the in vitro antiproliferative mechanisms of HLDA and the ethyl acetate fraction from S. heptaphylla in human melanoma A375 cells --- p.37 / Chapter 2.4.1 --- Flow cytometric analysis --- p.37 / Chapter 2.4.2 --- Western blot analysis --- p.38 / Chapter 2.5 --- Determination of the in vivo anticancer effects of the ethyl acetate fraction from S. heptaphylla --- p.41 / Chapter 2.5.1 --- Determination of cancer chemopreventive effect of the ethyl acetate fraction with DMBA/TPA-induced skin carcinogenesis model --- p.41 / Chapter 2.5.2 --- Determination of cancer therapeutic effect of the ethyl acetate fraction with athymic BALB/c nude mice model --- p.42 / Chapter 2.6 --- Statistical Analysis --- p.44 / Chapter Chapter 3 --- Results --- p.45 / Chapter 3.1 --- Effects of HLDA and the ethyl acetate fraction on viability and proliferation of different cancer cell lines by MTT assay --- p.45 / Chapter 3.2 --- Effects of HLDA and the ethyl acetate fraction on cell cycle and apoptosis in A375 cells determined by DNA flow cytometry --- p.46 / Chapter 3.3 --- Effects of HLD A and the ethyl acetate fraction on apoptosis induction in A375 cells determined by Western blotting --- p.53 / Chapter 3.4 --- Effects of HLD A and ethyl acetate fraction on caspases in A375 cells --- p.55 / Chapter 3.5 --- Effects of caspase inhibitors on the HLDA- and the ethyl acetate fraction-induced apoptosis in A375 cells --- p.57 / Chapter 3.6 --- Effects of HLD A and the ethyl acetate fraction on the expression of Bcl-2 family proteins in A375 cells --- p.62 / Chapter 3.7 --- Chemopreventive effect of the ethyl acetate fraction from S. heptaphylla on the DMBA/TPA-induced skin carcinogenesis model --- p.65 / Chapter 3.8 --- Chemotherapeutic effect of the ethyl acetate fraction from S. heptaphylla on A375 xenograft in athymic nude mice --- p.70 / Chapter Chapter 4 --- Discussion --- p.73 / References --- p.83

Different cucurbitacin derivatives have been compared for the gamma globin induction potential. Cucurbitacin D turned out to be the most potential inducer among the derivatives had been tested. Later I had screened more herbs for the gamma globin induction activities. One of the herbs showed a higher activity than Fructus Trichosanthis, which could be the potential candidate to isolate more potent inducer. In the toxicity study, cucurbitacin D only have a mild toxic effect on the normal cell lines and transgenic mice. Finally, the efficacy of cucurbitacin D was tested on a sickle cell anemia mouse model and demonstrated a significant induction of fetal haemoglobin production. Cucurbitacin D may be a potential drug candidate for treating beta globinopathies. / Thalassemia is a global disease. It was report in 2001 that there were 270 million people who carried the severe disease. Most of the cases were found in Africa and south-east Asia. China has a high incidence rate of 0.66% in 2001. In the past, the treatments of the disease were blood transfusion and bone marrow transplantation. However, many defects in such kinds of treatments were reported. The balance of relieving the syndrome of the disease and the adverse effects of the drugs was the consideration to the physician. The drug, hydroxyurea, can activate the gamma globin gene and produce hemoglobin F to replace the beta globin as an oxygen transporter is considered as an better treatment to ameliorate the syndrome. Safety and effectiveness in the long-term treatment using hydroxyurea are questionable. Cucurbatacin D purified from a Chinese herb demonstrates 2000 folds more potent than hydroxyurea. It can activate the gamma globin gene and produce hemoglobin F shown in ELISA and confocal microscopy. The fundamental work for drug development is carrying out through this project. In this project the biological property and toxicity were studied. / Liu, Shuk Ming. / Adviser: M.C. Tung. