A low-viscous and flowable zwitterionic liquid.

Zwitterionic liquids have attracted significant attention in various fields due to their low-toxicity and the ability to tune their functional properties. However, despite being liquid in thermo-dynamic definition, zwitterionic liquids are not commonly recognized as "liquids" by the general public because of their extremely high viscosity, comparable to that of peanut butter, which prevents stirring even with a strong magnetic stirrer. In this study, we developed a flowable and stirrable zwitterionic liquid, OEimOEC.

Dual-Functionalized Zwitterionic Polymers for Cell Cryopreservation.

Cryopreservation is an essential technique for the long-term preservation of cells. Some cells are challenging to cryopreserve, and novel cryoprotective agents are required. We previously reported a zwitterionic polymer (poly(ZI)) as a cryoprotectant that forms a polymer matrix surrounding the cells and partially prevents intracellular ice formation.

Unbiased picture of the ligand docking process for the hevein protein-oligosaccharide complex.

The ligand-docking behavior of hevein, the major latex protein from the rubber tree Hevea brasiliensis (Euphorbiaceae), has been investigated by the unguided molecular dynamics (MD) simulation method. An oligosaccharide molecule, initially placed in an arbitrary position, was allowed to move around hevein for a prolonged simulation time, on the order of microseconds, with the expectation of spontaneous ligand docking of the oligosaccharide molecule to the binding site of hevein. In the binary solution system consisting of a hevein molecule and a chito-trisaccharide (GlcNAc) molecule, three out of the six separate simulation runs successfully reproduced the complex structure of the observed binding from.

Optimization of Zwitterionic Polymers for Cell Cryopreservation.

Cryopreservation techniques are valuable for the preservation of genetic properties in cells, and the development of this technology contributes to various fields. In a previous study, an isotonic freezing medium composed of poly(zwitterion) (polyZI) has been reported, which alleviates osmotic shock, unlike typical hypertonic freezing media. In this study, the primitive freezing medium composed of emerging polyZI is optimized.

Protein Cryoprotectant Ability of the Aqueous Zwitterionic Solution.

Protein cryopreservation is important for the long-term storage of unstable proteins. Recently, we found that -acetylglucosaminyltransferase-V (GnT-V) can be cryopreserved in a deep freezer without temperature control using a dilute binary aqueous solution of 3-(1-(2-(2-methoxyethoxy)ethyl)imidazol-3-io)butane-1-carboxylate (OEimCC) [10 wt %, mole fraction of solute () = 7.75 × 10], an artificial zwitterion.

Cell-compatible isotonic freezing media enabled by thermo-responsive osmolyte-adsorption/exclusion polymer matrices.

During the long-term storage of cells, it is necessary to inhibit ice crystal formation by adding cryoprotectants. Non-cell-permeable cryoprotectants have high osmotic pressure which dehydrates cells, indirectly suppressing intracellular ice crystal formation. However, the high osmotic pressure and dehydration often damage cells.

Extended Ensemble Molecular Dynamics Study of Ammonia-Cellulose I Complex Crystal Models: Free-Energy Landscape and Atomistic Pictures of Ammonia Diffusion in the Crystalline Phase.

Here, we report extended ensemble molecular dynamics simulations of ammonia-cellulose I complex crystal models to evaluate the diffusion behavior of the guest ammonia molecules and the potential of mean force (PMF), namely, the free energy change along the chosen reaction coordinate, for migration of an ammonia molecule in the crystal models. Accelerated molecular dynamics simulations confirmed that ammonia molecules almost exclusively diffused through the hydrophilic channel even when the crystal framework was retained. Adaptive steered molecular dynamics simulations detected distinct PMF peaks with heights of approximately 7 kcal/mol as the ammonia molecule passed through the cellulose-chain layers.

Strong attractive interaction between finite element models of twisted cellulose nanofibers by intermeshing of twists.

Analysis of the attractive interaction between intrinsically twisted cellulose nanofibers (CNFs) is essential to control the physical properties of the higher-order structures of CNFs, such as paper and spun fiber. In this study, a finite element model reflecting the typical morphology of a twisted CNF was used to analyze the attractive interaction forces between multiple approaching CNF models. For two parallel CNF models, when one of the CNF models was rotated 90° around the long-axis direction, the twisting periods meshed, giving the maximum attraction force.

Tunability of the thermal diffusivity of cellulose nanofibril films by addition of multivalent metal ions.

