Plants secrete peptide ligands and use receptor signaling to respond to stress and control development. Understanding the signaling mechanisms and associated molecular trafficking is key to improving plant health and productivity for food, fiber and energy applications. However, one of the challenges to elucidating communication pathways in plants is to study the trafficking of molecules and signals iteratively and non-destructively. This study focuses on using fiber-optic fluorescence microscopy to image live plants iteratively and non-destructively after delivering both labeled and unlabeled phytosulfokine (PSK) into the plant. PSK is a sulfated peptide hormone involved in the regulation of plant cell division and growth via specific receptors, PSKRs. It also plays a role in regulating how plants are able to tolerate stress conditions. The microscope provides two-color (FITC/TRITC) optics and provides high-resolution (3–5 µm) epifluorescence micrographs via a 1-m coherent imaging fiber and a GRIN objective lens. To obtain high-quality images, the fiber was mounted either to a conventional upright microscope body equipped with a leaf compressor, or to a leaf clip with 5-axis positioning (X–Y–Z plus pitch and yaw) mounted on an extensible arm. PSK and TAMRA-labelled PSK were delivered into the roots of various Arabidopsis thaliana genotypes (wt; receptor-deficient: pskr1/pskr2; and tagged receptor overproducing: PSKR1‑GFP), and their movement in roots and leaves was tracked with the fiber-optic fluorescence microscope. Peptide trafficking was successfully observed in live plants non- destructively, confirming that PSK is mobile in both wt and receptor-deficient plants. Preliminary results suggest that the level of receptor PSKR1 may change in response to PSK, and that levels of PSKR1, PSKR2 or both may impact the trafficking of PSK. Understanding how PSK is trafficked in plants will offer insights into how we can improve plants health and productivity.

Reported herein is a brief summary of the history, properties, and applications of amine-boranes. The past methods devised for their preparation are described and the routes used to produce the compounds used in the work presented here are detailed. Building on prior synthetic approaches to amine-boranes, a new carbon dioxide mediated synthesis is presented. Proceeding through a monoacyloxyborane intermediate, the borane complexes of ammonia, primary, secondary, tertiary, and heteroaromatic amine are provided in 53-99% yields. Utilizing the amine-boranes obtained from the methods described, two divergent methods for direct amidation are introduced. The first uses amine-boranes as dual-purpose reagents, where the carboxylic acid is first activated by the borane moiety to form a triacyloxyborane-amine complex. This allows the delivery of the coordinated amine to form the amide products. A series of primary, secondary, and tertiary amides were prepared in 55-99% yields using this protocol, which displays a broad functional group tolerance. Extended from this dual-purpose methodology, a catalytic amidation is described. Utilizing ammonia-borane as a substoichiometric (10%) catalyst, a series of secondary and tertiary amide are prepared directly from carboxylic acids and amines in 59-99% yields, including amines containing typically borane reactive functionalities including alcohols, thiols, and alkenes. Amine-boranes are additionally used in two borylation methodologies. By reaction with <i>n</i>-butyl lithium, the amine-boranes are converted to the corresponding lithium aminoborohydrides, which upon reaction with a terminal alkyne provides the alkynyl borane-amine complexes in 65-98% yields. This process is compatible with both alkenes and internal alkynes, as well as a range of aprotic functionalities. A new strategy for aminoborane synthesis is also described and applied to the borylation of haloarenes. Activation of a series of amine-boranes with iodine produces the iodinated amine-borane, which undergoes dehydrohalogenation with an appropriate base to produce either monomeric or dimeric aminoboranes. Several aminoboranes were synthesized exclusively as the monomeric species, which due to their greater reactivity, were used directly in the synthesis of a series of aryl boronates in 65-99% yields.

