Sphingosine kinase (SphK) has emerged as an attractive target for cancer therapeutics due to its role in cell proliferation. SphK phosphorylates sphingosine to form sphingosine-1-phosphate (S1P) which has been implicated as a major player in cancer growth and survival. SphK exists as two different isoforms, namely SphK1 and SphK2, which play different roles inside the cell. The dearth of isoenzyme-selective inhibitors has been a stumbling block for probing the exact roles of these two isoforms in disease progression. This report documents our efforts in developing SphK2-selective inhibitors. We provide the first demonstration of a SphK inhibitor containing a quaternary ammonium salt. We developed highly potent and moderately selective inhibitors that were cell permeable and interfered with S1P signaling inside the cell. In an effort to improve the selectivity of our inhibitors and enhance their in vivo stability, we designed and synthesized second generation inhibitors containing a heteroaromatic linker and a guanidine headgroup. These inhibitors were more potent and selective towards SphK2 and affected S1P signaling in cell cultures and various animal models. / Ph. D.

Sphingosine 1-phosphate (S1P) has become a prevalent drug discovery target due to studies implicating it to several disease pathologies such as fibrosis, sickle cell disease, inflammation, diabetes, and cancer. S1P functions to induce cell proliferation and migration. S1P signaling occurs through intracellular targets or transport outside of the cell via ABC transporters, where it acts as a ligand to G-protein coupled receptors (S1P1-5). Sphingosine kinase (SphK) 1 and 2 phosphorylate sphingosine to S1P; these are the only enzymes known to mediate the phosphoryl transfer. Inhibiting either or both SphKs helps to modulate S1P, which may be useful as a therapeutic avenue for disease states where S1P signaling has gone awry. Herein, we document our efforts in profiling the structure-activity relationships (SAR) of SphK2 through an iterative process of synthesis and biological testing. First, an SAR structured around the head and linker region of our lead molecule, SLR080811, was performed. SLR080811 has a Ki of 1.3 µM and is 5-fold selective for SphK2. The modifications performed on SLR080811 yielded two promising inhibitors: SLP120701 (SphK2 selective with a Ki of 1.2 µM) and SLP7111228 (>200 fold selective for SphK1 with a Ki of 48 nM). In vitro studies in U937 cells yielded a decrease in S1P levels with the introduction of inhibitors. Mouse studies provided insight into the pharmacokinetic effect of our SphK2-selective inhibitors, revealing an increase in S1P levels in the blood. When in vivo studies were performed with the SphK1 selective inhibitor, S1P levels in blood decreased. These molecules provide the chemical biology tools to determine the effect of modulating S1P levels in vivo. We also focused our investigation on the tail region of the pharmacophore. From this study, SLM6031434 and SLM6041418 were discovered and both proved to be more potent and selective SphK2 inhibitors than SLR080811. SLM6031434 has a Ki of 370 nM and is 23-fold selective for SphK2. SLM6041418 has a Ki of 430 nM and is 24-fold selective for SphK2. Consistent with our previous observations, in vitro studies showed a decrease in S1P levels when inhibitor was introduced. Similarly, in vivo studies resulted in an increase of S1P levels in the blood. These compounds are positioned towards animal models of disease. / Master of Science

Sphingosine 1-phosphate (S1P) is a cellular signaling molecule that has been implicated in a variety of diseases including cancer, fibrosis, Alzheimer's, and sickle cell disease. It is formed from the phosphorylation of sphingosine (Sph) by sphingosine kinase (SphK) and SphK exists as two isoforms-"SphK1 and SphK2, which differ with respect to their cellular activity and localization. As the key mediators in the synthesis of S1P, SphKs have attracted attention as viable targets for pharmaceutical inhibition. To validate their potential as therapeutic targets, we aimed to develop potent, selective, and in vivo active inhibitors of SphK. Herein, we describe the design, synthesis and biological evaluation of SphK2 inhibitors. We first describe the development of six SphK2 inhibitors that assess the utility of replacing lipophilic tail groups with heterocyclic rings. These six compounds demonstrate that the lipid binding pocket for SphK2 cannot accommodate compounds with tail groups that are conformationally restricted or