LG2A

Laboratoire de Glycochimie, des Antimicrobiens
et des Agroressources UMR 7378 CNRS

UMR 7378 CNRS

Nos tutelles

  • Tutelle du CNRS
  • Tutelle UPJV

Nos Fédérations

Intranet

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Aurélie VALLIN

Ingénieur d’études en techniques de synthèse chimique (IGE)

Mail :

Tel : 03 22 82 75 60

Fax : 03 22 82 75 60

Axe de recherche : Chimie pour le Vivant

Description des travaux de recherche


Je participe à la réalisation des projets de recherche pour les 2 axes du laboratoire. Cela passe par toutes les étapes de synthèse des produits ainsi que de leur purification et de leur caractérisation (RMN, MS, IR, …).

Je suis chargée également de tester l’activité biologique des produits de synthèse du laboratoire sur différentes souches bactériennes (détermination de la Concentration Minimale Inhibitrice)

Mots clés : N.C.

Sélection de publications


Synthesis of novel S- and O-disaccharide analogs of heparan sulfate for heparanase inhibition
Koffi Teki, D. S. E.; Coulibaly, B.; Bil, A.; Vallin, A.; Lesur, D.; Fanté, B.; Chagnault, V.; Kovensky, J.
Org. Biomol. Chem. 2022.
Heparan sulfate (HS), a glycosaminoglycan related to heparin, is a linear polysaccharide, consisting of repeating disaccharide units. This compound is involved in multiple biological processes such as inflammation, coagulation, angiogenesis and viral infections. Our work focuses on the synthesis of simple HS analogs for the study of structure–activity relationships, with the aim of modulating these biological activities. Thioglycoside analogs, in which the interglycosidic oxygen is replaced by a sulfur atom, are very interesting compounds in terms of therapeutic applications. Indeed, the thioglycosidic bond leads to an improvement of their stability and can allow the inhibition of enzymes involved in physiological and pathological processes. In our previous work, we developed a synthetic sequence which led to a non-sulfated thiodisaccharide analog of HS. In this paper, we report our results of the development of a new synthetic method allowing access to the novel sulfated S-disaccharide, as well as to their oxygenated analogues (O-disaccharide and sulfated O-disaccharide). These 4 compounds were also tested for the inhibition of heparanase, an enzyme involved in biological processes like tumor growth and inflammation. The obtained IC50 values in the micromolar range showed the impact of the interglycosidic sulfur atom and the 6-sulfate group.
https://dx.doi.org/10.1039/d2ob00250g


Design, Synthesis and Antibacterial Activity Evaluation of 4,5-Diphenyl-1H-Imidazoles Derivatives
Bamoro, C.; Bamba, F.; Steve-Evanes, K. T. D.; Aurélie, V.; Vincent, C.
Open Journal of Medicinal Chemistry 2021, 11, 17-26.
Due to the continuous emergence and rapid spread of drug-resistant strains of bacteria, there is an urgent need for the development of novel antimicrobials. Along this line, the synthesis and antibacterial activity of 4,5-diphenylimidazol-2-thiol derivatives 2a-g and 6a-e are reported. The structures of the synthesized compounds were confirmed by Nuclear Magnetic Resonance (NMR) and High Resolution Mass Spectrometry (HRMS). All compounds were screened in vitro for their antibacterial activity against Pseudomonas aeruginosa and Escherichia coli (Gram-negative bacteria) and also against Staphyloccocus aureus and Enterococcus faecalis (Gram-positive bacteria). The results showed most of the synthesized compounds have no antibacterial activity. However compound 6d was two-fold potent than ciprofloxacin against Staphylococcus aureus with Minimum Inhibitory Concentration (MIC) of 4 μg/mL and 6c showed moderate biological activity against Staphylococcus aureus (16 μg/mL) and Enterococcus faecalis (16 μg/mL).
https://dx.doi.org/10.4236/ojmc.2021.112002


Uncommon Strong Inhibition of α-Glucosidase by Multivalent Glycoclusters built on Cyclodextrins Scaffolds
Alali, U.; Vallin, A.; Bil, A.; Khanchouche, T.; Mathiron, D.; Przybylski, C.; Beaulieu, R. R.; Kovensky, J.; Benazza, M.; Bonnet, V.
Org. Biomol. Chem. 2019.
The homeostasis disruption of D-glucose causes diabetes, a dramatic world wide chronic disease. The type 1 diabetes is a succesfully treatable form, where the blood D-glucose is regulated by insulin treatement. In contrast the type 2 diabetes , the non Insulin dependent one, is problematic. The control of the D-glucose blood level via intestinal α-D-glucosidase inactivation can be achieved by using competitive inhibitors as iminosugars (e.g. acarbose) or sulfonium sugar derivatives (e.g. salacinol). Recently, an unprecedented result showed that multivalent diamond nanoparticules grafted with unmodified sugars displayed α-glucosidase inhibition at low micromolar concentrations. We describe herein the synthesis of multivalent glycoclusters using cyclodextrines (CDs) as scaffolds and their assessment as inhibithors of α-D-glucosidase. The glycoclusters were efficiently obtained from per-azido α, β and γ-CDs derivatives and propargyl glycosides using click-chemistry under microwave irradiation. The methodology was successfully applied to various protected and non-protected propargylated monosaccharides, including both O- and S- glycosides, giving clear evidences of its versatility. The targeted 6-per-glycosylated CDs were isolated in moderate to excellent yields (30-90 %) by silica gel chromatography. The results showed inhibition of α-glucosidase from Saccharomyces cerevisiae with IC50 values in a 32-132 µM range, lower than that of acarbose (IC50 ~250µM), a well knowm competitive inhibitor used in clinical treatment of type 2 diabetes. Preliminary experiments suggest a mixed-type non-competitive inhibition mode of these new glycoclusters.
https://dx.doi.org/10.1039/C9OB01344J