Dissertations / Theses on the topic 'PHAST Library'

Les dendrimères sont très prometteurs du fait de leur structure unique et de leur multivalence. Cependant, leur synthèse souffre de problèmes de défauts de structure et de présence de produits secondaires très similaires. Des approches synthétiques alternatives sont donc fortement désirées. L'objectif de ma thèse consiste à explorer la synthèse sur support solide et l’approche d'autoassemblage pour la préparation de dendrimères.La première partie de ma thèse se concentre sur la synthèse de dendrimères en phase solide. Nous avons tout d'abord développé une méthode de synthèse pour les dendrimères poly(amidoamines) basée sur la chimie des peptides. Nous avons ensuite construit une petite bibliothèque de dendrimères de type triazine en faisant varier la taille et la terminaison des dendrimères pour créer une variété de dendrimères. Nous avons aussi tenté de synthétiser des dendrimères poly(aminoesters) bien que nous n'ayons pu les obtenir du fait du caractère labile de ces dendrimères.La deuxième partie de ma thèse vise à appliquer l’approche d'autoassemblage pour la construction de dendrimères supramoléculaires comme théranostiques combinant l'imagerie et la thérapie. Nous avons synthétisé un petit dendrimère amphiphile portant DOTA pour chélater le Gd (III). Ce dendrimère est capable de s'autoassembler en supramolécule et d’encapsuler l’agent anticancéreux doxorubicine, pour construire des agents théranostiques à base de dendrimères multivalents.L’ensemble de ma thèse se consacre au développement de stratégies en phase solide et de l'autoassemblage pour construire des dendrimères pour les applications dans les domaines biomédicaux et des matériaux<br>Dendrimers hold great promise for wide applications thanks to their unique structural architecture and multivalent cooperativity. However, dendrimer synthesis often suffers from structural defects caused by incomplete reactions and difficulties associated with purification. Consequently, alternative synthetic approaches to overcome the limitations of current dendrimer synthesis are in high demand.My first PhD project mainly focuses on establishing novel strategies and methodologies for solid-phase dendrimer synthesis with advantages of convenient complete synthesis and easy purification procedures. We first developed a new and concise solid-phase synthesis of PAMAM dendrimers based on the adoption of peptide synthesis chemistry. We then constructed a small library of triazine dendrimers varying in generations and surface groups with a view to rapidly synthesizing dendrimers with structural diversity. We also strived to synthesize poly(aminoester) dendrimers although we had difficult to get it thorough.My second PhD program aims to apply the self-assembly approach for constructing supramolecular dendrimer theranostics. A small DOTA-conjugated amphiphilic dendrimer with Gd(III)-chelation was synthesized and self-assembled into supramolecular nanomicelles to encapsulate the anticancer drug doxorubicin. The obtained system constitutes a multivalent nanotheranostic to combine imaging purpose with therapeutic utility.In summary, my PhD program mainly contributes to elaborating strategies for dendrimer synthesis using both solid-phase method and self-assembly approach in the view to realizing and broadening their applications in the arenas of biomedical and material sciences

Pin1 is a peptidyl prolyl isomerase (PPIase) enzyme with two domains, the catalytic domain and the WW domain. Both domains specifically bind pSer/pThrâ Pro motifs. Pin1 plays an important role in regulating the cell cycle, and it is involved in many diseases, such as cancer, HIV-1, Alzheimerâ s disease, asthma, hepatitis B, and rheumatoid arthritis. Pin1 is a very promising target for new drug development. Three stereoisomers: (R,S)-, (S,R)- and (S,S)-Acâ pSerâ Ψ[(Z)CH=C]â Pipâ 2-(2-naphthyl)ethylamine were synthesized as inhibitors binding to the Pin1 catalytic domain. The (R,S)- and (S,R)-isomers were synthesized via a 13-step route, with overall yields