The preparation of bicyclic systems containing an allylic, angular hydroxyl group (general structure 20 and compound 87b) is described. These materials have been prepared via a new annulation sequence involving (a) the alkylation of cyclic ketones with the bifunctional conjunctive reagents 129, 21 and 60, (b) the conversion of the alkylation products into keto vinyl iodides, and (c) cyclization of the keto vinyl iodides via low temperature metal halogen exchange with n-butyllithium. The cyclization process described in (c) has been employed in the first total synthesis of the diterpenoid (±)-ambliol B (94). Thus, 3,4-dimethyl-2-cyclohexen-l-one (96) was converted, in three steps, into the unstable enone 125. Reaction of this compound with the novel vinylgermane cuprate 110, followed by reaction of the resultant product with iodine, gave the cyclization precursor 106. Cyclization of 106 gave a single, trans-fused product (128) in high yield. The exocyclic methylene function of 128 was cyclopropanated and the vinyl substituent of the resultant cyclopropane was hydroborated to give the cyclopropane diol 149. Hydrogenolysis of the cyclopropane ring of compound 149 provided the required gem-dimethyl moiety. The resultant product was converted into (±)-ambliol B (94) via a four step sequence of reactions involving (a) oxidation of the primary alcohol function, (b) addition of 3-furyllithium to the so-formed unstable aldehyde, (c) acetylation of the secondary alcohol prepared in (b), and (d) reductive removal of the acetoxy function. A new annulation sequence which utilizes the vinylgermane cuprate 110 as a synthetic equivalent of the 1-butene a²,d⁴-synthon 153 is described. Thus, cyclic enones of the general structure 154 were treated with 110 to provide the keto vinylgermane intermediates 155. The latter materials were transformed into the corresponding keto vinyl iodides 156. Treatment of 156 with a palladium(0) catalyst and a base resulted in cyclization to provide the annulation products 157 or, when R₁ = H, the α,β-unsaturated ketones 185. [ Formulas omitted ] / Science, Faculty of / Chemistry, Department of / Graduate

No description available.

Croton é um gênero gigante de Euphorbiaceae com cerca de 1.300 espécies distribuídas em regiões tropicais e subtropicais da América, África, Ásia e Austrália. O Brasil é um importante centro de diversificação da espécie, com mais de 350 espécies descritas, sendo muitas endêmicas. Muitas espécies são utilizadas como plantas medicinais pelas populações locais, para o tratamento de diversos males, como câncer, diabetes, febre, hipercolesterolemia, hipertensão, entre outros. Mesmo assim, a maioria das espécies não apresenta estudo fitoquímico para determinação de atividades biológicas. Na bibliografia consultada terpenóides se apresentaram como compostos predominantes em Croton. O presente estudo foi realizado com a análise de óleos voláteis e de extratos metanólicos de folhas e caules de 10 amostras de Croton seção Lamprocroton Todas as espécies do estudo têm descrição química inédita. Foram identificados 44 compostos de óleos voláteis por CG/EM, sendo 14 monoterpenos e 30 sesquiterpenos. Alguns compostos oxigenados, importantes do ponto de vista de atividade biológica, ocorreram em altas concentrações, como 1,8-cineol (C. ericoides: 24,1%; C.linearifolius: 26,9%; C. muellerianus: 23,9%), linalol (C. dusenii: 18,2%), bisabolol (C. ceanothifolius: 49,9%), 1-isopropil-7-metil-4-metileno-1,3,4,6,8-hexa-hidro-2H-naftalen-4-ol (C. linearifolius: 25,2%; C. pallidulus var. pallidulus: 23,6%). Já no extrato metanólico foram identificados por CG/EM 15 diterpenos, 9 triterpenos e 13 esteróides. Grupo de metabólito secundário mais caracteristico de Croton, foram detectados 3 diterpenos de cadeia aberta (fitol, hexadecatetraenol e furanona), um diterpeno alcoólico (retinol), além de diterpenos com esqueleto tipo labdano, caurano, clerodano e podocarpano. Os dois clerodanos foram identificados com estrutura similar à trans-desidrocrotonina, composto com alto potencial farmacológico. Os podocarpanos até então registrados em apenas duas espécies de Croton foram comuns