The present dissertation is motivated by the search for alternatives of lead-free soldering by nanoparticles of metals and their alloys. The research focuses on the possibility of replacing lead-free solders by nanoparticles. This issue is currently being addressed by the use of lead-free solders but their properties are not entirely equivalent to properties of lead-tin based alloys. The theoretical part of the dissertation first summarizes up-to date knowledge on the development of lead-free alloys currently used for soldering in the electronics. The work compares these lead-free solder candidates with previously used Pb-Sn alloys. The second section of the theoretical part is devoted to nanotechnology that offers possible solutions of problems associated with the use of lead-free solders. The text contains a description of the properties of nanocrystalline materials in comparison with those of compact alloys having the same chemical composition. The possibility of preparation of nanoparticles and potential problems associated with small particle sizes are also presented. Introduction of the experimental part focuses on the preparation of nanoparticles of pure metals and alloys by chemical and physical ways as well as on an instrumentation for characterisation and analysis. Attention is focused on the silver in nanoparticle form that exhibits the low temperature sintering effect, which is thermally activated by decomposition of oxide envelope covering the Ag nanoparticles. This factor is critical for low-temperature sintering and thus also for possible future applications. The thermal effects of the low sintering process were studied by methods of thermal analysis. The preparation of the Cu / Ag nano / Cu joints was carried out in-situ in inert atmosphere and under the action of atmospheric oxygen. In both cases varying conditions of thermal treatment were used. The cross sections of the prepared joints were then used for the metallographic analysis of the local mechanical properties of the resulting silver layer, for the chemical composition evaluation of the resulting layers of the joint, and for the microstructure study. Strength characteristics are represented by testing shear strength of individual joints.

Die Inositol-Pyrophosphate (PP-InsPs) sind eine ubiquitäre Gruppe hochphosphorylierter eukaryotischer Signalmoleküle. Sie werden mit einer Vielzahl zentraler zellulärer Prozesse in Verbindung gebracht, doch fehlt oft ein detailliertes Verständnis der einzelnen Signalereignisse, was zum Teil auf einen Mangel an chemischen Werkzeugen zurückzuführen ist. Diese Arbeit beschreibt die chemische Synthese, Validierung und Anwendung von PP-InsP-Affinitätsreagenzien zur Identifizierung von Proteinbindungspartnern von Inositolhexakisphosphat (InsP6) und 5-Diphosphoinositol-Pentakisphosphat (5PP-InsP5), zwei wichtigen eukaryotischen Metaboliten. Die Affinitätsreagenzien wurden entwickelt, um InsP6 und ein metabolisch stabiles 5PP-InsP5-Analogon auf drei verschiedene Arten darzustellen. Die Anwendung dieser triplexierten Reagenzien auf Säugetier-Lysate lieferte einen ersten umfassenden Datensatz in HCT116- und HEK293T-Zellen. Die Interaktome wurden mittels quantitativer Proteomik annotiert und enthüllten Hunderte von potenziellen Proteinbindungspartnern. Die quantitative Analyse der InsP6- und 5PP-InsP5-bindenden Proteine zeigte Beispiele für hochspezifische Protein-Ligand-Interaktionen auf. Biochemische Untersuchungen ergaben, dass Inositol-5-Phosphatasen, PRPS1 und spezifische Phosphatidyl-Inositolphosphat-Kinasen potenziell unentdeckte Zielproteine von PP-InsPs sind. Darüber hinaus wurde durch die Entwicklung einer neuen Strategie der Myo-Inositol-Desymmetrisierung erstmals die Synthese eines Affinitätsreagens auf der Basis von 1,5-Bisdiphosphoinositol-Tetrakisphosphat (1,5(PP)2-InsP4) beschrieben. Die Affinitätsreagenzien und die proteomischen Datensätze stellen für die Gemeinschaft leistungsstarke Ressourcen dar, um künftige Untersuchungen zu den vielfältigen Signalmodalitäten von Inositolpyrophosphaten einzuleiten. / Inositol pyrophosphates (PP-InsPs) are a ubiquitous group of highly phosphorylated eukaryotic messengers. They have been linked to a panoply of central cellular processes, but a detailed understanding of the discrete signaling events is often missing, which can partially be attributed to a lack of chemical tools. This thesis describes the chemical synthesis, validation and application of PP-InsP affinity reagents to identify protein binding partners of inositol hexakisphosphate (InsP6) and 5-diphosphoinositol pentakisphosphate (5PP-InsP5), two important eukaryotic metabolites. The affinity reagents were developed to display InsP6 and a metabolically stable 5PP-InsP5 analog in three different ways. Application of these triplexed reagents to mammalian lysates provided a first comprehensive data set in HCT116 and HEK293T cells. The interactomes were annotated using quantitative proteomics and uncovered hundreds of potential protein binding partners. Quantitative analysis of InsP6 versus 5PP-InsP5 binding proteins highlighted examples of highly specific protein-ligand interactions. Biochemical studies primed inositol 5-phosphatases, PRPS1 and specific phosphatidyl inositol phosphate kinases as potentially undiscovered targets of PP-InsPs. Moreover, by developing a novel strategy of myo-inositol desymmetrization, the synthesis of an affinity reagent based on 1,5-bisdiphosphoinositol tetrakisphosphate (1,5(PP)2-InsP4) was described for the first time. The affinity reagents and the proteomic data sets constitute powerful resources for the community, to help launching future investigations into the multiple signaling modalities of inositol pyrophosphates.