positively charged. We then describe the development of aminothiazole-based analogues of an SphK1-selective inhibitor. A library of 37 aryl-substituted aminothiazole tail groups were synthesized, revealing a structure-activity relationship study that examines electronic effects on the aryl-substituted aminothiazoles and the effect of modifying the amino portion of the aminothiazole. These molecules show surprisingly good potency and selectivity for SphK2. In particular, we highlight 3.20dd (SLC4101431), a biphenyl aminothiazole that is the post potent and selective SphK2 inhibitor to date, with an SphK2 Ki of 90 nM and 100-fold selectivity for SphK2. This molecule's in vivo activity will also be discussed. Mitochondrial uncouplers are small molecules that shuttle protons from the inter membrane space to the mitochondrial matrix independent of ATP synthase, which disrupts oxidative phosphorylation and promotes increased nutrient metabolism for homeostasis to be maintained. Consequently, small molecule mitochondrial uncouplers have been pursued as probes for mitochondrial function and as potential therapeutics for the treatment of obesity and type 2 diabetes. Herein, we describe the design, synthesis, and biological evaluation of small molecule mitochondrial uncouplers. We report a library of 52 compounds that have good mitochondrial uncoupling activity over a wide therapeutic range, including 5.16t (SHC4111522) and 5.17i (SHC4091665), which have EC50 values of 0.63 uM and 1.53 uM, respectively, and achieve at least 2-fold increase in oxygen consumption rates relative to basal levels. With these molecules, we demonstrate that pKa and cLogP significantly contribute to uncoupling activity and must be accounted for when developing new generation small molecule mitochondrial uncouplers. / Ph. D.

Malaria is a severe and deadly mosquito-borne disease. Although treatable, the continuous emergence of multi-drug resistant parasite strains urgently calls for the development of novel antimalarial agents. P. falciparum parasites synthesize essential isoprenoid precursors, isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP), via a non-mevalonate pathway: the methylerythritol phosphate (MEP) pathway. This pathway is not utilized by humans. Thus, compounds that target the MEP pathway and disrupt isoprenoid biosynthesis in P. falciparum hold promise as potent and safe new antimalarial agents, that engage new targets. Previously, we and others identified MMV008138 from the Malaria Box as a MEP pathway targeting compound. Later work revealed that it targets the IspD enzyme within the MEP pathway. Work in the Carlier group has established preliminary structure-activity relationship (SAR) of MMV008138: 1) (1R,3S)-configuration is required; 2) 2', 4'-disubstitution of the D-ring with small, electronegative substituents; 3) functional importance of carboxylate acid at C3. In this work, I aim to gain further insight into the C3 SAR and A-ring SAR of lead compound MMV008138. Synthesized acid bioisosteres and A-ring analogs of MMV008138 were evaluated in their ability to inhibit P. falciparum parasite growth. We showed that the C3 substituent of MMV008138 has a very tight SAR, and likely interacts with a very constricted pocket within the PfIspD enzyme. A-ring modifications are limited to certain positions of MMV001838 and need to be sterically small. However, we have yet to identify a modification that significantly improves drug lead potency. Future work will continue towards understanding the A-ring SAR of MMV008138, as well as D-ring SAR and C1-SAR. Efforts will also be directed towards finding analogs with improved potency, transport and metabolic stability. / MS

Industrial chemicals in European Union produced or imported in volumes above 1 tonne annually, necessitate a registration within REACH. A common problem, concerning these chemicals, is deficient information and lack of data for assessing the hazards posed to human health and the environment. Animal studies for the type of toxicological information needed are both expensive and time consuming, and to that an ethical aspect is added. Alternative methods to animal testing are thereby requested. REACH have called for an increased use of in silico tools for non-testing data as structure-activity relationships (SARs), quantitative structure-activity relationships (QSARs), and read-across. The main objective of the studies underlying this thesis is related to explore and refine the use of in silico tools in a risk assessment context of industrial chemicals. In