à Croton seção Lamprocroton, sendo identificados podocarp-7-en-3-ona 13β-metil-13-vinil, podocarp-7,8-diien-3-ona-13-acetoxi, ácido podocarpa-7,13-dien-15-óico e metil-13(2-metoxi-2-oxoetildeno)-14-metil-7-oxopodocarpan-15-oato, distribuídos em 5 espécies. Os triterpenos e esteróides apresentaram alta diversidade e foram detectados para todas as espécies do estudo, com especial atenção para os triterpenos α-amirina, lupeol e lupenona; e os esteróides β e γ-sitosterol, pelas altas concentrações e pelo potencial farmacológico. Os dados obtidos possibilitaram listagem de compostos e atividades com sugestões de direcionamento para futuros testes e desenvolvimentos farmacológicos. / Croton is a large genus of Euphorbiaceae comprising around 1.300 species, widespread in tropical and subtropical regions of America, Africa, Asia and Australia. Brazil is one of the main hot spot in the world, with more than 350 species described, many of them endemic. Although several species are used in tradicional medicine for the treatement of diseases like cancer, diabetes, fever, high cholesterol and high blood pressure. Most species have no phytochemical studies concerning their biological activities. Literature shows terpenoids as predominant secondary metabolite constituents in Croton. The present study was carried outwith the analysis of essential oils and crude methanolic extracts obtained from leaves and bark of 10 samples of Croton sect. Lamprocroton. All species used on this study were submitted to their first chemical description. Forty four compounds were identified on essential oil by GC/MS, 14 monoterpenes and 30 sesquiterpenes. Some oxygenated compounds with important biological activity were detectaed in high concentrations: 1,8-cineol (C. ericoides: 24.1%; C.linearifolius: 26.9%; C. muellerianus: 23.9%), linalol (C. dusenii: 18.2%), bisabolol (C. ceanothifolius: 49.9%), 1-isopropil-7-metil-4-metileno-1,3,4,6,8-hexa-hidro-2H-naftalen-4-ol (C. linearifolius: 25.2%; C. pallidulus var. pallidulus: 23.6%). The metanolic extract analysis reveled by GC/MS15 diterpenes, 9 triterpenes e 13 steroids. Diterpenes are describe as the main secondary metabolite in Croton. Besides diterpenes with labdan, cauran, clerodan and podocarpan skeletal types, three opened ring diterpenes (fitol, hexadecatetraenol e furanona) and one alcoholic diterpene (retinol) were detected. Two clerodans were identified with trans-desidrocrotonin estructure-like, a compound with high pharmacological use. Podocarpans that have only been registered for two Croton species, were commonly found on Croton sect. Lamprocroton (podocarp-7-en-3-one 13β-metil-13-vinil; podocarp-7,8-diien-3-one-13-acetoxi; podocarpa-7,13-dien-15-oic acid; and metil-13(2-metoxi-2-oxoetildeno)-14-metil-7-oxopodocarpan-15-oate). Triterpenes and steroids shown high diversity and were detected at all studied species, with a highlight for compounds with high pharmacological potencial like triterpens α-amirine, lupeol and lupenone; and the steroids beta and gamma-sitosterol. The results obtained led to a list of compounds and suggestions for future pharmacological tests and developments.

丹參為雙子葉植物唇形科鼠尾草族植物的乾燥根及根莖。在中國，丹參為廣泛用於治療心血管疾病的藥用植物，而在西方，丹參也常作為一種輔助性藥物。《中國藥典2010版》收錄了35個以上含有丹參的複方或者方劑。在這些複方中，採用了富含丹酚酸和丹參酮的丹參水提物、乙醇提取物或兩者的混合物。丹參提取物具有較強的抗氧化作用，被認為在化學預防和化療的輔助治療中有一定用途。作為主要的丹參水溶性成分，熱敏感的丹酚酸在提取與加熱過程中可能會降解為其他丹酚酸。丹參水提取物的化學組成可能會在不同熱水提取溫度下有所不同，進而影響其藥理活性。在本研究中，通過加熱回流提取和在不同溫度下的微波提取（MAE-W）獲得了6種丹參水提取物，並對這些提取物進行化學成分和藥理分析，考察它們的抗氧化、抗凋亡和血管舒張作用。在這些提取物中，第三輪的微波提取物（100 oC）含有最多的丹酚酸和丹參酮，在1，1-二苯基-2-三硝基苯肼（DPPH）法和鐵還原/抗氧化能力（FRAP）法中具有最強的抗氧化活性，在2,2'-偶氮二(2-脒基丙烷)二鹽酸鹽（AAPH）誘導人血紅細胞的溶血實驗和過氧化氫誘導大鼠心肌細胞H9c2凋亡實驗中還顯示了最強的抑制作用，對大鼠腦基底動脈有最強的鬆弛效應。這些丹參水提取物的抗氧化作用與它們的血管舒張效應呈一定的線性關係（回歸係數r = 0.895 - 0.977）。通過多元線性回歸分析發現，丹參素可以作為丹參水提物的抗氧化和血管舒張功能的顯著性標記物，而丹參酮IIA則是抑制過氧化氫誘導大鼠心肌H9c2細胞凋亡的標記物。 / 作為丹參中主要的脂溶性成分，丹參酮在不同的腫瘤細胞系和荷瘤小鼠模型中展示了抗癌潛力。這些丹參酮的抗癌機制包括細胞週期阻滯，觸發半胱天冬酶（Caspase）依賴的內源性和外源性的凋亡途徑和絲裂原激活的蛋白激酶（MAPK）信號通路等。丹參新酮（miltirone）是從丹參中分離得到的松香烷型二萜醌類化合物，具有多種的藥理活性，如抗氧化，抗焦慮和抗腫瘤等。本研究評估了丹參新酮在人肝癌HepG2細胞系和P-糖蛋白（P-gp）過表達的阿霉素耐藥HepG2細胞系（R-HepG2）中的凋亡作用及其機制。丹參新酮在HepG2細胞中顯示了細胞毒性（EC₅₀值為7.06 微摩），而丹參新酮在抑制HepG2和R-HepG2細胞增殖中的濃度依賴性沒有顯著性差異。