The discovery and development of effective chemotherapeutic agents in the past few decades have immensely enhanced the treatment and management of human cancer. However, because these drugs are associated with adverse side effects, high genotoxicity, risk for secondary cancers and devastating effects on the patients’ immune system; the need for developing more effective anticancer agents remains. A priority Research shows that 9-aminoacridine (9AA) derivatives have substantial anticancer properties. The pharmacological properties of this agent are well characterized and this scaffold has been widely used to treat different diseases for decades. Quinacrine is a 9AA derivative, which was first discovered as an antimalarial compound in 1930’s and since then had been widely used in treating a variety of parasitic infections and demonstrated potential for cancer treatment. Importantly, the polypharmacology of Quinacrine makes it an attractive drug to treat a variety of cancers. Quinacrine acts by specifically targeting cellular signaling pathways that play an important role in cell survival. Given the distinctive cancer treating abilities of Quinacrine by specifically targeting cellular signaling pathways, it was the objective of this study to develop a compound that has similar properties as Quinacrine but has better efficacy and selectivity in targeting tumor cells. Therefore, for this project we created derivatives of 9AA compound using hybrid pharmapore approach and examined one of the derivatives of Quinacrine compound named VR118. After performing a series of experiments to test the efficacy and selectivity of the Quinacrine derivative VR118, I came to the conclusion that VR118 is highly effective in treating cancer cells and have the potential to selectively target cancer cells without causing severe harm to normal cells at concentrations applicable for malignant cell lines. This report discusses the efficacy and selectivity of VR118 compound in targeting cellular signaling pathways and the mechanisms through which VR118 kills cancer cells.

The structurally novel diterpenoid paclitaxel (Taxol®), originally isolated from <i>Taxus brevifolia</i>, is one of the most promising new anticancer drugs. Its structural complexity and unique biological activity have provided the impetus for a number of structure-activity relationship (SAR) studies for the last twenty years, with the aim of developing analogs with improved bioactivity. Because of the absence of information on the structure-activity relationship of the C-6 position and the ring C skeleton of paclitaxel, it was goal of this research to synthesize paclitaxel analogs modified in ring C in order to evaluate the effects of these modifications on biological activity and to reveal the chemistry of paclitaxel. The inactivity of the C-6 methylene group towards chemical modifications has been overcome by the formation of a double bond at the C- 6 and C-7 positions. Modification of the C-6 position has been achieved for the first time and over 20 new paclitaxel analogs modified at both the C-6 and C-7 positions have been synthesized. Biological evaluation of these compounds reveal that the C-6 and C-7 positions do not play significant roles in the biological activity of paclitaxel, although the two deoxygenated paclitaxel analogs, 7-deoxy-6α-hydroxypaclitaxel and 7,lO-dideoxy-6ahydroxypaclitaxel, were found to be more active than paclitaxel. Modification of the ring C skeleton has been accomplished for the first time, and several new C-<i>nor</i>-paclitaxel analogs have been synthesized. Biological evaluation showed that these C-<i>nor</i>-paclitaxel analogs were less active than paclitaxel, indicating that the ring C skeleton plays a crucial role in the biological activity of paclitaxel. Biological evaluation also showed that all oxetane ring-opened paditaxel analogs were essentially inactive. These results indicate that changes in the size and conformation of ring C and the attached oxetane ring make a significant contribution to the activity of paclitaxel. / Ph. D.

No description available.

