Spiro-γ-lactones are widely distributed among natural products, several of them being well known by their interesting biological activities. We describe herein the synthesis of 1-oxaspiro[4.4]nonan derivatives and (+-)-andirolactone starting from easily available Diels-Alder adducts of 5-methylene-2(5H)-furanome 1 and classical dianes / La química de les espiro-γ-lactones ha despertat un considerable interès principalment degut a què moltes molècules que posseeixen aquesta estructura presenten diverses i significatives activitats biològiques. En aquesta tesi doctoral, prenent com a precursors els adductes de Diels-Alder, s’han investigat noves rutes sintètiques cap a 2(3H)-dihidrofuanones 5.5-disubstituïdes i oxaspiro[4.4]nonans polifuncionalitzats. Es presenten dues noves síntesis de (+-)-andirolactona 2, sesquiterpenoid amb estructura d’espiro-γ-butirolactona, recentment aïllat del Cedrus Libanotica i interessant per les seves propietats medicinals i biològiques potencials

A study on application of combinatorial methods (CM) and high-throughput methods (HTM) to biomaterials design, characterization, and screening are reported in this thesis - focusing on screening the effects of biomaterial surface features on adherent bone cell cultures. Polymeric biomaterials were prepared on two-dimensional combinatorial libraries that systematically varied the size and shape of chemically-distinct microstructural patterns - generated from blends of biodegradable polyurethanes and polyesters. Characterization and screening were performed with high-throughput optical and fluorescence microscopy. A unique advance of this work is the application of data mining techniques to identify the controlling structural features that affect cell behavior from among the myriad variety of metrics from the microscope images. The results from this study demonstrated the potentials of CM/HTS to be applied to exploratory studies involving complex systems in life sciences. This study accomplishes the goal to demonstrate the efficient screening and exploration of vast and complex dataset, extracting important and meaningful information to narrow down the future path of study in this field. Further study aimed to tuning cellular responses via signals from surface cues will be necessary to examine the causal relationships beyond the observed correlations shown in this exploratory study. It is recommended for further studies to narrow down the range for surface patterning around each of the three 'activation' ranges found in this study: apoptotic, viable, and one unknown state to be studied further. Different cellular-function staining methods will be necessary to be used in cellular imaging techniques in order to explore this unknown state further.

<p>Dynamic Combinatorial Chemistry (DCC) is a recently introduced supramolecular approach to generate dynamically interchanging libraries of compounds. These libraries are made of different building blocks that reversibly interact with one another and spontaneously assemble to encompass all possible combinations. If a target molecule, for instance a receptor is added to the system and one or more molecules show affinity to the target species, these compounds will, according to Le Châtelier´s principle, be amplified on the expense of the other non-bonding constituents. To date, only a handful of different systems and formats have been used. Hence, to further advance the technique, especially when biological systems are targeted, new reaction types and new screening methods are necessary. This thesis describes the development of reversible sulfur reactions, thiol/disulfide interchange and transthiolesterification (the latter being a new reaction type for DCC), as means of generating reversible covalent bond reactions. Two different types of target proteins are used, enzymes belonging to the hydrolase family and the plant lectin Concanavalin A. Furthermore, two new screening/analysis methods not previously used in DCC are also presented; the quartz crystal microbalance (QCM)-technique and catalytic self-screening.</p>

Utiliser la liaison peptidique dans des systèmes dynamiques covalents est très difficile en raison de sa stabilité intrinsèque. Dans ce travail, une nouvelle méthodologie pour échanger fragments peptidiques dans des conditions biocompatibles est décrite. Légères modifications du groupe amine d'un résidu de cystéine en peptides modèle permettent l'activation spécifique de cette jonction peptidique pour des réactions d'échange covalent. Grâce à un mécanisme de ligation chimique native réversible, fragments peptidiques sont échangés en solution aqueuse à pH physiologique et en présence de dithiothréitol (DTT), avec des demi-temps d'équilibration de 2 à 10 heures. Différentes possibles applications biologiques de cette nouvelle réaction réversible à peptides et glycopeptides sont aussi proposées. / The possibility to use the peptide bond in dynamic covalent systems is very challenging because of its intrinsic stability. In this work, a novel methodology to exchange peptide fragments in bio-compatible conditions is described. The introduction of small modifications to the N-terminus of a cysteine residue in model peptides allows for the specific activation of that peptide bond for exchange reactions. Through a reverse Native Chemical Ligation (NCL) mechanism, peptide fragments were scrambled in aqueous solution at physiological pH and in the presence of dithiothreitol (DTT), with half-times of equilibration in the 2-10 h range. Additionally, possible biological applications of this new reversible reaction to both peptides and glycopeptides are proposed.

