Cyclic Poly(α-peptoid)s by Lithium bis(trimethylsilyl)amide (LiHMDS)-Mediated Ring-Expansion Polymerization: Simple Access to Bioactive Backbones

Cyclic polymers display unique physicochemical and biological properties. However, their development is often limited by their challenging preparation. In this work, we present a simple route to cyclic poly(α-peptoids) from N-alkylated-N-carboxyanhydrides (NNCA) using LiHMDS promoted ring-expansion polymerization (REP) in DMF. This new method allows the unprecedented use of lysine-like monomers in REP to design bioactive macrocycles bearing pharmaceutical potential against Clostridioides difficile, a bacterium responsible for nosocomial infections

New 8-nitroquinolinone derivative displaying submicromolar in vitro activities against both Trypanosoma brucei and cruzi

International audienceAn antikinetoplastid pharmacomodulation study was conducted at position 6 of the 8-nitroquinolin-2(1H)-one pharmacophore. Fifteen new derivatives were synthesized and evaluated in vitro against L. infantum, T. brucei brucei, and T. cruzi, in parallel with a cytotoxicity assay on the human HepG2 cell line. A potent and selective 6-bromo-substituted antitrypanosomal derivative 12 was revealed, presenting EC50 values of 12 and 500 nM on T. b. brucei trypomastigotes and T. cruzi amastigotes respectively, in comparison with four reference drugs (30 nM ≤ EC50 ≤ 13 μM). Moreover, compound 12 was not genotoxic in the comet assay and showed high in vitro microsomal stability (half life >40 min) as well as favorable pharmacokinetic behavior in the mouse after oral administration. Finally, molecule 12 (E° = −0.37 V/NHE) was shown to be bioactivated by type 1 nitroreductases, in both Leishmania and Trypanosoma, and appears to be a good candidate to search for novel antitrypanosomal lead compounds

Cooperation between Waterways and Railways, an Unnatural Alliance: Rail Strategic Development of River Ports in the Greater Paris Region

Les relations entre transports ferroviaires et fluviaux ont surtout été envisagées sous l’angle de l’impitoyable concurrence à laquelle se sont livrés les deux modes pour le transport de masse. Aujourd’hui toutefois, un intérêt croissant est porté à leur éventuelle complémentarité. Ce discours encore en émergence est porté aussi bien par les grands opérateurs de transport dans le couloir de la Seine que par les autorités portuaires qui ont hérité des installations ferroviaires portuaires. Le rapprochement des deux modes est aussi vivement encouragé par les autorités publiques avec pour ambition de faire jouer aux ports leur rôle de plates-formes multimodales en cohérence avec une politique de transfert modal. Cette contribution cherche à établir les possibles complémentarités entre les transports fluviaux et ferroviaires dans un contexte francilien, une perspective qui n’a pas fait jusque-là l’objet de travaux systématiques

Place de l'angioscanner dans la stratégie thérapeutique de l'artériopathie oblitérante des membres inférieurs

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Adaptive mesh refinement towards optimized mesh generation for large eddy simulation of turbulent combustion in a typical micro gas turbine combustor

International audienc

Improving the Monitoring of the Walnut Husk Fly (Diptera: Tephritidae) Using Male-Produced Lactones

peer reviewedIt is important to monitor fruit flies (Diptera: Tephritidae) efficiently to implement sustainable means of control. Attractants are often used to increase the efficiency of sticky traps deployed in orchards to monitor Lepidopterans, but remains to be developed to monitor fruit flies. Rhagoletis completa Cresson (Diptera: Tephritidae) is an invasive species in the walnut orchards of Europe, and is commonly monitored with yellow sticky traps. In this study, we collected the volatile compounds released by male and female R. completa, and identified two lactones released exclusively by males. We then formulated both lactones in long-lasting volatile dispensers, and we quantified their release rate over a 26-d period. Finally, during the entire period when female flies are present in the field, we compared the efficiency of the conventional monitoring method using unbaited yellow sticky traps with yellow sticky traps associated with a dispenser releasing both male-produced lactones. These assays were conducted in 54 walnut orchards in France, in 2017. The number of fruit flies caught with sticky traps associated with lactones dispensers was increased by up to 10 times each week. Lactone-baited traps also allowed earlier detection in the season. These field results are promising for R. completa monitoring. A complete chiral identification of these lactones should be performed along with a clarification of their role in the sexual communication of R. completa

Autonomous assembly of large structures in space: a technology review

International audienceAutonomous assembly of large structures in space is a key challenge to implement future missions that will necessitate structures to be self-deployed as a single piece. This paper presents a mission analysis of existing concepts for in-space assembly of telescopes, provides a survey of relevant robotics technologies and introduces the expected contribution of the PULSAR (Prototype of an Ultra Large Structure Assembly Robot) project to this challenge

Synthetic Polypeptide Polymers as Simplified Analogues of Antimicrobial Peptides

Antimicrobial peptides (AMPs) are naturally occurring macromolecules made of amino acids that are potent broad-spectrum antibiotics with potential as novel therapeutic agents. This review aims to summarize the fundamental principles concerning the structure and mechanism of action of these AMPs, in order to guide the design of polymeric analogues that organic chemistry can generate. Among those simplified analogues, this review particularly focuses on those made of amino acids called polypeptide polymers: they are showing great potential by providing one of the best biomimetic and bioactive structures for further biomaterials science applications.Analogues Polymériques de Peptides Antimicrobiens à Potentiel Thérapeutique anti-Clostridium difficil

Effect of N-alkylation in N-carboxyanhydride (NCA) ring-opening polymerization kinetics

International audiencePolypeptoids are an emerging class of biomimetic polymers prepared by ring-opening polymerization (ROP) of N-alkylated-N-carboxyanhydride (NNCA) monomers. The N-alkylation provides a unique structural isomerism with peptides but its influence on NNCA reactivity is not yet fully understood. In this report, we provide a comprehensive study using 12 monomers to better rationalize the contribution of the steric hindrance and electronic effects of the N-alkyl group toward the synthesis of NNCA and their reactivity in ring-opening polymerization (ROP) reactions. We found that varying the alkyl group does not significantly influence the formation of NNCAs prepared by the Leuchs’ method. In marked contrast, depending on the alkyl group, the efficiency of the NNCA polymerization initiated by allylamine showed that electron-donating groups enhanced the ROP kinetic rates through significant inductive effect and could counterbalance the negative influence of bulky groups during the propagation steps