particular, try to relate properties of the molecular structure to the toxic effect of the chemical substance, by using principles and methods of computational chemistry. The initial study was a survey of all industrial chemicals; the Industrial chemical map was created. A part of this map was identified including chemicals of potential concern. Secondly, the environmental pollutants, polychlorinated biphenyls (PCBs) were examined and in particular the non-dioxin-like PCBs (NDL-PCBs). A set of 20 NDL-PCBs was selected to represent the 178 PCB congeners with three to seven chlorine substituents. The selection procedure was a combined process including statistical molecular design for a representative selection and expert judgements to be able to include congeners of specific interest. The 20 selected congeners were tested in vitro in as much as 17 different assays. The data from the screening process was turned into interpretable toxicity profiles with multivariate methods, used for investigation of potential classes of NDL-PCBs. It was shown that NDL-PCBs cannot be treated as one group of substances with similar mechanisms of action. Two groups of congeners were identified. A group including in general lower chlorinated congeners with a higher degree of ortho substitution showed a higher potency in more assays (including all neurotoxic assays). A second group included abundant congeners with a similar toxic profile that might contribute to a common toxic burden. To investigate the structure-activity pattern of PCBs effect on DAT in rat striatal synaptosomes, ten additional congeners were selected and tested in vitro. NDL-PCBs were shown to be potent inhibitors of DAT binding. The congeners with highest DAT inhibiting potency were tetra- and penta-chlorinated with 2-3 chlorine atoms in ortho-position. The model was not able to distinguish the congeners with activities in the lower μM range, which could be explained by a relatively unspecific response for the lower ortho chlorinated PCBs. / Den europeiska kemikalielagstiftningen REACH har fastställt att kemikalier som produceras eller importeras i en mängd över 1 ton per år, måste registreras och riskbedömmas. En uppskattad siffra är att detta gäller för 30 000 kemikalier. Problemet är dock att data och information ofta är otillräcklig för en riskbedömning. Till stor del har djurförsök använts för effektdata, men djurförsök är både kostsamt och tidskrävande, dessutom kommer den etiska aspekten in. REACH har därför efterfrågat en undersökning av möjligheten att använda in silico verktyg för att bidra med efterfrågad data och information. In silico har en ungefärlig betydelse av i datorn, och innebär beräkningsmodeller och metoder som används för att få information om kemikaliers egenskaper och toxicitet. Avhandlingens syfte är att utforska möjligheten och förfina användningen av in silico verktyg för att skapa information för riskbedömning av industrikemikalier. Avhandlingen beskriver kvantitativa modeller framtagna med kemometriska metoder för att prediktera, dvs förutsäga specifika kemikaliers toxiska effekt. I den första studien (I) undersöktes 56 072 organiska industrikemikalier. Med multivariata metoder skapades en karta över industrikemikalierna som beskrev dess kemiska och fysikaliska egenskaper. Kartan användes för jämförelser med kända och potentiella miljöfarliga kemikalier. De mest kända miljöföroreningarna visade sig ha liknande principal egenskaper och grupperade i kartan. Genom att specialstudera den delen av kartan skulle man kunna identifiera fler potentiellt farliga kemiska substanser. I studie två till fyra (II-IV) specialstuderades miljögiftet PCB. Tjugo PCBs valdes ut så att de strukturellt och fysiokemiskt representerade de 178 PCB kongenerna med tre till sju klorsubstituenter. Den toxikologiska effekten hos dessa 20 PCBs undersöktes i 17 olika in vitro assays. De toxikologiska profilerna för de 20 testade kongenerna fastställdes, dvs vilka som har liknande skadliga effekter och vilka som skiljer sig åt. De toxicologiska profilerna användes för klassificering av PCBs. Kvantitativa modeller utvecklades för prediktioner, dvs att förutbestämma effekter hos ännu icke testade PCBs, och för att få ytterligare kunskap om strukturella egenskaper som ger icke önskvärda effekter i människa och natur. Information som kan användas vid en framtida riskbedömning av icke-dioxinlika PCBs. Den sista studien (IV) är en struktur-aktivitets studie som undersöker de icke-dioxinlika PCBernas hämmande effekt av signalsubstansen dopamin i hjärnan.

