On the route to mimic natural movements: synthesis and photophysical properties of a molecular arachnoid

The synthesis, photoswitchability and NIR emitting properties of a novel π-extended pyrene derivative, peripherally decorated with four azobenzenyl-ethynyl legs, are reported.     

Niclosamide Is Active In Vitro against Mycetoma Pathogens

Redox-active drugs are the mainstay of parasite chemotherapy. To assess their repurposing potential for eumycetoma, we have tested a set of nitroheterocycles and peroxides in vitro against two isolates of Madurella mycetomatis, the main causative agent of eumycetoma in Sudan. All the tested compounds were inactive except for niclosamide, which had minimal inhibitory concentrations of around 1 µg/mL. Further tests with niclosamide and niclosamide ethanolamine demonstrated in vitro activity not only against M. mycetomatis but also against Actinomadura spp., causative agents of actinomycetoma, with minimal inhibitory concentrations below 1 µg/mL. The experimental compound MMV665807, a related salicylanilide without a nitro group, was as active as niclosamide, indicating that the antimycetomal action of niclosamide is independent of its redox chemistry (which is in agreement with the complete lack of activity in all other nitroheterocyclic drugs tested). Based on these results, we propose to further evaluate the salicylanilides, niclosamide in particular, as drug repurposing candidates for mycetoma.     

Recherches en série diazépine-1,4 et triazépine-1,2,4. IX. Synthéses de nouvelles triazépines-1,2,4

The methods used to prepare five types of 1,2,4-triazepines disubstituted by oxo, thioxo, methoxy or methylthio groups in the 3 and 5 positions are described. Thus eleven triazepines have been synthesized and their structure established from the spectral data.     

Study of the critical current density and the thermodynamic critical field in deuterated κ-(BEDT-TTF)2Cu[N(CN)2]Br organic superconductor

ABSTRACT

We have studied the reversible and irreversible part of the hysteresis loops as a function of slow cooling rate through the order–disorder transformation near 80?K for the deuterated (κ-D₈-Br) κ-(BEDT-TTF)₂Cu[N(CN)₂]Br organic superconductor. We estimated the critical current density J_C and the thermodynamic critical field H_C from the magnetic hysteresis loops. Temperature dependence of the critical current density derived from the irreversible part using Bean’s model. The thermodynamic critical field H_C has been obtained from the reversible part of the hysteresis loops.     

Phenanthrenoids from Juncus acutus L., new natural lipopolysaccharide-inducible nitric oxide synthase inhibitors

The novel natural product juncutol (1), 1,4,7-trimethyl-8,9-dihydro-4H-cyclopenta[def]phenanthrene-2,6-diol, along with the three related metabolites juncusol (2), dehydrojuncusol (3), and 6-hydroxymethyl-1-methyl-5-vinyl-9,10-dihydrophenanthrene-2-ol (4), were isolated from the rhizomes of Juncus acutus L. (Juncaceae) growing in Egypt. The structural identity of 1 was determined on the basis of spectroscopic analyses, including 2D NMR spectroscopy. The inhibitory effect of these natural products on the expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide-stimulated RAW264.7 macrophage cells was determined for the first time. The unprecedented symmetrical compound juncutol (1) was found to be the most potent inhibitor against the induction of the proinflammatory iNOS protein.     

Diéthyl 10‐chloro‐7‐méthyl‐6‐oxo‐11b‐phényl‐2,3,5,6,7,11b‐héxa­hydro­oxazolino[3,2‐d][1,4]benzodiazépine‐2,3‐carboxylate

The structure of the title compound, C₂₄H₂₅ClN₂O₆, has been established and the central seven‐membered ring is fused to chlorobenzo and oxazolino rings to form the core of the molecule.     

DNA Nucleobase under Ionizing Radiation: Unexpected Proton Transfer by Thymine Cation in Water Nanodroplets

The effect of ionizing radiation on DNA constituents is a widely studied fundamental process using experimental and computational techniques. In particular, radiation effects on nucleobases are usually tackled by mass spectrometry in which the nucleobase is embedded in a water nanodroplet. Here, we present a multiscale theoretical study revealing the effects and the dynamics of water droplets towards neutral and ionized thymine. In particular, by using both hybrid quantum mechanics/molecular mechanics and full ab initio molecular dynamics, we reveal an unexpected proton transfer from thymine cation to a nearby water molecule. This leads to the formation of a neutral radical thymine and a Zundel structure, while the hydrated proton localizes at the interface between the deprotonated thymine and the water droplet. This observation opens entirely novel perspectives concerning the reactivity and further fragmentation of ionized nucleobases.     

Bis(ammonium) tris­(hexa­aqua­magnesium) tetra­kis(hydrogen phosphite)

The structure of the title compound, (NH₄)₂[Mg(H₂O)₆]₃(HPO₃)₄, consists of [Mg(H₂O)₆]²⁺ and (NH₄)⁺ cations and (HPO₃)²⁻ anions held together by an intricate network of hydrogen bonds involving all H atoms except for one linked directly to a P atom. The Mg²⁺ cations are octa­hedrally coordinated by six water mol­ecules. One of the Mg atoms is located on a site with 2/m symmetry, whereas the other Mg atom and the P and N atoms occupy sites with m symmetry.     

Efficient Approach for the Synthesis of Novel Functionalized Isoxazolines from Limonene

New functionalized isoxazolines were effeciently and easily prepared from limonene. The procedure involves a peri‐ and regioselective 1,3‐dipolar cycloaddition of nitrile oxides on the monoterpene external double bond, followed by a highly chemoselective RuCl₃‐NaIO₄ oxidative cleavage of the internal one. All the newly prepared isoxazolyl‐ketoacids were fully characterized from their spectroscopic data.