丹參新酮（1.56 - 6.25微摩）與阿霉素（DOX）對R-HepG2細胞的增殖具有協同效應，在達到50的生長抑制時，它們的聯合用藥指數為0.3至0.5。流式細胞術分析表明，丹參新酮降低了R-HepG2細胞中P-gp介導的阿霉素外排，分子對接研究表明該效果是通過抑制P-gp的藥物結合位點。在非壞死濃度（25微摩或以下），丹參新酮在HepG2和R-HepG2細胞中活化了Caspase依賴的凋亡途徑，誘導產生活性氧（ROS）和氧化應激，且觸發ROS介導的包括p38 MAPK，應激活化蛋白激酶/c-Jun氨基末端激酶（SAPK / JNK）以及細胞外調節激酶1和2在內的MAPK信號通路。綜上所述，在R-HepG2中丹參新酮是P-gp和細胞增殖的雙重抑制劑，顯示了其在治療肝癌（HCC）的潛力。 / 為了增加藥物開發的成功率，在藥物發現的早期階段應考察新化學實體（NCEs）的蛋白結合率，清除率，藥動學參數，以及藥物代謝相互作用等體內代謝參數。以往的研究已經顯示了從丹參中分離得到的四種主要丹參酮對人和大鼠的細胞色素P450酶介導的探針底物的代謝具有不同程度的抑制作用，需要注意丹參和其他藥物間的相互作用。本研究的另一目的是在人類肝微粒體中探討丹參新酮與探針底物間的細胞色素P450酶介導的代謝相關的相互作用。人肝微粒體孵育實驗結果表明丹參新酮對CYP1A2（IC₅₀值為 1.73微摩）和CYP2C9（IC₅₀值為8.61微摩）有中等強度的抑制，對CYP2D6（IC₅₀值為30.20微摩）和CYP3A4（IC₅₀值為33.88微摩）有弱的抑制。酶動力學和分子對接研究的結果進一步表明，丹參新酮為CYP1A2（Ki值為3.17微摩）的中等強度混合型抑制劑，是CYP2C9（Ki值為1.48微摩）的中等強度競爭型抑制劑，也是CYP2D6（Ki值為24.25微摩）和CYP3A4（Ki值為35.09微摩）的弱的混合型抑制劑。這些結果表明，應考慮丹參新酮與CYP1A2和CYP2C9代謝的藥物間的相互作用，但是可認為其與CYP2D6及CYP3A4代謝的藥物間幾乎不存在相互作用。 / 總之，本研究考察了不同提取方法對丹參提取物成份及其藥效的影響，確定了不同用途的丹參提取物的質控標記物。本研究還考察了丹參新酮體外抗肝癌的能力及其藥物代謝相互作用為基礎的類藥性,為其進一步的體內試驗提供了依據。 / Danshen, the dried root and rhizome of Salvia miltiorrhiza Bg. (Fam. Labiatae), is a widely used medicinal plant for the treatment of cardiovascular diseases in China and also a complementary medicine in the West. Danshen is indexed in the Pharmacopoeia of People’s Republic of China (2010 Edition), with more than 35 formulations and concoctions containing Danshen water-extracts, ethanolic extracts or their combination which are rich in phenolic acids and tanshinones with various contents. Danshen extracts have been considered for the use as an adjunct in chemoprevention and chemotherapy due to their strong antioxidant effects. Phenolic acids, the major water-soluble components in Danshen, are thermosensitive and may degrade to other phenolic acids during extractions upon heating. The chemical profiles of Danshen water-extracts may vary with different heat water extraction at different temperatures, affecting the composition and bioactivity of the extracts obtained. In this study, six water-extracts of Danshen obtained from heat reflux water extraction and microwave-assisted extraction with water (MAE-W) at different temperatures were prepared for evaluation of their composition and pharmacological effects such as antioxidant, anti-apoptosis and vascular relaxation. Among these extracts obtained, the third-round MAE-W (100 °C) product, which was the last round product obtained by extracting the same crude material three times, had the highest contents of phenolic acids and tanshinones, with the strongest antioxidant activity estimated by 2, 2-diphenyl-1-(2, 4, 6-trinitrophenyl) hydrazyl (DPPH) assay and ferric reducing / antioxidant potential (FRAP) assay. This extract also possessed the strongest inhibitory effects on 2, 2'-azobis-2-amidino-propane (AAPH)-induced haemolysis in human red blood cells, hydrogen peroxide-induced apoptosis in rat heart H9c2 cells and the highest relaxation effects on rat basilar artery. The antioxidant effects of Danshen water-extracts linearly correlated to their relaxation effects (r = 0.895 to 0.977). Through multiple linear regression analysis, danshensu was found to be the most significant marker in the antioxidant and vasodilation effects of Danshen water-extract, while tanshinone IIA as the marker on hydrogen peroxide-induced apoptosis in rat heart H9c2 cells. Danshensu is, therefore, a useful marker for the quality control of Danshen water-extracts in antioxidant and vasodilation, while tanshinone IIA for anti-apoptotic potential of water-extracts. / Tanshinones, the major lipid-soluble components isolated from Danshen, have been reported for their anti-cancer potential in various cell lines and tumor-bearing mice models. Their anti-cancer mechanisms are also well-studied, mainly through cell cycle arrest, caspase-dependent apoptotic pathways and mitogen activated protein kinase (MAPK) signaling pathways. Miltirone, another abietane type-diterpene quinone isolated from Danshen, has been reported for its anti-oxidative, anxiolytic and anti-cancer effects. This study evaluated the apoptotic effect of miltirone and the underlying mechanisms in a human hepatoma HepG2 cell line and its p-glycoprotein (P-gp)-overexpressed doxorubicin-resistant counterpart (R-HepG2). Miltirone showed similar cytotoxicity in HepG2 (EC₅₀ = 7.06 μM) and R-HepG2 (EC₅₀ = 12.0 μM), demonstrated synergistic effects (1.56 - 6.25 μM) with doxorubicin (DOX) on the growth inhibition of R-HepG2 (synergism: 0.3 < CI < 0.5 at 50 % inhibition). Flow cytometric analysis showed that miltirone decreased P-gp-mediated DOX efflux in R-HepG2, and molecular docking studies illustrated that this effect was through inhibition on the active site of P-gp. At non-necrotic concentrations (25 μM or below), miltirone activated caspase-dependent apoptotic pathways, and induced the generation of reactive oxygen species (ROS) and oxidative stress which triggered ROS-mediated MAPK signaling pathways, including p38 MAPK, stress-activated protein kinase / c-Jun N-terminal kinase (SAPK/JNK) and extracellular regulated kinase 1/2, in both HepG2 and R-HepG2 cells. It is therefore concluded that miltirone is a dual inhibitor on P-gp and cell proliferation in R-HepG2 cells, with potential for the treatment of human hepatocellular carcinoma (HCC). / In order to improve the successful rates in drug development, the in vivo metabolic parameters of new chemical entities (NCEs), such as protein bindings, clearance rate, pharmacokinetic parameters and metabolism-based drug-drug interactions, should be considered at the early stage of drug discovery. Previous studies have shown that major tanshinones isolated from Danshen inhibited the metabolism of model probe substrates of human and rat CYP450 enzymes, with potential in causing herb-drug interactions. The aim of this study was to study the effect of miltirone on the metabolism of model probe substrates of CYP1A2, 2C9, 2D6 and 3A4 in pooled human liver microsomes. Miltirone showed moderate inhibition on CYP1A2 (IC₅₀ = 1.73 μM) and CYP2C9 (IC₅₀ = 8.61 μM), and weak inhibition on CYP2D6 (IC₅₀ = 30.20 μM) and CYP3A4 (IC₅₀ = 33.88 μM). Enzyme kinetic studies showed that miltirone competitively inhibited CYP2C9 (Ki = 1.48 μM), and displayed mixed type inhibitions on CYP1A2, CYP2D6 and CYP3A4 with Ki values of 3.17 μM, 24.25 μM and 35.09 μM, respectively. Molecular docking study further confirmed the ligand-binding conformations of miltirone in the active sites of human CYP450 isoforms. These findings suggested that miltirone may have potential drug-drug interactions with CYP1A2- and CYP2C9-metabolized drugs, and to a lesser extent with CYP2D6- and CYP3A4-metabolized drugs. / In conclusion, this study investigated the effects of Danshen water-extracts produced by different extraction methods on the chemical compositions and pharmacological activities, and consequently confirmed the biomarkers for the quality control of Danshen water-extracts for different medicinal uses. This study also demonstrated the anti-cancer potential of miltirone for HCC in vitro and the metabolism-based drug-drug interactions for its drug-likeness, which may provide useful and promising data for in vivo anti-cancer study of miltirone and further pre-clinical studies. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhou, Xuelin / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 195-224). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / 論文摘要 --- p.v / Publications based on the work in this thesis --- p.viii / Acknowledgements --- p.x / Abbreviations --- p.xii / Table of Contents --- p.xv / Chapter Chapter 1 --- General introduction --- p.1 / Chapter 1.1 --- Reactive oxygen species and carcinogenesis --- p.1 / Chapter 1.2 --- Reactive oxygen species and tumor progression & metastasis --- p.2 / Chapter 1.3 --- Antioxidant enzymes in chemoprevention and chemotherapy --- p.3 / Chapter 1.3.1 --- Glutathione and Glutathione reductase --- p.5 / Chapter 1.3.2 --- Glutathione Peroxidase --- p.5 / Chapter 1.3.3 --- Glutathione S-transferases --- p.6 / Chapter 1.3.4 --- NAD(P)H: quinone reductase 1 --- p.7 / Chapter 1.3.5 --- Heme oxygenase-1 --- p.8 / Chapter 1.3.6 --- Thioredoxin reductase --- p.9 / Chapter 1.3.7 --- Superoxide Dismutase --- p.10 / Chapter 1.3.8 --- Catalase --- p.11 / Chapter 1.4 --- Medicinal uses of Danshen --- p.12 / Chapter 1.5 --- Analysis of Danshen and its components --- p.14 / Chapter 1.6 --- Antioxidant effects of Danshen extract and its bioactive compounds in chemoprevention and chemotherapy-related disease --- p.19 / Chapter 1.7 --- Anti-cancer effects of tanshinones isolated from Danshen --- p.21 / Chapter 1.7.1 --- Tanshinone IIA --- p.22 / Chapter 1.7.2 --- Tanshinone I --- p.26 / Chapter 1.7.3 --- Cryptotanshinone --- p.27 / Chapter 1.7.4 --- Dihydrotanshinone --- p.27 / Chapter 1.8 --- Metabolism / disposition of Danshen and its major active ingredients --- p.28 / Chapter 1.9 --- Herb-drug interactions with Danshen --- p.31 / Chapter 1.10 --- Effects of Danshen (and its major active ingredients) on model probe substrates of CYP isoforms --- p.33 / Chapter 1.11 --- CYPs induction by Danshen and its active components --- p.38 / Chapter 1.12 --- Effects of Danshen / active ingredients on drug transporter proteins --- p.40 / Chapter 1.13 --- CYP450 inhibition screening for new chemical entity --- p.42 / Chapter 1.14 --- Molecular docking analysis --- p.44 / Chapter 1.15 --- The Aim of this study --- p.45 / Chapter Chapter 2 --- Quantitative and qualitative studies to evaluate the efficiency of different heat water-extractions --- p.48 / Chapter 2.1 --- Introduction --- p.48 / Chapter 2.2 --- Materials and methods --- p.51 / Chapter 2.2.1 --- Materials and apparatus --- p.51 / Chapter 2.2.2 --- Extraction procedures --- p.51 / Chapter 2.2.3 --- HPLC analysis --- p.54 / Chapter 2.2.4 --- DPPH assay and FRAP assay --- p.54 / Chapter 2.2.5 --- Inhibition of 2,2'-azobis-2-amidinopropane (AAPH)-induced haemolysis in human red blood cells --- p.55 / Chapter 2.2.6 --- Protective effects on hydrogen peroxide-induced apoptosis in rat heart H9c2 cells --- p.56 / Chapter 2.2.7 --- Vasodilation effects on rat basilar artery --- p.57 / Chapter 2.2.8 --- Statistical analysis --- p.58 / Chapter 2.3 --- Results and Discussion --- p.59 / Chapter 2.3.1 --- Chemical profiles analyzed by HPLC analysis --- p.59 / Chapter 2.3.2 --- DPPH assay and FRAP assay --- p.63 / Chapter 2.3.3 --- Inhibition of AAPH-induced haemolysis --- p.65 / Chapter 2.3.4 --- Protective effects on hydrogen peroxide-induced apoptosis --- p.69 / Chapter 2.3.5 --- Vasodilation effects on rat basilar artery --- p.71 / Chapter 2.3.6 --- Multiple linear regression analysis --- p.76 / Chapter Chapter 3 --- Effects of miltirone on cell proliferation in a hepatoma HepG2 cell line and its doxorubicin-resistant counterpart --- p.83 / Chapter 3.1 --- Introduction --- p.83 / Chapter 3.2 --- Materials and Methods --- p.87 / Chapter 3.2.1 --- Chemicals --- p.87 / Chapter 3.2.2 --- Cell culture --- p.87 / Chapter 3.2.3 --- Cell viability test --- p.88 / Chapter 3.2.4 --- Drug-efflux study by flow cytometry --- p.89 / Chapter 3.2.5 --- Molecular docking study and Ligand-based prediction --- p.90 / Chapter 3.2.6 --- Measurement of ROS generation by confocal microscopy and flow cytometry --- p.91 / Chapter 3.2.7 --- GSH and GSSG determination for oxidative stress --- p.93 / Chapter 3.2.8 --- Apoptosis-related proteins expression detected by Western blotting analysis --- p.94 / Chapter 3.2.9 --- Data analysis --- p.96 / Chapter 3.3 --- Results --- p.97 / Chapter 3.3.1 --- Cytotoxicity in hepatoma cells --- p.97 / Chapter 3.3.2 --- Drug-efflux study by flow cytometry --- p.104 / Chapter 3.3.3 --- Molecular docking study and Ligand-based prediction --- p.108 / Chapter 3.3.4 --- ROS generation --- p.113 / Chapter 3.3.5 --- Determination of GSH/GSSG ratio --- p.117 / Chapter 3.3.6 --- Caspase-dependent apoptosis. --- p.121 / Chapter 3.3.7 --- Phosphorylation of MAPKs --- p.126 / Chapter 3.4 --- Discussion --- p.134 / Chapter Chapter 4 --- Enzyme kinetic and molecular docking studies of miltirone on major human cytochrome P450 isozymes inhibitions --- p.139 / Chapter 4.1 --- Introduction --- p.139 / Chapter 4.2 --- Material and Methods --- p.141 / Chapter 4.2.1 --- Materials and Reagents --- p.141 / Chapter 4.2.2 --- Incubation conditions --- p.142 / Chapter 4.2.3 --- Samples preparation --- p.143 / Chapter 4.2.4 --- HPLC analysis --- p.143 / Chapter 4.2.5 --- CYP inhibition and enzymatic kinetic study --- p.144 / Chapter 4.2.6 --- Molecular docking analysis --- p.145 / Chapter 4.2.7 --- Data analysis --- p.146 / Chapter 4.3 --- Results --- p.148 / Chapter 4.3.1 --- CYP inhibition and enzymatic kinetic study --- p.148 / Chapter 4.3.2 --- Molecular docking study of miltirone --- p.167 / Chapter 4.4 --- Discussions --- p.184 / Chapter Chapter 5 --- General discussion --- p.188 / References --- p.195

