Avec l'âge, les propriétés mécaniques des os se détériorent, conduisant à un risque accru de fracture. Bien que les mesures de densité minérale osseuse permettent de prédire, dans une certaine mesure, ces risques, elles restent insuffisantes dans un grand nombre de cas. Une compréhension plus complète des différents facteurs permettant de définir la « qualité » d'un os est donc souhaitable. Il est connu que la résistance à la fracture de tissus osseux est affectée non seulement par la glycosylation non-enzymatique du collagène, mais aussi par des protéines non collagéneuses comme l'ostéocalcine (OC) et l'ostéopontine (OPN). Cependant, le rôle structural de ces deux protéines dans l'os est mal connu, de même que la façon dont elles contribuent aux propriétés mécaniques globales. L'objectif de cette thèse est donc de répondre à ces deux points. Un modèle synthétique a ainsi été développé pour élucider quelles sont les interactions-clés gouvernant l'interaction de l'OC et l'OPN avec la phase minérale osseuse. Par ailleurs, en utilisant des os de souris génétiquement modifiées (déficientes en OC et/ou OPN), des études RMN solide ont été menées, pour élucider le rôle de l'OC et l'OPN à l'interface organique-inorganique. Leur lien avec les propriétés mécaniques a aussi été étudié en détail, via des tests de rupture, de fatigue et de fluage. Les résultats obtenus montrent que l'OC et l'OPN ont un rôle structural important dans les tissus osseux, et qu'elles contribuent aux propriétés mécaniques par le biais de leurs interactions ioniques, au niveau des interfaces entre les fibrilles de collagène minéralisés. / The decrease in bone mechanical properties occurs with age. The associated fragility fractures present a global public health concern. The use of bone mineral density as a predictor of risk of fracture is, however, limited. A more comprehensive understanding of bone quality and its link to bone fragility is thus desirable. Besides the brittleness caused by nonenzymatic glycation of collagen, bone fracture resistance is also influenced by noncollagenous components such as osteocalcin (OC) and osteopontin (OPN). The structural role of OC and OPN in bone and how they contribute to mechanical properties is however unclear. The objective of this thesis is to elucidate these two aspects. Key interactions associated with the binding of OC and OPN to bone mineral were studied in a synthetic model. Using genetically modified animal model lacking OC and/or OPN, the role of OC and OPN in organic-inorganic interface was examined by solid state NMR, and their link to mechanical properties was studied via a series of tissue level mechanical tests, measuring fracture toughness, creep, or fatigue. Based on the results obtained, it is concluded that OC and OPN are present as structural elements in bone and contribute to tissue mechanical properties via ionic interactions at the interfaces between mineralized fibrils.

Since its discovery in the 1950's, DNP has been a topic of significant interest in magnetic resonance. DNP is the transfer of polarization between single electrons and nuclei, driven by micro-wave irradiation. Since its renaissance at high field in the 90's, due to the introduction of gyrotrons as high-power, high-frequency microwave sources most application of this technique have been samples of biological interest in frozen solution. The long standing interest of our group in the characterization of surface species such as supported catalysts on silica lead us to apply this technique to the study of surfaces. The goal of this thesis is the development of this method, dubbed DNP Surface Enhanced NMR Spectroscopy. To that end, we first introduce new polarizing agents, soluble in organic solvents. The influence of the electron relaxation times on the DNP enhancements is demonstrated and efficient tailored polarizing agents are introduced. The optimization of the sample preparation to obtain optimal sensitivity is also discussed, as well as the interaction between the radical and the surface. These developments made it possible to apply the technique to many functionalized materials, with some examples developed in this manuscript. Finally, the issue of DNP on polarization conductors is discussed, and we show how microcrystals can be efficiently polarized using DNP.

