bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrating Regioselective E→Z Isomerization of Trienones with Cascade Sequences under Photosensitizer‐Free Direct Irradiation at 390 nm
Authors: Maity Rajib , Ghosh Subhadeep , Das Indrajit 
Published: March 2023

AbstractThe regioselective E→Z isomerization of a target olefin unit embedded in a conjugated polyene is challenging. Examples are limited to retinal and its derivatives only. The problem is further amplified when such an isomerization is integrated into cascade sequences, among which the regioselectivity and subsequent directionality are the major bottlenecks. Indeed, there are no reports till date for such a transformation. Herein, it is reported that such a controlled isomerization and subsequent cyclization cascade can be enabled by photosensitizer‐free direct irradiation of linearly conjugated acyclic polyenes in dichloromethane solvent using a 390 nm LED. The directionality results from deconjugation of the extended π‐system in the transient Z‐isomer due to stabilizing n→π* interactions between 1,4‐dicarbonyls (C=O→C=O) or 1,4‐carbonyl/‐aryl (C=O→aryl) groups. The involvement of such noncovalent interactions has been supported by X‐ray crystallography and control experiments. Thus, conjugated trienones can be stereoselectively converted into oxabicyclo[3.2.1]octadienes in an atom‐ and step‐economic manner, including the first example by regioselective isomerization of a tetrasubstituted alkene. The reaction conditions are very general (>46 examples). The reaction can be conducted under open air atmosphere at ambient temperature. Such a cascade cyclization can also be realized in solid state.
Photomodulation on Active Sites of Adsorbents: Controllable Adsorption Processes with Improved Efficiency
Authors: Tan Peng , Bao Yu‐Fen , Liu Ding‐Hua , Liu Xiao‐Qin , Sun Lin‐Bing 
Published: March 2023

AbstractAdsorption is a widely applied technique in producing high‐purity chemicals with advantages of low energy consumption, high selectivity, and mild operating conditions. However, traditional adsorbents have inflexible properties and suffer from the trade‐off between selective adsorption and efficient desorption. Recently, the emerging photoresponsive adsorbents have provided new avenues for adsorption techniques. Active sites of photoresponsive adsorbents can be regulated through steric hindrance or tunable adsorbent‐adsorbate interactions. Therefore, variation in adsorptive capacity is able to readily achieve through photomodulation, and the corresponding adsorption/desorption cycles are energy‐saving. This concept mainly summarizes recent efforts on the fabrication and application of photoresponsive adsorbents with tunable active sites. Also, the future opportunities and critical challenges of photoregulation on adsorptive sites are presented.
Biocatalytic Cascade Synthesis of Enantioenriched Epoxides and Triols from Biomass‐Derived Synthons Driven by Specifically Designed Enzymes
Authors: Grandi Eleonora , Crotti Michele , Sigmund Marie‐Cathérine , Xu Guangcai , Tepper Pieter G. , Poelarends Gerrit J. 
Published: March 2023

AbstractMulti‐enzymatic cascades exploiting engineered enzymes are a powerful tool for the tailor‐made synthesis of complex molecules from simple inexpensive building blocks. In this work, we engineered the promiscuous enzyme 4‐oxalocrotonate tautomerase (4‐OT) into an effective aldolase with 160‐fold increased activity compared to 4‐OT wild type. Subsequently, we applied the evolved 4‐OT variant to perform an aldol condensation, followed by an epoxidation reaction catalyzed by a previously engineered 4‐OT mutant, in a one‐pot two‐step cascade for the synthesis of enantioenriched epoxides (up to 98 % ee) from biomass‐derived starting materials. For three chosen substrates, the reaction was performed at milligram scale with product yields up to 68 % and remarkably high enantioselectivity. Furthermore, we developed a three‐step enzymatic cascade involving an epoxide hydrolase for the production of chiral aromatic 1,2,3‐prim,sec,sec‐triols with high enantiopurity and good isolated yields. The reported one‐pot, three‐step cascade, with no intermediate isolation and being completely cofactor‐less, provides an attractive route for the synthesis of chiral aromatic triols from biomass‐based synthons.
Messebericht ACHEMA 2022: Zerkleinern
Authors: Mütze Thomas 
Published: March 2023