of 2.0% and 1.4%, respectively. The newly formed stereogenic center in the piperidyl ring was introduced by a Luche reduction, followed by a stereoselective [2,3]-Still-Wittig rearrangement. The configuration of the stereocenter was determined by NOESY of a bicyclic derivative. The (Z)- to (E)-alkene ratio in the rearrangement was (5.5:1). The (S,S)-isomer was obtained as the epimerized by-product resulting from the (S,R)-isomer in the Na/NH3 deprotection step. The IC50 values for Pin1 inhibition were: 52, 85, and 141 μM, respectively. We concluded that in this Z-alkene isostere, the R-configuration would be preferred at both stereogenic centers, as mimics of L-Ser and L-Pip, to improve the affinity. Combinatorial chemistry is a powerful method to discover biologically active compounds, and solid-phase synthesis is most commonly used to synthesize combinatorial libraries. To identify ligands for the Pin1 WW domain, a library, R1COâ pSerâ Proâ NHR2, was designed. A new solid-phase phosphorylating reagent (SPPR) containing a phosphoramidite function was synthesized in one step from commercially available Wang resin. The SPPR was applied in the preparation of a designed library through parallel synthesis. The library contained 357 members (17 à 21), and was screened by an enzyme-linked enzyme binding assay (ELEBA). The best hits were resynthesized, and the competitive dissociation constants, Kd-rel, were measured by ELEBA, with a Kd-rel value of 130 μM for the best ligand. The absolute dissociation constants will be measured by our collaborator, Prof. Jefferey Peng, University of Notre Dame, using NMR methods. Besides the identification of the Pin1 WW domain ligands, I created a practical method for solid-phase synthesis of phosphopeptides.<br>Ph. D.

This thesis describes different aspects of protein interactions. Initially the function of peptides and their conjugates with small molecule inhibitors on the surface of Human Carbonic Anhydrase isoenzyme II (HCAII) is evaluated. The affinities for HCAII of the flexible, synthetic helix-loop-helix motif conjugated with a series of spacered inhibitors were measured by fluorescence spectroscopy and found in the best cases to be in the low nM range. Dissociation constants show considerable dependence on linker length and vary from 3000 nM for the shortest spacer to 40 nM for the longest with a minimum of 5 nM for a spacer with an intermediate length. A rationale for binding differences based on cooperativity is presented and supported by affinities as determined by fluorescence spectroscopy. Heteronuclear Single Quantum Correlation Nuclear Magnetic Resonance (HSQC) spectroscopic experiments with 15N-labeled HCAII were used for the determination of the site of interaction. The influence of peptide charge and hydrophobicity was evaluated by surface plasmon resonance experiments. Hydrophobic sidechain branching and, more pronounced, peptide charge was demonstrated to modulate peptide – HCAII binding interactions in a cooperative manner, with affinities spanning almost two orders of magnitude. Detailed synthesis of small molecule inhibitors in a general lead discovery library as well as a targeted library for inhibition of α-thrombin is described. For the lead discovery library 160 members emanate from two N4-aryl-piperazine-2-carboxylic acid scaffolds derivatized in two dimensions employing a combinatorial approach on solid support. The targeted library was based on peptidomimetics of the D-Phe-Pro-Arg showing the scaffolds cyclopropane-1R,2R-dicarboxylic acid and (4-amino-3-oxo-morpholin-2-yl)- acetic acid as proline isosters. Employing 4-aminomethyl-benzamidine as arginine mimic and different hydrophobic amines and electrophiles as D-phenylalanine mimics resulted in 34 compounds showing IC50 values for α-thrombin ranging more than three orders of magnitude with the best inhibitor showing an IC50 of 130 nM. Interestingly, the best inhibitors showed reversed stereochemistry in comparison with a previously reported series employing a 3-oxo-morpholin-2-yl-acetic acid scaffold.