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 245-270). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Zhang, Siwei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 87-98). / Abstracts in English and Chinese. / Chapter 1. --- General introduction --- p.1 / Chapter 1.1. --- "Types, structure and function of human hemoglobin" --- p.1 / Chapter 1.1.1. --- Structure and functions of human hemoglobin --- p.1 / Chapter 1.1.2. --- Types of human hemoglobin --- p.2 / Chapter 1.2. --- Regulatory mechanism of human hemoglobin expression --- p.3 / Chapter 1.2.1. --- The human a and β locus --- p.3 / Chapter 1.2.2. --- Development of globin genes switching concept --- p.4 / Chapter 1.2.3. --- Factors that regulate globin gene expression --- p.5 / Chapter 1.2.3.1. --- The locus control region (LCR) --- p.5 / Chapter 1.2.3.2. --- The cis-regulatory elements --- p.5 / Chapter 1.2.3.3. --- The trans-acting factors --- p.6 / Chapter 1.3. --- The human hemoglobinopathies --- p.8 / Chapter 1.3.1. --- α-thalassemia --- p.8 / Chapter 1.3.2. --- β-thalassemia --- p.9 / Chapter 1.3.3. --- Sickle cell anemia --- p.10 / Chapter 1.4. --- Current approaches towards β-thalassemia treatment --- p.11 / Chapter 1.4.1. --- Blood transfusion --- p.11 / Chapter 1.4.2. --- Bone marrow transplantation --- p.12 / Chapter 1.4.3. --- Drug-induced activation of fetal hemoglobin production --- p.12 / Chapter 1.4.3.1. --- Hydroxyurea --- p.12 / Chapter 1.4.3.2. --- Butyrate and short-chain fatty acids --- p.13 / Chapter 1.4.3.3. --- "Mutagens, DNA methyltransferase inhibitors and other HbF inducible agents" --- p.13 / Chapter 1.4.3.4. --- Cucurbitacin D --- p.14 / Chapter 1.4.4. --- Gene therapy --- p.14 / Chapter 1.5. --- Research Objectives --- p.15 / Chapter 2. --- "Analysis of CuD, Hydroxyurea and other inducers on the induction of α, β, γ, δ， ε，ζ BP-1 genes and fetal hemoglobin induction" --- p.16 / Chapter 2.1. --- Introduction --- p.16 / Chapter 2.1.1. --- Properties of human K562 cell line --- p.16 / Chapter 2.1.2. --- Induction and measurement of fetal hemoglobin --- p.16 / Chapter 2.1.3. --- "Induction of α, β, γ, δ, ε , ζ and BP-1 gene and Real-time RT-PCR analysis" --- p.17 / Chapter 2.2. --- Materials --- p.18 / Chapter 2.2.1. --- Chemicals and reagents --- p.18 / Chapter 2.2.2. --- Kits --- p.19 / Chapter 2.2.3. --- Buffers and solutions --- p.19 / Chapter 2.2.4. --- Cell lines --- p.20 / Chapter 2.3. --- Experimental procedures --- p.20 / Chapter 2.3.1. --- Hemoglobin quantity measurement by HbF ELISA --- p.20 / Chapter 2.3.1.1. --- MTT assay --- p.21 / Chapter 2.3.1.2. --- Preparation of capture-antibody coated ELISA plates --- p.21 / Chapter 2.3.1.3. --- Plate blocking --- p.22 / Chapter 2.3.1.4. --- Sample and standard preparation --- p.22 / Chapter 2.3.1.5. --- HRP antibody and colorimetric detection --- p.23 / Chapter 2.3.1.6. --- Statistical analysis --- p.23 / Chapter 2.3.2. --- Preparation of mRNA extract from K562 cells --- p.23 / Chapter 2.3.3. --- Reverse transcription and Real-time PCR analysis --- p.24 / Chapter 2.4. --- Results --- p.25 / Chapter 2.4.1. --- CuD significantly upregulates HbF expression in K562 cells --- p.25 / Chapter 2.4.2. --- "CuD augments α, β, γ, δ, ε , ζ and BP-1 genes at different level in K562 cells" --- p.28 / Chapter 2.4.3. --- Cucurbitacin D-induced γ-globin gene activation requires12-24 hours in K562 cells --- p.31 / Chapter 2.5. --- Discussion --- p.33 / Chapter 