Discovering principles to tune the heat-transport properties of cellulose nanofibril (CNF) films will open the door for the development of biomass-derived heat-transfer materials and break away from existing petroleum-based polymer composites. In this study, we added various multivalent metal ions to CNF films with surface carboxy groups formed by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation and measured their thermal diffusivities in the dry state by an original method to verify the tunability of the thermal diffusivity. We found that the in-plane thermal diffusivity of the film is inversely proportional to the ionic radius and directly proportional to the Pauling electro-negativity.

Ether-Functionalized Pyrrolidinium-Based Room Temperature Ionic Liquids: Physicochemical Properties, Molecular Dynamics, and the Lithium Ion Coordination Environment.

The physicochemical properties of room temperature ionic liquids (RTILs) consisting of bis(trifluoromethanesulfonyl)amide (TFSA ) combined with 1-hexyl-1-methylpyrrolidinium (Pyr ), 1-(butoxymethyl)-1-methylpyrrolidinium (Pyr ), 1-(4-methoxybutyl)-1-methyl pyrrolidinium (Pyr ), and 1-((2-methoxyethoxy)methyl)-1-methylpyrrolidinium (Pyr ) were investigated using both experimental and computational approaches. Pyr TFSA, which contains two ether oxygen atoms, showed the lowest viscosity, and the relationship between its physicochemical properties and the position and number of the ether oxygen atoms was discussed by a careful comparison with Pyr TFSA and Pyr TFSA. Ab initio calculations revealed the conformational flexibility of the side chain containing the ether oxygen atoms.

Molecular and Crystal Structure of a Chitosan-Zinc Chloride Complex.

We determined the molecular and packing structure of a chitosan-ZnCl complex by X-ray diffraction and linked-atom least-squares. Eight D-glucosamine residues-composed of four chitosan chains with two-fold helical symmetry, and four ZnCl molecules-were packed in a rectangular unit cell with dimensions = 1.1677 nm, = 1.

Irregular and suppressed elastic deformation by a structural twist in cellulose nanofibre models.

The elastic responsiveness of single cellulose nanofibres is important for advanced analysis of biological tissues and their use in sophisticated functional materials. However, the mechanical responsiveness derived from the twisted structure of cellulose nanofibres (CNFs) has remained unexplored. In this study, finite element simulations were applied to characterize the deformation response derived from the torsional structure by performing tensile and bending tests of an unconventionally very long and twisted rod model, having the known dimensional parameters and properties of CNFs.

Molecular Dynamics Simulation of Cellulose Synthase Subunit D Octamer with Cellulose Chains from Acetic Acid Bacteria: Insight into Dynamic Behaviors and Thermodynamics on Substrate Recognition.

The present study reports the building of a computerized model and molecular dynamics (MD) simulation of cellulose synthase subunit D octamer (CesD) from . CesD was complexed with four cellulose chains having DP = 12 (G12) by model building, which revealed unexpected S-shaped pathways with bending regions. Combined conventional and accelerated MD simulations of CesD complex models were carried out, while the pyranose ring conformations of the glucose residues were restrained to avoid undesirable deviations of the ring conformation from the form.

Non-aqueous, zwitterionic solvent as an alternative for dimethyl sulfoxide in the life sciences.

Dimethyl sulfoxide (DMSO) is widely used as a solvent in the life sciences, however, it is somewhat toxic and affects cell behaviours in a range of ways. Here, we propose a zwitterionic liquid (ZIL), a zwitterion-type ionic liquid containing histidine-like module, as a new alternative to DMSO. ZIL is not cell permeable, less toxic to cells and tissues, and has great potential as a vehicle for various hydrophobic drugs.

Nanocellulose enriches enantiomers in asymmetric aldol reactions.

Cellulose nanofibers obtained from wood pulp by TEMPO-mediated oxidation acted as a chiral enhancer in direct aldol reactions of 4-nitrobenzaldehyde and cyclopentanone with ()-proline as an organocatalyst. Surprisingly, catalytically inactive TEMPO-oxidized cellulose nanofibers enriched the (,)-enantiomer in this reaction, affording 89% ee in the form with a very high yield (99%). Conversely, nanocellulose-free ()-proline catalysis resulted in poor selectivity (64% ee, form) with a low yield (18%).

Correction: The effects of the position of the ether oxygen atom in pyrrolidinium-based room temperature ionic liquids on their physicochemical properties.