Dynamic Combinatorial Chemistry (DCC) is a recently introduced supramolecular approach to generate dynamically interchanging libraries of compounds. These libraries are made of different building blocks that reversibly interact with one another and spontaneously assemble to encompass all possible combinations. If a target molecule, for instance a receptor is added to the system and one or more molecules show affinity to the target species, these compounds will, according to Le Châtelier´s principle, be amplified on the expense of the other non-bonding constituents. To date, only a handful of different systems and formats have been used. Hence, to further advance the technique, especially when biological systems are targeted, new reaction types and new screening methods are necessary. This thesis describes the development of reversible sulfur reactions, thiol/disulfide interchange and transthiolesterification (the latter being a new reaction type for DCC), as means of generating reversible covalent bond reactions. Two different types of target proteins are used, enzymes belonging to the hydrolase family and the plant lectin Concanavalin A. Furthermore, two new screening/analysis methods not previously used in DCC are also presented; the quartz crystal microbalance (QCM)-technique and catalytic self-screening. / QC 20101118

Dynamic systems for screening, control and identification of different protein-ligand interactions are presented. Dynamic chemistry is used to produce new compounds/constituents in situ that can interact with a target molecule. Several entities can be introduced at the same time and interact with one another. These molecules make a dynamic combinatorial library (DCL) which is used in dynamic combinatorial chemistry (DCC). DCC is a recently introduced approach to generate dynamically interchanging libraries of compounds. These libraries are made of different building blocks that reversibly interact with one another and spontaneously assemble to encompass all possible combinations. If a target molecule, for instance a receptor is added to the system and one or more molecules show affinity to the target species, these compounds will, according to Le Châtelier´s principle, be amplified on the expense of the other non-bonding constituents. To further advance the technique, especially when biological systems are targeted, new reaction types and new screening methods are necessary. This thesis describes the development of different reversible reactions, thiol/disulfide interchange, transthiolesterification and the nitroaldol (Henry) reaction as means of generating reversible covalent bond reactions. Two different types of target proteins are used, enzymes belonging to the hydrolase family and the plant lectin Concanavalin A. Dynamic combinatorial resolution (DCR) is presented. This new concept relies on the consecutive kinetic resolution of dynamic combinatorial libraries, leading to complete amplification and control of dynamically interchangeable processes. By applying a kinetically controlled step to a thermodynamically controlled system, complete transformation and amplification can be obtained. The concept has been demonstrated by developing transthiolesterification and nitroaldol exchange reactions to generate diversity, forming libraries under thermodynamic control, and used in one-pot processes with kinetically controlled enzyme-mediated resolution. The results demonstrate that the reaction types are useful for the generation of dynamic libraries, and that the dynamic combinatorial resolution concept is highly valuable for efficient substrate identification, asymmetric synthesis, and library screening. The thesis also describes three other dynamic chemistry protocols. The first one describes dynamic kinetic resolution (DKR) of nitroaldol adducts by combined lipase catalysis. The second one describes finding lectin inhibitors from a glycodisulfide library and the third one describes finding an inhibitor of acetylcholinesterase using a tandem driven dynamic self-inhibition approach. / <p>QC 20100818</p>