The thesis describes the development of new and improved methods for analyzing degradation markers from organophosphorus Chemical Warfare Agents (CWAs). Paper I and II describes an innovative and significantly improved method for the enrichment, derivatization (trimethysilylation) and GC-MS analysis of a broad range of organophosphorus CWAs degradation markers, namely the alkylphosphonic acids and a zwitterionic compound. That was achieved using solid phase disc extraction in combination with solid phase derivatization. The new method overcomes most limitations observed with existing techniques: it offers almost 100 % recoveries, requires no elution or evaporation steps, facilitates miniaturization of the solid sorbent and reagent, is compatible with in-vial derivatization, and minimizes the chromatographic background due to the use of a highly selective anion exchange sorbent disc. Paper III describes the development of new fluorinated diazomethane derivatization reagents and their evaluation for rapid and high sensitivity screening and identification of nerve agent degradation markers. The reagents are water-tolerant to some extent, which simplifies the derivatization step. The best reagent identified was 3,5-bis(trifluoromethyl)benzyl diazomethane, which outperformed the other reagent isomers tested and also the established commercial alternative, pentafluorobenzylbromide, allowing for the rapid (5 min) and direct derivatization of a 25 μL aqueous sample in acetonitrile. The spectra of the formed derivatives (high-energy collision induced fragmentation MS/MS) were used to construct a database (Paper IV) that proved to be superior in terms of match factor and probability compared to EI data gathered for trimethylsilyl derivatives. The study also focused on efforts towards achieving detailed structure information on the alkyl chains of the compounds in question using diagnostic ion interpretation. The final paper (paper V) describes the first rapid direct derivatization method for analyzing nerve agent metabolites in urine at trace levels. The method is based on the derivative from the paper III and the unambiguous identification was proven using a combination of low resolution and high resolution negative ion chemical ionization selected ion monitoring techniques. Novel results presented in these papers include: the first in-situ derivatization of alkylphosphonic acids on an SPE disc; the first direct derivatization of nerve agent markers in water and biomedical samples; the first high sensitivity GC-MS screening for these markers; and the first highly reproducible high-energy isomer specific CID MS/MS library. Overall, the results presented in this thesis represent significant contributions to the analysis of nerve agent degradation products.

Modern techniques like automated microscopy and spectroscopy now make it possible to study quantitatively, across multiple phenotypic and molecular parameters, how cell populations are affected by different treatments and/or environmental disturbances. As the technology development at the instrument level often is ahead of the data analytical tools and the scientific questions, there is a large and growing need for computational algorithms enabling desired data analysis. These algorithms must have capacity to extract and process quantitative dynamic information about how the cell population is affected by different stimuli with the final goal to transform this information into development of new powerful therapeutic strategies. In particular, there is a great need for automated systems that can facilitate the analysis of massive data streams for label-free methods such as phase contrast microscopy (PCM) imaging and spectroscopy (NMR). Therefore, in this thesis, algorithms for quantitative high-throughput phenotypic and systemic profiling of in vitro growing cell populations via label-free microscopy and spectroscopy are developed and evaluated. First a two-dimensional filter approach for high-throughput screening for drugs inducing autophagy and apoptosis from phase contrast time-lapse microscopy images is studied. Then new methods and applications are presented for label-free extraction and comparison of time-evolving morphological features in phase-contrast time-lapse microscopy images recorded from in vitro growing cell populations. Finally, the use of dynamic morphology and NMR/MS spectra for implementation of a reference database of drug induced changes, analogous to the outstanding mRNA gene expression based Connectivity Map database, is explored. In conclusion, relatively simple computational methods are useful for extraction of very valuable biological and pharmacological information from time-lapse microscopy images and NMR spectroscopy data offering great potential for biomedical applications in general and cancer pharmacology in particular.