2.5.1. --- Enhancement of fetal hemoglobin production using different chemical compounds --- p.33 / Chapter 2.5.2. --- CuD increased HbF synthesis by increasing γ-globin mRNA amount --- p.35 / Chapter 2.5.3. --- CuD and HU down-regulated the BP-1 gene expression --- p.36 / Chapter 3. --- Determination of potential signal transduction pathways during CuD and HU-mediated fetal hemoglobin production --- p.36 / Chapter 3.1. --- Introductions --- p.36 / Chapter 3.1.1. --- The p38 MAPK family --- p.37 / Chapter 3.1.2. --- The JAK2-STAT3 pathway --- p.38 / Chapter 3.1.3. --- Fundamentals on inhibition assay of p38 MAPK and JAK2-STAT3 pathway --- p.39 / Chapter 3.1.4. --- Fundamentals on nuclear translocation of STAT3 --- p.41 / Chapter 3.2. --- Materials --- p.41 / Chapter 3.2.1. --- Chemicals and reagents --- p.41 / Chapter 3.2.2. --- Kits --- p.44 / Chapter 3.2.3. --- Buffers and solutions --- p.44 / Chapter 3.3. --- Experimental procedures --- p.45 / Chapter 3.3.1. --- Detection of p3 8 MAPK phosphorylation status --- p.46 / Chapter 3.3.1.1. --- Preparation of cytosolic protein extracts --- p.46 / Chapter 3.3.1.2. --- Quantitative measurement of phospho-p38 and pan-p38 by ELIS A method --- p.46 / Chapter 3.3.1.2.1. --- Antigen adsorption and establishment of standard curves --- p.46 / Chapter 3.3.1.2.2. --- Plate washing and application of detection antibody --- p.47 / Chapter 3.3.1.2.3. --- Plate washing and application of secondary antibody --- p.47 / Chapter 3.3.1.2.4. --- Plate washing and chromogen detection --- p.48 / Chapter 3.3.2. --- Detection of signal cascade on JAK2-STAT3 pathway --- p.48 / Chapter 3.3.2.1. --- Preparation of cytosolic protein extracts for Western Blot detection --- p.48 / Chapter 3.3.2.2. --- Gel running and Western Blot detection --- p.48 / Chapter 3.3.3. --- Quantitative measurement of phospho-STAT3-Tyr705 using ELISA method --- p.50 / Chapter 3.3.3.1. --- Preparation of cytosolic protein extracts --- p.50 / Chapter 3.3.3.2. --- Reconstitution and Dilution of STAT3 [pY705] Standard --- p.50 / Chapter 3.3.3.3. --- Measurement of STAT3 [pY705] concentration in cell lysates --- p.51 / Chapter 3.3.4. --- Inhibitor assay of JAK2-STAT3 and p38 MAPK pathway --- p.52 / Chapter 3.3.4.1. --- Establishment of inhibitor assay --- p.52 / Chapter 3.3.4.2. --- HbF ELISA detection --- p.53 / Chapter 3.3.5. --- Detection of STAT3 nuclear translocation and DNA binding affinity --- p.53 / Chapter 3.3.5.1. --- Preparation of nuclear extract from K562 cells --- p.53 / Chapter 3.3.5.2. --- EMS A detection of transcriptional factors binding to γ-promoter region --- p.54 / Chapter 3.3.5.2.1. --- 3´ة end-labeling of EMS A probes --- p.54 / Chapter 3.3.5.2.2. --- Dot blotting for labeling efficiency estimation --- p.56 / Chapter 3.3.5.2.3. --- EMSA binding reaction and non-denaturing gel electrophoresis --- p.57 / Chapter 3.3.5.2.4. --- Membrane development and chemiluminescence detection --- p.58 / Chapter 3.3.5.3. --- Preparation of K562 samples for immunofluorescence detection --- p.60 / Chapter 3.3.5.3.1. --- Slide coating for cell capture --- p.60 / Chapter 3.3.5.3.2. --- Preparation of cell slide --- p.60 / Chapter 3.3.5.3.3. --- Sample fixation and antibody probing treatment --- p.60 / Chapter 3.3.5.3.4. --- Sample imaging and immunofluorescence detection --- p.61 / Chapter 3.4 --- Results --- p.62 / Chapter 3.4.1. --- Activation of p38 MAPK pathway and STAT3 phosphorylation by hydroxyurea --- p.62 / Chapter 3.4.1.1. --- "The p38 MAPK pathway is activated by hydroxyurea, but not activated by Cucurbitacin D" --- p.62 / Chapter 3.4.1.2. --- Increased p38 phosphorylation level elicits STAT3 phosphorylation