The synthesis of metal-redox active ligand complexes is described, along with reactivity studies aimed at facilitating novel C-N bond forming reactions. A copper bis(iminosemiquinone) structure is characterized, analyzed and its reduction series are characterized and the reactivity of the Cu(II) bis(amidophenolate) analog is investigated with tosyl azide. The identification of the major reaction product and its characterization is detailed, with reaction sensitivities and heavily distorted x-ray diffraction single crystal structure generating a complex data set. The characterization of the isolated product is ongoing, with EPR studies aimed at identifying the radical nature of the complex. Unusual solvent effects and solubility issues have been noted with these initial EPR studies and more data is necessary before analysis can be properly attempted. An ytterbium bis(amidophenolate) complex was synthesized and its reactivity studied with aryl azides. Initial reactivities generate the first documented lanthanide tetrazenes in-lieu of the targeted ytterbium imido. Reactivities and characterization of these complexes support a stable, heavily ionic tetrazene-metal complex with no observed redox nature, UV light sensitivities, or imido azide-tetrazene equilibrium observed in various tetrazene transition metal complexes. Synthesis of a sterically blocked ytterbium imido was attempted, utilizing DMAP. Initial isolation was achieved with characterization and reactivity studies supporting the imido nature of the complex. The weak coordinating of the DMAP provided instability that proved in opposition to crystallization, however, so the imido could not be confirmed. Initial reactions using alternative steric hinderance from triphenylphosphine oxide and pyridine N-oxide prove promising to increasing the stability of the presumed ytterbium imido. Organic synthesis was performed generating a potential antibacterial agent. The synthesis of cyclopropenes was initiated as antagonists for ETR proteins in fruits and plants. The intermediates proved highly sensitive to harsh chemical conditions, which was overcome utilizing a tin-mediated Barbier allylation. The cyclopropene alcohol synthon was synthesized, though protecting group optimization is necessary.

