3-Halo-3-nitro-aza/thioflavanones: DNMT inhibitors with a two-site binding mode in the hDNMT3A catalytic pocket.

Flavonoid derivatives are natural product analogues that have shown great interest for therapeutic applications as modulators of DNA methylation. In this article we report new synthesis pathways to access ten novel flavonoid derivatives (i.e.

Water-Pore Flow Permeation through Multivalent H-Bonding Pyridine-2,6-dicarboxamide-histamine/Histidine Water Channels.

Aquaporins (AQPs) are natural proteins that can selectively transport water across cell membranes. Heterogeneous H-bonding of water with the inner wall of the pores of AQPs is of maximal importance regarding the optimal stabilization of water clusters within channels, leading to selective pore flow water transport against ions. To gain deeper insight into the water permeation mechanisms, simpler artificial water channels (AWCs) have been developed.

Partitioning / Self-assembly of Artificial Water Channels - Toward Controlled Permselectivity through Bilayer Membrane.

Artificial water channels (AWCs) have been extensively explored to mimic natural proteins, which enables to effectively transport water while blocking ions. As one of the first AWCs, self-assembled I-quartets (HCx) have showcased high water-permselectivity that can be enhanced by improving their distribution and stability within membrane. The use of long alkyl chains (n>8) is constrained by their low solubility and aggregation.

High-Resolution O Solid-State NMR as a Unique Probe for Investigating Oxalate Binding Modes in Materials: The Case Study of Calcium Oxalate Biominerals.

Oxalate ligands are found in many classes of materials, including energy storage materials and biominerals. Determining their local environments at the atomic scale is thus paramount to establishing the structure and properties of numerous phases. Here, we show that high-resolution O solid-state NMR is a valuable asset for investigating the structure of crystalline oxalate systems.

Structural, Hirshfeld surface and molecular docking studies of a new organotin(IV)-phosphoric triamide complex and an amidophosphoric acid ester proposed as possible SARS-CoV-2 and Monkeypox inhibitors.

Phosphoramides and their complexes are attractive compounds due to their significant inhibiting functionality in biological medicine. In this paper, a novel organotin(IV)-phosphoramide complex (Sn(CH)Cl{[(3-Cl)CHNH]P(O)[NCHO]}, ), derived from a reaction between phosphoric triamide ligand with dimethyltin dichloride, and a new amidophosphoric acid ester ([OCHC(CH)CHO]P(O)[N(CH)CHCH], ), prepared from the condensation of a cyclic chlorophosphate reagent with -methylbenzylamine, are structurally characterized and investigated as potential SARS-CoV-2 and Monkeypox inhibitors by molecular docking simulation. Both compounds crystallize in the monoclinic crystal system with space group 2/.

Preparation of Confined One-Dimensional Boron Nitride Chains in the 1-D Pores of Siliceous Zeolites under High-Pressure, High-Temperature Conditions.

Low-dimensional boron nitride (BN) chains were prepared in the one-dimensional pores of the siliceous zeolites theta-one (TON) and Mobil-twelve (MTW) by the infiltration, followed by the dehydrocoupling and pyrolysis of ammonia borane under high-pressure, high-temperature conditions. High-pressure X-ray diffraction in a diamond anvil cell and in a large-volume device was used to follow in situ these different steps in order to determine the optimal conditions for this process. Based on these results, millimeter-sized samples of BN/TON and BN/MTW were synthesized.

Structural and Molecular Packing study of Three New Amidophosphoric Acid Esters and Assessment of Their Inhibiting Activity Against SARS-CoV-2 by Molecular Docking.

Three new compounds of amidophosphoric acid esters with a [OCHC(CH)CHO]P(O)[] segment (where =cyclopentylamido (), 2-aminopyridinyl () and pyrrolidinyl ()) were synthesized and studied using FT-IR and P/C/H NMR spectroscopies and single-crystal X-ray diffraction analysis. The compounds crystallize in the triclinic space groups for and and in the orthorhombic space group 2 for , where the asymmetric unit consists of three symmetrically-independent molecules for and one molecule for and . The intermolecular interactions and supramolecular assemblies are assessed by Hirshfeld surface analysis and enrichment ratios.

