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The least efficient substrate for trypsin-catalysed hydrolysis was the acidified, intact protein with a specificity constant (kcat/Km) nearly five times lower than that of the acidified, pepsin-hydrolysate. Our results illustrate the synergy between pepsin and trypsin hydrolysis, and indicate that gastric hydrolysis increases the efficiency of the subsequent trypsin-catalysed hydrolysis of a model protein in the small intestine.For large-scale analysis of complex protein mixtures, liquid chromatography - tandem mass spectrometry (LC-MS/MS) has been proven to be one of the most versatile tools due to its high sensitivity and ability to both identify and quantify thousands of proteins in a single measurement. Sample preparation typically comprises site-specific cleavage of proteins into peptides, followed by desalting and concomitant peptide enrichment, which is commonly performed by solid phase extraction. Desalting workflows may include multiple liquid handling steps and are thus error prone and labour intensive. To improve the reproducibility of sample preparation for low amounts of protein, we present a centrifugal microfluidic disk that automates all liquid handling steps required for peptide desalting by solid phase extraction (DesaltingDisk). Microfluidic implementation was enabled by a novel centrifugal microfluidic dosing on demand structure that enabled mapping multiple washing steps onto a microfluidic disk. Evaluation of tow. The presented centrifugal microfluidic DesaltingDisk demonstrates the potential to improve reproducibility in the sample preparation workflow for proteomic mass spectrometry, especially for application with limited amount of sample material.Overlimiting current through a perm-selective membrane has been actively researched not only for the fundamental advancement of electrokinetics but also for energy/environmental applications such as electrodialysis, fuel cells, etc. In particular, various strategies were reported for the enhancement of overlimiting current because these applications demand efficient mass transport through the membrane. In this work, we presented in operando visualization and rigorous numerical study for the overlimiting current density enhancement using a pulsed electric field which is one of the most cost-effective parameters to be externally controlled. We clearly demonstrated that the current density had a peak value as a function of the pulse frequency and would suggest its correlation to a concentration profile and diffusion relaxation time ([small tau, Greek, tilde]diff). As the pulse frequency was chosen which is similar to ([small tau, Greek, tilde]diff)-1, the concentration profiles (i.e. established current paths) were maintained even in off-state due to remnant current paths helping the fast ion transportation. The fundamental evidence presented in this work would provide a strategical design of a perm-selective membrane system for a higher mass transportation efficiency.The development of turn-on detection sensors for methanol vapor remains challenging in materials science. Methanol sensing materials are generally based on vapor-triggered color changes or are turn-off types. Additionally, in general, the selectivity for methanol is limited, and the recyclability is low. Turn-on type sensing, high selectivity, rapid response time, and recyclability are favorable for achieving real-time detection systems. Herein, platinum(ii) dihalide (PtX2, X = Cl, Br, and I) complexes with 21-dibenzoarsacrown-7 were synthesized and their structures were characterized by single-crystal diffraction analysis. The PtCl2 complex showed intense emission when capturing methanol molecules in the crystalline matrix. In addition, this sensing system possessed high selectivity for methanol vapor and required facile recycling procedures.Copper nitrene complexes are highly reactive species and are known as intermediates in the copper catalyzed C-H amination. In this study, three novel copper tosyl nitrene complexes were synthesized at low temperatures, stabilized with heteroscorpionate ligands of the bis(pyrazolyl)methane family. The copper nitrenes were obtained by the reaction of a copper(i) acetonitrile complex with SPhINTs in dichloromethane. We show that the ligand design has a major influence on the catalytic activity and the thermal stability of the copper nitrene complex. Not only the choice of the third N donor, but also the substituent in the 5-position of the pyrazolyl moiety, have an impact on the stability. Furthermore, the novel copper nitrene complexes were used for catalytic aziridination of styrenes and C-H amination reactions of aromatic and aliphatic substrates under mild reaction conditions. Even challenging substrates like benzene and cyclohexane were aminated with good yields. The copper nitrene complexes were characterized using UV/Vis spectroscopy, low temperature Evans NMR spectroscopy, density functional theory, domain-based local pair natural orbital coupled cluster calculations (DLPNO-CCSD(T)) and cryo-UHR mass spectrometry.Psychoactive natural products play an integral role in the modern world. The tremendous structural complexity displayed by such molecules confers diverse biological activities of significant medicinal value and sociocultural impact. Accordingly, in the last two centuries, immense effort has been devoted towards establishing how plants, animals, and fungi synthesize complex natural products from simple metabolic precursors. The recent explosion of genomics data and molecular biology tools has enabled the identification of genes encoding proteins that catalyze individual biosynthetic steps. Once fully elucidated, the "biosynthetic pathways" are often comparable to organic syntheses in elegance and yield. ART558 price Additionally, the discovery of biosynthetic enzymes provides powerful catalysts which may be repurposed for synthetic biology applications, or implemented with chemoenzymatic synthetic approaches. In this review, we discuss the progress that has been made toward