AbstractAuf der ACHEMA 2022 waren in Frankfurt 38 Anbieter von Zerkleinerungstechnik vertreten. Der vorliegende Bericht fasst kurz zusammen, welche Aussteller vertreten waren und was – vor allem an Neuerungen – gezeigt wurde. Schwerpunkte waren einerseits Maschinen zum Dispergieren verklumpter bzw. sehr feinkörniger Pulver zur besseren Verarbeitbarkeit oder zum Einmischen in Flüssigkeiten sowie andererseits Mahlkörpermühlen zur Fein‐ und Feinstmahlung.
Advancements in droplet reactor systems represent new opportunities in chemical reactor engineering: A perspective
Authors: Zhang Meng , Vokoun Asher E. , Chen Boyuan , Deng Weichen , Dupont Robert L. , Xu Yang , Wang Xiaoguang 
Published: March 2023

AbstractTraditional chemical reactors, such as batch reactors, continuous reactors, and semi‐batch reactors, have been extensively studied and frequently act as central components of modern chemical plants. Recently, various advances in reaction times, surface‐to‐volume ratios, required amounts of reagents, and throughput have led to new directions in the design of miniaturized chemical reactors. In this Perspective, we provide an overview of the progress from traditional to miniaturized chemical reactors by summarizing the characteristics and applications of different types of reactors. Furthermore, we compare classical chemical reactors and miniaturized droplet reactors to highlight advancements in the design of droplet reactor systems based on open functional surfaces. Finally, we provide an outlook on the research directions of miniaturized droplet reactors.
Molecular and cellular level characterization of cytoskeletal mechanics using a quartz crystal microbalance
Authors: Kerivan Emily M. , Tobin Lyle , Basil Mihir , Reinemann Dana N. 
Published: March 2023

AbstractA quartz crystal microbalance (QCM) is an instrument that has the ability to measure nanogram‐level changes in mass on a quartz sensor and is traditionally used to probe surface interactions and assembly kinetics of synthetic systems. The addition of dissipation monitoring (QCM‐D) facilitates the study of viscoelastic systems, such as those relevant to molecular and cellular mechanics. Due to real‐time recording of frequency and dissipation changes and single protein‐level precision, the QCM‐D is effective in interrogating the viscoelastic properties of cell surfaces and in vitro cellular components. However, few studies focus on the application of this instrument to cytoskeletal systems, whose dynamic parts create interesting emergent mechanics as ensembles that drive essential tasks, such as division and motility. Here, we review the ability of the QCM‐D to characterize key kinetic and mechanical features of the cytoskeleton through in vitro reconstitution and cellular assays and outline how QCM‐D studies can yield insightful mechanical data alone and in tandem with other biophysical characterization techniques.
CYP3A4 Catalyzes the Rearrangement of the Dual Orexin Receptor Antagonist Daridorexant to 4‐Hydroxypiperidinol Metabolites
Authors: Treiber Alexander , Aissaoui Hamed , Delahaye Stéphane , Glutz Sven , Grimont Julien , Müller Claus , Seeland Swen , Siefken Valérie , Boss Christoph 
Published: March 2023