The Unexpected Helical Supramolecular Assembly of a Simple Achiral Acetamide Tecton Generates Selective Water Channels.

Invited for the cover of this issue is the collaborative research team coordinated by Arie van der Lee at the University of Montpellier. The image depicts chiral channels with highly mobile water molecules resulting from the robust self-organization of a simple achiral acetamide. Fully reversible release and re-uptake of water molecules takes place near ambient conditions, with efficient water transport and a good selectivity against NaCl suggesting it to be an efficient candidate for desalination processes.

Experimental and theoretical study of novel amino-functionalized P(V) coordination compounds suggested as inhibitor of M of SARS-COV-2 by molecular docking study.

Amino-functionalized P(V) derivatives providing both - and -donor modes have attracted interest owing to their potential to form interesting coordination assemblies with applications such as biological drugs. Novel coordination modes of two- and four-dentate tris (pyridin-2-yl)phosphoric triamide OP[NH-Py] as ([Co{[O][NH-Py]P(O)[Ph]}(DMF)], ) and ([CuCl{[NH-Py]P(O)[N-Py]}].DMF, ) have been synthesized and structurally studied.

Temperature-Dependent Structural Phase Transition in Rubrene Single Crystals: The Missing Piece from the Charge Mobility Puzzle?

Accurate structural models for rubrene, the benchmark organic semiconductor, derived from synchrotron X-ray data in the temperature range of 100-300 K, show that its cofacially stacked tetracene backbone units remain blocked with respect to each other upon cooling to 200 K and start to slip below that temperature. The release of the blocked slippage occurs at approximately the same temperature as the hole mobility crossover. The blocking between 200 and 300 K is caused by a negative correlation between the relatively small thermal expansion along the crystallographic -axis and the relatively large widening of the angle between herringbone-stacked tetracene units.

Synergistic Copper/Enamine Catalysis for the Regio-, Stereo-, and Enantioselective Intermolecular α-Addition of Aldehydes to Allenamides.

We herein describe an intermolecular enantioselective α-addition of aldehydes to allenamides using a dual copper/enamine catalytic system. Highly enantioselective addition of aldehydes was obtained thanks to secondary amine catalysts. The process was found to be highly regio-, stereo-, and enantioselective under mild conditions.

Bilayer versus Polymeric Artificial Water Channel Membranes: Structural Determinants for Enhanced Filtration Performances.

Artificial water channels (AWCs) and their natural aquaporin counterparts selectively transport water. They represent a tremendous source of inspiration to devise biomimetic membranes for several applications, including desalination. They contain variable water-channel constructs with adaptative architectures and morphologies.

Dynamic Kinetic Resolution Processes Based on the Switchable Configurational Instability of Allenyl Copper Reagents.

The configurational instability of allenyl copper reagents is unveiled. An experimental study highlights the crucial role of Li and of the reaction temperature in the control of the configurational stability of allenyl copper reagents. A judicious choice of the reaction conditions allows efficient dynamic kinetic resolution processes and gives a one-pot access to homopropargylic alcohols or amines bearing up to four contiguous defined stereogenic centers.

Molecular dynamics simulations reveal statistics and microscopic mechanisms of water permeation in membrane-embedded artificial water channel nanoconstructs.

Understanding water transport mechanisms at the nanoscale level remains a challenge for theoretical chemical physics. Major advances in chemical synthesis have allowed us to discover new artificial water channels, rivaling with or even surpassing water conductance and selectivity of natural protein channels. In order to interpret experimental features and understand microscopic determinants for performance improvements, numerical approaches based on all-atom molecular dynamics simulations and enhanced sampling methods have been proposed.