Depuis sa découverte dans les années 50, la DNP suscite un intérêt croissant en résonance magnétique. La DNP peut être définie comme le transfert d'aimantation entre des électrons célibataires et les noyaux de l'échantillon induit par irradiation micro-onde. Depuis sa renaissance à hauts champs dans les années 90, grâce à l'introduction des gyrotrons comme source micro-onde haute fréquence haute puissance, la plupart des développements et applications de la méthode concernent des échantillons d'intérêt biologique en solution solide. L'intérêt de notre groupe pour la caractérisation d'espèces de surface, tels que les catalyseurs supportés sur silice nous a conduit à appliquer la DNP à des espèces de surface. Le but de cette thèse est le développement de cette méthode nommée DNP SENS. Pour cela de nouveaux agents de polarisations sont tout d'abord introduits, avec une discussion sur l'influence des temps de relaxation électroniques sur l'efficacité DNP. L'optimisation de la préparation des échantillons pour maximiser la sensibilité RMN est discutée, ainsi que l'interaction entre les radicaux et la surface. Ces développements ont permis la caractérisation de nombreux matériaux et quelques exemples sont donnés ici. Enfin, une dernière partie se concentre sur l'application de la DNP à des conducteurs de polarisation, et montre la possibilité d'hyperpolarisés des objets de taille micrométrique. / Since its discovery in the 1950's, DNP has been a topic of significant interest in magnetic resonance. DNP is the transfer of polarization between single electrons and nuclei, driven by micro-wave irradiation. Since its renaissance at high field in the 90's, due to the introduction of gyrotrons as high-power, high-frequency microwave sources most application of this technique have been samples of biological interest in frozen solution. The long standing interest of our group in the characterization of surface species such as supported catalysts on silica lead us to apply this technique to the study of surfaces. The goal of this thesis is the development of this method, dubbed DNP Surface Enhanced NMR Spectroscopy. To that end, we first introduce new polarizing agents, soluble in organic solvents. The influence of the electron relaxation times on the DNP enhancements is demonstrated and efficient tailored polarizing agents are introduced. The optimization of the sample preparation to obtain optimal sensitivity is also discussed, as well as the interaction between the radical and the surface. These developments made it possible to apply the technique to many functionalized materials, with some examples developed in this manuscript. Finally, the issue of DNP on polarization conductors is discussed, and we show how microcrystals can be efficiently polarized using DNP.

Das Verständnis der Mechanismen, nach denen biologische Systeme ablaufen, ist ein wichtiger Fokus der aktuellen Strukturbiologie. Kernmagnetische Resonanzspektroskopie (NMR) ist eine geeignete Technik, um solche Ziele anzustreben sowie Struktur und Dynamik von Biomolekülen zu erforschen, um komplementäre Informationen zum Verständnis von Proteinfunktionalität zu erhalten. Rasante Fortschritte sind vor nicht langer Zeit auf dem Gebiet biologischer Festkörper-NMR (ssNMR) erzielt worden, was zu vollständiger Strukturaufklärung zahlreicher Peptide und kleiner Proteine, der Beschreibung von Protein-Komplexbildung sowie der der dynamischen Eigenschaften kleiner Proteine geführt hat. Festkörper-NMR ist die Methode der Wahl bei struktureller und dynamischer Charakterisierung von Membranproteinen und aggregierten amyloidogenen Systemen, die schwer löslich und kaum mit Lösungs-NMR oder Röntgenkristallographie zugänglich sind. Moderne Festkörper-NMR ist noch immer limitiert, was Auflösung und Empfindlichkeit betrifft, und macht weitere Entwicklungen auf den Gebieten der Probenpräparation und des Pulssequenz-Designs erforderlich. In meiner Arbeit untersuche ich die potenzielle Verwendung von Deuterierung in der Protein Festkörper-NMR zur Erhöhung von Empfindlichkeit und Auflösung in 15N-1H Korrelationsexperimenten. Der erzielte Fortschritt auf diesen Gebieten erlaubt die Verfolgung von Proteinrückgratbewegungen mit hoher Genauigkeit, die vorher nicht verfügbar war. Wir zeigen zum ersten Mal, dass TROSY Experimente für Festkörper-NMR gewinnbringend sind. Außerdem wurde eine Pulssequenz für 13C-13C J Kopplung zur Erhöhung der Auflösung in der Kohlenstoff-Dimension entwickelt. / Understanding the mechanisms how biological systems work is an important objective of current structural biology. Nuclear magnetic resonance (NMR) spectroscopy is a well suited technique to approach these goals and to study structure and dynamics of biomolecules in order to obtain complimentary information for understanding functionality of proteins. Recently, rapid progress has been made in the field of biological solid state NMR (ssNMR), which resulted in complete structure elucidation of several peptides and small proteins, the characterization of protein complex formation and the characterization of dynamic properties of small proteins. Solid state NMR is the method of choice for structural and dynamic characterization of membrane proteins and aggregated amyloidogenic systems, which are poorly soluble and can not be easily studied by solution state NMR and X-ray spectroscopy. Modern solid state NMR is still limited in resolution and sensitivity, and requires developments in sample preparation and pulse sequence design. In my thesis, I study the potential use of deuteration in protein solid state NMR for sensitivity, as well as for resolution enhancement in 15N-1H correlation experiments. Achieved progress in these fields allows to monitor backbone motion with high accuracy, which has not been available before. We show for the first time that TROSY type experiments can be beneficial for solid state NMR. In addition, a pulse sequence for 13C-13C J decoupling was developed to increase resolution in the carbon dimension.

