All four possible diastereoisomers of phosphinoferrocenyloxazoline (Phosferrox type) ligands containing three elements of chirality were synthesized as single enantiomers. The Sc configured oxazoline moiety (R = Me, i-Pr) was used to control the generation of planar chirality by lithiation, with the alternative diastereoisomer formed by use of a deuterium blocking group. In each case subsequent addition of PhPCl2 followed by o-TolMgBr resulted in a single P-stereogenic diastereoisomer (Sc,Sp,Sphos and Sc,Rp,Rphos, respectively). The alternative diastereoisomers were formed selectively by addition of o-TolPCl2 followed by PhMgBr ((Sc,Sp,Rphos and Sc,Rp,Sphos, respectively). Preliminary application of these four ligand diastereoisomers, together with (Sc,Sp) and (Sc,Rp) Phosferrox (PPh2), to palladium catalyzed allylic alkylation of trans-1,3-diphenylallyl acetate revealed a stepwise increase/decrease in ee, with the configuration of the matched/matched diastereoisomer as Sc,Sp,Sphos (97% ee).This work contributes to an improved understanding of the fluid-phase behavior and diffusion processes in mixtures of 1-hexanol and carbon dioxide (CO2) at temperatures around the upper critical end point (UCEP) of the system. Raman spectroscopy and dynamic light scattering were used to determine the composition at saturation conditions as well as Fick and thermal diffusivities. An acceleration of the Fick diffusive process up to CO2 mole fractions of about 0.2 was found, followed by a strong slowing-down approaching vapor-liquid-liquid equilibrium or critical conditions. The acceleration of the Fick diffusive process vanished at temperatures much higher than the UCEP.  https://www.selleckchem.com/products/liraglutide.html  Experimental Fick diffusivity data were compared with predictions from equilibrium molecular dynamics simulations and excess Gibbs energy calculations using interaction parameters from the literature. Both theoretical methods were not able to predict that the thermodynamic factor is equal to zero at the spinodal composition, stressing the need for new methodologies under such conditions. Thus, new sets of temperature-dependent interaction parameters were developed for the nonrandom two-liquid model, which improve the prediction of the Fick diffusion coefficient considerably. The link between the Fick diffusion coefficient and the nonrandomness of the liquid phases is also discussed.The flavivirus NS3 protein is a helicase that has pivotal functions during the viral genome replication process, where it unwinds double-stranded RNA and translocates along the nucleic acid polymer in a nucleoside triphosphate hydrolysis-dependent mechanism. Crystallographic and computational studies of the flavivirus NS3 helicase have identified the RNA-binding loop as an interesting structural element that may function as a component of the RNA-enhanced NTPase activity observed for this family of helicases. Microsecond-long unbiased molecular dynamics and extensive replica exchange umbrella sampling simulations of the Zika NS3 helicase have been performed to investigate the RNA dependence of this loop's structural conformations. Specifically, the effect of the bound single-stranded RNA (ssRNA) oligomer on the putative "open" and "closed" conformations of this loop is studied. In the Apo substrate state, the two loop conformations are nearly isoergonic (ΔAO→C = -0.22 kcal mol-1), explaining the structural ambiguity observed in Apo NS3h crystal structures. The bound ssRNA is seen to stabilize the "open" conformation (ΔAO→C = 1.97 kcal mol-1) through direct protein-RNA interactions at the top of the loop. Interestingly, a small ssRNA oligomer bound over 13 Å away from the loop is seen to affect the free energy surface to favor the "open" structure, while minimizing barriers between the two states. Both the mechanism of the "open" to "closed" transition and important residues of the RNA-binding loop structures are characterized. From these results, point mutations that are hypothesized to stabilize the "closed" RNA-binding loop and negatively impact RNA-binding and the RNA-enhanced NTPase activity are posited.Glycosyltransferases (GTs) are a ubiquitous group of enzymes that catalyze the synthesis of glycosidic bonds. In this work, we focused on the retained reaction catalyzed by xyloside α-1,3-xylosyltransferase (XXYLT1) from Mus musculus. Our calculations revealed that the xylose transfer reaction follows the SNi-like mechanism, which involves a short-lived oxocarbenium-phosphate ion-pair intermediate (IP). The previously obtained crystal structure of the UDP-Xyl ternary Michaelis reaction complex was found to be an inactive form. Accordingly, the β-phosphate oxygen O3B of the donor should first undergo a conformational change to reach an active state where the donor forms a strong hydrogen bond with the acceptor, facilitating the departure of the phosphate group. Our calculations also revealed that two predicated transition states for the sugar-phosphate bond cleavage and glycosidic bond formation are structurally similar to the short-lived intermediate, which contains a three-member ring formed by the β-phosphate oxygen, the hydroxyl oxygen in the acceptor, and the anomeric carbon. It can be considered as a typical characteristic of the SNi-like mechanism. In addition, a nearby polar residue, Q330, is responsible for stabilizing the short-lived intermediate by electrostatic interactions. Thus, the Q330A mutant can abolish the activity of XXYLT1. In addition, using UDP-glucose as the donor, our calculations revealed that glucose transfer would correspond to a higher energy barrier owing to the steric repulsion between the glucosyl moiety and the nearby residue L327, indicating the requirement of active site architecture for glucose transfer. These findings not only explain the experimental observations but also are meaningful for clarifying the mechanism of GTs.Monolayer transition-metal dichalcogenides (TMDs) manifest exceptional optical properties related to narrow excitonic resonances. However, these properties have been so far explored only for structures produced by techniques inducing considerable large-scale inhomogeneity. In contrast, techniques which are essentially free from this disadvantage, such as molecular beam epitaxy (MBE), have to date yielded only structures characterized by considerable spectral broadening, which hinders most of the interesting optical effects. Here, we report for the first time on the MBE-grown TMD exhibiting narrow and resolved spectral lines of neutral and charged exciton. Moreover, our material exhibits unprecedented high homogeneity of optical properties, with variation of the exciton energy as small as ±0.16 meV over a distance of tens of micrometers. Our recipe for MBE growth is presented for MoSe2 and includes the use of atomically flat hexagonal boron nitride substrate. This recipe opens a possibility of producing TMD heterostructures with optical quality, dimensions, and homogeneity required for optoelectronic applications.