Au cours des dernières années, une nouvelle classe de composés anticancéreux à base de ruthénium, appelés RDCs (Ruthenium-Derived Compounds), a été développé pour dépasser les limitations des agents chimiothérapiques contenants du platine. Contrairement à ces derniers, l’activité anticancéreuse des RDCs est en partie indépendante de l'interaction avec l'ADN. L’objectif principal de ma thèse a été ainsi de comprendre les mécanismes moléculaires quiinter viennent dans l’action anticancéreuse et antimétastatique des RDCs au-delà du dommage à l’ADN.J’ai démontré que le RDC11, contrairement au cisplatine, affecte les voies de signalisation de HIF-1 et mTOR, deux voies qui jouent un rôle clé dans le métabolisme cellulaire et qui sont souvent altérées dans les cellules cancéreuses.En parallèle, j’ai effectué un analyse structure/activité pour sélectionner des nouveaux RDCs ayant meilleures propriétés chimiques et pharmacologiques que le RDC11. Cette étude a permis d’identifier deux nouveaux RDCs qui réduisent la croissance tumorale in vivo avec un dosage beaucoup plus faible que le RDC11 et qui induisent la mort des cellules cancéreuses par une surproduction d'espèces réactives de l'oxygène et par l'activation de la caspase8. En conclusion, mes travaux ont conduit à l’identification de nouveaux mécanismes à la base de l’activité anticancéreuse du RDC11 qui pourraient expliquer certaines différences entre le mode d’action du RDC11 et du cisplatine. De plus, ils ont permis de sélectionner deux nouveaux RDCs plus efficaces que le RDC11. Ces résultat sont un impact important pour le développement de nouvelles thérapies anticancéreuses ou antimétastatiques. / In recent years, a new class of anticancer ruthenium-based drugs, called RDCs (Ruthenium-Derived Compounds), has been developed to overcome the limitations of classic platinum chemotherapeutics. Unlike the latter, the anticancer activity of RDCs is in part independent of DNA interaction. Therefore, the main objective of my thesis work was to elucidate the molecular mechanisms involved in RDCs anticancer and antimetastatic activity beyond DNA damage. I demonstrated that RDC11, unlike cisplatin, affects the HIF-1 and mTOR signaling pathways, two pathways that play a key role in cellular metabolism and that are frequently altered in cancer cells. In parallel, I performed a structure/activity analysis to select new RDCs endowed with better chemical and pharmacological properties than RDC11. This study allowed to identify two novel RDCs that reduce tumor growth in vivo at much lower doses than RDC11 and that induce cancer cell death by an overproduction of reactive oxygen species and activation of caspase 8. In conclusion, my work led to the identification of new mechanisms underlying the anticancer activity of RDC11 that could explain some of the differences between the mode of action of RDC11 and cisplatin. In addition, it allowed to select two novel RDCs which are more effective than RDC11. These results have a significant impact on the development of new anticancer or antimetastatic therapies.

Realizou-se um estudo estrutura-atividade sobre os efeitos citoprotetor/citotóxico de 5 flavonóides envolvendo processos mitocondriais, com ênfase na apoptose. Nossos resultados mostram que a dupla ligação na posição 2-3 / grupos 3-OH em conjugação com a função 4-oxo no anel C da estrutura dos flavonóides parece favorecer a interação destes compostos com a membrana mitocondrial, diminuindo a sua fluidez, e tanto inibindo a cadeia respiratória das mitocôndrias, quanto causando desacoplamento. Por outro lado, a estrutura o-di-OH no anel B parece favorecer a inibição da cadeia respiratória, sendo que a ausência desta estrutura parece favorecer a atividade desacopladora. Os flavonóides que não afetaram a respiração mitocondrial, induziram a transição de permeabilidade mitocondrial. A capacidade dos flavonóides em liberar o Ca2+ acumulado pelas mitocôndrias correlaciona-se com a sua capacidade de afetar a respiração mitocondrial e sua inabilidade em induzir a transição de permeabilidade mitocondrial. Já os dados referentes aos estudos da atividade protetora contra a formação de radicais livres demonstraram que a quercetina, luteolina e a galangina foram substancialmente mais potentes que a taxifolina e a catequina em conferir proteção contra a lipoperoxidação, embora somente a quercetina tenha sido um efetivo seqüestrador tanto de DPPH?, quanto de O2?