10 research outputs found
DĂ©fense (processus de) et Illustrations
International audienceDécryptage des signes inventés par Pierre Richar
DĂ©fense (processus de) et Illustrations
International audienceDécryptage des signes inventés par Pierre Richar
Simple and Rapid Mechanochemical Synthesis of Lactide and 3S-(Isobutyl)morpholine-2,5-dione-Based Random Copolymers Using DBU and Thiourea
International audienceThere is a growing interest surrounding morpholine-2,5-dione-based materials due to their impressive biocompatibility as well as their capacity to break down by hydrolytic and enzymatic pathways. In this study, the ring-opening (co)polymerization of leucine-derived 3S-(isobutyl)morpholine-2,5-dione (MD) and lactide (LA) was performed via ball-milling using a catalytic system composed of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 3-[3,5-bis(trifluoromethyl)phenyl]-1-cyclohexylthiourea (TU). Once the homopolymerizations of MD and LA optimized and numerous parameters were studied, the mechanochemical ring-opening copolymerization of these monomers was explored. The feasibility of ring-opening copolymerizations in mechanochemical systems was demonstrated and a range of P(MD-co-LA) copolymers were produced with varying proportions of MD (23%, 48%, and 69%). Furthermore, the beneficial cocatalytic effects of TU with regards to ROP control were found to be operative within mechanochemical systems. Further parallels were observed between solution- and mechanochemical-based ROPs
Synthesis and revised stereochemical assignment of C -allyl glucopyranosides and derivatives
International audienc
Sustainable Mechanosynthesis of Biologically Active Molecules
International audienceSynthetic mechanochemistry, the use of mechanical force produced by milling, grinding or extruding, as an activation technique, provides access to chemical entities of all kinds. This Review is focused on examples reported so far of known Active Pharmaceutical Ingredients (APIs), and effectively evaluated bioactive molecules, all prepared by mechanosynthesis. Three families of molecules are discussed: heterocyclic compounds, metal complexes and peptides. Advantages of the mechanochemistry approach are highlighted especially from a green chemistry and efficacy point of view
A mechanochemical approach to access the proline–proline diketopiperazine framework
International audienceBall milling was exploited to prepare a substituted proline building block by mechanochemical nucleophilic substitution. Subsequently , the mechanocoupling of hindered proline amino acid derivatives was developed to provide proline-proline dipeptides under solvent-free conditions. A deprotection-cyclization sequence yielded the corresponding diketopiperazines that were obtained with a high stereoselectivity which could be explained by DFT calculations. Using this method, an enantiopure disubstituted Pro-Pro diketopiperazine was synthesized in 4 steps, making 5 new bonds using a ball mill. 216
C-glyco“RGD” as αIIbβ3 and αvβ integrin ligands for imaging applications: synthesis, in vitro evaluation and molecular modeling
International audienceThe design of conjugates displaying simultaneously high selectivity and high affinity for different subtypes of integrins is a current challenge. The arginine-glycine-aspartic acid amino acid sequence (RGD) is one of the most efficient short peptides targeting these receptors. We report herein the development of linear and cyclic fluoro-C-glycoside"RGD" conjugates, taking advantage of the robustness and hydrophilicity of C-glycosides. As attested by in vitro evaluation, the design of these C-glyco"RGD" with a flexible three-carbon triazolyl linker allows distinct profiles towards αIIbβ3 and αvβ3 integrins. Molecular-dynamics simulations confirm the suitability of cyclic C-glyco-c(RGDfC) to target αvβ3 integrin. These C-glyco"RGD" could become promising biological tools in particular for Positron Emission Tomography imaging