AbstractThe dual orexin receptor antagonist daridorexant was approved in 2022 in the USA and EU for the treatment of insomnia. The purpose of this study was the identification of its metabolic pathways and the human cytochrome P450 (P450) enzymes involved in its biotransformation. With human liver microsomes, daridorexant underwent hydroxylation at the methyl group of the benzimidazole moiety, oxidative O‐demethylation of the anisole to the corresponding phenol, and hydroxylation to a 4‐hydroxy piperidinol derivative. While the chemical structures of the benzylic alcohol and the phenol proved to be products of standard P450 reactions, 1D and 2D NMR data of the latter hydroxylation product was incompatible with the initially postulated hydroxylation of the pyrrolidine ring and suggested the disappearance of the pyrrolidine ring and formation of a new 6‐membered ring. Its formation is best explained by initial hydroxylation of the pyrrolidine ring in 5‐position to yield a cyclic hemiaminal. Hydrolytic ring opening then results in an aldehyde that subsequently cyclizes onto one of the benzimidazole nitrogen atoms to yield the final 4‐hydroxy piperidinol. The proposed mechanism was substantiated using an N‐methylated analogue, which might hydrolyze to the open‐chain aldehyde but cannot undergo the final cyclization step. CYP3A4 was the major P450 enzyme responsible for daridorexant metabolism, accounting for 89 % of metabolic turnover.
Bis‐Catecholamide‐Based Materials for Uranium Extraction
Authors: Mossand Guillaume , Lelong Evan , Xing Chen , Ndebulia Watchou Frantz , Leydier Antoine , Arrachart Guilhem , Pellet‐Rostaing Stéphane 
Published: March 2023

AbstractInvited for this month′s cover is the collaborating group of Dr Guilhem Arrachart and Dr Stéphane Pellet‐Rostaing at Institut de Chimie Séparative de Marcoule (ICSM). The cover picture shows a person going uranium fishing thanks to the use of bis‐catecholamide materials. These materials have shown interesting performance for the recovery of uranium in saline environments such as seawater. More information can be found in the Research Article by G. Arrachart, S. Pellet‐Rostaing, and co‐workers.
Thermal Decomposition Assisted Construction of Nano‐Li3N Sites Interface Layer Enabling Homogeneous Li Deposition
Authors: Li Hongyang , Li Ling , Zheng Jingang , Huang Hao , Zhang Han , An Baigang , Geng Xin , Sun Chengguo 
Published: March 2023

AbstractLithium (Li) metal is a highly desirable anode for all‐solid‐state lithium‐ion batteries (ASSLBs) due to its high theoretical capacity and being well matched with solid‐state electrolytes. However, the practical applications of Li metal anode are hindered by the uneven Li metal plating/stripping behavior and poor contact between electrolyte and Li anode. Herein, a convenient and efficient strategy to construct the Li3N‐based interlayer between solid poly(ethylene oxide) (PEO) electrolyte and Li anode is proposed by in situ thermal decomposition of 2,2′‐azobisisobutyronitrile (AIBN) additive. The evolved Li3N nanoparticles are capable of combining LiF, cyano derivatives and PEO electrolyte to form a buffer layer of about 0.9 μm during the cell cycle, which can buffer Li+ concentration and homogenize Li deposition. The Li||Li symmetric cells with Li3N‐based interlayer show excellent cycle stability at 0.2 mA cm−2, which is at least 4 times longer cycle life than that of PEO electrolytes without Li3N layer. This work provides a convenient strategy for designing interface engineering between solid‐state polymer electrolyte and Li anode.
Long‐term exclusion of invasive ungulates alters tree recruitment and functional traits but not total forest carbon
Authors: Allen Kara , Bellingham Peter J. , Richardson Sarah J. , Allen Robert B. , Burrows Larry E. , Carswell Fiona E. , Husheer Sean W. , St. John Mark G. , Peltzer Duane A. 
Published: March 2023