-. Esses resultados sugerem que a dupla ligação na posição 2-3 em conjugação com a função 4-oxo na estrutura dos flavonóides são os fatores mais importantes na atividade antioxidante dos flavonóides sobre as mitocôndrias. Ainda, a presença da estrutura o-di-OH no anel B, conforme observado na quercetina, favorece essa atividade via seqüestro de O2?-, enquanto que a ausência dessa característica estrutural na galangina, a favorece via diminuição da fluidez de membrana e/ou desacoplamento mitocondrial. Os ensaios realizados para avaliar o efeito dos flavonóides sobre as células HepG2 mostraram que galangina, luteolina e quercetina são capazes de induzir morte celular. Esse efeito parece estar associado à dissipação do potencial de membrana mitocondrial e à diminuição na capacidade energética celular, mais pronunciada no caso dos dois primeiros; porém, como essa diminuição na concentração de ATP não é drástica, a morte celular pode ocorrer por apoptose. Os experimentos realizados para avaliar essa possibilidade sugerem uma ativação das caspases via mitocôndria, observada pelo aumento das atividades de caspase -9 e -3 e também pela exposição de fosfatidil serina. A taxifolina que não apresentou capacidade de produzir dano celular, apresentou, por outro lado, capacidade de prevenir parcialmente a diminuição de viabilidade das células HepG2 induzida pelo pró-oxidante t-butilhidroperóxido, aparentemente por meio de sua atividade antioxidante que inibiu, também de forma parcial, o acúmulo de espécies reativas de oxigênio. / We carried out a structure-activity study addressing the protective/toxic effects of 5 flavonoids (quercetin, taxifolin, luteolin, catechin and galangin) upon mitochondrial aspects with emphasis on the mechanisms potentially involved in cell apoptosis. The major findings were: The 2,3 double bond/3-OH group in conjugation with the 4-oxo function on the C-ring in the flavonoid structure seems favour the interaction of these compounds with the mitochondrial membrane, decreasing its fluidity either inhibiting the respiratory chain of mitochondria or causing uncoupling; while the o-di-OH on the B-ring seems favour the respiratory chain inhibition, the absence of this structure seems favour the uncoupling activity. The flavonoids not affecting the respiration of mitochondria induced MPT. The ability of flavonoids to induce the release of mitochondria-accumulated Ca2+ correlated well with their ability to affect mitochondrial respiration on the one hand, and their inability to induce MPT, on the other. The data concerning the protective activity against the free radical formation showed that quercetin, luteolin and galangin were far more potent than taxifolin and catechin in affording protection against lipid peroxidation, although only quercetin was an effective scavenger of both DPPH? and O2?-. These results suggest that the 2,3-double bound in conjugation with the 4-oxo function in the flavonoid structure are major determinants of the antioxidant activity of flavonoids on mitochondria, the presence of an o-di-OH structure on the B-ring, as occurring in quercetin, favouring this activity via O2?- scavenging, while the absence of this structural feature in galangin, favouring it via decrease in membrane fluidity and/or mitochondrial uncoupling. The assays addressing the flavonoids effects on HepG2 cells showed that galangin, luteolin and quercetin are able to induce cell death. This effect appears to be linked to the mitochondrial membrane potential dissipation and consequent decrease in the cellular energy charge, more pronounced for the galangin or luteolin treatment. However, since this decrease in ATP content is not drastic, the apoptosis process can occur. The set of experiments performed in order to evaluate this possibility demonstrated caspases-9 and -3 activation and also phosphatidylserine exposure on the cell membrane. On the other hand, taxifolin, that did not present ability to induce injury to the cell, was able to partially inhibit a viability decrease of HepG2 cell exposed to the pro-oxidant t-butylhydroperoxide, probably on account of its capacity to partially decrease ROS formation.