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Yes / Emtricitabine (ECB) afforded dimorphic cocrystals (Forms I, II) of benzoic acid (BA), whereas with p-hydroxybenzoic acid (PHBA), p-aminobenzoic acid (PABA) are resulted in as high Z'' cocrystals. Intriguingly, the Z'' of cocrystals are trends from two to fourteen based on the manipulation of functional groups on the para position of BA (where H atom is replaced with that of OH or NH2 group). ECB‒PABA cocrystal consists of six molecules each and two water molecules in the asymmetric unit (Z''=14) with 2D planar sheets represents the rare pharmaceutical cocrystal. The findings suggest that the increment of H bond donor(s) systematically via a suitable coformer are in correspondence with attaining high Z'' cocrystals. Further, solid state NMR spectroscopy in conjunction with single crystal X-ray diffraction are demonstrated as significant tools to enhance the understanding of the number of symmetry independent molecules in the crystalline lattice and provide insights to the mechanistic pathways of crystallization. / Department of Science and Technology (DST) Fund for improvement of S & T Infrastructure (FIST) with grant no. SR/FST/CST-266/2015(c) to PS and VP. AN and VV acknowledge the Government of India under National Overseas Scholarship (2012-13) and High Commission of India, London UK for PhD studentship.

Amino-functionalized organic–inorganic hybrid materials with a narrow distributed nanostructure of 2–4 nm in size were obtained by means of a template-free and non-aqueous procedure. Simultaneous twin polymerization of novel amino group containing twin monomers with 2,2′-spirobi[4H-1,3,2-benzodioxasiline] has been applied for this purpose. The amino groups of the organic–inorganic hybrid material are useful for post derivatization. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Ziel der vorliegenden Promotionsarbeit war die Entwicklung einer Methode zur Quantifizierung saurer Zentren auf Festkörperoberflächen mittels 15N-Festkörper-NMR-Spektroskopie von adsorbierten Pyridinmolekülen. Die 15N-Festkörper-NMR von adsorbiertem Pyridin ermöglicht die Unterscheidung verschiedener Arten von sauren Zentren, wie Lewis- und Brønsted-Zentren. Die Bestimmung der Art und der Konzentration auftretender saurer Zentren ist entscheidend, um die katalytische Aktivität fester Katalysatoren in einer Reaktion zu verstehen. Da 15N-NMR-Messungen zumeist zeitaufwendig sind, wurde in dieser Arbeit eine zeitoptimierte Messroutine entwickelt, die auf der Messung von 15N-Einzelpuls-Spektren mit kurzen Pulswiederholzeiten beruht. Um diese Spektren quantitativ auswerten zu können, müssen die detektierten NMR-Signale bezüglich ihrer T1-Relaxation korrigiert werden. Zudem treten in 15N-Einzelpuls-NMR-Spektren oft starke Störungen der Basislinie auf. Zur Unterdrückung dieser Störsignale wurde die EASY-Methode entwickelt, die auf der Messung von zwei schnell aufeinander folgenden Spektren basiert. Mittels dieser Methode können auftretende Störsignale in quantitativen 15N-NMR-Spektren unterdrückt werden. Die entwickelte zeitoptimierte Quantifizierungsmethode wurde an zwei Probenserien von festen Säuren getestet; zum einen an Aluminiumhydroxidfluoriden, als Vertreter von Verbindungen mit stark sauren Zentren, und zum anderen an hydroxylierten Magnesiumfluoriden, als Vertreter schwach saurer Verbindungen. Der Vergleich mit anderen quantitativen Methoden zeigte, dass die 15N-Festkörper-NMR-Spektroskopie von adsorbiertem Pyridin hervorragend für die Quantifizierung saurer Zentren geeignet ist und Einblicke in die katalytische Aktivität fester Katalysatoren ermöglicht. / The aim of the present dissertation was to develop a method for the quantification of acidic sites on solid surfaces by 15N solid-state NMR with pyridine as probe molecule. 15N NMR of adsorbed pyridine allows to distinguish different types of acidic sites like Lewis and Brønsted sites. The determination of the kind and concentrations of occurring acidic sites is crucial to understand the catalytic activity of a solid catalyst in a reaction.15N NMR measurements are often time-consuming. Hence, a time-optimized NMR quantification procedure was developed which uses 15N single pulse spectra with short pulse repetition delays. For quantitative analysis of these spectra, occurring signals were corrected according to their T1 relaxation. Furthermore, often strong baseline disturbances are observed in single pulse spectra. For the suppression of these disturbances, the EASY method was developed. The EASY method uses two successive scans to obtain quantitative NMR spectra, in which baseline disturbances are suppressed. The developed time-optimized method for the quantification of acidic sites was applied on two series of samples. One series of aluminum hydroxide fluorides as representatives of catalysts with strong acid sites and one series of hydroxylated magnesium fluorides as representatives of weak acidic catalysts. The comparison with other quantitative methods shows that 15N solid-state NMR of adsorbed pyridine is an excellent method for the quantification of acidic sites, because insights in the catalytic activity of a catalyst can be gained.