at Ser727 site --- p.64 / Chapter 3.4.2. --- Activation of JAK2 and STAT3 phosphorylation by Cucurbitacin D --- p.66 / Chapter 3.4.2.1. --- Cucurbitacin D promotes JAK2 activation --- p.66 / Chapter 3.4.2.2. --- Cucurbitacin D and hydroxyurea promote STAT3 phosphorylation at Tyr705 site --- p.66 / Chapter 3.4.3. --- Basal activity of signal transduction pathways is essential for HbF induction --- p.69 / Chapter 3.4.3.1. --- Activation of γ-globin gene requires presence of basal phosphorylation level of p38 MAPK --- p.69 / Chapter 3.4.3.2. --- Inhibition on JAK2-STAT3 pathway results in reduced fetal hemoglobin production --- p.71 / Chapter 3.4.4. --- Translocation and DNA binding of STAT under Cucurbitacin D induction --- p.72 / Chapter 3.4.4.1. --- Cucurbitacin D and hydroxyurea both enhance binding affinity of transcriptional factors to the Gγ/Aγ promoter --- p.72 / Chapter 3.4.4.2. --- Cucurbitacin D and hydroxyurea induces nuclear translocation of STAT3 --- p.75 / Chapter 3.5. --- Discussion --- p.77 / Chapter 3.5.1. --- The role of p38 MAPK activation during γ-globin gene activation --- p.77 / Chapter 3.5.2. --- STAT3 phosphorylation at Ser727 site promotes transcription factor activity and γ-globin gene expression --- p.77 / Chapter 3.5.3. --- The role of JAK2-STAT3 activation during γ-globin gene activation --- p.78 / Chapter 3.5.4. --- Inhibitor assay --- p.79 / Chapter 3.5.5. --- Relations between STAT3 nuclear translocation and enhanced fetal hemoglobin production --- p.82 / Chapter 4. --- Summery and Prospect --- p.83 / Chapter 5. --- References --- p.87

No description available.

Mogrosides, the main active components in S. grosvenorii SWINGLE, are considered to be some 250 times sweeter than sucrose and to possess several medicinal attributes. Previous isolation processes used large quantities of toxic solvent that resulted in toxic residues of organic solvent in this high value food. Supercritical fluids fulfill the requirements of non-toxicity, recycle ability, and useful solvent characteristics. The work presented in this thesis is directed to the extraction of mogrosides from the powdered S. grosvenorii concentrate (SG) and the crude extract after resin treatment (MG) with sub critical water and supercritical CO2. / Because no source of mogroside V reference material is available commercially, the first objective of this research was to isolate mogroside V of sufficient purity that it could be crystallized. This objective was achieved by selecting suitable eluates from resin chromatography coupled with preparative thin layer chromatography (TLC). Crystalline white isolate was further characterized by 13C-NMR and by MS and determined to be mogroside V, which was suitable as a reference material for subsequent experiments. / The process variables for both sub critical water and supercritical carbon dioxide extraction were evaluated and optimized so that conclusions could be formulated regarding the relative merits of the two proposed extraction methods. The efficiency of extraction was determined spectrophotometrically based on the recovery of mogrosides from the starting material following the vanillin-HClO4 method. / When compared with Soxhlet solvent extraction, supercritical fluid extraction with either sub critical water or supercritical CO2 provided improved recoveries and consumed less organic solvent. In addition, the purity of the extracts differed greatly. For identical SG samples, sub critical water extraction was demonstrated to be more efficient (62.4% recovery) compared with 37.0% recovery by EtOH modified scCO2 extraction or 5.1% for Soxhlet extraction with hexane.