碩士<br>國立東華大學<br>化學系<br>90<br>Abstract Combinatorial chemistry has become an important part of the discovery and optimization process for novel drugs, affinity ligands, and catalysts. The technology has been applied in both academic and industrial institutions to provide a number of unique approaches to satisfy the ever-growing need for new chemical entities with proven utility. This thesis use Liquid Phase Combinatorial Chemistry for synthesis of four kinds Heterocyclic Libraries. 1.Guanidine Heterocyclic Library 2.Benzimidazole Heterocyclic Library 3.1,2,3,4-Tetrahydro-β —Carbolines Heterocyclic Library 4.Diketopiperazine Heterocyclic Library

碩士<br>國立交通大學<br>應用化學系所<br>92<br>Abstract Using sulfinate functionalized resin as a solid support, we have developed a new cleavage reagent, Al(CH3)3, and successfully synthesized a small library of compounds with structures like compound Ⅰ and Ⅱ. First of all, benzene sulfinic acid sodium salt was used as starting material in liquid phase experiment. Through six reaction steps, we obtained compound 7 in about 15% total yield, which demonstrated that compounds similar to Ⅰ and Ⅱ can be synthesized. Then, we successfully prepared resin 8 which has sulfone linker. Using resin 8 as solid support in SPOS, similar reaction conditions in liquid phase and Al(CH3)3 as cleavage reagent, we obtained the products form solid support. Application of SPOS technique, we synthesized a library of compounds which includes 16, 18, 21, 26, 28, 31, 33, 38, 41, 46 and 48. In the future, we hope to search a cooperative group in the academia to test the potential bioactivity of these compounds. Compound I Compound Ⅱ

碩士<br>國立清華大學<br>生醫工程與環境科學系<br>97<br>The aim of this research is to generate the monosaccharide, disaccharide, trisaccharide and tetrasaccharide of galactose bearing amine groups which would be used for coupling with numerous carboxylic acids. The coupled products in the mixture was directly submitted to a screen assay for their cytotoxicities against the cancer cell lines. Monosaccharide Gal-O-(CH2)3CH2N3, disaccharide Gal(1→6)Gal, trisaccharide and tetrasaccharide have been successfully prepared. Glycosylation of the 2-(azidomethyl)-6- ((trichloromethylamino)methoxy)tetrahydro-2H-pyran-3,4,5-triyl tribenzoate, bearing the active leaving group of imidate, with the acceptors of galactose and lactose derivative to provide (2R,3S,4S,5R,6S)-2-(((2S,3R,4S,5S,6R)-6-(azidomethyl)-3,4,5-tris(benzoyloxy)tetrahydro-2H-pyran-2-yloxy)methyl)-6-((2R,3R,4S,5R,6S)-4,5-bis(benzoyloxy)-2-(benzoyloxymethyl)-6-(p-tolylthio)tetrahydro-2H-pyran-3-yloxy)tetrahydro-2H-pyran-3,4,5-triyl tribenzoate and (2R,3S,4S,5R,6S)- 2-(((2S,3R,4S,5S,6R)-6-(azidomethyl)-3,4,5-tris(benzoyloxy)tetrahydro-2H-pyran-2-yloxy)methyl)-6-((2R,3R,4S,5R,6S)-2-(((2S,3R,4S,5S,6R)-6-(azidomethyl)-3,4,5-tris(benzoyloxy)tetrahydro-2H-pyran-2-yloxy)methyl)-4,5-bis(benzoyloxy)-6-(p-tolylthio)tetrahydro-2H-pyran-3-yloxy)tetrahydro-2H-pyran-3,4,5-triyl tribenzoate in 70% and 63% yield, respectively. The ratio of α-form and β-form of the trisaccharide was α/β=1/9. On the other hand, a poor yield of the glycosylation of 2-(azidomethyl)-6- ((trichloromethylamino)methoxy)tetrahydro-2H-pyran-3,4,5-triyl tribenzoate, Phenyl O-(2,6-Di-O-benzoyl-3,4-O-isopropylidene-β-D- galactopyranosyl)-( 1-4)-2,6-di-O-benzoyl-1-thio-β-D-glucopyranoside and (2S,3R,4S,5R,6R)-4-acetoxy-5-((2S,3R,4S,5R,6R)-3-(benzoyloxy)- 6-(benzoyloxymethyl)-4,5-dihydroxytetrahydro-2H-pyran-2-yloxy)-6-(benzoyloxymethyl)-2-(p-tolylthio)tetrahydro-2H-pyran-3-yl benzoate was observed. This could be accounted for the steric hindrance of the second alcohol at C-3, C-3’ and C-4’ of Phenyl O-(2,6-Di-O-benzoyl- 3,4-O-isopropylidene-β-D-galactopyranosyl)-( 1-4)-2,6-di-O-benzoyl-1-thio-β-D-glucopyranoside and (2S,3R,4S,5R,6R)-4-acetoxy-5- ((2S,3R,4S,5R,6R)-3-(benzoyloxy)-6-(benzoyloxymethyl)-4,5-dihydroxytetrahydro-2H-pyran-2-yloxy)-6-(benzoyloxymethyl)-2-(p-tolylthio)tetrahydro-2H-pyran-3-yl benzoate. 2-(azidomethyl)-6-((trichloromethylamino)methoxy)tetrahydro -2H-pyran-3,4,5-triyl tribenzoate can be prepared via a 8 step synthesis in total 5% yield. The extended linker with azide group of 4-azidobutan-1-ol after hydrogenation could provide the desired core amine, (2R,3R,4S,5R,6R)-2-(4-aminobutoxy)-6-(aminomethyl)tetrahydro-2H-pyran-3,4,5-triol. It will be submitted to the library construction and the corresponding bioassay.