by Wing Shun Cheung. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (p. 159-178). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

O extrato metan&oacute;lico da esponja Darwinella sp. coletada na costa do Rio do Janeiro, exibiu atividade leishmanicida. O extrato bruto foi particionado em tr&ecirc;s fraç&otilde;es: fraç&atilde;o hex&acirc;nica, fraç&atilde;o de AcOEt e fraç&atilde;o XAD (extraç&atilde;o da fraç&atilde;o org&acirc;nica do extrato aquoso mediante mistura de resinas XAD-2, XAD-4 e XAD-7). Cada uma das fraç&otilde;es foi avaliada em bioensaio atividade leishmanicida, mostrando que a fraç&atilde;o AcOEt apresentou 100% da morte dos parasitas. A fraç&atilde;o de AcOEt foi fracionada usando cromatografia por exclusão de tamanho (Sephadex&reg LH-20) e extrações em fase sólida (SPE) com diferentes colunas pr&eacute;-empacotadas. Os compostos foram isolados e purificados por cromatografia de alta efici&ecirc;ncia acoplada a detector ultravioleta (CLAE-UV). Sete compostos foram isolados, dos quais quatro deles foram identificados espectroscopicamente. O membranol&iacute;deo, o &eacute;ster met&iacute;lico da oxeatamida A, a oxeatamida H e a oxeatina s&atilde;o diterpenos espongianos que possuem um esqueleto aplysulfurano nitrogenado, excetuando o membranol&iacute;deo. Tanto o &eacute;ster met&iacute;lico da oxeatamida A quanto a oxeatamida H, pertencem a uma s&eacute;rie de compostos denominados de oxeatamidas. O membranol&iacute;deo, o &eacute;ster met&iacute;lico A e a oxeatina foram avaliados em teste de atividade antiparasit&aacute;ria contra Leishmania infantum, por&eacute;m nenhum deles apresentou atividade leishmanicida. / The sponge Darwinella sp. was collected in Rio de Janeiro&rsquo;s coast and its methanolic extract showed leishmanicidal activity. The crude extract was partitioned in three fractions: hexane, AcOEt and XAD fractions. This last one was obtained by resin adsorption (mixture of XAD-2, XAD-4 and XAD-7 resins) of organic constituents from the aqueous fraction and subsequent recovery by extraction from the resins mixture. All of three fractions were also tested in leishmanicidal bioassay. The AcOEt fraction promoted 100% of parasite death. This fraction was separated into less complex fractions by size exclusion chromatography (Sephadex&reg LH-20) and solid phase extractions (SPE). The compounds were isolated and purified by high-performance liquid chromatography (HPLC) combined with on-line UV detector. Seven substances were isolated, which four of them were spectroscopically identified. The membranolide, the oxeatamide A methyl ester, the oxeatamide H and the oxeatin are spongian diterpenes with nitrogenous aplysulphurane skeleton, except for the membranolide. The oxeatamides are a series of nitrogenous aplysulphurane metabolites that includes the oxeatamide A methyl ester and the oxeatamide H. All of these compounds, except the oxeatamide H, were evaluated for antiprotozoal activity against Leishmania infantum. None of these compounds displayed leishmanicidal activity.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Este trabalho descreve a investigaÃÃo quÃmica de plantas dos gÃneros Abarema e Calliandra, ambas pertencentes à famÃlia Leguminosae. A prospecÃÃo quÃmica de Abarema cochliacarpos culminou no isolamento de 11 substÃncias, enquanto de Calliandra depauperata foram isolados 10 compostos. Dos extratos etanÃlicos das diversas partes de A. cochliacarpos (madeira do caule, casca do caule e folhas) foram isolados e caracterizados os esterÃides: espinasterol, 3-O-&#946;-D-glicopiranosil-espinasterol e 3-O-&#946;-D-(6â-O-dodecanoil)-glicopiranosil-espinasterol; a mistura dos triterpenos Ãcido oleanÃico e Ãcido