<p>  </p> <p>A historically important reaction, the Ueno-Stork reaction promotes, through the use of toxic organotin species, the cyclization of a haloacetal onto an alkene generating bicyclic acetals. This reaction has been used over the years in several total syntheses of biologically relevant natural products, especially the prostaglandin class of natural products. Herein, will be described the development of a novel nickel-catalyzed Ueno-Stork cyclization reaction, which no toxic organotin and radical promoters are used, and instead a greener, operationally friendly, and non-toxic earth abundant nickel catalyst is applied. Optimization studies, substrate scope, scalability, relative stereochemistry of the bicyclic acetals, as well as derivatization of the products were studied. Furthermore, the newly developed reaction was applied on the total synthesis of tricyclic-PGDM Methyl ester, a prostaglandin D2 metabolite of important clinical relevance that currently suffers from material supply issues.</p> <p>Cyclopropanol ring opening reactions have different reactivity modes. Either a metal homoenolate species or a b-keto radical species can be formed after ring opening depending on the reaction conditions applied. More specifically, hydroxycyclopropanols have been studied to access several important motifs present in an array of natural products and medicinally important molecules. The Dai group has used this strategy to access several motifs through intramolecular trapping of the homoenolate species with and without the presence of carbon monoxide to generate oxaspirolactones, THF/THP-fused bicyclic lactones, and disubstituted THF/THP heterocycles. Herein, it will be discussed the application of similar concepts to access new classes of heterocycles 4-ketovalerolactones and 3-furanones. The optimization of two reaction conditions to selectively synthesize each product starting from the same starting material was studied. Furthermore, the substrate scope, scale-up, and derivatization studies of each motif will be disclosed. </p>

<p>Polycomb repressive complex 1 (PRC1) is critical for mediating gene expression during development. Five chromobox (CBX) homolog proteins, CBX2,4,6,7,8, are incorporated into PRC1 complexes, where they mediate targeting to trimethylated lysine 27 of histone H3 (H3K27me3) via the N-terminal chromodomain (ChD). Individual CBX paralogs have been implicated as drug targets in cancer; however, high similarity in sequence and structure among the CBX ChDs provide a major obstacle in developing selective CBX ChD inhibitors. Here a selection of small, focused, DNA-encoded libraries (DELs) against multiple homologous ChDs was reported to identify modifications to a parental ligand that confer both selectivity and potency for the ChD of CBX8. This on-DNA, medicinal chemistry approach enabled the development of SW2_110A, a selective, cell-permeable inhibitor of the CBX8 ChD. SW2_110A binds CBX8 ChD with a Kd of 800 nM, with minimal 5-fold selectivity for CBX8 ChD over all other CBX paralogs in vitro. SW2_110A specifically inhibits the association of CBX8 with chromatin in cells and inhibits the proliferation of THP1 leukemia cells driven by the MLL-AF9 translocation. In THP1 cells, SW2_110A treatment significantly decreases expression of MLL-AF9 target genes, including HOXA9, validating the previously established role for CBX8 in MLL-AF9 transcriptional activation, and defining the ChD as necessary for this function. The success of SW2_110A provides great promise for the development of highly selective and cell permeable probes for the full CBX family. In addition, the approach taken provides a proof-of-principle demonstration of how DELs can be used iteratively for optimization of both ligand potency and selectivity.</p> <p>CBX2 is upregulated in a variety of cancers, particularly in advanced prostate cancers. Using CBX2 inhibitors to understand and target CBX2 in prostate cancer is highly desirable. Here, selections of focused DNA encoded libraries (DELs) were performed for the discovery of a selective CBX2 chromodomain probe, SW2_152F. SW2_152F binds to CBX2 ChD with a Kd of 80 nM and displays 24-1000-fold selectivity for CBX2 ChD over other CBX paralogs <em>in vitro</em>. SW2_152F is cell permeable, selectively inhibits CBX2 chromatin binding in cells, and blocks neuroendocrine differentiation of prostate cancer cell lines in response to androgen deprivation.