En Si Wang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 126-140 (2nd gp.)). / Acknowledgements --- p.i / Contents --- p.ii / Abstract --- p.iv / List of Acronyms and Abbreviations --- p.vi / introduction --- p.1 / Chapter I. --- "Platelet Activating Factor (PAF)´ؤPast, Present, and Future" --- p.1 / Chapter I-1. --- What is PAF? --- p.1 / Chapter I-2. --- Biochemistry of PAF --- p.2 / Chapter I-2-1. --- Metabolic Cycle of PAF --- p.3 / Chapter I-2-1-A. --- Biosynthesis of PAF --- p.4 / Chapter I-2-1 -B. --- Inactivation of PAF --- p.6 / Chapter I-2-2. --- Role of Endogenous PAF in Cell --- p.7 / Chapter I-3. --- Chemistry of PAF --- p.8 / Chapter I-4. --- Pathobiology of PAF --- p.9 / Chapter II. --- PAF Receptor --- p.10 / Chapter II-1. --- Presence and Characteristics of PAF Receptor --- p.10 / Chapter II-l-l. --- Solubilization of PAF Receptor --- p.10 / Chapter II-1-2. --- G-Protein Involvement --- p.11 / Chapter II-1-3. --- Species Differences --- p.11 / Chapter II-1-4. --- Multiple Conformational States of PAF Receptor --- p.12 / Chapter II-1-5. --- PAF Receptor Heterogeneity --- p.12 / Chapter II-2. --- Putative Conformation of PAF Membrane Binding Sites --- p.13 / Chapter II-3. --- Recent Progress in PAF Receptor Research --- p.15 / Chapter III. --- PAF Receptor Antagonist --- p.18 / Chapter III-1. --- Classification of PAF Antagonists --- p.18 / Chapter III-2. --- Inhibition Types of PAF Receptor Antagonists --- p.19 / Chapter III-2-1. --- Nonspecific Inhibition of the Effects of PAF --- p.21 / Chapter III-2-2. --- Specific Inhibition of PAF --- p.22 / Chapter III-3. --- Recent Progress in PAF Receptor Antagonist Research --- p.22 / Chapter IV. --- Pharmacology and Syntheses of Spiro-Ether Structural Units --- p.26 / Chapter IV-1. --- Natural Products Containing Spiro-Ether and Related Structural Units --- p.30 / Chapter IV-1-1. --- Labdane Diterpenoids Containing Spiro-Ether Structural Units --- p.30 / Chapter IV-1-2. --- Leucodrin and Related Derivatives --- p.32 / Chapter IV-2. --- Synthetic Methods of Spiro-Ethers and Related Derivatives --- p.34 / Chapter V. --- Aim of the Present Work --- p.45 / RESULTS AND DISCUSSION --- p.47 / Chapter I. --- Isolation and Structure Elucidation of Prehispanolone (1) and Preleoheterin (3) --- p.47 / Chapter I-1. --- Material and Isolation --- p.47 / Chapter I-2. --- Structure Elucidation of Prehispanolone (1) and Preleoheterin (3) --- p.47 / Chapter II. --- Synthesis of Model Compounds --- p.53 / Chapter II-l. --- "Synthesis of 2-Methyl-1,7-dioxaspiro[4.4]nonane (137)" --- p.53 / Chapter II-2. --- "Synthesis of 2,2-Dimethyl-l,7-dioxaspiro[4.4]nonane (139)" --- p.68 / Chapter II-3. --- "Synthesis of 2,2-Diphenyl-1,7-dioxaspiro[4.4]nonane (141) and 2,2-Diphenyl-l,7-dioxaspiro[4.4]non-8-ene (142)" --- p.72 / Chapter III. --- "Partial Synthesis of 13R, 14,15-Dihydroprehispanolone (5)，13S,14,15-Di- hydroprehispanolone (135) and prehispanolone (1)" --- p.76 / CONCLUSION --- p.89 / EXPERIMENTAL SECTION --- p.91 / REFERENCES --- p.126 / APPENDIX --- p.141