biosynthetic pathway elucidation amongst four classes of psychoactive natural products hallucinogens, stimulants, cannabinoids, and opioids. Compounds of diverse biosynthetic origin - terpene, amino acid, polyketide - are identified, and notable mechanisms of key scaffold transforming steps are highlighted. We also provide a description of subsequent applications of the biosynthetic machinery, with an emphasis placed on the synthetic biology and metabolic engineering strategies enabling heterologous production.Cholinium amino acid-based (Ch-AA) biocompatible ionic liquids (bio-ILs) are synthesized from renewable components and are efficiently used for biomass processing. However, their microscopic structural features that lead to their application as biomass solvents remain undetermined. Herein, we use atomistic simulations to investigate the structures of six different Ch-AA bio-ILs up to the nanometer length scale and demonstrate that, depending on the anion side chain structure, the respective IL exhibits structural ordering at different length scales. All the six Ch-AA bio-ILs investigated here show a generic feature of having a strong hydrogen bonding network between the hydroxyl group of the cholinium cation and the carboxyl group of the amino acid anions. We illustrate that each of these bio-ILs also displays a unique feature. Distinctive intermediate range structural ordering leads to heterogeneity in methioninate- and phenylalaninate-based ILs caused by the anion side chain segregation. Intermediate range ordering is not observed in glutaminate- and glutamate-based ILs because significant anion side chain and backbone interactions hinder the formation of side chain clusters. Interestingly, for the cysteinate-based IL, the side chains do not interact with the backbones and the intermediate range ordering is not observed because of a shorter anionic side chain.Perfluorocarbon emulsion droplets are interesting colloidal systems with applications, ranging from diagnostics and theranostics to drug delivery, due to their controllable phase transition into microbubbles via heat application or acoustic droplet vapourisation. This work highlights the application of small- and ultra-small-angle neutron scattering (SANS and USANS, respectively), in combination with contrast variation techniques, in observing the in situ phase transition of polydopamine-stabilised perfluorohexane (PDA/PFH) emulsion droplets into microbubbles during heating. Results show peak USANS intensities at temperatures around 90 °C, which indicates that the phase transition of PDA/PFH emulsion droplets occurs at significantly higher temperatures than the bulk boiling point of pure liquid PFH (56 °C). Analysis and model fitting of the SANS and USANS data allowed us to estimate droplet sizes and interfacial properties at different temperatures (20 °C, 90 °C, and 20 °C after cooling), giving valuable insights about the transformation of these polydisperse emulsion droplet systems.To predict barrier heights at low temperatures, it is not enough to employ highly accurate electronic structure methods. We discuss the influence of quantum tunnelling on the comparison of experimental and theoretical activation parameters (Ea, ΔH‡, ΔG‡, or ΔS‡), since the slope-based experimental techniques to obtain them completely neglect the tunnelling component. The intramolecular degenerate rearrangement of four fluxional molecules (bullvalene, barbaralane, semibullvalene, and norbornadienylidene) were considered, systems that cover the range between fast deep tunneling and small but significant shallow tunnelling correction. The barriers were computed with the composite W3lite-F12 method at the CCSDT(Q)/CBS level, and the tunnelling contribution with small curvature tunnelling. While at room temperature the effect is small (∼1 kJ mol-1), at low temperatures it can be considerable (in the order of tens of kJ mol-1 at ∼80 K).In this work, the nucleophilic substitution reactions of the cyclotetraphosphazene, tetramer, (1) (N4P4Cl8) with the disodium salt of 1,2-ethanediol in THF solution at different mole ratios were demonstrated. Surprisingly, one double bridged (2) and three ansa derivatives [bis (3), tris (4) and tetrakis (5)] were formed demonstrating two competing pathways in these reactions. The new type cyclotetraphosphazene compounds (2-5) consisting of multiple rings were characterized by elemental analysis, mass spectrometry, 1H and 31P NMR spectroscopy and X-Ray crystallography. Although 1,2-ethanediol, a short chain diol, can only produce spiro type products with cyclotriphosphazene, (N3P3Cl6), it was able to give ansa type products with cyclotetraphosphazene which suggests the role of the ring flexibility of 1. Crystallographic evidence shows the distortion of the cyclotetraphosphazene ring.In this study, we experimentally measured the viscosity, η, and ionic conductivity, σ, of the electrolyte solutions of 1 mol kg-1 of LiPF6 or LiFSA dissolved in the binary mixture solvent of EC and DMC in a temperature range of 288 ≤ T/K ≤ 328 by varying the EC content from 0 to 60 vol%, which translates into the molar fraction of EC of 0 ≤ xEC ≤ 0.7. The diffusion coefficient, D, of each species, Li+, PF6-, FSA-, EC and DMC, was determined by pulse gradient spin-echo NMR. The state of molecules around Li+ was examined using the Raman spectra of the solvents and anions; the quantitative analysis suggests that EC is about twice as much preferred as DMC in the solvation shell at low xEC, while the EC-preference decreases with an increase in xEC. The classical Stokes-Einstein relation still quantitatively holds when evaluating the hydrodynamic radius, rSt, of transporting entities from D and η, in that (i) rSt,EC and rSt,DMC without the solute do not significantly differ from those in the solution; (ii) rSt,Li roughly coincides with the size estimated from the solvation number determined by Raman spectroscopy, which implies that rSt,Li reflects the solvation shell size; and (iii) rSt,anion is close to the static size, suggesting that anions are little solvated.