Academic literature on the topic 'Glycoderivatives'

The synthesis of new biocompatible antiviral materials to fight against the development of multidrug resistance is being widely explored. Due to their unique globular structure and excellent properties, [60]fullerene-based antivirals are very promising bioconjugates. In this work, fullerene derivatives with different topologies and number of glycofullerene units were synthesized by using a SPAAC copper free strategy. This procedure allowed the synthesis of compounds 1-3, containing from 20 to 40 mannose units, in a very efficient manner and in short reaction times under MW irradiation. The glycoderivatives were studied in an infection assay by a pseudotyped viral particle with Ebola virus GP1. The results obtained show that these glycofullerene oligomers are efficient inhibitors of EBOV infection with IC50s in the nanomolar range. In particular, compound 3, with four glycofullerene moieties, presents an outstanding relative inhibitory potency (RIP). We propose that this high RIP value stems from the appropriate topological features that efficiently interact with DC-SIGN.

The research project is focused on the development and the synthesis of glycoderivatives as potential drug candidates, for therapeutic use, and as molecular tools, for the study of biological processes. The project includes the study of SGLT1 (Sodium-Glucose co-transporter 1), its role in inflammatory processes and the development of potential carbohydrate-based anti-inflammatory agents. Furthermore, new glycoderivatives and glycoconjugates will be synthetized for other potential pharmacological applications such as the targeting of cytotoxic drugs, as novel potential anticancer agents, and for the development of molecular tools to study several biological phenomena.