Correction for 'The effects of the position of the ether oxygen atom in pyrrolidinium-based room temperature ionic liquids on their physicochemical properties' by Kazuki Yoshii et al., Phys. Chem.

The effects of the position of the ether oxygen atom in pyrrolidinium-based room temperature ionic liquids on their physicochemical properties.

Room temperature ionic liquids (RTILs) containing ether oxygen atoms have been investigated for a gamut of science and technology applications owing to their superior physicochemical properties. However, the effect of the position of the ether oxygen atom in the side chain on their physicochemical properties is not clearly understood. This study investigates, using both experimental and computational approaches, the effect of ether oxygen atoms on the physicochemical properties of RTILs consisting of bis(trifluoromethylsulfonyl)amide (TFSA-) with 1-methyl-1-propylpyrrolidinium (MPP+), 1-butyl-1-methylpyrrolidinium (BMP+), 1-methoxymethyl-1-methylpyrrolidinium (MOMMP+), 1-ethoxymethyl-1-methylpyrrolidinium (EOMMP+), and 1-methoxyethyl-1-methylpyrrolidinium (MOEMP+).

Evaluation of artificial crystalline structure from amylose analog polysaccharide without hydroxy groups at C-2 position.

In this study, we found that a new artificial crystalline structure was fabricated from an amylose analog polysaccharide without hydroxy groups at the C-2 position, i.e., 2-deoxyamylose.

Molecular Dynamics Simulation of Cellulose I-Ethylenediamine Complex Crystal Models.

Cellulose I fibrils swell on exposure to ethylenediamine (EDA), which forms the cellulose I-EDA complex. These are regarded as host materials with guest intercalation. The present study reports molecular dynamics (MD) simulations of cellulose I-EDA crystal models with finite fiber to reproduce desorption of EDA molecules.

DFT Optimization of Isolated Molecular Chain Sheet Models Constituting Native Cellulose Crystal Structures.

Because of high crystallinity and natural abundance, the crystal structures of the native cellulose allomorphs have been theoretically investigated to elucidate the cellulose chain packing schemes. Here, we report systematic structure optimization of cellulose chain sheet models isolated from the cellulose Iα and Iβ crystals by density functional theory (DFT). For each allomorph, the three-dimensional chain packing structure was partitioned along each of the three main crystal planes to construct either a flat chain sheet model or two stacked chain sheet models, each consisting of four cello-octamers.

Understanding dissolution process of chitin crystal in ionic liquids: theoretical study.

Chitin is a promising biomass resource and has high potential for industrial applications owing to its huge annual production in nature. However, it exhibits poor processability and solubility due to its very stable and crystalline character. Recently, ionic liquids (ILs) have attracted attention as solvents for structural polysaccharides - for example, 1-allyl-3-methylimidazolium bromide (AMIMBr) has been found to dissolve chitin.

Molecular dynamics simulations of theoretical cellulose nanotube models.

Nanotubes are remarkable nanoscale architectures for a wide range of potential applications. In the present paper, we report a molecular dynamics (MD) study of the theoretical cellulose nanotube (CelNT) models to evaluate their dynamic behavior in solution (either chloroform or benzene). Based on the one-quarter chain staggering relationship, we constructed six CelNT models by combining the two chain polarities (parallel (P) and antiparallel (AP)) and three symmetry operations (helical right (H), helical left (H), and rotation (R)) to generate a circular arrangement of molecular chains.

Double helix formation from non-natural amylose analog polysaccharides.

Double helix formation from the non-natural anionic and cationic amylose analog polysaccharides (amylouronic acid and amylosamine, respectively) was achieved through electrostatic interactions. A water-insoluble complex was obtained by simply mixing the two polysaccharides in water. The H NMR analysis indicated that the formation of the complexes with an approximately equimolar unit ratio from the two polysaccharides was resulted regardless of feed ratios for mixing.

Cellulose Crystal Dissolution in Imidazolium-Based Ionic Liquids: A Theoretical Study.

The highly crystalline nature of cellulose results in poor processability and solubility, necessitating the search for solvents that can efficiently dissolve this material. Thus, ionic liquids (ILs) have recently been shown to be well suited for this purpose, although the corresponding dissolution mechanism has not been studied in detail. Herein, we adopt a molecular dynamics (MD) approach to study the dissolution of model cellulose crystal structures in imidazolium-based ILs and gain deep mechanistic insights, demonstrating that dissolution involves IL penetration-induced cleavage of hydrogen bonds between cellulose molecular chains.