碩士<br>國立清華大學<br>生醫工程與環境科學系<br>97<br>本論文之研究目的為合成神經醯胺醇之類似物，作為核心化合物與各種類之酸耦合形成醯胺鍵後，以之建立分子庫篩選實驗。 以絲胺酸作為起始物，經五步合成獲得Garner’s aldehyde，而後以Wittig reaction、Sharpless dihydroxylation。再將裸露之雙醇基以Benzyl基保護，接著除去Boc及acetonide保護基，形成神經醯胺醇之結構((2S,3S,4R)-2-amino-3,4-bis(benzyloxy)heptadecan-1-ol)。以TfN3將胺基轉換成azido基後，欲將官能基轉換(1°OH→NH2)時，以triflate作為離去基， 卻無法得到目標物，反而形成五員環之Jaspin B類似物。而後改用tosylate作為離去基時，以吡啶及二氯甲烷(體積比為一比一)作為溶劑下成功地將醇基轉換為tosylate。再以疊氮化鋰將tosylate取代為azido基，最後嘗試一系列之氫化條件，欲將兩個azido基及benzyl基一併去除，但無法達成，benzyl基無法完全還原。故改用以三氯化硼的條件，欲先除去兩個benzyl基，在此條件下，不僅成功地還原了兩benzyl基，另外亦還原其一azido基，總計十三步合成，產率4%。 未來此化合物將與各式羧酸經由活化條件來進行耦合提供生物上細胞活性實驗，以期能篩選出具有潛力之化合物。

Thesis (Ph.D) -- New Jersey Institute of Technology, Committee for the Interdisciplinary Program in Materials Science and Engineering, 2004.<br>Includes bibliographical references. Also available via the World Wide Web.

This study assessed the information literacy (IL) skills of first-year students at Mangosuthu Technikon (MANTEC) at a pre-library orientation and instruction phase. What is evident is that students do, to a greater or lesser degree, display inadequate levels of IL skills. What is not so evident is the extent and nature of these inadequacies. The purpose of the study was to establish the level of these inadequacies. Background information concerning the MANTEC library orientation and instruction programme and the Eastern Seaboard Association of Libraries (esAL) User Education Pilot Project study was provided and an overview of MANTEC and its library was given. The assessment of IL skills in higher education libraries, with reference to the MANTEC library was discussed. The MANTEC students' IL skills were assessed using Bloom's Taxonomy of Educational Objectives, which are evident throughout the objectives of the study. The research method used for this study was the descriptive survey method. The sample consisted of 170 first-year students. A purposive sampling procedure was used. The questionnaire consisted of two main sections, one which elicited demographic data of students and the other extracted data that addressed the objectives of the study. Results were coded and analyzed using the SPSS program. The findings of the survey indicated that there is a dearth of IL skills among the majority of MANTEC first-year students. Like many other studies it revealed that many first-year students, especially from the historically disadvantaged institutions (HDI) are under-prepared for tertiary education generally and for IL demands made on them at the tertiary level. Even those who have had previous library exposure appear to bring with them little or no IL competencies to tertiary institutions. Based on the findings for this study, recommendations were made with the aim of improving MANTEC students' IL skills.<br>Thesis (M.I.S.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2016<br>Analytical methods based on mass spectrometry and coupled to a chromatographic separation technique such as HPLC or GC, are crucial for investigating human metabolome, UPLC coupled with ESI-MS is a recent methodology representing an effective tool to separate and analyze molecules. The mains focus of this experimental work was to elucidate the influence of HILIC and Reversed-Phase chromatography on the analysis of compounds through ESI-MS. One additional aim was also to collect the identification data of selected compounds on a database for the building of a metabolomics library. This tool would allow to establish a match with results of subsequent analyses, minimizing the time spent on the identification of future analytes. Herein