AbstractForests are major carbon (C) sinks, but their ability to sequester C and thus mitigate climate change, varies with the environment, disturbance regime, and biotic interactions. Herbivory by invasive, nonnative ungulates can have profound ecosystem effects, yet its consequences for forest C stocks remain poorly understood. We determined the impact of invasive ungulates on C pools, both above‐ and belowground (to 30 cm), and on forest structure and diversity using 26 paired long‐term (>20 years) ungulate exclosures and adjacent unfenced control plots located in native temperate rainforests across New Zealand, spanning 36–41° S. Total ecosystem C was similar between ungulate exclosure (299.93 ± 25.94 Mg C ha−1) and unfenced control (324.60 ± 38.39 Mg C ha−1) plots. Most (60%) variation in total ecosystem C was explained by the biomass of the largest tree (mean diameter at breast height [dbh]: 88 cm) within each plot. Ungulate exclusion increased the abundance and diversity of saplings and small trees (dbh ≥2.5, <10 cm) compared with unfenced controls, but these accounted for ~5% of total ecosystem C, demonstrating that a few, large trees dominate the total forest ecosystem C but are unaffected by invasive ungulates at a timescale of 20–50 years. However, changes in understory C pools, species composition, and functional diversity did occur following long‐term ungulate exclusion. Our findings suggest that, although the removal of invasive herbivores may not affect total forest C at the decadal scale, major shifts in the diversity and composition of regenerating species will have longer term consequences for ecosystem processes and forest C.
Developing the “single‐session mindset” in eating disorder research: Commentary on Schleider et al., 2023 “Realizing the untapped promise of single‐session interventions for eating disorders”
Authors: Wade Tracey D. 
Published: March 2023

AbstractSchleider and colleagues' paper on the application of single‐session interventions (SSIs) to eating disorders is timely given the broader focus in mental health on flexible approaches to delivering support at the time the person needs it most. The eating disorder field needs to embrace these innovations including developing a “single‐session mindset” with greater attention paid to testing the relevance of SSI for eating disorders. The use of well‐powered trials of brief, focused and rapidly scalable interventions is an ideal vehicle for generation and evaluation of new and longer interventions. Our future research agenda needs to carefully consider our target audience, the primary outcome variable of most relevance, and the SSI topic that would be most likely to effect change. Research in prevention might focus on weight concern and evaluation of SSIs that focus on self‐compassion or cognitive dissonance related to appearance ideals in the media. Work in early intervention could target denial and disordered eating using SSIs on growth mindset, behavioral activation, and imagery rescripting. Treatment waitlists provide another suitable opportunity, evaluating SSIs that aim to increase hope for change, treatment retention, and kick start early change in therapy, a robust predictor of better treatment outcome.
Cascading impacts of changes in subsidy quality on recipient ecosystem functioning
Authors: Osakpolor Stephen E. , Manfrin Alessandro , Leroux Shawn J. , Schäfer Ralf B. 
Published: March 2023

AbstractResource quantity and quality can differ between adjacent ecosystems, and these differences can impact subsidies exchanged between ecosystems. The quantity and quality of subsidies are rapidly changing in response to stressors associated with global environmental change, but while we have models to predict the effects of changes in subsidy quantity, we currently lack models to predict the effects of changes in subsidy quality on recipient ecosystem functioning. We developed a novel model to predict the effects of subsidy quality on recipient ecosystem biomass distribution, recycling, production, and efficiency. We parameterized the model for a case study of a riparian ecosystem subsidized by pulsed emergent aquatic insects. In this case study we focused on a common measure of subsidy quality that differs between riparian and aquatic ecosystems: the higher content of long‐chain polyunsaturated fatty acids (PUFAs) in aquatic ecosystems. We analyzed how changes in the PUFA concentration of aquatic subsidies affect the dynamics in biomass stocks and functions of the riparian ecosystem. We also conducted a global sensitivity analysis to identify key drivers of subsidy impacts. Our analysis showed that subsidy quality increased the functioning of the recipient ecosystem. Recycling increased more strongly than production per unit subsidy quality increase, meaning there was a threshold where an increase in subsidy quality led to stronger effects of subsidies on recycling relative to the production of the recipient ecosystem. Our predictions were most sensitive to basal nutrient input, highlighting the relevance of recipient ecosystem nutrient levels to understanding the effects of ecosystem connections. We argue that recipient ecosystems that rely on high‐quality subsidies, such as aquatic–terrestrial ecotones, are highly sensitive to changes in subsidy–recipient ecosystem connections. Our novel model unifies the subsidy hypothesis and food quality hypothesis and provides testable predictions to understand the effects of ecosystem connections on ecosystem functioning under global changes.
Magnesium Complexes Supported by 6,6’‐Dimethylbiphenyl‐Bridged Salen Ligands: Synthesis, Characterization and Catalysis for rac‐Lactide Polymerization
Authors: Chen Ruyi , Ma Haiyan 
Published: March 2023

