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La thématique développée concerne la synthèse de nouveaux composés polysaccharidiques et en particulier les glycoaminoglycanes (GAG). Cette famille de polysaccharide est présente dans les tissus biologiques de nombreux organismes vivants (humains, bactéries). Ces GAGs jouent un rôle fondamental dans des phénomènes physiologiques (reconnaissance, développement et croissance) ou pathologiques (inflammation, métastase). Ils constituent alors une cible de choix pour le traitement de pathologies variées.
Nous cherchons alors à synthétiser de nouveaux oligosaccharides anioniques qui puissent mimer les substrats naturels en variant la nature de la liaison glycosidique, en modulant la position des groupements anioniques et en apportant des modifications aussi bien de nature stéréochimiques que fonctionelles sur l’unité saccharidique.
Pour ce faire nous utilisons des méthodes modernes de synthèse organique comme la fonctionnalisation régio- et stéréosélective, l’introduction de la diversité structurale via des voies de synthèse divergentes et non-linéaires et tout en limitant notre impact environnemental (C-H activation, absence de groupes protecteurs, micro-onde).
DP2, a Carbohydrate Derivative, Enhances In Vitro Osteoblast Mineralisation |
Mechanochemical synthesis of (4S)-N-alkyl-4,5-bis-sulfooxypentanamide via a one-pot sequential aminolysis-sulfation reaction of (S)-γ-hydroxymethyl-γ-butyrolactone (2H-HBO) |
Synthesis of new sulfated disaccharides for the modulation of TLR4-dependent inflammation |
First Sustainable Aziridination of Olefins Using Recyclable Copper-Immobilized Magnetic Nanoparticles |
Efficient Synthesis of N-Alkyl Polyhydroxylated Pipecolamide Compounds from d-Glucurono-6,3-lactone |
Oligogalacturonic Acid Inhibits Vascular Calcification by Two Mechanisms: Inhibition of Vascular Smooth Muscle Cell Osteogenic Conversion and Interaction With Collagen |
Glycochemical Applications of Diels-Alder Reaction |
Chapter 11 Anionic oligosaccharides: synthesis and applications |
To valorize further the highly valuable bio-based platform (S)-γ-hydroxymethyl-γ-butyrolactone (2H-HBO), whose sustainable kiloscale-synthesis from cellulose-derived levoglucosenone (LGO) has been validated, a mechanochemical strategy was developed to produce new potential bio-based surfactants under solventless conditions. First, the reaction of 2H-HBO with primary or secondary amines was investigated followed by a sulfation reaction with the isolated N-alkyl-amide derivatives to obtain the corresponding N-alkyl sulfated compounds. The latter was then obtained by an optimized one-pot sequential aminolysis–sulfation in a planetary ball mill with excellent efficiency. For the first time, sulfated compounds arising from bio-based/renewable resources were obtained exclusively via a mechanochemical process. As a result, the sulfated derivatives of 2H-HBO were formed quantitatively and isolated in 69–79% overall yields. The critical micelle concentration (CMC) was determined for some of them which exhibited interesting anionic surfactant properties.
Natural sulfated glycans are key players in inflammation through TLR4 activation, and therefore synthetic exogenous sulfated saccharides can be used to downregulate inflammation processes. We have designed and synthesized new sulfated compounds based on small and biocompatible carbohydrates able to cross the BBB. Suitable protected donor and acceptor, obtained from a unique precursor, have been stereoselectively glycosylated to give an orthogonally protected cellobiose disaccharide. Selective deprotection and sulfation allowed to synthesize four differentially sulfated disaccharides, which have been characterized by NMR, HRMS and MS/MS. Together with their partially protected precursors, the new compounds were tested on HEF-TLR4 cells. Our results show the potential of small oligosaccharides to modulate TLR4 activity, confirming the need of sulfation and the key role of the 6-sulfate groups to trigger TLR4 signalization.
Carbohydrates and their analogs are key molecules with a wide range of biological activities. These bioactive compounds are usually synthesized through derivatization of naturally occurring carbohydrates. Nevertheless, this strategy suffers from a limited range of naturally available monosaccharide building blocks and the necessity of laborious steps of protection and deprotection. Consequently new methods began to emerge and Diels-Alder reaction appeared to be a method of choice for their de novo production. The synthesis of carbohydrates and their analogs by means of cycloaddition reactions will be reviewed here. Moreover the potentiality of the use of monosaccharides to induce chirality in Diels-Alder reaction will be presented. Efficient methods for the synthesis of di- and tri-saccharides using the developments shown previously will be also introduced.