a UHPLC–MS method was applied for the first time to detect and identify a series of human metabolites and compounds found naturally on the human body. The procedures and molecules subjected to analysis are based on the protocol “Mass Spectrometry Metabolite Library of Standards”, commercially available by IROA Technologies. The kit contains a set of 619 standards. This work covers the first 253 compounds of the list. The analysis of compounds previously prepared as mixtures consisted on the chromatographic separation by HILIC or RP followed by positive or negative ESI-MS/MS. All the compounds were analyzed by the four possible combinations (HILIC, positive ESI; HILIC, negative ESI; RP, positive ESI; RP, negative ESI) as mixes of 12 standards distributed by four vials, one for each type of analysis. The results obtained were compiled and it was possible to conclude that HILIC is suitable to polar analytes whereas RP is preferable to non-polar compounds. Relatively to ESI, the positive ionization mode is applied with advantage to compounds that are able to accept a proton. Conversely, negative ESI is more effective to molecules which contain functional groups that readily lose a proton. Zwitterionic molecules are suitable to be analyzed by both modes. Some examples and exceptions to these general statements are presented.<br>Os métodos analíticos baseados em espectrometria de massa e acoplados a uma técnica de separação cromatográfica como HPLC ou GC, são cruciais para investigar o metaboloma humano. A análise por UPLC acoplada a ESI-MS é uma metodologia recente que representa uma ferramenta eficaz para separar e analisar moléculas. O foco principal deste trabalho experimental foi elucidar a influência de HILIC e cromatografia em fase reversa na análise de compostos através de ESI-MS. Um objectivo adicional foi também recolher os dados de identificação de compostos seleccionados numa base de dados para a construção de uma biblioteca de metabolitos. Esta ferramenta permitiria estabelecer uma correspondência com resultados de análises subsequentes, minimizando o tempo gasto na identificação de futuros analitos. Neste projecto, o método de análise por UHPLC-MS foi aplicado pela primeira vez para detectar e identificar uma série de metabolitos humanos e compostos encontrados naturalmente no corpo humano. Os procedimentos e moléculas submetidos à análise são baseados no protocolo "Mass spectrometry Metabolite Library of Standards", comercialmente disponível pela IROA Technologies. O kit contém um conjunto de 619 padrões. Este trabalho abrange os primeiros 253 compostos da lista. A análise de compostos previamente preparados em misturas consistiu na separação cromatográfica por HILIC ou RP seguida por ESI-MS/MS positiva ou negativa. Todos os compostos foram analisados pelas quatro combinações possíveis (HILIC, ESI positivo/ HILIC, ESI negativo/ RP, ESI positivo/ RP, ESI negativo) como misturas de 12 padrões distribuídos por quatro frascos, um para cada tipo de análise. Os resultados obtidos foram compilados e foi possível concluir que a separação por HILIC é adequada para analitos polares, enquanto que por RP é preferível para compostos não polares. Relativamente à ionização por ESI, o modo de ionização positiva melhor aplicado a compostos capazes de aceitar um protão. Por outro lado, a ESI negativa é mais eficaz para moléculas que contêm grupos funcionais que facilmente perdem um protão. As moléculas zwitteriónicas são passíveis de ser analisadas por ambos os modos. Alguns exemplos e excepções a estas ideias gerais são apresentadas.