Hung Sau Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 131-137). / Table of Contents --- p.1 / Acknowledgements --- p.V / Abbreviations --- p.VI / Aim of investigation --- p.IX / Abstract --- p.XI / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Cancer Chemotherapy --- p.2 / Chapter 1.2 --- Plants as sources of useful drugs --- p.4 / Chapter 1.3 --- Potent antitumor compounds found in Goniothalamus giganteus --- p.7 / Chapter 1.4 --- Brief introduction of GONIOTRIOL --- p.8 / Chapter 1.5 --- The study on the antitumor activities of the antitumor compounds --- p.9 / Chapter 1.6 --- Biochemistry study of the anticancer agents --- p.10 / Chapter Chapter 2 --- Materials and Methods --- p.18 / Chapter 2.1 --- Materials --- p.19 / Chapter 2.1.1 --- Animals --- p.19 / Chapter 2.1.2 --- "Buffers, Culture Media and Chemicals" --- p.19 / Chapter 2.1.3 --- Cell lines --- p.20 / Chapter 2.1.4 --- Dye solutions --- p.21 / Chapter 2.1.5 --- Reagents and buffers for Agarose gel --- p.21 / Chapter 2.1.6 --- Synthetic goniotriol and its derivatives --- p.21 / Chapter 2.2 --- Methods --- p.23 / Chapter 2.2.1 --- Radioactive Precursor Incorporation Assays --- p.23 / Chapter 2.2.2 --- MTT assay --- p.24 / Chapter 2.2.3 --- Neutral Red assay --- p.24 / Chapter 2.2.4 --- Isolation and preparation of cells --- p.25 / Chapter 2.2.5 --- Assay for the solvent effect --- p.25 / Chapter 2.2.6 --- Assay for the in vitro antitumor activity THC88 on different cell lines --- p.27 / Chapter 2.2.7 --- Assay of the effect of THC86 on solid sarcoma Scl80 in vivo --- p.28 / Chapter 2.2.8 --- Assay of the effect of THC86 on peritoneal Scl80 in vivo --- p.28 / Chapter 2.2.9 --- Assay of the effect of THC89 on peritoneal EAT in vivo --- p.28 / Chapter 2.2.10 --- Assay of synthetic compound (THC89 and THC87) on the mitogenic activity of spleen lymphocytes --- p.29 / Chapter 2.2.11 --- Assay of synthetic compound (THC87) on the proliferation of murine bone marrow cells from compound- treated mice --- p.30 / Chapter 2.2.12 --- "Assay of synthetic compounds (Ml, P51 and P1) on nonmalignant cell-line" --- p.31 / Chapter 2.2.13 --- Assay of antitumor activity of synthetic compound (THC86)on PU5-1.8 --- p.31 / Chapter 2.2.14 --- Assay of the cytocidal effect of THC86 --- p.32 / Chapter 2.2.15 --- "Assay on the effect of THC86 on the synthesis of DNA, RNA and protein" --- p.32 / Chapter 2.2.16 --- Direct DNA cleavage by THC86 --- p.33 / Chapter 2.2.17 --- DNA fragmentation assay / Chapter 2.2.18 --- Assay of the effect of the synthetic compound (THC86) on different growth fraction of the cells / Chapter 2.2.19 --- Mitosis Study / Chapter 2.2.20 --- Assay for the stability of the synthetic compounds / Chapter Chapter 3 --- Structure / activity relationship of the synthetic compounds --- p.36 / Chapter 3.1 --- Results --- p.37 / Chapter 3.1.1 --- In vitro antitumor activity of the synthetic compounds --- p.37 / Chapter 3.2 --- Discussion --- p.45 / Chapter Chapter 4 --- Antitumor activities of the synthetic compounds --- p.63 / Chapter 4.1 --- Results --- p.64 / Chapter 4.1.1 --- Solvent effect in the screening process --- p.64 / Chapter 4.1.2 --- The effect of the synthetic compound (THC88) on different cell lines --- p.69 / Chapter 4.1.3 --- In vivo anti-tumor activities of the synthetic compounds --- p.71 / Chapter 4.1.3a --- Effect of THC86 on solid sarcoma Sc180 in vivo --- p.71 / Chapter 4.1.3b --- Effect of THC86 on peritoneal Scl80 in vivo --- p.71 / Chapter 4.1.3c --- Effect of THC89 on peritoneal EAT in vivo --- p.72 / Chapter 4.1.4 --- Cytotoxic effect of the tested compounds on normal cells --- p.77 / Chapter 4.1.4a --- Cytotoxic effect of THC89 on normal splenocytes in vitro --- p.77 / Chapter 4.1.4b --- Effect of THC87 on the proliferation of splenocytes --- p.77 / Chapter 4.1.4c --- Effect of THC87 on the proliferation of murine bone marrow cells --- p.78 / Chapter 4.1.4d --- Cytotoxic effect on