Made available in DSpace on 2015-05-14T12:59:46Z (GMT). No. of bitstreams: 1 parte1.pdf: 1352046 bytes, checksum: 652ad199b6ea962633d92a6c63ac8749 (MD5) Previous issue date: 2009-11-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The family Malpighiaceae is predominantly found in tropical and subtropical areas and comprises about 75 genera and 1,300 species. The Byrsonima genus has about 150 species and is mainly found in Mexico, spreading across South America. According to the bibliographic research on Byrsonima gardneriana A. Juss there are no studies about chemical constituents and pharmacological studies are rare. This work describes the isolation and structural identification of some chemical constituents of the stem bark of Byrsonima gardneriana A. Juss, with the objective of increasing the chemical knowledge on the genus Byrsonima, as well as on the family Malpighiaceae. The phytochemical study of the chloroform phase of B. gardneriana resulted in the isolation of five triterpenes: 3β- hydroxiolean-12-ene, first reported in the species, 3-oxo-5-ene-glutinone and friedoolean-14- en-3-one, first described in the genus, friedelan-3-one and lup-20(29)-en-3-ol both first reported in the species. The chemical constituents were identified by analysis of data obtained by spectroscopic methods such as Infrared, 1H and 13C Nuclear Magnetic Resonance, with the aid of two-dimensional techniques, besides comparison with literature data. / A família Malpighiaceae é encontrada predominantemente nas regiões tropicais e subtropicais, compreendendo cerca de 75 gêneros com aproximadamente 1300 espécies. O gênero Byrsonima é composto por cerca de 150 espécies e encontrado principalmente a partir do México, difundindo-se por toda América do Sul. Byrsonima gardneriana A. Juss, de acordo com levantamento bibliográfico, não apresenta estudos sobre seus constituintes químicos, possuindo poucos estudos farmacológicos. O presente trabalho descreve o isolamento e a identificação estrutural de alguns constituintes químicos das partes aéreas de Byrsonima gardneriana A. Juss, com o objetivo de ampliar o conhecimento químico sobre o gênero Byrsonima, bem como da família Malpighiaceae. O estudo fitoquímico da fase clorofórmica de B. gardneriana resultou no isolamento de cinco triterpenos: 3β-hidroxiolean- 12-eno, relatado pela primeira vez na espécie; 3-oxo-5-ene-glutinona e friedoolean-14-en-3- ona, descritos pela primeira vez no gênero; friedelan-3-ona e lup-20(29)-en-3-ol, ambos relatados pela primeira vez na espécie. Os constituintes químicos foram identificados através da análise de dados obtidos por métodos espectroscópicos como IV e RMN de 1H e 13C uni e bidimensionais, além de comparação com valores da literatura.