</p> <p>Targeted covalent inhibitors (TCIs) are rationally designed inhibitors that bind to a target protein and specifically label a non-conserved amino acid on proteins by means of reactive moieties (warheads). TCIs typically function by two steps, in which inhibitors first non-covalently bind to the target protein and then covalent bond formation occurs between the inhibitor- warhead and a proximal nucleophile on protein. Covalent inhibitors or drugs have prolonged target engagement and enhanced pharmacokinetic potency in vivo, compared to non-covalent molecules. Strategies to develop effective warheads of TCIs have been reported for labeling different nucleophilic amino acid residues, of which cysteine and lysine are the most established for covalent labeling. Tyrosine is recently becoming an attractive nucleophile for TCIs as an alternative choice, yet currently developed warheads that label tyrosine do so with modest specificity over other side chains. Here, I report the development of novel Mannich electrophiles and use those electrophiles as covalent warheads on an inhibitor to specifically target tyrosine in protein labeling. To my knowledge, this is first demonstration of the use of Mannich electrophiles in covalent inhibitors. Specifically, I leveraged a previously developed CBX8 chromodomain inhibitor to specifically label a non-conserved tyrosine within CBX8 using cyclic imine derivatives as warheads. This ligand-directed, specific tyrosine conjugation on CBX8 but not on CBX2, significantly improves both the potency and selectivity of inhibition. Biochemical, proteomic, and cellular validation further showed the cyclic imine covalent inhibitors can increase both potency and selectivity to the target protein CBX8 in cells, serving as a robust chemical probe for target function evaluation and modulation. This new type of tyrosine labeling warhead is a useful addition to the toolbox of medicinal chemists for covalent inhibitor development.</p> <p>The following chapters are modified from following publications, with permissions from Sijie Wang, Emily C.Dykhuizen, and Casey J. Krusemark. </p> <p>Wang, S., Denton, K. E., Hobbs, K. F., Weaver, T., McFarlane, J. M., Connelly, K. E., Gignac, M.C., Milosevich, N., Hof, F., Paci, I., Musselman, C. A., Dykhuizen, E.C., Krusemark, C. J. Optimization of Ligands Using Focused DNA-Encoded Libraries To Develop a Selective, Cell-Permeable CBX8 Chromodomain Inhibitor. <em>ACS Chem Biol. </em>2020, 15, 112-131</p> <p>Wang, S., Alpsoy, A., Sood, S., Ordonez-Rubiano, S. C., Dhiman, A., Sun, Y., Krusemark, C. J., Dykhuizen, E. C. A Potent, Selective CBX2 Chromodomain Ligand and its Cellular Activity During Prostate Cancer Neuroendocrine Differentiation. <em>ChemBioChem.</em> 2021, 22, 2335-2344</p> <p>Wang, S., Ordonez-Rubiano, S. C., Dhiman, A., Jiao G., Strohmier B. P., Krusemark, C. J., Dykhuizen, E. C. Polycomb Group proteins in cancer: multifaceted functions and strategies for modulation Modulators. <em>NAR Cancer</em>. 2021, 3, zcab039</p>

No / Biarylpyrimidines are characterized as selective ligands for higher-order nucleic acid structures. A concise and efficient synthesis has been devised incorporating Suzuki biaryl cross-coupling of dihalopyrimidines. Two ligand series are described based on the parent thioether 4,6-bis[4-[[2-(dimethylamino)ethyl]mercapto]-phenyl]pyrimidine (la) and amide 4,6-bis(4[(2-(dimethylamino)ethyl)carboxamido]phenyl)pyrimidine (2a) compounds. In UV thermal denaturation studies with the poly(dA)·[poly(dT)]2 triplex structure, thioethers showed stabilization of the triplex form (¿Tm ¿ 20 °C). In contrast, amides showed duplex stabilization (¿Tm ¿ 15 °C) and either negligible stabilization or specific destabilization (¿Tm = -5 °C) of the triplex structure. Full spectra of nucleic acid binding preferences were determined by competition dialysis. The strongest interacting thioether bound preferentially to the poly(dA)·[poly(dT)]2 triplex, Kapp = 1.6 x 105 M-1 (40 x Kapp for CT DNA duplex). In contrast, the strongest binding amide selected the (T2G20T2)4 quadruplex structure, Kapp = 0.31 x 105 M-1 (6.5 x Kapp for CT DNA duplex).