Durch parallele SPOT-Synthese wurden trisamino- und amino-oxo-substituierte [1,3,5]-Triazine auf Zellulose- und Polypropylenmembranen dargestellt. Neben der Entwicklung geeigneter Linkerstrategien und dem Einsatz von Aminen und Phenolaten als Bausteine konnte eine Mikrowellenbestrahlung für die Substitution an den membrangebundenen Monochlor-[1,3,5]-triazinen nutzbar gemacht werden. Der Einsatz von gasförmiger TFA zur Abspaltung der Syntheseprodukte von den planaren Oberflächen erlaubte den Erhalt der örtlichen Adressierbarkeit der Verbindungen für Analyse und Screening. Zusätzlich wurde ein neues Konzept für die Synthese von makrocyclischen Peptidmimetika entwickelt. Diese Methode bedient sich der sequenziellen SNAr-Reaktion von ursprünglich orthogonal geschützten Aminogruppen eines Peptides und anderer linearer Oligomere an halogenierten Heteroaromaten wie 2,4,6-Trichloro-[1,3,5]-triazin, 2,4,6-Trichloropyrimidin, 4,6-Dichloro-5-nitropyrimidin und 2,6,8-Trichloro-7-methyl-7H-purin. Die Möglichkeiten dieses neuen Zugangs zu Makrocyclen wurde systematisch mittels SPOT-Synthese untersucht. So wurden Fragen wie zugängliche Ringgrössen, Kompatibilität mit Aminosäuren, Cyclisierungsrichtungen und Verwendung von unterschiedlichen linearen Oligomeren adressiert. Es stellte sich heraus, dass eine Reihe von Peptidmimetika mit unterschiedlichen Ringgrössen (11- bis 37-gliedrige Ringe) und verschiedenen chemischen Strukturen des Rückgrades erhalten werden können. Die erhaltenden [1,3,5]-Triazin-Bibliotheken wurden sowohl in einem Festphasen-Screening als auch in einem Assay in Lösung eingesetzt. Es gelang, de novo Bindungspartner für den monoklonalen Antikörper TAB-2 aus einer Bibliothek aus 8000-zellulosegebundenen [1,3,5]-Triazinen zu finden und neuartige cyclische Peptid-Triazinderivate als Agonisten für einen Somatostatinrezeptor zu entwickeln. / Effective spatially addressed parallel assembly of trisamino- and amino-oxy-1,3,5-triazines was achieved by applying the SPOT-synthesis technique on cellulose and polypropylene membranes. In addition to developing a suitable linker strategy and employing amines and phenolate ions as building blocks, a highly effective microwave assisted nucleophilic substitution procedure at membrane-bound monochlorotriazines was developed. The 1,3,5-triazines obtained could be cleaved in parallel from the solid support by TFA-vapor to give compounds adsorbed on the membrane surface in a conserved spatially addressed format for analysis and screening. A novel concept for the synthesis of macrocyclic peptidomimetics which incorporate heteroaromatic units was developed. The method involves sequential SNAr reactions of former orthogonally protected amino groups of peptides and other linear oligomers on halo-genated heterocycles such as 2,4,6-trichloro-[1,3,5]-triazine, 2,4,6-trichloropyrimidine, 4,6-dichloro-5-nitropyrimidine and 2,6,8-trichloro-7-methyl-7H-purine. The scope of this novel solid phase approach was systematically evaluated by means of the SPOT-synthesis metho-dology. Besides the question of the accessibility of different ring sizes and the compatibility with protecting groups of commonly used amino acids, cyclization direction and the applicability of the technique towards peptidomimetics was studied. It was found that the procedure is well suited to assemble a wide variety of cyclic peptidomimetics differing in both size (11 to 37-membered rings) and chemical nature of the assembled backbones. The obtained [1,3,5]-triazine libraries were subjected to heterogeneous and homogeneous screening assays. De novo binding partners for the monoclonal antibody Tab2 were detected from a 8000-membered library of cellulose-bound 1,3,5-trazines. In addition novel cyclic peptide-triazine derivatives were identified as agonists for a somatostatin receptor.

Depuis la fin du XXème siècle, la chimie combinatoire dynamique permet de synthétiser sous contrôle thermodynamique des récepteurs macrocycliques pour des molécules invités cibles. Ainsi, de nombreux hôtes supramoléculaires capables d’effectuer de la reconnaissance de molécules d’intérêt biologique dans l’eau ont été reportés dans la littérature. Nous avons décrit une nouvelle famille de récepteurs macrocycliques hydrosolubles appelés dyn[n]arènes polycarboxylates. Leur propriété de reconnaissance moléculaire vis-à-vis des polyamines, des métaux et des acides aminés ont permis d’envisager des applications biologiques. D’un point de vue fondamental, le rôle des divers paramètres, dont le solvant, a été étudié pour identifier les forces motrices responsables des associations. Des expériences in cellulo ont permis de démontrer un effet cytostatique anti-prolifératif transitoire du dyn[4]arène sur les cellules cancéreuses HeLa. Dans le but de moduler leurs propriétés de reconnaissance moléculaire, des réactions d’extrusion de soufre ont été envisagées pour synthétiser des dérivés plus robustes des dyn[n]arènes. Enfin, une famille d’objets macrocycliques apparentée a été envisagée basée sur le motif imino-1,5-dithiocines. Des études synthétiques et physico-chimiques pour l’élaboration de ces nouveaux cavitands laissent entrevoir de possibles applications biologiques similaires à celle de leurs analogues, les bases de Tröger / Since the end of the 20th century, dynamic combinatorial chemistry under thermodynamic control has enabled the synthesis of macrocyclic receptors towards targeted guest. So, many supramolecular hosts have been reported to be efficent in the molecular recognition of biologically relevant molecules in water. We describe a new family of hydrosoluble macrocycles called polycarboxylated dyn[n]renes. Their molecular recognition properties with polyamines, amino acids and metals allow biological studies. From the fundamental view, the role of each parameters, including the solvent, has been deeply studied to identify the strength of the association. In cellulo experiments have shown an antiproliferative and cytostatic effect of the dyn[4]arene on HeLa cancer cells for several hours. In order to modulate their molecular recognition properties, sulfur extrusion process has been carried out to synthesize more robust derivatives of dynarenes. Finally, a new family of similar macrocycles has been studied, based on imino-1,5-dithiocines. Syntheses and physico-chemical studies for the design of futurs cavitands pave the way for similar biological applications as described for Tröger’s bases