Les pyrrolodiazépinones ont des activités biologiques intéressantes sur différents récepteurs biologiques, ce qui en font une cible de choix pour développer de nouvelles petites molécules biologiquement actives. Une méthodologie en solution a été développée pour synthétiser des pyrrolo[3,2-e][1,4]diazépin-2-ones, qui utilise la réaction de Pictet-Spengler pour former le cycle diazépinone, comme réaction clé. Il a été démontré que le pyrrolo[3,2-e][1,4]diazépin-2-one mime un tour-γ inverse par l’analyse de cristaux par rayon X. Cette méthodologie a été transposée sur trois types de support, soit la résine de Merrifield, de Wang et un support soluble (TAP). Le système urotensinergétique joue un rôle dans certaines pathologies du système cardiovasculaire, comme l’hypertension artérielle, l’insuffisance cardiaque et l’athérosclérose. Le système urotensinergétique est exprimé dans le système circulatoire, extractoire et le système nerveux central et comprend l’UII, l’URP et le récepteur UT. L’UII et l’URP humains sont composés respectivement des séquences d’acides aminés : H-Glu-Thr-Pro-Asp-c[Cys-Phe-Trp-Lys-Tyr-Cys]-Val-OH et H-Ala-c[Cys-Phe-Trp-LysTyr-Cys]-Val-OH. L’UII est le peptide vasoconstricteur le plus puissant connu à ce jour, dont l’URP est son isoforme. Les deux peptides ont des effets biologiques différents et on peut supposer qu’ils jouent un rôle distinct dans certaines pathologies. Il a été démontré que la partie active de l’UII est composée du tripeptide : Trp-Lys-Tyr. Dans l’URP, il a été démontré que ce tripeptide forme un tour-γ inverse, ce qui fait du récepteur UT une bonne cible biologique pour tester une librairie de pyrrolo[3,2-e][1,4]diazépin-2-ones, reprenant le tripeptide Trp-Lys-Tyr. Dernièrement, l’équipe du professeur David Chatenet a mis au point un peptide, l’urocontrin en remplaçant le segment Trp par un groupement biphénylalanine, qui a démontré un comportement spécifique comme antagoniste du récepteur UT. La Librairie de pyrrolo[3,2-e][1,4]diazépin-2-ones est basée sur la séquence TrpLys-Tyr de l’UII et de l’URP et de la séquence Trp-Lys-Bip de l’urocontrin. La synthèse de la librairie est faite sur la résine de Wang. La chaîne latérale de Tyr est mimée en utilisant la tyramine, Lys et Orn sont utilisés et la chaîne latérale de Trp a été reproduite II en utilisant le biphényle (comme dans l’urocontrin), le 1-naphthyle et le 2-naphthyle, sont introduits en employant les aldéhydes respectifs dans la réaction de Pictet-Spengler, ce qui donne les pyrrolo[3,2-e][1,4]diazépin-2-ones insaturés et les saturés S- et R-. L’évaluation de l’activité biologique des pyrrolo[3,2-e][1,4]diazépin-2-ones obtenues sur le récepteur UT se fait par des tests in vitro et ex vivo. Les tests in vitro consistent en un essai de liaisons sur des cellules CHO exprimant le récepteur UT en employant hUII-125I, comme contrôle radiomarqé. Les tests ex vivo sont effectués sur des aortes de rats pour mesurer la capacité à induire des contractions ou de moduler les contractions induites par hUII et URP. Certains R-pyrrolo[3,2-e][1,4]diazépin-2-ones causent une réduction de 50% du signal radioactivité du hUII-125I. Les pyrrolo[3,2-e][1,4]diazépin-2-ones ne montrent guère d’activité ex vivo, mais ils ont la capacité de moduler les contractions induites par l’hUII et l’URP. Par exemple, l’analogue Lys R-saturé avec le biphényle inhibe toutes les contractions de l’aorte à 14 µM avec un pKb de 5,54 à 4 µM, sans influencer les contractions de l’aorte induites par l’URP. Les pyrrolo[3,2-e][1,4]diazépin-2-ones ont une sélectivité pour le système urotensinergétique et sont inactifs sur le récepteur de l’endotheline-1. Les pyrrolo[3,2-e][1,4]diazépin-2-ones sont les premières petites molécules qui peuvent moduler l’activité biologique de l’UII et URP et offrir un potentiel intéressant comme outil pour étudier le système urotensinergétique.