AbstractA series of racemic 6,6’‐[(6,6’‐dimethyl‐[1,1’‐biphenyl]‐2,2’‐diyl)bis(nitrylomethilidyne)]‐bis(2‐R1‐4‐R2‐phenol) proligands (L1H2, R1=R2=Me; L2H2, R1=tBu, R2=Me; L3H2, R1=R2=cumyl; L4H2, R1=CPh3, R2=Me) were reacted with {Mg[N(SiMe3)2]2}2 to provide mononuclear and dinuclear magnesium complexes [L12Mg2] (1), L2–4Mg (2–4), {L1–3[MgN(SiMe3)2]2} (5–7). Complexes 3* and 4* in which each metal center is coordinated with a THF molecule were obtained when the corresponding crude complexes were recrystallized with a mixture of THF and n‐hexane. Similarly, the formation of THF coordinated structure 7* of the heteroleptic dinuclear complex 7 was identified. The molecular structures of complexes 3*, 6 and 7* were established by X‐ray single crystal diffraction studies, which show that mononuclear complex 3* possesses a five‐coordinated metal center adopting a distorted square pyramid configuration, the two metal centers of the dinuclear complex 6 are bridged by two phenoxy oxygen atoms and each has a four‐coordinated distorted tetrahedral configuration, and each metal center of the dinuclear complex 7* is still four‐coordinated upon the coordination of THF but without bridging to each other. All complexes were investigated for the ring‐opening polymerization (ROP) of rac‐lactide (rac‐LA) at 60 °C in toluene or tetrahydrofuran. Compared with the mononuclear counterparts, the dinuclear magnesium silylamido complexes showed significantly higher activities.
Complexes of Fe(III) and Ga(III) Derived from the Cyclic 6‐ and 7‐Membered Hydroxamic Acids Found in Mixed Siderophores
Authors: Jewula Pawel , Grandmougin Mickaël , Choppin Mélanie , Tivelli Anna Maria Chiara , Amati Agnese , Rousselin Yoann , Karmazin Lydia , Chambron Jean‐Claude , Meyer Michel 
Published: March 2023

AbstractSix‐ and seven‐membered cyclic hydroxamic acids are found as terminal binding units in different families of siderophores, including exochelins and mycobactins. The simplest models of these preorganized chelating ligands were known, but their coordination chemistry with Fe3+, the target metal ion of siderophores, had never been reported. Four complexes were synthesized and studied: two Fe3+ complexes, one with the six‐membered ring hydroxamate PIPO− and one with the seven‐membered ring hydroxamate AZEPO−, and the two corresponding Ga3+ complexes. X‐ray diffraction studies showed that the interligand repulsion energies were better minimized in the case of the AZEPO− complexes whatever the metal cation considered, and that the Fe−O bond distances were shorter in [Fe(AZEPO)3] by comparison with [Fe(PIPO)3].
Synthesis of the N‐Amykitanosyl Tetramic Acid Moiety of Amycolamicin
Authors: Meguro Yasuhiro , Enomoto Masaru , Kuwahara Shigefumi 
Published: March 2023