Depuis les années 1990, la chimie combinatoire dynamique permet la découverte et la préparation de nouveaux récepteurs synthétiques à partir de briques moléculaires simples sous contrôle thermodynamique. Dans ce contexte, nous avons récemment décrit une nouvelle famille de para-cyclophanes dynamiques: les dyn[n]arènes. Ces macrocycles, composés de briques moléculaires 1,4-bisthiophénoliques fonctionnalisées, ont pu être obtenus à l'échelle du gramme à partir d'une procédure simple ne mettant pas en jeu de purification par chromatographie. Cette accessibilité synthétique a rendu possible une étude structurale permettant la rationalisation des forces motrices mises en jeu lors des processus d'auto-assemblage, mais aussi de leurs propriétés de reconnaissance moléculaire vis-à-vis de molécules ioniques. A partir de données expérimentales et de calculs réalisés en chimie théorique, les phénomènes physiques responsables de la sélectivité et de l'affinité remarquables observées entre l'un des membres de cette famille, un dyn[4]arène poly anionique, et une série d'a,?-alkyle-diamines ont été étudiés. Finalement, au cours de cette étude, nous avons redécouvert une voie de synthèse simple menant à une famille de molécules encore peu étudiée : les dithiocines. La fonctionnalisation de ces objets a été explorée dans le but d'obtenir une plateforme multifonctionnelle pour des applications biologiques / Since the 1990s, dynamic combinatorial chemistry has allowed the discovery and preparation of new synthetic receptors from simple building blocks under thermodynamic control. In this context, we have recently described a new family of dynamic para cyclophanes, the so-called dyn[n]arenes. These macrocycles, made from functionalized 1,4-bisthiophenolic building blocks, could be obtained on a gram scale from a simple purification procedure, and without any chromatography. Their synthetic accessibility allows us to study the driving forces behind their self-assembly, as well as their molecular recognition properties towards ionic guest molecules. Experimental and computational experiments were also conducted to reveal the subtle physical phenomena that are responsible for the remarkable selectivity and affinity observed between a poly-anionic dyn[4]arene and a series of a,?-alkyl-diamines. During these previous studies, we rediscovered a simple synthetic route towards a family of molecules that is unexploited so far: the dithiocins. The functionalization of these molecular objects has been explored in order to generate versatile platforms for biological applications

Combinatorial techniques have changed the paradigm of materials research by allowing a faster data acquisition in complex problems with multidimensional parameter space. The focus of this thesis is to demonstrate biomaterials design and characterization via preparation of two dimensional combinatorial libraries with chemically-distinct structured patterns. These are prepared from blends of biodegradable polymers using thickness and temperature gradient techniques. The desired pattern in the library is chemically-distinct cell adhesive versus non-adhesive micro domains that improve library performance compared to previous implementations that had modest chemical differences. Improving adhesive contrast should minimize the competing effects of chemistry versus physical structure. To accomplish this, a method of blending and crosslinking cell adhesive poly(季aprolactone) (PCL) with cell non-adhesive poly(ethylene glycol) (PEG) was developed. We examine the interaction between MC3T3-E1 osteoblast cells and PCL-PEG libraries of thousands of distinct chemistries, microstructures, and roughnesses. These results show that cells grown on such patterned biomaterial are sensitive to the physical distribution and phases of the PCL and PEG domains. We conclude that the cells adhered and spread on PCL regions mixed with PEG-crosslinked non-crystalline phases. Tentatively, we attribute this behavior to enhanced physical, as well as chemical, contrast between crystalline PCL and non-crystalline PEG.