ursÃlico; os flavonÃides catequina, taxifolina, miricetrina e 3â,4â,7,8-tetrahidroxiflavonol, alem do Ãcido gÃlico e galato de etila. O composto 3-O-&#946;-D-(6â-O-dodecanoil)-glicopiranosil-espinasterol esta sendo registrado pela primeira vez. Do extrato etanÃlico das raÃzes de C. depauperata isolou-se os flavonÃides 5-metoxi-3â,4â,7-trihidroxiflavona; 3â,4â,7-trihidroxiflavona e 4â,6â,7-trimetoxi-3â-hidroxiflavona; os diterpenos de esqueletos cassano 7&#946;,17-dihidroxi-12-oxo-cassan-13,15-dieno; 15,16-bisnor-7&#946;,17-dihidroxi-12-oxo-cassan-13-eno e depauperatina, alem dos Ãsteres graxos: tetracosanodioato de bis-(2,3-dihidroxipropila); docosanodioato de bis-(2,3-dihidroxipropila); 24-hidroxi-tetracosanoato de 2,3-dihidroxipropila e 26-hidroxi-hexacosanoato de 2,3-dihidroxipropila. Os compostos 4â,6â,7-trimetoxi-3â-hidroxiflavona; 15,16-bisnor-7&#946;,17-dihidroxi-12-oxo-cassan-13-eno e depauperatina, assim como todos os Ãsteres graxos estÃo sendo registrados na literatura pela primeira vez. A determinaÃÃo estrutural dos metabÃlitos secundÃrios isolados envolveu o uso de tÃcnicas espectromÃtricas como IV, EM e RMN 1H e 13C, incluindo tÃcnicas bidimensionais como COSY, HMQC, HMBC e NOESY, bem como comparaÃÃo com dados descritos na literatura. / This work describes the chemical investigation of plants from the genera Abarema and Calliandra both belonging to Leguminosae family. The chemical prospection of Abarema cochliacarpos resulted in the isolation of 11 substances while from Calliandra depauperata was isolated 10 compounds. From EtOH extracts of different parts of A. cochliacarpos (wood, wood bark and leaves) were isolated and characterizated of steroids: spinasterol, 3-O-&#946;-D-glucopiranosyl-spinasterol and 3-O-&#946;-D-(6â-O-dodecanoil)-glucopiranosyl-spinasterol), the mixture triterpenes oleanolic and ursolic acids; the flavonoids catechin, taxifolin, miricetrin and 3â,4â,7,8-tetrahydroxyflavonol, besides of galic acid and ethyl galate. Compound 3-O-&#946;-D-(6â-O-dodecanoil)-glucopiranosyl-spinasterol) was isolated for the firs time. From roots EtOH extract of C. depauperata were isolated the flavonoids 5-methoxy-3â,4â,7-trihydroxyflavone; 3â,4â,7-trihydroxyflavone and 4â,6â,7-trimethoxy-3â-hydroxyflavone; the cassane diterpenes: 7&#946;,17-dihydroxy-12-oxo-cassan-13,15-diene, 15,16-bisnor-7&#946;,17-dihydroxy-12-oxo-cassan-13-ene and depauperatin, besides the fatty esters bis-(2,3-dihydroxypropil) tetracosanodioate, bis-(2,3-dihydroxypropil) docosanodioate, 24-hydroxy-tetracosanoate-2,3-dihydroxypropil and 26-hydroxy-hexacosanoate-2,3-dihydroxypropil. Compounds 4â,6â,7-trimethoxy-3â-hydroxyflavone; 15,16-bisnor-7&#946;,17-dihydroxy-12-oxo-cassan-13-ene and depauperatin, and all fatty esters are being reported for the first time. The structural determination of all secondary metabolites isolated in this work involved spectrometric techniques such as: IR, MS and NMR including 2D (COSY, HMQC, HMBC e NOESY) experiments, as well as, comparison with published data

A method for the separation and detection of standard resin acids (RAs), commonly found in pulp mill effluent and known to bioaccumulate in fish bile, was optimized using cyclodextrin modified electrokinetic capillary electrophoresis (CD-EKC) with ultra violet (UV) and laser induced fluorescence (LIF) detection. Optimal separation conditions were found with RA standards using UV detection at 214 nm, with a 72 mM sodium borate buffer pH 9.25, containing 35 mM beta-cyclodextrin sulfobutyl ether (SPCD), 15 mM of methyl-beta-cyclodextrin (MECD) and a 37 cm capillary with an internal diameter of 50pm. This resulted in a 12-min separation and the identification of 9 peaks, with a LOD of 10 ppm. To enable increased sensitivity, RAs were derivatized using the fluorescent label 4-BrMMc. A method for extracting resin acids from spiked fish bile and pulp mill effluent was developed, the extracted samples were derivatized, separated and identified using CD-EKC with LIF detection. The method of extraction and derivatization using CD-EKC was applied to biological samples of contaminated effluent and fish bile. (Abstract shortened by UMI.)