Thermal expansion properties of organic crystals: a CSD study.

The thermal expansion properties of crystalline organic compounds are investigated by data mining of the Cambridge Structural Database (CSD). The mean volumetric thermal expansion coefficient is 168.8 × 10 K and the mean uniaxial thermal expansion coefficient is 71.

Self-Assembled H-Bonding Superstructures for Alkali Cation and Proton Transport.

Transmembrane protein channels are of significant importance for the design of biomimetic artificial ion channels. Regarding the transport principles, they may be constructed from amphiphilic compounds undergoing self-assembly that synergistically generate directional superstructures across bilayer membranes. Particularly interesting, these alignments may impose an artificial pore structure that may control the ionic conduction and translocate water and ions sharing one pathway across the cell membrane.

Hydroxy Channels-Adaptive Pathways for Selective Water Cluster Permeation.

Artificial water channels (AWCs) are known to selectively transport water, with ion exclusion. Similarly to natural porins, AWCs encapsulate water wires or clusters, offering continuous and iterative H-bonding that plays a vital role in their stabilization. Herein, we report octyl-ureido-polyol AWCs capable of self-assembly into hydrophilic hydroxy channels.

Coordination hydrogen bonds in the structures of different tris(pyridin-2-yl)phosphoric triamide derivatives.

The crystalline forms of tris(pyridin-2-yl)phosphoric triamide, OP[NH-Py] were investigated using single crystal X-ray diffraction, both as a metal complex [Co{(O)P[NH-Py][NH-PyH]}]Cl, compound 1, and as the purely organic pseudopolymorphs, the pure/anhydrate OP[NH-Py], 2, monohydrate 2OP[NH-Py]·HO, 3 and solvate 2OP[NH-Py]·2DMF·HO, 4, respectively. An improved model of the metal organic framework (MOF) structure of Cu(ii)O {[Cu(OCHO)][(CH)NH]} , 5 is also reported. Compound 1 is the first example of a discrete chelate phosphoric triamide (PT) complex with an [N]P(O)-based backbone which in the PT compound acts as a flexible tridentate ligand.

Effect of glucose-induced Maillard reaction on physical, structural and antioxidant properties of chitosan derivatives-based films.

This work focused on studying the physicochemical and antioxidant properties changes of varying molecular weight (Mw) chitosan-depolymerization products (CDP)-based films occurring after crosslinking by heat-treatment and Maillard reaction (MR). Based on color properties and browning index, an enhancement of films properties was observed after treatment at 90 °C with a reduction in their water content, solubility and contact angle. Brown MR products were developed in heated films containing glucose thus improving their barrier properties.

Functionalised polyhedral oligomeric silsesquioxane with encapsulated fluoride - first observation of fluxional SiF interactions in POSS.

The synthesis of a styryl functionalised POSS incorporating an encapsulated fluoride ion within a (SiO) cage (T-F) is reported. It was characterised by single crystal XRD, MALDI-MS, FTIR, solution (Si, F, C, H) and solid state (Si, F) NMR. In the absence of H decoupling, the Si solution NMR spectrum exhibited a triplet of doublets.

A positive to negative uniaxial thermal expansion crossover in an organic benzothienobenzothiophene structure.

Compound 6,6'-([1]benzothieno[3,2-b][1]benzothiophene-2,7-diyl)bis(butan-1-ol) (BTBT-C4OH) displays a continuous type 0 first-order isosymmetric phase transition at 200 K which is accompanied by a continuous change of the thermal expansion along the b axis from positive to negative. The equivalent isotropic atomic displacement parameters for all non-hydrogen atoms as well as all the eigenvalues of the anisotropic atomic displacement tensor show discontinuous behavior at the phase transition. The eigenvalues of the translational tensor in a rigid-body description of the molecule are all discontinuous at the phase transition, but the librational eigenvalues are discontinuous only in their temperature derivative.