La 20(S)-camptothécine (CPT) est un alcaloïde pentacyclique doté d'une activité anticancéreuse remarquable, agissant comme inhibiteur de la topoisomérase I (topo I). Le problème majeur de ce composé (et de la plupart de ses dérivés) est la fragilité de son cycle E qui s'hydrolyse rapidement à pH physiologique pour conduire au carboxylate correspondant inactif. L'une des approches permettant de pallier ce problème d'hydrolyse consiste à modifier le cycle E. Ce travail de thèse porte sur la synthèse totale de deux nouveaux analogues de la CPT modifiés au niveau du cycle E. Chacune de ces synthèses fait appel à une cycloaddition [3+2] afin de préparer l'hydroxypyridone de départ (cycles C et D), à un réarrangement de Claisen permettant de mettre en place le cycle E et à une condensation de Friedländer pour installer le motif quinoléinique (cycles A et B). Le premier analogue synthétisé, la (±) 17 norcamptothécine (17-norCPT), possède une α-hydroxy γ-lactone à la place de l'α-hydroxy δ-lactone de la CPT. Ce composé a été obtenu en neuf étapes avec un rendement de 4,4% à partir de l'hydroxypyridone de départ. Le test d'inhibition de la topo I a été réalisé, mais cette molécule s'est révélée totalement inactive. Cependant, une étude de la cinétique d'hydrolyse de la 17-norCPT, réalisée par spectroscopie de fluorescence, a permis de montrer que cet analogue était très instable en milieu aqueux. Le second composé préparé est en fait un homologue de la 17 norCPT possédant un méthylène entre l'oxygène et le carbonyle de la lactone. Cette molécule, comportant un motif céto éther, est donc un isomère de la CPT. Elle a été obtenue par deux voies de synthèse différant l'une de l'autre par l'ordre des réactions mises en œuvre. Chacune de ces approches permet d'obtenir le composé souhaité en neuf étapes à partir de l'hydroxypyridone de départ, avec un rendement de 16% et 10% respectivement. Les tests biologiques sur le composé final sont actuellement en cours. / 20(S)-Camptothecin (CPT) is a pentacyclic alkaloid endowed with remarkable anticancer activity, acting as an inhibitor of topoisomerase I (topo I). The major problem with this compound (and many of its derivatives) is the fragility of its E-ring, which suffers rapid hydrolysis at physiological pH to yield the inactive corresponding carboxylate. One of the approaches to overcome this problem of hydrolysis consists in modifying the E-ring. This thesis focuses on the total synthesis of two new E-ring modified CPT analogs. Each of the syntheses involves a [3+2] cycloaddition to prepare the starting hydroxypyridone (rings C and D), a Claisen rearrangement to realize the E-ring, and a Friedländer condensation to install the quinoline system (rings A and B). The first analog synthesized, (±) 17 norcamptothecin (17-norCPT), has an α-hydroxy γ-lactone in place of the α-hydroxy δ-lactone of CPT. This compound has been obtained in nine steps with a yield of 4.4% from the starting hydroxypyridone. Unfortunately, though, this molecule has proved to be totally inactive in the topo I assay. A kinetic hydrolysis study of 17-norCPT, carried out by fluorescence spectroscopy, has demonstrated, however, that this analog is, in fact, unstable in aqueous media. The second compound prepared is a homolog of 17-norCPT with a methylene between the lactone oxygen and carbonyl, thus a CPT keto ether isomer. It has been obtained through two synthetic routes that differ from each other in the order of the steps. Each of the approaches yields the desired compound in nine steps from the starting hydroxypyridone, with yields of 16% and 10% for the two syntheses. Biological tests on the final compound are currently underway.

Nous avons synthétisé des composés d'étain avec des acides undécylénique, ricinoléique et caprylique. Ils ont une activité importante contre certaines souches de microrganismes, puisque ils agissent pour certains d’entre eux à des concentrations nanomolaires. Staphylococcus aureus semble être 4000 fois plus sensible à leur toxicité que les cellules de mammifères. Nous avons obtenu des composés du ruthénium qui présentent cytotoxicité contre des cellules cancéreuses suivant un mécanisme d'action différent de ceux observés pour le Cisplatine ou d'autres composés de Ru, grâce à leur grande stabilité dans les réactions de substitution. Enfin, pendant la vectorisation des composés dérivés du Ru avec une Affitine nous avons pu acquérir des connaissances importantes sur un éventuel mécanisme d'action de ce type de molécules dont le potentiel redox très abaissé par rapport aux composés correspondants pourrait être responsable de la polymérisation de protéines cibles par transfert d’électron. / Related to antimicrobial research, we synthesized tin compounds derived from undecylenic, ricinoleic and caprylic acids and we found that they show very high activity against some strains of bacteria and yeast, even in nM range, being up to four thousand times more potent against Staphylococcus aureus than against mammalian cells. For ruthenium compounds, in turn, we have confirmed that the mode of action of some compounds that were synthesized recently is undoubtedly different from Cisplatin or other ruthenium compounds, because of their high stability toward substitution reactions. Finally, during the vectorization of compounds derived from Ru with Affitin we have gained important knowledge about a possible mechanism of action of this type of molecule: it could indeed be possible that these compounds which have a very reduced redox potential compared to corresponding compounds can cause polymerization of proteins by electron transfer.