143 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-09-24T14:26:15Z No. of bitstreams: 1 Dissertação Maria Candeia Kuliakita.pdf: 4339184 bytes, checksum: 54063fe95edeaa2662c649acf009c9ae (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-09-24T14:27:50Z (GMT) No. of bitstreams: 1 Dissertação Maria Candeia Kuliakita.pdf: 4339184 bytes, checksum: 54063fe95edeaa2662c649acf009c9ae (MD5) / Made available in DSpace on 2013-09-24T14:27:50Z (GMT). No. of bitstreams: 1 Dissertação Maria Candeia Kuliakita.pdf: 4339184 bytes, checksum: 54063fe95edeaa2662c649acf009c9ae (MD5) Previous issue date: 2012 / CNPq / Desenvolveram-se neste trabalho atividades experimentais empregando as reações de Mannich, utilizando-se o dímero di-hidróxi-acetona, um derivado da glicerina. A glicerina obtém-se como co- produto da produção de biodiesel. Sem êxitos nas tentativas feitas para a reação de Mannich, partiu-se então para reações aldólicas organocatalisadas. Nesta rota preparou-se a di-hidroxi-acetona sililada (97% de rendimento), que foi empregada como reagente na reação aldólica com o 4-nitrobenzaldeído. O aldol foi obtido como mistura enantiomérica enriquecida, na proporção diastereoisomérica de 5:1 (syn/anti). Posterior acetilação em 90% de rendimento permitiu avaliar, através de HPLC com coluna quiral, o excesso enantiomérico em cerca de 90%. O aldol acetilado teve seu grupo TBS primário removido (96-100 % de rendimento). No entanto, as tentativas de oxidação e preparação do ácido não foram exitosas. Como alternativa, reações de redução para a obtenção de dióis foram feitas obtendo-se dióis com estreoquímica relativa 1,3-anti em rendimento de 80%. Reações de redução por aminação também foram realizadas, mas sem resultados satisfatórios. Em paralelo a estas reações foram preparados derivados de ácidos triterpênicos (ácidos betulínico e ursólico), triterpenos (lupeol) e esteroides (estigmasterol e β-sitosterol) com ácidos oleico e hexanoico, preparando-se compostos com potencial atividade anticâncer e anti-AIDS. / Salvador

Cette thèse s’inscrit dans le cadre de la thématique du laboratoire de Pharmacognosie de l’UFR Pharmacie, au sein de l’Université de Bourgogne. Elle vise essentiellement la recherche de molécules d’origine végétale issue de la biodiversité tropicale dotées d’une activité antitumorale, dont principalement les saponines. Ce sont des glycosides triterpéniques ou stéroïdiques connus pour leurs nombreuses propriétés pharmacologiques. L’étude de 6 espèces végétales appartenant à 3 familles à savoir Acanthophyllum elatius, A. lilacinum, A. sordidum et Arenaria montana (Caryophyllaceae), Securidaca welwitschii (Polygalaceae) et Allium schoenoprasum (Alliaceae) a conduit à l’isolement et à la caractérisation de 24 glycosides naturels. Il s’agit de 13 saponines triterpéniques parmi lesquelles 10 sont de structure nouvelle ainsi que 11 saponines stéroïdiques dont 7 nouvelles. Les structures ont été élucidées principalement par l’utilisation de la RMN 2D ainsi que la spectrométrie de masse. 10 des 24 molécules isolées ont été testées en vue d’évaluer leurs activités cytotoxiques sur deux lignées cellulaires cancéreuses coliques (HT-29 et HCT 116). Nos résultats montrent que 9 d’entre elles possèdent une activité cytotoxique significative. Des relations structure/activité ont été ainsi proposées. / This thesis was realized in the laboratory of Pharmacognosy, in the Pharmacy section of the Bourgogne University. The main theme of this laboratory is the research of natural saponins from the tropical biodiversity, with antitumoral activities. These molecules are triterpenic or steroidic glycosides, well known for their various pharmacological activities. The study of 6 species belonging to 3 different families : Acanthophyllum elatius, A. lilacinum, A. sordidum and Arenaria montana (Caryophyllaceae), Securidaca welwitschii (Polygalaceae) and Allium schoenoprasum (Alliaceae), led to the isolation and characterization of 24 natural glycosides. Among them, 13 were triterpenic saponins with 10 new structures and 11 were steroidic saponins with 7 new structures. The spectral analysis was achieved using mainly 2D NMR and mass spectrometry. The cytotoxic activities of 10 isolated compounds were evaluated on 2 strains of human colon cancer cells (HT-29 et HCT 116) and 9 were active ones. Structure/activity relationships were also proposed.