A new life for nitrosocarbonyls in pericyclic reactions

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(2S)-[3-(Anthracen-9-yl)-4,5-dihydroisoxazol-5-yl]methyl 2-[(tert-butoxycarbonyl)amino]propanoate

The synthesis of the (2S)-[3-(anthracen-9-yl)-4,5-dihydroisoxazol-5-yl]methyl 2-[(tert-butoxycarbonyl)amino]propanoate is obtained through the 1,3-dipolar cycloaddition of the stable anthracenenitrile oxide and the N-Boc protected (S)-alanine allyl ester as dipolarophile. The structure and the fluorescence properties are described upon the relative analytical and spectroscopic data

High-pressure behavior of methylammonium lead iodide (MAPbI3) hybrid perovskite

In this paper we provide an accurate high-pressure structural and optical study of MAPbI3 hybrid perovskite. Structural data show the presence of a phase transition towards an orthorhombic structure around 0.3 GPa followed by full amorphization of the system above 3 GPa. After releasing pressure the systems keeps the high-pressure orthorhombic phase. The occurrence of these structural transitions is further confirmed by pressure induced variations of the photoluminescence signal at high pressure. These variations clearly indicate that the bandgap value and the electronic structure of MAPI change across the phase transition.Comment: 23 pages, 9 figure

9-Anthraldehyde oxime: a synthetic tool for variable applications

Abstract Oximes are one of the most important and prolific functional groups in organic chemistry; among them, 9-anthraldehyde oxime represents a valuable example both from the preparative side and the synthetic applications. There are many strategies to prepare 9-anthraldehyde oxime from different functional groups that were summarized in the present review, focusing on the most recent and innovative. The main synthetic applications of 9-anthraldehyde oxime are presented and thoroughly discussed, focusing on the most recent and innovative synthetic strategies. Graphic abstrac

Three-Dimensional Heterocycles: New Uracil-Based Structures Obtained by Nucleophilic Substitution at the sp2 Carbon of Bromoisoxazoline

none4The regioisomeric cycloadducts of bromonitrile oxide and N-benzoyl-2,3-oxazanorborn-5-ene were easily prepared and elaborated into a novel class of uracil-based scaffolds. The key-synthetic step is the nucleophilic substitution at the sp2 carbon atom of the bromoisoxazoline three-dimensional heterocycles. The protocol to perform the nucleophilic substitution of uracil anions was optimized and adapted to the steric requirements of the substrates. A library of pyrimidine derivatives was prepared in very good yields and the products were fully characterized. They are proposed as nucleoside analogues and as synthons for β-turn motifs within PNA structures.Memeo M. G.; Lapolla F.; Bovio B.; Quadrelli P.Memeo, MISAL GIUSEPPE; Lapolla, F.; Bovio, Bruna; Quadrelli, Paol

Naked-Eye Food Freshness Detection: Innovative Polymeric Optode for High-Protein Food Spoilage Monitoring

An innovative smart label for naked-eye protein food freshness evaluation, based on polymeric sensing films, is presented. The proposed device consists of six miniaturized sensors, obtained by cova..

Inhibition of the RNA-dependent RNA-polymerase from SARS-CoV-2 by 6-chloropurine isoxazoline-carbocyclic monophosphate nucleotides

Isoxazoline-carbocyclic monophosphate nucleotides were designed and synthesized through the chemistry of nitrosocarbonyl intermediates and stable anthracenenitrile oxide. Docking and molecular dynamics studies were first conducted for determining the best candidate for polymerase SARS-CoV-2 inhibition. The setup phosphorylation protocol afforded the nucleotides available for the biological tests. Preliminary inhibition and cytotoxicity assays were then performed, and the results showed a moderate activity of the nucleotides accompanied by cytotoxicity

Rational Design of Allosteric and Selective Inhibitors of the Molecular Chaperone TRAP1

Summary: TRAP1 is the mitochondrial paralog of the heat shock protein 90 (HSP90) chaperone family. Its activity as an energy metabolism regulator has important implications in cancer, neurodegeneration, and ischemia. Selective inhibitors of TRAP1 could inform on its mechanisms of action and set the stage for targeted drug development, but their identification was hampered by the similarity among active sites in HSP90 homologs. We use a dynamics-based approach to identify a TRAP1 allosteric pocket distal to its active site that can host drug-like molecules, and we select small molecules with optimal stereochemical features to target the pocket. These leads inhibit TRAP1, but not HSP90, ATPase activity and revert TRAP1-dependent downregulation of succinate dehydrogenase activity in cancer cells and in zebrafish larvae. TRAP1 inhibitors are not toxic per se, but they abolish tumorigenic growth of neoplastic cells. Our results indicate that exploiting conformational dynamics can expand the chemical space of chaperone antagonists to TRAP1-specific inhibitors with wide therapeutic opportunities. : The molecular chaperone TRAP1 regulates energy metabolism, and its activity is relevant in cancer and degenerative diseases. Here, Sanchez-Martin et al. identify highly selective allosteric inhibitors of TRAP1. These compounds revert biochemical and pro-neoplastic effects of TRAP1 and could both enlighten its mode of action and disclose novel therapeutic strategies. Keywords: chaperone inhibitors, anticancer compound, molecular dynamics, allosteric ligands, TRAP1, HSP90, mitochondria, mitochondrial biology, zebrafish, cancer cells, neurofibrom

Synthesis of 2-heterosubstituted cyclopent-2-en-1-ones: A preliminary study of the strategic design of antiviral compounds

A synthetic approach to heterosubstituted cyclopent-2-en-1-ones through a robust protocol that leads to single 2-substituted compounds is reported. In view of a strategic design of antiviral compounds, the methodology was applied to substituted benzoimidazoles as neutral heterocyclic systems, as models for preliminary evaluation of their antiviral activities. By virtue of NMR investigations the synthetized compounds were structurally completely defined and the conformations were also located from DFT calculations. The preliminary biological tests revealed a general inactivity for most of the products with significant predictions for some bearing specific substituents. The results suggested possible structural changes apt to trigger the relative biological activities, to implement them in the new compounds

U-PHOS Project: Development of a Large Diameter Pulsating Heat Pipe Experiment on board REXUS 22

U-PHOS Project aims to analyse and characterise the behaviour of a large diameter Pulsating Heat Pipe (PHP) on board REXUS 22 sounding rocket. A PHP is a passive thermal control device consisting of a serpentine capillary tube, evacuated, partially filled with a working fluid and finally sealed. In this configuration, the liquid and vapour phases are randomly distributed in the form of liquid slugs and vapour plugs. The heat is efficiently transported by means of the self-sustained oscillatory fluid motion driven by the phase change phenomena. On ground conditions, a small diameter is required in order to obtain a confined slug flow regime. In milli-gravity conditions, buoyancy forces become less intense and the PHP diameter may be increased still maintaining the slug/plug flow configuration typical of the PHP operation. Consequently, the PHP heat power capability may be increased too. U-PHOS aims at proving that a Large Diameter PHP effectively works in milli-g conditions by characterizing its thermal response during a sounding rocket flight. The actual PHP tube is made of aluminum (3 mm inner diameter, filled with FC-72), heated at the evaporator by a compact electrical resistance, cooled at the condenser by a Phase Change Material (PCM) embedded in a metallic foam. The tube wall temperatures are recorded by means of Fibre Bragg Grating (FBG) sensors; the local fluid pressure is acquired by means of a pressure transducer. The present work intends to report the actual status of the project, focusing in particular on the experiment improvements with respect to the previous campaign