Studies toward the total synthesis of (+)-providencin (1), a highly oxygenated cembranoid dipterpene with a unique bicyclo[12.2.0]hexadecane skeleton and pronounced biological activity, are described. These studies resulted in the synthesis of advanced intermediates 320 and 332 which contain all of the carbon atoms of 1. In a first generation approach toward 1, a zirconium-mediated deoxygenative ring contraction of furanose 177 was used to furnish enantiopure cyclobutanol 176. Olefination of furan aldehyde 197 with phosphonate 214 completed cyclobutylfuran segment 215. A second generation approach toward cyclobutylfuryl subunit 221 via ring-closing metathesis of diene 237 was unproductive, but the iodolactone subunit 228 needed for 1 was prepared successfully using carbometallation-iodination of alkyne 231. Nucleophilic substitution of tosylate 230 with the dianion of phenylselenyl acetic acid (252) followed by acid-catalyzed lactone formation was employed for construction of the γ-lactone moiety of 228. A third generation route to the cyclobutylfuryl subunit of 1 involved a tin(II) chloride-mediated stereoselective allenol synthesis by reaction of aldehyde 302 with propargyllic bromide 264. A silver-catalyzed allenone-to-furan isomerization of 309 completed the synthesis of cyclobutylfuran subunit 288. Attempts to couple the two major fragments, 228 and 288, using palladium-catalyzed C-H activation of the furan component were unsuccessful, but linkage of two major subunits was achieved at the C12-C13 bond via an intermolecular aldol reaction to give 332 and at the C6-C7 bond using intermolecular palladium-catalyzed cross-coupling to afford 320. / Graduation date: 2012

Made available in DSpace on 2015-05-14T12:59:25Z (GMT). No. of bitstreams: 1 parte1.pdf: 3145814 bytes, checksum: 359baf714900cf01b47378154bf15642 (MD5) Previous issue date: 2011-02-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Xylopia langsdorffiana (Annonaceae), popularly known pimenteira-da-terra, is a tree that can reach 5-7 m of height. Phytochemical studies reported the presence of alkaloids and terpenoids type trachylobane, atisane, labdane and kaurane of the fruits, stem and leaves. In this work we report the isolation and structural elucidation of terpenes isolated from roots of X. langsdorffiana. Chromatographic analysis of the crude ethanolic extract of the roots allowed the isolation of seven diterpenes: ent-7β-acetoxytrachyloban-18-oic acid, reported in the species, ent-trachyloban-18-oic acid, ent-kauran-16β-ol, ent-kaur-16-en-19-oic acid and ent-kaur-16-en-19-ol, first reported in the species, ent-atisan-7α-acetoxy-16α-ol and entatisan- 7-oxo-16α-ol first reported in the literature, and trivially named Acetato de Xylodiol and Xylopinona. The chemical constituents were identified by date analysis obtained for spectroscopic methods as Infrared, high and low resolution Mass Spectrometry obtained by ESI (HR-ESI-MS), 1H, 13C Nuclear Magnetic Resonance unidimensional and bidimensional techniques (COSY, NOESY, HMQC e HMBC), and compared with previously reported data. The roots were subjected to essencial oil extraction by hydrodistillation in Clevenger apparatus and characterized in GC-MS, was possible identify 89.9% of the chemical constituents oil. The major constituent is the trans-isolimonene (56.63%) and espathulenol 0.11% that is considered the marker of Xylopia genus. This way, the obtained results contributed with chemotaxonomic knowledge of Annonaceae family, especially Xylopia langsdorffiana. / Xylopia langsdorffiana (Annonaceae) é conhecida popularmente como pimenteira da terra , sendo considerada uma árvore que pode atingir de 5-7 metros de altura. Estudos fitoquímicos relataram a presença de alcalóides, e terpenóides do tipo traquilobano, atisano, labdano e caurano, em frutos, caule e folhas. Neste trabalho reportaremos o isolamento e elucidação estrutural de diterpenos isolados das raízes de X. langsdorffiana. Análises cromatográficas do extrato etanólico bruto das raízes permitiram o isolamento de sete diterpenos: ácido ent-7β- acetoxytraquiloban-18-óico, já relatado na espécie, ácido ent-traquiloban-18-óico, ent-cauran- 16β-ol, ácido ent-caur-16-en-19-óico e ent-caur-16-en-19-ol, relatados pela primeira vez na espécie, ent-atisan-7α-acetoxi-16α-ol e ent-atisan-7-oxo-16α-ol relatado pela primeira vez na literatura, e nomeados trivialmente de Acetato de Xylodiol e Xylopinona. Os constituintes químicos foram identificados através da análise de dados obtidos por métodos espectroscópicos como Infravermelho, Espectrometria de Massas de alta e baixa resolução, obtido por ESI (HR-ESI-MS), Ressonância Magnética Nuclear de 1H, 13C unidimensionais e técnicas bidimensionais (COSY, NOESY, HMQC e HMBC), além de comparação com dados descritos na literatura. As raízes também foram submetidas a extração de óleo essencial por hidrodestilação em aparelho tipo clevenger, e caracterizado em CG-EM, sendo possível identificar 89,39% dos constituintes químicos do óleo, que apresentou como constituinte majoritário o trans-isolimoneno (56,63%), e 0,11 % de espatulenol, considerado marcador para o gênero Xylopia. Desta forma, os resultados obtidos contribuíram para a ampliação do conhecimento químiotaxonômico da família Annonaceae, em especial Xylopia langsdorffiana.