<p dir="ltr">Vegetable oils are a fundamental part of human civilization. Beyond their nutritional value and functional implementation in food applications, their triglyceride structure facilitates their implementation as industrial inputs. Furthermore, applications such as metal gear fluids and gear oil represent a valuable market due to their environmental impact and widespread application. Soybean oil is one of the most produced oilseeds in the U.S., and recently, novel oil varieties such as high oleic soybean oil (HOSBO) tackle drawbacks in the use of vegetable oil such as the heterogeneous fatty acid composition by increasing the concentration of oleic acid. This dissertation evaluates the successful implementation of HOSBO and SBO as lubricant and gear oils through epoxy ring opening reactions for synthesizing polyols and estolides. Epoxidation of double bonds in unsaturated fatty acids creates reaction sites for the branching of fatty acids in estolides or hydroxylated moieties in the case of polyols. The difference in fatty acid composition is shown in terms of thermomechanical characteristics. HOSBO polyols and estolides are solid to semi-solid greases with high viscosities and SAE grades as gear oils from 85W up. In contrast, SBO-derived oils have lower viscosities and a larger viscosity index.</p><p dir="ltr">The second part of this research focuses on the kinetics of the hydroxylation defined by distinctive fatty acid compositions. The sites of reaction in the double bonds can be, in part, sterically hindered by the glycerol backbone. Thus, this chapter focuses on the influence of the reaction rates given the fatty acid composition of the oil. Consumption of epoxide groups in HOSBO and SBO was modeled under pseudo-first-order kinetics. The results highlight the benefit of using HOSBO with reaction rates at least 30% faster than SBO. Furthermore, the progress of the reaction was monitored by FTIR, which highlighted the formation of ether groups corresponding to the addition of 1-propanol branches. However, further optimization steps must focus on the controlled removal of water in order to prevent the esterification of the oil and the resulting increase of free fatty <a href="" target="_blank">acids</a><a href="#_msocom_1" target="_blank">[EAS1]</a> .</p><p dir="ltr"><a href="#_msoanchor_1" target="_blank">[EAS1]</a>Seems to end abruptly</p><p><br></p>

Le sujet de thèse s’inscrit dans le cadre des stratégies visant à organiser des nanostructures, plus particulièrement les stratégies visant à augmenté la densité d’information dans les médias magnétique. Les techniques de synthèse en chimie douce utilisés au LPCNO-INSA on permet d’élaborer des nano-bâtonnets monocristallins de cobalt dont les propriétés ferromagnétiques en termes d’anisotropie et d’aimantation présentent un grand intérêt pour des applications dans le domaine du stockage magnétique. La maitrise de la croissance de ces nano-bâtonnets de Co organisés perpendiculairement sur un substrat peut permettre de réaliser un média de forte densité. Nous avons dans un premier temps vérifié la croissance perpendiculaire de nano bâtonnets de cobalt monocristallins sur une couche continue de Pt (111) épitaxiée sur un substrat de saphir (Al2O3) et montré que cette combinaison de deux types de dépôts (physique et chimique) donne effectivement lieu à un réseau dense et perpendiculaire de bâtonnets de Co. Pour but d’organiser cette croissance et découpler physiquement les bâtonnets de Co nous avons alors étudié la croissance de ces bâtonnets de Co sur des îlots 3D métalliques de Pt et de Co.En première partie nous avons étudié la structure cristalline, La morphologie, les distributions en taille et l’état des contraintes des îlots de Pt et Co déposée sur la surface (0001) du saphir et la surface (001) du MgO par pulvérisation cathodique. Et en deuxième partie, nous avons étudié la croissance des nano bâtonnets de Co sur les ilots de Pt et de Co maitrisés dans l’étape précédente / The subject of this thesis is to be part of strategies in order to organize nanostructures, particularly strategies to increase information density in magnetic media. The synthesis techniques used in chemistry (LPCNO-INSA laboratory) is allowed to develop monocrystalline nanorods of cobalt whose ferromagnetic properties in terms of anisotropy and magnetization present a great interest for applications in the field of magnetic storage. The success in controling the growth of these nanorods arranged perpendicularly on a substrate can lead to achieve a high density media. We tested the perpendicular growth of monocrystalline nanorods of cobalt on a continuous and epitaxial layer of Pt (111) grown on a substrate of sapphire (Al2O3) and showed that this combination of two types of deposits (physical and chemical) give actually a dense and perpendicular network of Co nanorods. In the aim to organizing this growth and decoupling physically the nanorods we studied the growth of these Co nanorods on 3D metallic islands of Pt and Co. In the first part we studied the crystal structure, morphology, size distributions and the stress state of Pt and Co islands deposited on the surface (0001) of sapphire and (001) surface of MgO by sputtering. And in the second part, we studied the growth of Co nanorods on a Pt and Co islands mastered in the previous step