This Thesis is part of a multidisciplinary project entitled Synthesis and characterization of multivalent glycoconjugates as antibacterial agents carried out by University of Pavia (Biocatalysis and Pharmaceutical Analysis Laboratories), University Pierre & Marie Curie (Institute of Molecular Chemistry) and Complutense University of Madrid (Department of Organic and Pharmaceutical Chemistry). Glycoproteins play a pivotal role in bacterial and viral infections as well as cancer metastasis. The synthesis of glycoconjugates is hampered by the complexity of the chemical strategies required for the preparation of the saccharide moiety and, consequently, the development of new drug candidates is strongly limited. Due to the structural complexity and the arduous extraction from natural sources, the synthesis of pure oligosaccharides is a paramount challenge in glycobiology. In this Thesis, an efficient and scalable method based on an integrated approach between chemistry and biotechnology for the synthesis of oligosaccharides has been developed. In particular, by means of a chemo-biocatalytic approach, different mannose-based glycans were synthesized in good yields. These oligosaccharides were activated in anomeric position with a reactive group useful to the conjugation with protein carriers. The carbohydrates are poorly immunogenic and to induce an effective T-dependent immune response need to be linked to a protein carrier. For this purpose, the previously prepared trisaccharides will be used in the coupling reaction with the ε-amino groups of lysine of immunogenic proteins expressed by Mycobacterium tuberculosis with the aim to prepare glycoconjugates useful as antitubercular vaccines. Different glycoconjugates will be then assayed by in-vitro biological testing by using surface plasmon resonance, in collaboration with the Department of Organic and Pharmaceutical Chemistry of Complutense University of Madrid.
Questo lavoro di Tesi è parte integrante di un progetto multidisciplinare intitolato Sintesi e caratterizzazione di glicoconiugati multivalenti come agenti antibatterici condotto dallUniversità degli Studi di Pavia (Dipartimento di Scienze del Farmaco, Laboratorio di Biocatalisi e Analisi Farmaceutica), Università Pierre & Marie Curie di Parigi (Istituto di Chimica Molecolare) e Università Completense di Madrid (Dipartimento di Chimica Organica e Farmaceutica). Le glicoproteine ricoprono un ruolo chiave nelle infezioni batteriche e virali, così come nelle infezioni tumorali. La sintesi e lo sviluppo di nuovi farmaci a struttura complessa, come gli oligosaccaridi e i loro derivati glicoconiugati, è fortemente condizionata dalla mancanza di strategie chimiche semplici ed efficienti. Ciò si traduce nella scarsa disponibilità di nuovi candidati farmaci. Vista la complessità strutturale e le difficoltà di estrazione da fonti naturali, la sintesi di oligosaccaridi risulta la principale sfida in glicobiologia. In questa Tesi, sono state sviluppate diverse vie di sintesi efficienti e facilmente scalabili basato su un approccio integrato tra chimica e biotecnologie. In particolare, mediante un approccio chemoenzimatico, sono stati sintetizzati con buone rese, trisaccaridi derivati del mannosio attivati con un gruppo reattivo in posizione anomerica utile per la coniugazione a carrier proteici. Di per sé i carboidrati sono scarsamente immunogenici e per indurre una risposta immunitaria efficace T-dipendente necessitano di essere legati a un carrier di natura proteica. A questo scopo, i trisaccaridi precedentemente preparati, saranno usati nella reazione di coupling con i gruppi ε-amminici di lisine di proteine immunogeniche espresse dal Mycobacterium tuberculosis, allo scopo di preparare glicoconiugati utili come vaccini antitubercolari. I diversi glicoconiugati saranno successivamente saggiati mediante test in-vitro utilizzando la risonanza plasmonica di superficie, in collaborazione con il dipartimento di Chimica Organica e Farmaceutica dellUniversità Completense di Madrid.
Sintesi chemoenzimatica di trisaccaridi come precursori di potenziali vaccini antitubercolari
MARZATICO, SARA
2018/2019
Abstract
This Thesis is part of a multidisciplinary project entitled Synthesis and characterization of multivalent glycoconjugates as antibacterial agents carried out by University of Pavia (Biocatalysis and Pharmaceutical Analysis Laboratories), University Pierre & Marie Curie (Institute of Molecular Chemistry) and Complutense University of Madrid (Department of Organic and Pharmaceutical Chemistry). Glycoproteins play a pivotal role in bacterial and viral infections as well as cancer metastasis. The synthesis of glycoconjugates is hampered by the complexity of the chemical strategies required for the preparation of the saccharide moiety and, consequently, the development of new drug candidates is strongly limited. Due to the structural complexity and the arduous extraction from natural sources, the synthesis of pure oligosaccharides is a paramount challenge in glycobiology. In this Thesis, an efficient and scalable method based on an integrated approach between chemistry and biotechnology for the synthesis of oligosaccharides has been developed. In particular, by means of a chemo-biocatalytic approach, different mannose-based glycans were synthesized in good yields. These oligosaccharides were activated in anomeric position with a reactive group useful to the conjugation with protein carriers. The carbohydrates are poorly immunogenic and to induce an effective T-dependent immune response need to be linked to a protein carrier. For this purpose, the previously prepared trisaccharides will be used in the coupling reaction with the ε-amino groups of lysine of immunogenic proteins expressed by Mycobacterium tuberculosis with the aim to prepare glycoconjugates useful as antitubercular vaccines. Different glycoconjugates will be then assayed by in-vitro biological testing by using surface plasmon resonance, in collaboration with the Department of Organic and Pharmaceutical Chemistry of Complutense University of Madrid.È consentito all'utente scaricare e condividere i documenti disponibili a testo pieno in UNITESI UNIPV nel rispetto della licenza Creative Commons del tipo CC BY NC ND.
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https://hdl.handle.net/20.500.14239/21454