<br>The pyrrolodiazepinones have interesting biological activities on various biological receptors, which makes them a prime target for developing new biologically active small molecules. A methodology in solution had been developed for synthesizing pyrrolo[3,2-e][1,4]diazepin-2-ones, which utilized the Pictet-Spengler condensation as the key reaction to form the diazepinone ring. Pyrrolo[3,2-e][1,4]diazepin-2-ones were found to mimic an inverse γ-turn conformation by X-ray crystallographic analysis. The methodology was subsequently implemented on three types of support: Merrifield resin, Wang resin and the soluble TAP support. The urotensinergic system plays a role in certain diseases of the cardiovascular system, such as hypertension, heart failure and atherosclerosis. The urotensinergic system is expressed in the circulatory system, excretory and central nervous systems and includes the endogenous ligands urotensin II (UII) and urotensin II-related peptide (URP), and the urotensin receptor UT. The ligands UII and human URP are composed of the respective amino acid sequences: H-Glu-Thr-Pro-Asp-c[Cys-Phe-Trp-Lys-Tyr-Cys]-Val-OH and H-Ala-c[Cys-Phe-Lys-Tyr-Trp-Cys]-Val-OH. The peptide UII is the most potent vasoconstrictor known to date. The two peptides have different biological effects and may exhibit distinct roles in certain diseases. Their common Trp-Lys-Tyr sequence is believed to play an important role in the activity of UII and URP, and has been suggested to adopt an inverse γ-turn conformation. Notably, the laboratory of Professor David Chatenet developed the UT receptor antagonist peptide urocontrin by replacing the Trp residue by biphenylalanine (Bip) in URP. A library of pyrrolo[3,2-e][1,4]diazepin-2-one analogs was thus designed to mimic the inverse γ-turn sequence and targeted against UT. The pyrrolo[3,2-e][1,4]diazepin-2-one library was designed based on the Trp-Lys-Tyr sequence of UII and URP, and Trp-Lys-Bip sequence of urocontrin. The synthesis of the pyrrolo[3,2-e][1,4]diazepin-2-one library was achieved on Wang resin. The side chain of Tyr was mimicked using tyramine, Lys and Orn were used as the basic amino acid component, and the side chain of Trp was replicated using biphenyl (as in urocontrin) 1-naphthyl and 2-naphthyl groups that were introduced by employing their respective aldehydes in a Pictet-Spengler reaction, which furnished unsaturated and saturated S- and R-pyrrolo[3,2-e][1,4]diazepin-2-ones. Evaluation of the biological activity of the pyrrolo[3,2-e][1,4]diazepin-2-ones on the UT receptor was performed in vitro and ex vivo. Tests in vitro measured binding in CHO-cells which expressed UT by employing hUII-125I as radiolabeled control. In rat aorta, ex vivo tests measured capacity to induce contraction, or modulate the contractions induced by hUII and URP. Certain R-pyrrolo[3,2-e][1,4]diazepin-2-ones caused an up to 50% reduction of the radioactive signal of hUII-125I. Pyrrolo[3,2-e][1,4]diazepin-2-ones exhibited little activity ex vivo; however, they modulated contractions induced by hUII and URP. For example, the saturated R-analog possessing lysine and a biphenyl side chain inhibited completely hUII-induced contractions of the aorta at 14 µM with a pKb of 5.54 at 4 µM, without influencing URP-induced contractions. Pyrrolo[3,2-e][1,4]diazepin-2-ones were selective for the urotensinergic system and inactive on the related receptor endothelin-1. Pyrrolo[3,2-e][1,4]diazepin-2-ones represent the first small molecules that can differently modulate the biological activities of UII and URP, and offer interesting potential as tools for studying the urotensinergic system.