non-malignant cell-line BALB/c 3T3/A31 --- p.78 / Chapter 4.2 --- Discussion --- p.85 / Chapter Chapter 5 --- The study on the antiproliferative mechanisms of the synthetic compounds --- p.88 / Chapter 5.1 --- Results --- p.89 / Chapter 5.1.1 --- "Effect of the synthetic compounds on Cell Growth, DNA, RNA and Protein" --- p.89 / Chapter 5.1.1a --- Effect of THC86 on PU5-1.8 (macrophage-like tumor) --- p.89 / Chapter 5.1.1b --- Cytocidal effect of THC86 on EAT --- p.89 / Chapter 5.1.1c --- "Effect of the synthetic compounds on synthesis of DNA, RNA and protein" --- p.90 / Chapter 5.1.2 --- Study of the synthetic compounds on the interactions of DNA --- p.101 / Chapter 5.1.2a --- DNA cleavage assay --- p.101 / Chapter 5.1.2b --- DNA fragmentation assay --- p.101 / Chapter 5.1.3 --- Effect of the synthetic compounds on different growth fraction of the cells --- p.104 / Chapter 5.1.4 --- Mitosis study of the synthetic compounds --- p.106 / Chapter 5.1.5 --- Investigation of the stability of the synthetic compounds in culture medium --- p.112 / Chapter 5.2 --- Discussion --- p.117 / Chapter Chapter 6 --- General Discussion --- p.122 / References --- p.131

Les analogues synthétiques des nucléosides naturels constituant des acides nucléiques occupent une place importante dans le domaine du médicament comme principes actifs antiviraux ou anticancéreux. Ces nucléosides agissent comme « prodrogues » en perturbant la biosynthèse des acides nucléiques viraux ou des cellules cancéreuses après phosphorylation. Dans la recherche de nouveaux médicaments antiviraux, nous avons cherché à synthétiser de nouveaux analogues des nucléosides naturels, les 2-désoxy-adénosine et -guanosine, et de l’aciclovir et de ses dérivés (vanciclovir, ganciclovir…) qui sont très utilisés dans le traitement de l’Herpès. Des premiers travaux en série adénine et guanine, n’ont pas permis d’obtenir les dérivés cycliques recherchés dans lesquels la base et la chaîne latérale introduite en position 9 de la base sont liés par un atome d’oxygène se trouvant en position 8 pour former un nouveau cycle. Quatre analogues cycliques en série guanine ont été synthétisés dans lesquels la base et la chaîne latérale en position 8 sont liés soit par un hétéroatome (préparés par réaction de substitution nucléophile), soit par une liaison carbone-carbone (préparés par réaction radicalaire) et sont en cours d’évaluation antivirale. / The synthetic analogues of the natural 2’-deoxyribonucleosides, linked by phosphodiester groups in nucleic acids, constitute major classes of antiviral and anticancer drugs. Such nucleosides act as “prodrugs” disturbing the biosynthesis of nucleic acids after phosphorylation. Searching for new antiviral drugs, the aim of this work was the synthesis of new modified nucleosides analogues of 2’-deoxyadenosine and -guanosine also analogues of aciclovir and its derivatives (vanciclovir, ganciclovir…) widely used for Herpes treatment. In the first works in adenine and guanine series, the cyclic analogues in which the base and a side chain introduced at position 9 of the base are linked at position 8 by an oxygen atom could not be obtained. Four cyclic analogues in the guanine series were prepared in which the base and the 9-side chain are linked at position 8 are either linked by a heteroatom (synthesized by nucleophilic substitution) or by a carbon-carbon bond (synthesized by free radical reaction). The evaluation of the antiviral activity of these compounds is underway.