Durante il terzo anno di dottorato mi sono occupata della sintesi finale dei glicomimetici del substrato naturale dell’enzima AGM1 GlcNAc-6P o del prodotto GlcNAc-1P. Le sintesi messe a punto sono necessarie per ottenere prodotti finali utilizzabili come strumenti molecolari chimici per studiare il ruolo dell’HBP nella regolazione della proliferazione e la sopravvivenza delle cellule tumorali. I prodotti presentati (caratterizzati mediante NMR (1H. COSY, HSQC e 13C) e Massa) sono stati preparati protetti (acetilati sugli ossidrili) per i test cellulari per favorire la loro diffusione attraverso la membrana cellulare e nella forma de-protetta per il test enzimatico, per poterne valutare la potenza inibitoria direttamente sull’enzima AGM1. La messa a punto del test enzimatico ha come obiettivo la valutazione dell’effettiva capacità inibitoria dei composti sintetizzati. Il test prevede la comparazione della quantità di UDP-GlcNAc prodotto dalla reazione accoppiata dell’enzima AGM1 e AGX1, utilizzando un estratto enzimatico cellulare, in assenza e in presenza dei potenziali inibitori. La quantificazione è stata effettuata mediante l’utilizzo della tecnica cromatografica HPLC, con un metodo ion-pair a fase inversa associato ad un rilevatore UV impostato ad una lamda di 254 nm. Inizialmente è stata preparata la retta di taratura dell’UDP-GlcNAc costruita partendo da una madre 1.5 mM e attraverso diluzioni sono state effettuate le analisi in triplicato per ogni punto della retta. Sono stati calcolati i valori del limite di rilevabilità (LOD) e di quantificazione (LOQ). Il test messo a punto prevede la quantificazione della produzione di UDP-GlcNAc a partire dai substrati GlcNAc-6P e UTP utilizzando estratti cellulari lisati. In una prima analisi si è esaminato l’estratto enzimatico per verificare la presenza di UDP-GlcNAc endogena, che non è stata riscontrata. Quindi si è verificata l’effettiva efficacia dell’estratto nel catalizzare la produzione di UDP-GlcNAc a partire dai substrati forniti e si sono messe a punto le condizioni di reazione. Infine, si è proceduto con l’analisi degli inibitori sintetizzati. Dati preliminari non hanno evidenziato una diminuzione del segnale di UDP-GlcNAc, il che farebbe escludere una buona attività inibitoria. Durante il periodo di Traineeship presso il CycloLab di Budapest ho potuto effettuare l'incapsulamento di un potenziale inibitore enzimatico in ciclodestrine funzionalizzate per il targeting di cellule tumorali. Alcuni dei composti sintetizzati possiedono caratteristiche chimico-fisiche che rendono il loro passaggio attraverso la membrana cellulare molto difficile: la presenza di gruppi solfati, solfonati e fosforamidati, che possiedono cariche negative, li rendono particolarmente polari. Lo scopo del progetto è quello di sfruttare ciclodestrine (CD) opportunamente funzionalizzate come un “cavallo di Troia” per veicolare gli inibitori enzimatici all'interno delle cellule tumorali. Al CycloLab mi sono quindi occupata della sintesi dello scaffold di interesse e dell’incapsulamento del potenziale inibitore.
The project carried out during the 3 years-Ph.D. has had the objective to identify and synthesize new glycomimetics as molecular tools to study the Hexosamine Biosynthetic Pathway (HBP), which role is to regulate the proliferation and survival of cancer cells. The project has been funded by AIRC and the principal aim was to identify the Adenocarcinoma of the Pancreatic Duct (PDAC) as the target of research. The synthesis of innovative chemical tools helps the understanding of the HBP pathway and its response in PDAC: new potential inhibitors, which are similar to the natural substrate of enzyme, can be recognized but trick the enzyme and block its activity in order to decrease the UDP-GlcNAc production and consequently modify the protein glycosylation. Due to the important role of the HBP in the cells, alteration of this pathway can bring to alteration of N- and O- glycosylation and activate the Unfolded Protein Response (UPR) during the Endoplasmic Reticulum (ER) stress. The description of the research target helps the understanding of the design of molecular tools: the focus point is the inhibition of the enzyme N-acetylglucosamine-phosphate mutase (AGM1): its inhibition could represent the way to induce apoptosis in cancer cells. Through the Molecular Design, a rational design of potential inhibitors has been done. This design is based on the similarity with the structures of the natural substrate of enzyme AGM1, with some modifications. All of the drawn structures have been used for Molecular Docking in order to get a first virtual screening on the compounds library. Starting from preliminary results of theoretical approach, the synthesis of compounds have been done following three different synthetic strategies. All the steps and reaction condition are described in details and are shown the characterization (1H, 13C NMR spectra, m/z) of all the synthetized compound. The optimization of the analytical method on High Performance Liquid Chromatography is necessary in order to achieve experimental data on the ability of the designed compounds to inhibit the target enzyme, data to be compared to those obtained through a computational theoretical approach. To this aim an HPLC method has been set-up for the quantification of UDP-GlcNAc produced using the cellular extract as enzyme source, and carrying out the reaction with the natural substrates GlcNAc-6P, UTP in the presence or not of the test molecules. Using 10 and 30 µL of extract, three compounds lead to a decrease of production of UDP-GlcNAc. The computational data ”describes” the interaction between the enzyme and the molecules. The calculation of C LogP has confirmed the most apolar character of compound 3B in the acetylated form. Some preliminary evaluation of the effect of compound 2B in a Triple Negative Breast Cancer (TNBC) cell model has been carried out. In conclusion, the study of the target of this research, the HBP pathway, and the focus on the inhibition of AGM1 are the starting point for a complete project, that includes at first the design of a library of compound based on the structural properties of the natural substrate. the “in silico” evaluation of their interaction with the target enzyme, the synthesis and the screening through an enzymatic assay.. The tuning of the strategy of synthesis is important to obtain the compound for the in vitro test. The analytical method with HPLC gives results comparable to the docking scores, and then, after a calculation of C LogP, the test on cells gives the final results of potency of compound 3B (2B the acetylated form). The last part describes the collaboration with CycloLab (Budapest): some compounds of the library possess chemical-physical characteristics that make their passage through cell membrane very harsh: they are very polar and some of them possess negative charges (sulphate, sulphonates, phosphoramidate). This preliminary work is still in progress.