AbstractAn improved five‐step synthetic route from l‐fucose to an N‐glycosyl l‐valine methyl ester has been developed. The new route involves glycosidation of l‐fucose with phenol in a β‐selective manner without protection/deprotection steps and one‐pot stereochemical inversion of a secondary alcohol intermediate and is superior to our previous one both in the number of steps and in overall yield. An N‐glycosyl l‐valine benzyl ester, prepared from l‐fucose in an analogous way, has been elaborated into an N‐amykitanosyl tetramic acid derivative, Li's synthetic intermediate for amycolamicin, via a four‐step sequence which features the utilization of Bestmann's ylide to stereoconvergently construct an N‐glycosyl tetramic acid intermediate in a single step, opening of a cyclic carbonate ring with an amine to regioselectively install a carbamate functionality, and visible light‐mediated oxidative debenzylation of an N,N‐dibenzyl carbamate.
Pd/Ni Co‐catalyzed Selective Cross‐Coupling of Aryl Bromides and Aryl Fluorosulfonates at Room Temperature
Authors: Zhang Guofu , Luo Xuefei , Guan Chenfei , Cui Yin , Ding Chengrong 
Published: March 2023

AbstractMultimetallic catalysis can effectively enhance the selectivity for the heterocoupling product over homocoupling products in cross‐electrophilic couplings. We report the selective cross‐coupling of aryl bromides with aryl fluorosulfonates via palladium and nickel cooperative catalysis for the synthesis of biaryls, which can be carried out at room temperature while having marvelous chemoselectivity. In addition, the reaction also has a good performance on the gram‐scale reaction.
Site‐directed mutagenesis improves the practical application of L‐glutamic acid decarboxylase inEscherichia coli
Authors: Fengmin Liu , Heng Zhang , Xiangjun Zhang , Xiaobo Wei , Huiyan Liu , Haitian Fang 
Published: March 2023

Abstractγ‐Aminobutyric acid (GABA) is a kind of non‐proteinogenic amino acid which is highly soluble in water and widely used in the food and pharmaceutical industries. Enzymatic conversion is an efficient method to produce GABA, whereby glutamic acid decarboxylase (GAD) is the key enzyme that catalyzes the process. The activity of wild‐type GAD is usually limited by temperature, pH or biotin concentration, and hence directional modification is applied to improve its catalytic properties and practical application. GABA was produced using whole cell transformation of the recombinant strainsEscherichia coliBL21(DE3)‐Gad B,E. coliBL21(DE3)‐Gad B‐T62S andE. coliBL21(DE3)‐Gad B‐Q309A. The corresponding GABA concentrations in the fermentation broth were 219.09, 238.42, and 276.66 g/L, and the transformation rates were 78.02%, 85.04%, and 98.58%, respectively. The results showed that Gad B‐T62S and Gad B‐Q309A are two effective mutation sites. These findings may contribute to ideas for constructing potent recombinant strains for GABA production.Practical Application: Enzymatic properties of the GAD fromEscherichia coliand GAD site‐specific mutants were examined by analyzing their conserved sequences, substrate contacts, contact between GAD amino acid residues and mutation energy (ΔΔG) of the GAD mutants. The enzyme activity and stability of Gad B‐T62S and Gad B‐Q309A mutants were improved compared to Gad B. The kinetic parameters Kmand Vmaxof Gad B, Gad B‐T62S, and Gad B‐Q309A mutants were 11.3 ± 2.1 mM and 32.1 ± 2.4 U/mg, 7.3 ± 2.5 mM and 76.1 ± 3.1 U/mg, and 7.2 ± 3.8 mM and 87.3 ± 1.1 U/mg, respectively. GABA was produced using whole cell transformation of the recombinant strainsE. coliBL21(DE3)‐Gad B,E. coliBL21(DE3)‐Gad B‐T62S, andE. coliBL21(DE3)‐Gad B‐Q309A. The corresponding GABA concentrations in the fermentation broth were 219.09, 238.42, and 276.66 g/L, and the transformation rates were 78.02%, 85.04%, and 98.58%, respectively.